The US National Academy of Science today published its long-awaited Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials. I won’t comment extensively on the report as I was a member of the committee that wrote it.  But I did want to highlight a number of aspects of it that I think are particularly noteworthy:

Great progress so far, but it’s time to change gears. Something we grappled with as a committee was what the value of yet another research strategy was going to be.  After all, it wasn’t so long ago that the US federal government published a well received strategy of its own.  A key driver behind our strategy was a sense that the past decade has been one of defining the challenges we face as the field of nanotechnology develops, while the next decade will require more focus as an ever greater number of nanotechnology-enabled products hit the market.  In other words, from a research perspective it’s time to change gears, building on past work but focusing on rapidly emerging challenges.

Combining life cycle and value chain in a single framework for approaching nanomaterial risk research.  As a committee, we spent considerable time developing a conceptual framework for approaching research addressing the health and environmental impacts of engineered nanomaterials.  What we ended up using was a combination of value chain – ranging from raw materials to intermediate products to final products – and material/product life cycle at each stage of the value chain.  This effectively allows risk hot spots to be identified at each point of a material and product’s development, use and disposal cycle.

Principles, not definitions.  Rather than rely on a single definition of engineered nanomaterial to guide risk-related research, we incorporated a set of principles into our conceptual framework to help identify materials of concern from an environment, health and safety impact perspective.  These build on the principles proposed by myself, Martin Philbert and David Warheit in a toxicology review published last year.  From the National Academies report:

Cross-posted from The Risk Science Blog:

In a recent letter to the journal Nature (Nature 476; 399), Hermann Stamm of the European Commission Joint Research Centre Institute for Health and Consumer Protection (JRC-IHCP) defended the need to define engineered nanomaterials for regulatory purposes. The letter, titled “Nanomaterials should be defined”, was a direct response to my earlier commentary in Nature “Don’t define nanomaterials”.

Stamm’s letter is behind a paywall and so not easily accessible to many readers. But these are the main points he makes:

• A definition for engineered nanomaterials is required for labeling purposes, and would assist industry and regulators in identifying where specific safety assessments might be necessary.
• This should identify a general class of materials for attention, whether they are benign or hazardous.
• Nanomaterials have many properties not shared by their larger-scale counterparts, some of which have safety implications. And an increasing number of products containing novel nanomaterials are entering the market.
• Engineered nanomaterials are heterogeneous. But, they all have structures on the nanoscale which modify their other properties. Because of this, size is therefore most appropriate parameter to base a regulatory definition on.

Stamm also references a Joint Research Center Reference Report on “Considerations on a Definition of Nanomaterial for Regulatory Purposes”, co-authored by him and published in 2010.

As is probably clear from my Nature commentary (an early draft is freely available here), I have some sympathies with the challenges the JRC and regulators across the world are facing. Without a doubt, sophisticated materials arising from nanoscale science and engineering are presenting safety challenges that are not readily captured by current regulatory regimes. Yet I am increasingly concerned that, with the momentum that has built up behind the field of nanotechnology, it is becoming increasingly difficult to formulate evidence-based questions that will lead to science-justified regulation. And despite policy makers repeatedly stating that any form of nanomaterial regulation should be science-based, I have the sense that they are scrambling to use science to justify a predetermined conclusion – that engineered nanomaterials should be regulated on the basis of a hard and fast definition – rather than using science to guide their actions.

Instead, I would suggest that we need to put aside preconceptions of what is important and what is not here, and start by asking how new generations of sophisticated (or advanced) materials interact with biological systems; where these interactions have the potential to cause harm in ways not captured within current regulatory frameworks; and how these frameworks can be adapted or altered to ensure that an increasing number of unusual substances are developed and used as safely as possible – no matter what label or “brand” is applied to them.

Back in the mists of time, I was approached with a crazy proposition – would I help co-edit a book on nanotechnologies regulation!  In a moment of weakness I said yes, and a little more than two and a half years later, the book is finally about to hit the shelves.

I actually think the resulting International Handbook on Regulating Nanotechnologies rather a useful, coherent and engaging collection of chapters – my co-editors Di Bowman and Graeme Hodge did a wonderful job encouraging a bunch of top thinkers in the field to write under occasionally whimsical but always relevant titles.

To whet your appetite prior to the book’s release sometime in November, here’s a sneak peak at the contents:

PART I:    Concepts and Foundations

1.    Introduction: the regulatory challenges for nanotechnologies

Graeme A. Hodge, Diana M. Bowman and Andrew D. Maynard

2.    Philosophy of technoscience in the regime of vigilance

Alfred Nordmann

3.    Tracing and disputing the story of nanotechnology

Chris Toumey

4.    The age of regulatory governance and nanotechnologies

Roger Brownsword

PART II:    Frameworks for Regulating Nanotechnologies

5.    Nanotechnology captured

John Miles

6.    The scientific basis for regulating nanotechnologies

David Williams

7.    The current risk assessment paradigm in relation to the regulation of nanotechnologies

Qasim Chaudhry, Hans Bouwmeester and Rolf F. Hertel

8.    Regulating risk: the bigger picture

Karinne Ludlow and Peter Binks

9.    Producing safety or managing risks? How regulatory paradigms affect insurability

Thomas K. Epprecht

PART III:    Case Studies in Regulating Nanotechnologies and Nano-Products

10.    The evolving nanotechnology environmental, health, and safety landscape: A business perspective

Oliver Tassinari, Jurron Bradley and Michael Holman

11.    Regulation of carbon nanotubes and other high aspect ratio nanoparticles: approaching this challenge from the perspective of asbestos

Robert J. Aitken, Sheona Peters, Alan D Jones and Vicki Stone

12.    Approaching the nanoregulation problem in chemicals legislation in the EU and US

Markus Widmer and Christoph Meili

13.    A good foundation? Regulatory oversight of nanotechnologies using cosmetics as a case study

Geert van Calster and Diana M. Bowman

14.    Therapeutic products: regulating drugs and medical devices

Rogério Sá Gaspar

15.    Regulatory perspectives on nanotechnologies in foods and food contact materials

Anna Gergely, Qasim Chaudhry and Diana M. Bowman

16.    Regulation of nanoscale materials under media-specific environmental laws

Linda Breggin and John Pendergrass

17.    Military applications: special conditions for regulation

Jürgen Altmann

18.    Regulating nanotechnology through intellectual property rights

Gregory N. Mandel

PART IV:    The Future Regulatory Landscape

19.    The role of NGOs in governing nanotechnologies: challenging the ‘benefits versus risks’ framing of nanotech innovation

Georgia Miller and Gyorgy Scrinis

20.    Voluntary measures in nanotechnology risk governance: the difficulty of holding the wolf by the ears

Christoph Meili and Markus Widmer

21.    The role of risk management frameworks and certification bodies

Thorsten Weidl, Gerhard Klein and Rolf Zöllner

22.    Risk governance in the field of nanotechnologies: core challenges of an integrative approach

Ortwin Renn and Antje Grobe

23.    International coordination and cooperation: the next agenda in nanomaterials regulation

Robert Falkner, Linda Breggin, Nico Jaspers, John Pendergrass and Read Porter

24.    Transnational regulation of nanotechnology: reality or romanticism?

Kenneth W. Abbott, Douglas J. Sylvester and Gary E. Marchant

25.    From novel materials to next generation nanotechnology: a new approach to regulating the products of nanotechnology

J. Clarence Davies

PART V:    Conclusion

26.    Conclusions: triggers, gaps, risks and trust

Andrew D. Maynard, Diana M. Bowman and Graeme A. Hodge

More information on the International Handbook on Regulating Technologies can be found here.  The anticipated publication date is late November.

New technologies depend on uncommon materials, and society depends on new technologies.  Which means that economies that develop the former and control the latter have something of an upper hand in today’s interconnected and technology-dependent world.

This has clearly not escaped the notice of the Chinese.  China, which controls around 90% of the world’s rare earth minerals – many of which are essential to advanced materials – has being blocking shipments of these materials to Japan for the last month. And now, according to yesterday’s New York Times, it has “quietly halted some shipments of those materials to the United States and Europe”.

At the same time, according to the journal Nature,

“Alternative energy, biotechnology, advanced materials and fuel-efficient vehicles will be promoted in China’s newly mapped 2011–15 development plan, according to a report published by the country’s state council on 18 October.”

In other words, China is simultaneously controlling the flow of materials that are essential to many new technologies, while actively working on the very technologies that exploit these materials.

Rare earth elements aren’t that rare, despite the name.  But in recent years, it has become increasingly unprofitable for economies outside China to mine and process them.  As Technology Review noted a few days ago:

“Rare earths are comprised of 17 elements, such as terbium, which is used to make green phosphors for flat-panel TVs, lasers, and high-efficiency fluorescent lamps. Neodymium is key to the permanent magnets used to make high-efficiency electric motors. Although well over 90 percent of the minerals are produced in China, they are found in many places around the world, and, in spite of their name, are actually abundant in the earth’s crust (the name is a hold-over from a 19^th-century convention). In recent years, low-cost Chinese production and environmental concerns have caused suppliers outside of China to shut down operations.”

One solution to the looming monopoly is to begin extraction processes elsewhere.  Another is to look for alternatives to these increasingly valuable resources.  As Tim Harper of Cientifica noted in a recent report:

“Through the use of nanotechnologies we can now start to develop processes that do not use rare resources, for example using carbon nanotubes and metallic nanoparticles in polymers to make them conducting rather than applying thin layers of indium tin oxide.”

There are difficulties to this approach, as Dexter Johnson at IEEE Spectrum noted.  But one way or another, China’s actions are shining a searing spotlight on some of the hidden dependencies of technology innovation, and some of the less obvious challenges to developing technology-based solutions to problems in what is becoming an increasingly resource-constrained world, no matter how you look at it.

]]> http://2020science.org/2010/10/20/limited-resources-and-emerging-technologies-china-does-the-math/feed/ 0 http://2020science.org/2010/10/13/nanotechnology-2-0-the-next-ten-years-of-nano-risk-research/ http://2020science.org/2010/10/13/nanotechnology-2-0-the-next-ten-years-of-nano-risk-research/#comments Wed, 13 Oct 2010 15:43:57 +0000 Andrew Maynard http://2020science.org/?p=3643

Sometime in the past couple of weeks – I’m not entirely sure when as accounts are conflicting – the World Technology Evaluation Center (WTEC) posted a draft of a new report examining the long-term impacts and research directions of nanotechnology.  The “Nano2″ study was supported by the National Science Foundation under the direction of Mike Roco, and included input from an impressive array of nano-experts from round the world.  What resulted was a 13 chapter behemoth of a report on the current state and next ten years of nanotechnology worldwide.

Having just started to look through the report (I was traveling when it was posted … I think) I can’t really comment on it’s overall relevance and authority.  But if the chapter dealing with environment, health and safety (EHS) issues is anything to go by, this is a report to take seriously…

The EHS chapter (chapter 4) is authored by twelve recognized experts in the field of nano-risks, and presents a comprehensive perspective on near-term research challenges and opportunities.  The chapter is far from perfect – as you would expect, it reflects the perspectives and interests of the authors – but then most reports of this type do.  It also contains some rather jangling statements. For instance on the first page the definition of “the environmental, health and safety (EHS) of nanomaterials” seems to miss out environmental impact beyond “animal health”.  And a rather outmoded focus on educating the public on page 25, where the authors state

“A key issue therefore is for academia, industry and government is to find appropriate mechanisms to reach consensus, and effectively communicate and educate the public on the beneficial implications of nanotechnology, the potential for risk, and what is being done to ensure safe implementation of the technology.”

Mmm, not quite what they are teaching in engagement 101 these days!

But this is a draft, and these and other questionable statements do not detract from the overall usefulness of the chapter.

In many ways, the chapter reflects challenges that have been raised before.  Many of the issues highlighted can be traced back to the 2006 commentary in Nature I co-authored on nanotechnology safety challenges, and a number of reports that preceded it.  So questions surrounding exposure monitoring, toxicity screening, predictive modeling, safety by design and taking a life cycle approach to emerging nanomaterials abound.  But many of these are unpacked and explored in a fresh and useful way in this document. There is also a very welcome tie-in to risk-governance [a topic near and dear to my heart, having just co-edited a forthcoming book on the subject], reflecting the need for integrative approaches to understanding and addressing the challenges presented by engineered nanomaterials.

That said, the report fails to break out of old ruts when it comes to identifying materials of concern.  The old chestnuts are there – carbon nanotubes, zinc oxide, titanium dioxide, nano-silver and the like.  But there’s little mention of the next wave of emerging nanomaterials – nanoscale cellulose for instance, or active nanomaterials.  Neither do prevalent but poorly studied engineered nanomaterials like platinum/palladium nanoparticles in auto catalysts get a look-in.  Granted that the document is only looking forward 10 years, but it would have been good to have seen more thought given to complex nanomaterials, and novel approaches to exploring whether they present emergent risks, and how to handle them.

That aside though, this chapter is a strong addition to the literature on nanomaterial risks, and how we need to start addressing them – from risk identification and assessment through to risk management, mitigation and avoidance.  The areas highlighted for further research/action aren’t comprehensive, but they are important.  These include:

• Developing validated nano-EHS screening methods and harmonized protocols that promote standardized engineered nanomaterials risk assessment at levels commensurate with the growth of nanotechnology.
• Developing risk reduction strategies that can be implemented incrementally through commercial nanoproduct data collection, regulatory activity, and EHS research directly linked to decision-making.
• Developing a clearly defined strategy for nano-EHS governance that is compatible with incremental knowledge generation and stepwise decision-making
• Developing computational analysis methods capable of providing in silico modeling of nano-EHS risk assessment and modeling.
• Developing high-throughput and high-content screening as a universal tool for studying nanomaterial toxicology, ranking hazards, prioritizing animal studies and nano-Quantitative Structure Activity Relationship models, and guiding the safe design of nanomaterials.
• Improving safety screening and safe design of nanomaterials used in therapeutics and diagnostics.
• Developing advanced instrumentation and analytical methods for more competent and reliable engineered nanomaterial characterization, and detection in complex biological and environmental media.
• Development of computational models, algorithms, and multidisciplinary resources for increasingly sophisticated predictive modeling.
• Developing workforce capacity through interdisciplinary education and training, particularly in the nano-EHS field, where a large number of research areas are converging.

If you have an interest in nanotechnology impacts, I would definitely put the chapter on your reading list.  If you are actively involved in the field – it’s a must-read.

I mentioned that this is a draft report, and it’s actually open for public comment – you can sign up to comment here.  But you’d better be fast – just as there is some ambiguity over when the draft was posted, there is also ambiguity over when the comment period closes.  One source suggests it could be the end of this week – but I couldn’t find any confirmation of that.  So the sooner you get reading and commenting, the better!

A guest blog by John Dorr, Vice President of Business Development Nanocomp Technologies Inc.

Despite all the fuss over nanotechnology, it’s surprisingly difficult to get a clear sense of how the technology is contributing to new products.  So when the company Nanocomp Technologies Inc. approached me with an idea of writing a guest blog about what they are doing with carbon nanotubes, I jumped at the chance.  I’ve been aware of Nanocomp’s business for some time now and know the company’s President and CEO Peter Antionette, and have been both impressed and intrigued by their use of carbon nanotube sheets and yarns.  At the same time, I didn’t want 2020 Science turning into an industry PR conduit.  So I agreed to the guest blog with one condition – that it stick to science and technology, and not turn into a corporate publicity piece.  As it turns out, John Dorr’s piece is about as far from the hype that often accompanies nanotech stories as you can get. At the same time, this is clearly a significant and potentially important technology – one to watch I think.  Andrew Maynard

In the early 1990’s, a new form of carbon was discovered with highly unusual properties – it was strong, light, and conducted electricity and heat exceptionally well. Because the material was formed from incredibly thin tubes of carbon atoms, it rapidly became know as carbon nanotubes – or CNT for short.

Since their discovery, researchers and businesses have been working hard to exploit the unusual properties of carbon nanotubes – not as easy a task as many people initially thought. However, new and commercially viable uses for the material are now beginning to emerge.

Because of their shape and format, carbon nanotubes can be used in ways similar to other fibers.  As a result, carbon nanotube sheets, yarns and their derivative products are beginning to be introduced into the marketplace. The most productive and scalable manufacturing method in play today employs a gas phase pyrolysis  process for making very large format CNT non-woven textile sheets directly from the reactor without post processing.  As the process grows, a mesh of interconnected, millimeter length CNTs emerges as opposed to a loose powder of micron-scale CNTs. The result is a product that is fundamentally different from Bucky papers, which are made from short tubes that have been dispersed in solvent and subsequently membrane-filtered into film-like structures. They are similar in appearance only.

Figure 1. A 25-foot roll of double wall CNT material is shown being prepared for a customer.

One example of this difference is in mechanical performance. The mechanical strength of the raw, large format sheets is up to 1 GigaPascal (GPa) — five to twenty times better than buckypaper and in the class of m

etals and alloys. Moreover, their electrical conductivity–typically greater than 2 x 10⁶ Si/m–makes them ideal for replacing copper shielding in weight sensitive applications such as for aerospace.

It is also possible to impregnate rolls of these CNT sheets using commercial equipment with a wide variety of thermoset resins such as bismaleimide toughened epoxy (BMI). Figure 1 shows an example of a roll of these sheets.

In addition to sheet material, in a serendipitous blend of traditional and future industry, CNT yarns can be produced by harvesting carbon nanotubes from the reactor onto spools of finished spun material, much like traditional textile-like threads. These yarns can then be braided on commercial wire braiding machines to produce CNT wires of various gauge sizes, as is seen here:

Although the base CNT material is conductive, it can be post-processed to further increase conductivity using a very basic chemistry. This is particularly useful for applications requiring particularly high conductivity – including for application as a high performance, light weight electromagnetic interference (EMI) shield.

Figure 2. An example of four CNT panels seamed together. The people are shown for scale only!

Today, Nanocomp can fabricate sheets that are about four by eight feet long. The sheets can be easily seamed together into panels (see figure 2) or into rolls of any length desired. Such rolls are the standard form factor needed for pre-pregging or other types of resin infiltration, so the material can be easily integrated into such processes.

There are many applications for these materials generally focused on exploiting the unique electrical, thermal and mechanical properties of carbon nanotube sheets and yarns:

Electrical—applications include lightweight conductors, EMI shielding, ground planes and lightning protection, among others. The excellent shielding quality allows CNT material to be used as a substitute for copper braid in single- or multiple-conductor shielded cable. Weight savings from this step alone may range from 30 to 50 percent as compared to conventional materials. Another application is to replace copper conductors at very high frequencies, where the conductivity of CNT yarns can outperform copper.

Thermal—applications include heat straps, thermal interfaces for Integrated Circuit (IC) cooling and thermal interface materials. The thermal conductivity of individual carbon nanotubes can be very high, exceeding 40,000 Watts per Kelvin per meter (W/m-°K) at the nanoscale. Thermal conductivity at the macroscale, as seen in CNT sheets, is generally around 60 W/m-°K). As a comparison, copper has a thermal conductivity of around 400 W/m-°K. However, CNT sheets have a density of 0.5 g/cc while copper has a density of almost 9. On a weight-for-weight basis the CNT sheets have 3.5 times better thermal conductivity than the metal. The material also acts like a black body at wavelengths in the near-UV to the long IR, meaning that strips of the material can be used very effectively as Joule heaters at very high specific power.

Mechanical—potential applications include hybridized vehicular and body armor solutions as well as structural composites for a wide range of applications.  The lightness and strength of carbon nanotubes makes them particularly attractive for forming lightweight yet strong materials, and the carbon nanotube sheets produced by Nanocomp are particularly versatile in this respect.  Preliminary work in armor has focused on the use of the Company’s CNT sheets in thin, lightweight composites capable of stopping civilian handgun threats while maintaining durability and flexibility. While Nanocomp continues to improve the mechanical properties of our materials, we have achieved tensile strength values ranging from 1.1 – 3.5 GPa with CNT yarn, which compares favorably with Kevlar® and its published value of 2.9 GPa whether in sheet format or as yarn that can be subsequently woven into a hybrid fabric.

As with any advanced material, safety is an obvious concern when creating carbon nanotubes.  As mentioned previously, most CNT manufacturers develop products as a powder of short tubes. They can become easily airborne and pose an inhalation hazard.  Nanocomp does not produce material in this form, in fact it does not produce short CNTs at all.  Instead, its reactors produce sheet and yarn articles into which the company’s long CNTs have been inexorably bound, a property that has been borne out by rigorous testing done in partnership with leading government and academic labs. The sheets and yarn articles do not release nanomaterial under typical industrial processing, handling, and storage, and it is the conclusion of outside authorities that the company’s CNTs are simply too big to become airborne or be respirable.

John Dorr is Vice President of Business Development at Nanocomp Technologies, a manufacturer of CNT sheet and yarn materials and value-added products. Nanocomp is one of the only companies to efficiently manufacture and fill customer-ready orders for such carbon nanotube products, and widescale adoption of the material is really quite feasible. The company is set to expand its manufacturing capabilities within the coming year, in response to growing government and commercial market demand. To learn more see: http://www.nanocomptech.com/

[2020 Science has no commercial involvement with Nanocomp, and did not receive any form of financial support for this guest blog.  And as you would expect, the views expressed here are Nanocomp's, and not necessarily mine - just wanted to make that clear   Andrew Maynard]

A few weeks ago, I set Friends of the Earth a challenge - What is your worst case estimate of the human health risk from titanium dioxide and/or zinc oxide nanoparticles in sunscreens?

The challenge came out of an article from FoE on nanomaterials and sunscreens, which I subsequently critiqued on 2020 Science.  Georgia Miller and Ian Illuminto from FoE kindly responded to my challenge – not by rising to it as such, but by fleshing out the justification for the position that they take on nanomaterials and sunscreens.

That post led to a useful discussion on the issues, with comments from the NGO community, regulators and respected scientists – it’s one that I would highly recommend anyone interested in nanomaterials and sunscreens reading.

To wrap things up (for the time being), I thought it would be worth reflecting on some of the issues raised by Georgia and Ian in their response, and the ensuing discussion:

Getting nanomaterials’ use in context. First, Georgia and Ian, very appropriately in my opinion, brought up the societal context within which new technologies and products are developed and used:

“why not support a discussion about the role of the precautionary principle in the management of uncertain new risks associated with emerging technologies? Why not explore the importance of public choice in the exposure to these risks? Why not contribute to a critical discussion about whose interests are served by the premature commercialisation of products about whose safety we know so little, when there is preliminary evidence of risk and very limited public benefit.”

This is a legitimate issue, and one that is touched on by a number of people in the comments.  Decisions on what is developed, what people are exposed to, who decides what is appropriate and what is not, and who pays the consequences while who reaps the benefits, go far beyond the science and technology itself.  This is touched on by Jennifer Sass from NRDC:

I strongly support a dialogue that has space for both scientific calculations and values and perceptions of risk. We need to make that dialogue public, inclusive, transparent, and thoughtful. Risk is more than a number – its a face, a person, a community.

Guillermo Foladorio also touches on this broader societal context:

We have here 2 kind of issues. One is the “scientific” knowledge (are nano-sunscreens harmful?). This is a never endend issue. Science is a process and not a fact. The other issue, although hidden, is of great importance: focusing on a never ended scientific discussion is the field that corporations like, in the meanwhile the market of such products grows and consolidates, aside from any wondering of the needs for such new stuff; or better which percentage of the population will benefit in the case.

I would suggest that forcing a technology on society has never been acceptable behavior.  But it has certainly been easier to do in the past.  These days though, we live in a much more crowded, resource-constrained and interconnected world than ever before.  Which means that the consequences of ill-conceived technology implementation are magnified, and the dynamics of introducing new – and possibly beneficial – technologies – are far more complex than they were in the past.

This means that we need to think critically about the broader societal issues associated with technology innovation, and we need to push the dialogue further upstream in the development process – a point Jeff Morris from EPA makes.  This means rethinking how we make decisions in partnership across society, and how we begin to apply ideas like the precautionary principle in a complex world – a point eloquently made by Richard Jones.

But it also means that we need to think carefully about how we use scientific knowledge and data – “evidence” – in making decisions.

Evidence-informed decision-making. At some point, decisions need to be based on information, and in the long run you cannot get away with making that information up!  It’s one thing to evaluate critically the current state of evidence in making decisions, but quite another to preferentially select evidence that supports a predetermined position.  Yet the latter is often the default position when it comes to influencing decisions – whether by policymakers or consumers.

Having worked at the heart of science-based policy in the US for a number of years, I’m all too familiar with the line of argument that goes “what do we want to achieve?” followed by “what evidence can we find that supports us?”.  Yet this is an approach that ultimately devalues the importance of evidence in making decisions, one that can have serious adverse consequences when decisions are made on dodgy information, and one that is patently unsustainable in the long run.

My original critique of FoE’s article challenged their use of “evidence” in supporting the position they took.  To me, they showed a tendency to use selective pieces of information to sow seeds of doubt in the mind of the reader, rather than to empower the reader to make informed decisions. The social agenda was a laudable one – the use of selective science sound-bytes, less so.

This begins to come out when you read the comments on Georgia and Ian’s response from three scientists who have worked on nanoscale materials on the skin.  Despite FoE’s implications that nanoparticles in sunscreens might cause cancer because they are photoactive, Peter Dobson points out that there are nanomaterials used in sunscreens that are designed not to be photoactive. Brian Gulson, who’s work on zinc skin penetration was cited by FoE, points out that his studies only show conclusively that zinc atoms or ions can pass through the skin, not that nanoparticles can pass through.  He also notes that the amount of zinc penetration from zinc-based sunscreens is very much lower than the level of zinc people have in their body in the first place.  Tilman Butz, who led one of the largest projects on nanoparticle penetration through skin to date, points out that – based on current understanding – the nanoparticles used in sunscreens are too large to penetrate through the skin.

These three comments alone begin to cast the potential risks associated with nanomaterials in sunscreens in a very different light to that presented by FoE.  Certainly there are still uncertainties about the possible consequences of using these materials – no-one is denying that.  But the weight of evidence suggests that nanomaterials within sunscreens – if engineered and used appropriately – do not present a clear and present threat to human health.

Yet, because there are uncertainties still, we cannot afford to be complacent here.

Handling uncertainty. And this brings me to the thorny issue of uncertainty.  When we are lacking absolute evidence on safety or risk, what do we do – do we halt progress until we are sure about how safe something is, or do we muddle along until more information is available?

This question is becoming increasingly important as the rate of technology innovation – and the complexity of emerging technologies – accelerates.  Consumers, regulators, businesses and others are being forced more and more to make decisions in the face of increasing uncertainty.  At the same time, we are dependent on technology innovation as a global society – although the idea of “going back to basics” is an attractive one, it’s not going to help the marginalized in an overcrowded and resource-constrained world.  Rather, we need new ideas on how to use science and technology in ways that ensure as many people as possible have an acceptable quality of life.

The question is, how do we do this when we cannot be sure of how safe or dangerous a new technology is?

The Precautionary Principle is one approach – and a very misunderstood and misused one – to addressing this, and one brought up by FoE and others in the context of sunscreens.  It has many formulations – it’s not a hard and fast principle.  But it is currently described in the European Union in this way:

The precautionary principle should be informed by three specific principles:

• implementation of the principle should be based on the fullest possible scientific evaluation. As far as possible this evaluation should determine the degree of scientific uncertainty at each stage;
• any decision to act or not to act pursuant to the precautionary principle must be preceded by a risk evaluation and an evaluation of the potential consequences of inaction;
• once the results of the scientific evaluation and/or the risk evaluation are available, all the interested parties must be given the opportunity to study of the various options available, while ensuring the greatest possible transparency.

Besides these specific principles, the general principles of good risk management remain applicable when the precautionary principle is invoked. These are the following five principles:

• proportionality between the measures taken and the chosen level of protection;
• non-discrimination in application of the measures;
• consistency of the measures with similar measures already taken in similar situations or using similar approaches;
• examination of the benefits and costs of action or lack of action;
• review of the measures in the light of scientific developments.
• The burden of proof

This is a pragmatic principle, that looks to using evidence and an evaluation of consequences in making informed decisions in the face of uncertainty.  It certainly does not preclude the development or implementation of a new technology until there is certainty on safety.

The emphasis on the potential consequences of inaction are particularly relevant to today’s world, where we are stuck on a technological tight-rope, and where the consequences of not doing something may be more harmful than taking action.  Richard Jones picked up on this in his suggestion for a more relevant application of the Precautionary Principle to emerging technologies:

what are the benefits that the new technology provides – what are the risks and uncertainties associated with not realising these benefits?

what are the risks and uncertainties attached to any current ways we have of realising these benefits using existing technologies?

what are the risks and uncertainties of the new technology?

This seems a useful place to start from when faced with the reality of having to make the best possible decisions in the face of uncertainty, and where inaction isn’t a option.

But to make decisions – even when there are gaping holes in the data – you need something to go on.

So why did I pose the challenge in the first place? Despite suspicions from some that I was merely being provocative with this question, I asked it in all seriousness.  In the face of uncertainty, playing out different potential scenarios is a powerful tool in helping identify the magnitude and nature of the consequences of different choices.

When it comes to using nanomaterials in sunscreens, I genuinely would like to know whether in the worst case we are looking at mass illness and death, isolated cases of skin rashes, or something in between.  Because the likely implications of the use of such materials in the future have profound implications on the actions we take now.

If decisions are made now on futures that are unlikely to be realized, not only do we waste resources and effort, but we potentially endanger people’s lives through ill-informed choices.  This cuts both ways – if TiO2 and ZnO nanomaterials in sunscreens are likely to harm a significant number of people to a significant degree, action should be taken to avoid this as soon as possible.  But if the benefits are positive and the impacts likely to be inconsequential, inhibiting the use of such materials could cost lives.

Using the best available information to work through possible scenarios provides insight into which futures are more likely, and where efforts are best focused.  This isn’t about setting exposure levels or conducting quantitative risk assessments – it’s about helping people making informed choices.

And who should do this?  I think any group that has a stake in how contemporary decisions affect future outcomes has a part to play.  I focused on FoE because they were pushing the issue.  And I think they have sufficient people they can draw on to make a stab at working through some scenarios and estimating likely impact.

But at the end of the day, this is something that all stakeholders should be involved in.

Because these are decisions that we are all going to have to live with the consequences of.

Following up from my previous post, here’s an open question to Friends of the Earth:

What is your worst case estimate of the human health risk from titanium dioxide and/or zinc oxide nanoparticles in sunscreens?

What I am interested in is a number – a probability of a specific human health impact being caused by using a given amount of nano-sunscreen over a certain amount of time.  Something like:

“In the worst case, it is estimated that using [number] grams per day of sunscreen comprising [percent] TiO2/ZnO nanoparticles over [number] days could lead to an [percent] risk of the user developing [disease].”

This can be based on an extrapolation of the current state of the science to a worst case scenario.  But it must be plausible.  And the calculations/sources to get to the end number must be transparent.

I’m asking because I am interested to see whether it is possible to place an upper bound on the safety of nanoparticle-based sunscreens, and whether this will be useful in moving the dialogue over nano-enabled sunscreens away from ungrounded speculation, towards evidence-based discussion.

So that’s the challenge.  I’m hoping my good friends at Friends of the Earth will rise to it.

A bit of a wonky blog I’m afraid, but having seen relatively little on the recently introduced Safe Chemicals Act of 2010 and its relevance to engineered nanomaterials on the web, I thought I would post something short and sweet here.

Just over a week ago, Senator Lautenberg introduced a bill in the US Senate aimed at a long-overdue reform of toxic substances regulation in the United States – the Safe Chemicals Act of 2010.  At the same time, Congressmen Rush and Waxman released a discussion draft in the House – The Toxic Chemicals Safety Act of 2010 – covering much of the same ground.  Both documents aim to update substantially the Toxic Substances Control Act, or TSCA – which has been the mainstay of US chemicals regulation since 1976.

Both the 169-page Safe Chemicals Act of 2010 and the slightly shorter 119 page long Toxic Chemicals Safety Act of 2010 aim to bring US chemicals safety regulation into the 21st century.  Richard Denison at EDF has already posted a comprehensive overview of proposed changes to the regulation that I would recommend reading if you are into this stuff.  But here, I thought I would highlight what the proposed changes mean for the engineered nanomaterials – a class of substances that have been a bit of a thorn in TSCA’s side for the past few years.

The problem with TSCA (the old version) is that it is built on a chemicals world-view – substances are regulated based on their unique “molecular identity” – how they are described as chemicals. This works well for substances that do what they do because of their chemistry.  But it runs into problems where something behaves in a certain way because of its physical form, as well as its chemical makeup.  In other words, where you have stuff that is more harmful that molecular identity would suggest because of how the constituent atoms and molecules are put together, you have a problem.

There are workarounds to this within TSCA – a new substance that is chemically identical to an existing one can be regulated under the “Significant New Use Rule” for instance – but it’s a bit of a bootstrap.  And with the emergence of an increasing number of engineered nanomaterials where functionality – and possibly toxicity – depend on physical form as well as molecular identity, this bootstrap has been stretched to breaking point.

So there’s been considerable interest in how the new-look TSCA will handle this.

Fortunately, things are looking good at this stage.  The Senate bill has language that is in effect a substance “get out of jail free” card for EPA.  Section 4 of the bill proposes amending section 3(2) of the original Toxic Substances Control Act with

“Notwithstanding molecular identity, the Administrator may determine, under section 5(a)(6), that a variant of a chemical substance is a new chemical substance.” (page 6)

In other words, EPA can decide when something with the same molecular identity as an existing substance should be treated as a new substance.

And the determiners of when this is justified? The bill proposes that section 3(13) of the 1976 TSCA act is amended with

“(C) SPECIAL SUBSTANCE CHARACTERISTICS.—The term ‘special substance characteristics’ means, such physical, chemical, or biological characteristics, other than molecular identity, that the Administrator determines, by order or rule, may significantly affect the risks posed by substances exhibiting those characteristics. In determining the existence of special substance characteristics, the Administrator may consider—

(A) size or size distribution;

(B) shape and surface structure;

(C) reactivity; and

(D) any other properties that may significantly affect the risks posed.” (page 13)

In other words, the new bill allows many of the characteristics that potentially lead to engineered nanomaterials presenting novel risks to trigger them being treated as new substances.

The House draft document is a little more explicit.  It recommend amending section 3(2) of the original act with:

“(C) For purposes of this Act, such term may include more than 1 form of a substance with a particular molecular identity as described in sub-paragraph (A) if the Administrator has determined such forms to be different substances, based on variations in the substance characteristics. New forms of existing chemical substances so determined shall be considered new chemical substances.” (page 6)

with the clarification that

“The term ‘substance characteristic’ means, with respect to a particular chemical substance, the physical and chemical characteristics that may vary for such substance, and whose variation may bear on the toxicological properties of the chemical substance, including—

(A) chemical structure and composition

(B) size or size distribution

(C) shape

(D) surface structure

(E) reactivity; and

(F) other characteristics and properties that may bear on toxicological properties” (page 11)

Both the Senate bill and the House discussion document provide EPA with the authority to regulate any substance that presents a new or previously unrecognized risk to human health as a new substance.  This is critical to ensuring the safety of engineered nanomaterials, where risk may depend on more than just the chemistry of the substance.  But it also creates a framework for regulating any new material that presents a potential risk – whether it is a new chemical, a relatively simple nanomaterial, a more complex nanomaterial – possibly one that changes behavior in response to its environment, or a novel material that has yet to be invented.  In other words, these provisions effectively future-proof the new regulation.

Of course there’s a long way to go yet.  The final details of the new legislation have to be hashed out between the Senate and the House before they are finally signed off on.  Then the process of interpreting and enacting the new regs starts – including working out how exactly to determine when something should be considered new for regulatory purposes.

But at least things seem on the right track as far as enabling the safe development and use of engineered nanomaterials goes.

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The two documents can been downloaded here:

The Safe Chemicals Act of 2010 (US Senate)

The Toxic Chemicals Safety Act of 2010 (US House of Representatives)

If you ever wanted proof that the nanotechnology research community is floundering when it comes to safe working practices, look no further than a paper just published in the journal Nature Nanotechnology.  The paper, written by researchers at the Nanoscience Institute of Aragon (NIA) in Spain, surveys nanosafety practices in labs around the world.  Sadly, the flaws in the paper make the point that more needs to be done to raise safety awareness far more eloquently than its content.

The paper “Reported nanosafety practices in research laboratories worldwide” by Balas, Arruebo and Santamaria sets out to survey safety practices used in engineered nanomaterials research.  This is a critical area – anecdotal evidence suggests that good work practices are patchy in research labs, and that dismissive attitudes to safety or lack of awareness of recommended safety measures are not uncommon.  A survey of current safety practices that replaced anecdotes with hard data would have been extremely useful in helping raise the bar here.  Unfortunately, this is not that survey.

NIA is a nanotech research lab – its expertise is in creating new stuff, rather than assessing safety.  In fact the paper’s corresponding author Jesus Santamaria is the laboratory’s Vice Director.  In other words, NIA would have been a perfect participant in a safe practices survey.  But whether they have the necessary expertise to conduct such a survey is another matter entirely.

I would love to deconstruct this paper as I did the Daily Mail nanotech story on “Grey Goo” a few weeks ago.  But due to copyright I cannot reproduce it in full here, so that’s out.  Instead, I thought it would be interesting to extract a few of the key statements and recommendations the authors make, and see how they stand up to scrutiny:

“An online survey shows that most researchers do not use suitable personal and laboratory protection equipment when handling nanomaterials that could become airborne”

This is the top-level summary of the paper.  It’s a sub-heading that wouldn’t look out of place in a Tabloid newspaper.  And its impact hinges on two words – “most” and “suitable.”  Unfortunately, neither seem justified.

The paper reports the results of survey of people selected from the authors of nanomaterial-related publications published between 2007 – 2009.  240 surveys were completed – around 10% of those solicited.  Extrapolating these data to the entirety of nanomaterials researchers with that phrase “most researchers” is a large jump.  But more significant is the term “suitable.”

Out of all those researchers surveyed who thought the materials they were using might become airborne at some stage, 21% didn’t use any form of “special protection” and 30% didn’t use respiratory protection.  Yet there is no way of telling from the survey whether “special protection” (the authors’ terminology) was needed, or indeed whether any respiratory protection was needed.  A researcher handling small amounts of fumed silica for example – used as a food additive amongst other places – might well handle it using established lab safety procedures that are entirely adequate and don’t include the use of a respirator – in this survey they would be classed in the category of “most researchers” not using “suitabe personal and laboratory protection.”

“We find that only about 10% of researchers who are working with nanomaterials reported using nano-enabled hoods, and one in four did not use any form of general laboratory protection.”

The survey question associated with this statistic was “General laboratory safety during synthesis and handling: No special protection; local extraction on lab-bench; standard fume hood; fume hood with nanosized filters (i.e. HEPA); special “nano-safe” fume hood; Other.”

The jump from “no special protection” (which I would interpret as general lab safety procedures were used) to “did not use any form of genera laboratory protection” is eye-poppingly large, to say the least.  And without information on material quantities and characteristics, who knows whether “nano-enabled” hoods were in fact needed by all of these researchers?

“Despite knowing the materials they made could become airborne, about 30% of researchers did not use any type of personal respiratory protection.”

The associated survey questions were “May the nanomaterials become airborne at any stage of the synthesis: Yes; no; I don’t know?” and “Personal protection equipment when handling nanomaterials: None; mouth mask w/o filters; respiratory mask w. standard filters; full face shield w. filter; full body protective equipment; other?”

If a material became airborne in an enclosed part of the process, but not where exposure could occur, a respondent could easily answer “yes” to the first question and “none” to the second – placing them amongst the 30% alluded to.  And yet they would not have been acting inappropriately.

Around 90% of the respondents were either not aware of or did not think there were regulations at the local or national levels for handling nanomaterials… This is not surprising because only a few regulations on nanomaterials have been enacted.

Respondents were asked questions like “Are you aware of any international legislation for handling nanomaterials?”, “Is there applicable a State/Local legislation for handling nanomaterials?” and “Is there applicable a Federal/National legislation for handling nanomaterials?” As no such “legislation” for handling nanomaterials safely in laboratories exist, it’s not surprising that most respondents weren’t aware of them, or didn’t think they had been written.  I’m not sure what useful information was expected out of this question.  But it does worry me that the responses are presented to suggest a lack of awareness amongst researchers, rather than a lack of regulations.

“…nearly three quarters of respondents reported not having internal rules to follow regarding the handling of nanomaterials; approximately half did not have rules and 27.1% were not aware of any internal regulations.”

Despite the potentially confusing use of “rules” and “regulations” this is actually a useful piece of information.  The question was “Does your organization have an internal set of rules or handling nanomaterials: Yes; no; I don’t know?” One would hope that the answer was yes in most cases – clearly this is an area where more effort is needed.

“Regarding general laboratory protection measures, 24% of respondents did not use any type of protection, and 15.2% reported only using local extraction on the lab bench… Taken together this means that nearly 40% of researchers working with nanomaterials reported using none or only weak means of general laboratory protection.”

To recap, the question here was “General laboratory safety during synthesis and handling: No special protection; local extraction on lab-bench; standard fume hood; fume hood with nanosized filters (i.e. HEPA); special “nano-safe” fume hood; Other.” Looking at this, the statement made is patently wrong. “No special protection” is not the same as “did not use any type of protection.”  And local extraction on the lab-bench is not necessarily a “weak means” of control.  As a consequence, this statement is misleading at best.

“When it comes to the use of PPE [Personal Protective Equipment], about 48.8% of researchers reported not using any type of respiratory protection and 24.4% used a mouth mask without filters, which is clearly an ineffective form of protection.”

That 48.8% of researchers not using PPE includes researchers using materials unlikely to become airborne (according to the survey) – so it’s perhaps not surprising the figure is so high.  I’m still trying to work out what a “mouth mask without filters” is – not something I have ever come across.  If, as I suspect, the authors were envisaging a N95 respirator, authoritative organizations like NIOSH do not class this as “an ineffective form of protection.”

About 85% of researchers declared disposing of nanomaterials either without a special procedure (24.3%) or with the same procedure as for other chemicals (61.0%).  This seems at odds with the fact that 81% of researchers stated that nanomaterials should be treated as hazardous waste unless they are known to be non-hazardous.”

There is considerable confusion here, and it stems from an assumption that nanomaterials need to be disposed of in some unique way.  The associated question on the survey was “Do you follow a special procedure for disposing of nanomaterials?  No special procedure; the same as for other chemicals; yes, a special procedure designed for disposing nanomaterials; others?” In answering this, anyone who routinely treated nanomaterials as a hazardous material would answer “no special procedure” or “the same as for other chemicals” – which makes perfect sense.  The interpretation of the survey returns as indicating poor practices here does not hold up well to scrutiny.

51.7% of the researchers reported using the same Materials Safety Data Sheet irrespective of whether they were handling bulk or nanosized material”

The trouble is, 60% percent of researchers were synthesizing their own material, and so wouldn’t have associated Materials Safety Data Sheets – unless they wrote their own.

“Until widely accepted exposure levels and monitoring procedures become available, the general guidelines provided by reliable organizations should be immediately implemented.”

This makes sense – although some help on what defines a “reliable” organization would be useful.

“Finally, scientists should self-regulate, because they are the ones who decide how nanomaterials are handled in the laboratory and are ultimately responsible for implementing nanosafety practices.  One effective way to speed-up the adoption of safety precautions would be for journals to require a specific description of nanosafety measures within the methods or experimental section of all papers dealing with nanomaterials”

So, a survey that appears to suggest that scientists are doing a lousy job of working safely with nanomaterials in the lab suggests that self-regulation is the way to go. And to “enforce” this self-regulation, journals should impose a burden on authors that is not necessary when publishing work on a thousand and one other extremely noxious materials.  I’m still trying to get my head round this one!.

I really don’t want to slam this paper – safe lab practices for working with engineered nanomaterials are critical, and greater efforts are urgently needed.  At the same time though, it’s hard to see how questionable research like this will support progress. The trouble is, this survey seems to have been conducted by team who understand little about crafting effective questionnaires, and who have a poor grasp of what is relevant and what is not when it comes to working safely with engineered nanomaterials.

But here’s the irony – the inadequacies of the paper illuminates more eloquently perhaps than the survey itself that researchers in nanotech laboratories are out at sea when it comes to understanding safety issues: This particular group of asked the wrong questions, didn’t ask the right ones, and interpreted what they got back within a questionable framework.

Clearly, they need help.

And this is perhaps the strongest message to come out of the paper, inadvertent as it is – that more is needed and faster from “reliable organizations” on working safely with engineered nanomaterials in the lab – before someone does themselves an injury.

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I didn’t want to make a big deal of it above, but I found it worrying that on two of the questions in the supplementary information, the questions and answers are transposed.  What you have in is:

“If dry synthesis, please specify method: Co-precipitation; thermal decomposition; sono-chemistry; polymerization; reverse micelles; other”

“If wet synthesis, please specify method: Laser pyrolysis; CVD/PECVD’ mechanical attrition; electrical discharge; laser ablation; other”

Anyone involved in nanomaterial synthesis will spot that the wrong answers have been mateched with the wrong questions.  Hopefully this was just an error in the supplementary information, and the original survey was correct.  But I guess someone should check…

In the wake of a new study linking “nanotechnology” to two deaths and five additional cases of lung disease, the emerging technology of the ultra-small could be in for a rough ride.  Yet the real risk is that in the rush to use or even abuse the findings, the science and it’s true relevance are overlooked.

It’s never good news when a new technology is associated with a death.

The emerging area of nanotechnology has had a fairly smooth ride so far.  Sure, there have been questions over possible new health risks associated with some of its more esoteric offerings.  But no one has actually got sick from the technology.

Until now it seems…

A new study to be published in the European Respiratory Journal describes seven cases of unusual and progressive lung disease and two deaths amongst workers at a Chinese factory, and pins the likely cause on nanoparticles—which the authors link inextricably with nanotechnology.

The study presses a number of emotional and political buttons that are likely to elevate its significance—workers died; a new class of material, already under suspicion, is implicated; and in the journal’s press release, parallels are drawn with asbestos—a material that continues to be associated with tens of thousands of deaths around the world each year.

As news coverage surrounding the study gathers momentum, there will be the temptation for opponents and proponents of nanotechnology to either parade it as proof of nanotech’s dangers, or to dismiss it as ill-conceived, flawed and irrelevant.  But either approach would be a serious mistake, and in the long term could jeopardize the safe, successful and beneficial development of nanotechnology.

For years it’s been speculated that nanotechnology-derived materials—including nanoparticles—could present new health risks.  Some materials begin to exhibit novel physical and chemical properties at the nanoscale.  Nanometer-sized particles can get to places inaccessible to larger particles.  And particle size, shape and surface area have been linked to unusual biological behavior for some materials.  Backed by an increasing number of lab studies, it’s becoming increasingly clear that the potential health impact of some nanomaterials depends on more than just chemistry.

But hard data on any actual risks associated with nanomaterials remain tantalizingly elusive.  More to the point, no one has knowingly got sick after being exposed to an engineered nanomaterial yet.  And while proactively avoiding potential nanomaterial-related risks sounds awfully laudable, industry and governments are notoriously loath to take serious action on avoiding possible dangers in the absence of actual bodies.

This presents groups advocating proactive risk management or a precautionary approach to emerging technologies with a dilemma—how do you convince decision-makers to take action before people fall ill, rather than in response to a tragedy?  To some of these groups, this new study could well be seen as just the leverage they need to press for more risk research, stronger regulation, and less rapid nanotechnology commercialization.

On the other hand, industries and governments have a vested interest in ensuring the tens of billions of dollars they have invested in nanotechnology turns a profit—financially, politically and socially.  I may be being over-cynical here, but I can’t see them passively sitting by while a study associating nanotechnology with lung disease threatens to undermine this investment.  At the very least, the scientific integrity of the new study will be examined minutely.  And if it is found wanting, the temptation will be to dismiss it as flawed and irrelevant.

Unfortunately, neither of these approaches will help avoid similar incidents occurring in the future, or support the development of safe nanotechnologies in the long run.

This new study adds to a growing body of research into the potential health impacts of nanoparticles.  Eventually, it will no doubt play a role in helping to understand and avoid the potential dangers associated with some nanomaterials under some conditions. But on its own, it is limited and incomplete.  At the end of the day, the study says little about the potential hazards of nanoparticles in general, and next to nothing about the possible dangers of nanotechnology.  If the sad deaths of the two workers and the lung disease of their five colleagues were used to press home a preordained nanotechnology agenda, it would amount to little more than a cynical misuse of the data—not a move that is likely to encourage evidence-based decisions on either workplace safety or safe nanotechnology.

Yet to dismiss the study as flawed and irrelevant would be equally foolish.  The reality is that two workers died and nanoparticles were implicated, at a time when increasing numbers of nanoparticle-containing products are entering the market.  As the details of the study become known, people are going to want to know what the findings mean for them—whether there are risks associated with emerging nanotechnologies, and what government and industry are doing about it.  If nanotech-promoters downplay or even discredit the work, the move is more likely to engender suspicion than allay fears in many quarters.  And once again, evidence-based decision-making will be in danger of being sacrificed in favor of maintaining a set agenda.

Fortunately, there is a middle way; one that hopefully the proponents and opponents of nanotechnology—and all those in between—will take.  And this is to be science-grounded yet socially responsive in how the study is assessed and acted upon.

This is not a perfect study.  There are key pieces of information missing that prevent its application to nanoparticles more generally.  Yet I believe the questions it raises on the safe development of nanotechnology transcend its limitations.  The study places emerging nanotechnologies in the spotlight, and forces consumers, developers and decision-makers to think afresh about how they might be used safely.  Irrespective of the circumstances surrounding the tragic illnesses and deaths reported, the study will prompt people to ask how safe they are while working with and using products based on nanotechnology.

And where there are no satisfactory answers, these same people are going to want to know why.

Posturing in response to the study will only alienate people and hamper progress towards the science-informed development of safe and beneficial nanotechnology.  Rather, this is a chance for everyone with an interest in safe and beneficial nanotechnologies start working together towards science-grounded progress that ultimately serves everyone’s needs.

Talking together about the way forward is a good start, but to be effective it must lead to informed actions. Given the current lack of knowledge on the potential risks of some nanomaterials, these will depend on well-funded, strategic research that addresses the many existing information gaps.  While this new knowledge is being generated—a process that could take decades—innovative new approaches will be needed for working with and using the products of nanotechnology as safely as possible.  And to cap it all, decision-makers—from manufacturers to workers to policy-makers to consumers—will need access to clear, relevant and understandable information on nanotechnologies, and what they mean to them.

Working together along these lines, the groundwork will be laid for making progress that is based on the best possible science, yet doesn’t ignore the concerns and aspirations of the people it touches.

Tragically, the lung damage experienced by the seven Chinese workers in the European Respiratory Journal study could most likely have been prevented if accepted occupational hygiene practices had been followed. Ultimately, this is a story of a human failing, not an emerging technology.  Yet it does stimulate important questions that will need addressing if the long-term benefits of nanotechnology are to be realized.  The question is, are we prepared to put aside preconceived notions and work together to find effective answers?  I hope we are.

I’m often intrigued by the evolution of an article from its early drafts to the final version.  To complement today’s commentary on nanotechnology regulation in the journal Nature, written jointly with David Rejeski, I thought it would be interesting to post an early draft of the same paper here.  This is what the piece looked like before we started working with the journal’s editors on cleaning it up and squeezing it into an impossibly small number of words (apart from a couple of very small edits to make sure it was up to date and relatively error-free)…

As nanotechnology makes the leap from the lab to the marketplace, regulators are faced with the tough challenge of ensuring safety without stifling innovation.  Get it right and everyone stands to benefit from the economic and technological returns that engineering matter at the nanometer scale promises.  But get it wrong, and people, the environment and business all loose out.  However, developing approaches to effective regulation depends on good science and reliable information—delivered at the right point and at the right time.  In 2006, the UK government initiated a voluntary reporting scheme to collect data from industry on the commercial production, use and handling of engineered nanomaterials as a step towards evidence-based oversight.  Followed shortly after by a similar scheme in the US, both have failed to live up to expectations.  Canada and France are now working on instituting mandatory reporting programs to collect similar information.  This is a welcome move towards the effective oversight of nanotechnology-based products.  But it is only one of many steps that are needed if the promise of this emerging technology is to be realized.

Me handling multi-walled carbon nanotubes some years ago. Data are still needed on how to get the most out of this innovative material while using it safely.

Nearly five years ago, the UK Royal Society and Royal Academy of Engineering stressed the need for evidence-driven oversight of engineered nanomaterials.(RS/RAE 2004)  Since then, the global investment in nanotechnology R&D by the public and private sectors has risen to over $18 billion annually (Lux Research 2009) and nanotechnology has passed from a scientific curiosity to a market reality, with hundreds of substances and products in commerce. Yet discussions continue to revolve around the safety of the technology rather than the many and varied products it leads to… In 2006, five research challenges were proposed that, if addressed, would help underpin evidence-based decisions on using the products of nanotechnology safely (Maynard, Aitken et al. 2006).  Movement has been made towards addressing all five of challenges, which covered exposure monitoring, toxicity testing, predicting and avoiding harmful behavior, evaluating material impact from cradle to grave, and establishing strategic research programs for addressing possible risks.  Yet developers and regulators are still a long way from understanding how to predict and manage the potential risks associated with new nanomaterials (National Academies 2009; SCENIHR 2009).

In addition to new science-based knowledge, regulators need clear information on engineered nanomaterials already in commerce—what is being produced, in what quantities, how is it being handled and used, and what is known about assessing and managing possible risks?  Without this basic information, they are grappling with ensuring the safety of unknown quantities of unknown materials, being used in unknown ways.  It was exactly this information-vacuum that the UK and US voluntary data collection programs aimed to fill.  Yet by the end of its two-year duration, the UK program had received just thirteen submissions (DEFRA 2009). The US program did not fare much better. Even before it was launched, a number of experts warned that the program would be ineffective because it lacked strong incentives for industry participation and the backup of mandatory measures.  The US Environmental Protection Agency moved forward – slowly – and received only 29 submissions by the end of 2008 (USEPA 2009).  The agency’s own assessment concluded “it appears that approximately 90% of the different nanoscale materials that are likely to be commercially available were not reported under the Basic Program”—an assessment based in comparing submissions with publicly available information on engineered nanomaterials being produced and used (USEPA 2009).

Against this backdrop, Canadian officials announced in January the country’s intentions to make data reporting on the production and use of engineered nanomaterials mandatory (PEN 2009).  The one-time request will be aimed at gathering information to help develop a regulatory framework and will target companies and institutions that manufacture or import more than 1kg of a given nanomaterial.  France is also in the final stages of establishing mandatory data reporting requirements.  In a move that could put the country at odds with its European neighbors, the “Grenelle de l’environnement”—a large piece of environmental legislation working its way through the French political system—includes language covering mandatory reporting on the identity, quantities and uses of engineered nanomaterials (including materials containing nanoparticles) in industry (Assemblée Nationale 2009). While these moves to make data collection mandatory are not necessarily linked directly to the UK and US experiences, there is little doubt that they were influenced by them.  Representatives from all four countries regularly share information on nanotechnology oversight through the auspices of the Organization for Economic Co-operation and Development (OECD) Working Party on Manufactured Nanomaterials.

This move towards mandatory data reporting is a welcome one.  Given the reticence of industry to volunteer information, it will enable regulators to make decisions based on reality rather than speculation.  In principle, such data calls and any resulting evidence-based regulations will benefit industry, reducing uncertainty and providing clear operational guidelines. For instance, a recent report on strategic business issues identified regulatory and compliance risk as its number one risk faced by industry worldwide (Ernst & Young 2008).  And a survey of nanotechnology firms in the US highlighted a “lack of sufficient data to quantify risks.” as a major barrier to understanding and managing nanotechnology risks (Lindberg and Quinn 2007). The current dearth of risk data is even raising eyebrows amongst insurance companies—Lloyd’s of London and Zurich Insurance have both placed nanotechnology in their top tier of emerging risks. Canadian Underwriter 2007; Lloyd’s 2007).

Supporting effective nanotechnology risk management and oversight will require action on a number of fronts.  Well-funded and implemented research strategies are still needed that fill current knowledge gaps and inform evidence-based oversight.  Government and industry partnerships are essential to ensuring access to relevant and trusted data on nanomaterial risks.  Small firms and start-up companies need help to address potential risks and meet regulatory requirements.  Innovative data transfer mechanisms are needed between information producers and information users.  And nanotechnology-relevant regulations need to be streamlined and clarified, reducing unnecessary burdens on industry while ensuring safe use.

Progress is being made on all these fronts, but it is patchy.  Agencies including the US EPA have clarified the regulatory status of substances like carbon nanotubes; a major step towards establishing oversight clarity.  Discussions are ongoing on how new European chemicals policy under REACH applies to nanomaterials (Pelley and Saner 2009).  The OECD is coordinating international efforts to generate toxicity data on 14 nanomaterials currently in use (OECD 2008).  And research addressing specific risk-related information gaps is ramping up around the world.  Yet there is still a large and growing chasm between what is needed for effective regulation, and what current plans will provide.  If the economic and social benefits of nanotechnology are to be realized without unnecessary harm being caused, regulators need to get a move on.

Moves towards mandatory data collection are a step in the right direction.  But in the long term, safe and successful nanotechnologies will depend on strategic research, successful government-industry partnerships and responsive, transparent oversight.

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Nature subscribers can compare this draft with what was finally published – an interesting exercise.  I’m more comfortable with how the story develops and flows in this draft.  But I have to say, the final version – helped along by three editors – is much sharper in it’s focus and recommendations, as well as being a good bit shorter!  And on balance, I think that our ideas as presented in the final paper reflect a maturity of thought that is lacking in the draft above.

Always pleasantly surprising what a good editor (or three) can bring to a piece!

References

Assemblée Nationale (2009). Projet de loi [modifie par le Senat] de programmation relatif a la mise en oeuvre du Grenelle de l’environnement, Texte Nº 1442 transmis a l’Assemblee nationale le 10 fevrier 2009.  Paris, France. 2009.

Canadian Underwriter (2007). Nanotechnology, climate change, infrastructure among top risks. Canadian Underwriter.

DEFRA (2009). Peronal communication on the UK Voluntary Reporting Scheme for Engineered Nanoscale Materials. London.

Ernst & Young (2008). Strategic Business Risk 2008 – The Top 10 Risks for Business. Enst & Young (in collaboration with Oxford Analytica).

Lindberg, J. E. and M. Quinn (2007). A Survey of Environmental, Health and Safety Risk Management Information Needs an Practices among Nanotechnology Firms in the Massachusetts Region. Washington DC. Project on Emerging Nanotechnologies.

Lloyd’s (2007). Nanotechnology.  Recent developments, risks and opportunities. London, UK. Lloyd’s.

Lux Research (2009). Nanomaterials State of the Market Q1 2009. New York, N.Y. Lux Research Inc.

Maynard, A. D., R. J. Aitken, et al. (2006). “Safe handling of nanotechnology.” Nature 444(16): 267-269.

National Academies (2009). Review of the federal strategy for nanotechnology-related environmental, health, and safety research. Washington DC. The National Academies Press.

OECD (2008). LIST OF MANUFACTURED NANOMATERIALS AND LIST OF ENDPOINTS FOR PHASE ONE OF THE OECD TESTING PROGRAMME. Paris, France. Organization for Economic Co-operation and Development.

Pelley, J. and M. Saner (2009). International Approaches to the Regulatory Governance of Nanotechnology. Regulatory Governance Initiative, Carleton University, Canada.

PEN (2009). World’s First Mandatory National Nanotech Requirement Pending. Washington DC. 2009.
RS/RAE (2004). Nanoscience and nanotechnologies:  Opportunities and uncertainties. London, UK. The Royal Society and The Royal Academy of Engineering: 113 pp.

SCENIHR (2009). Risk Assessment of Products of Nanotechnologies. Brussels. Scientific Committee on Emerging and Newly Identified Health Risks.

USEPA (2009). Nanoscale materials stewardship program.  Interim report. Washington DC. US Enviromental Protection Agency.

Just a quick post (at least, as far as the text goes). Last week, I had the pleasure of appearing on Twit TV’s Dr. Kiki’s Science Hour with Kristen Sanford and Leo Laporte. The conversation covered nanotechnology from every conceivable angle. I should have known with Leo’s opening question – asking what I thought of Eric Drexler’s ideas – that we were in for a fun ride!

As Kiki and Leo managed to get in a whole bunch of questions about what nanotech is (and isn’t), where and how it’s being used, what’s so great about it, and what some of the possible barriers to it’s development are, I thought it worth posting the show here.

I should warn you, it’s long, running just shy of 70 minutes. The full show can be streamed below. But for anyone who wants to fast forward through the boring bits or watch it at their leisure, it can also be downloaded here. [Quicktime, 199 MB]

The show was recorded by the folks at On Demand Twit Video, and is reproduced here under the Attribution-Noncommercial-Share Alike 2.5 Canada Creatives Commons license:

Part 6 of a series on rethinking science and technology for the 21st century

The story so far: We are facing an unprecedented confluence of three factors that are forcing us to rethink how we develop and use science and technology to the benefit of society.  Coupling between our action’s and the Earth’s re-actions is more significant now than at any previous point in human history. Global Communications are dissolving previously rigid boundaries throughout society at a seemingly ever-increasing rate.  And then there’s the third “C” – Control…

Not to put too fine a point on it, control is what science and technology are ultimately about.  Science provides the tools for understanding how the world works; technology puts them to use.  This is how it’s been for the past 10,000 years.  So what’s different now?  The answer is that we are finally getting down to being able to manipulate the basic building blocks of matter – atoms and molecules.  Over the past 50 years we have made tremendous strides in being able to visualize and engineer materials at near-atomic scales.  And by doing so we have opened the door to a vast array of technological advances that were the stuff of dreams just a few decades ago.

In the previous post in this series, I wrote about three defining features of nanoscale control – smallness, strangeness and sophistication.  Here, I want to dwell a little more on the third of those – sophistication – as it is likely to underpin some of the more radical advances in science and technology over the next few years.

Three defining characteristics of controlling matter at the nanoscale

Over the past century, synthetic chemistry has changed the world.  The ability to systematically combine atoms together to make new molecules has revolutionized the way we live – virtually everything we touch depends on synthesized chemicals in some way.  Yet chemists are the first to admit that the number of chemicals that have so far been synthesized is minuscule compared to those just waiting to be discovered and made – although we appear to have had good control over the world of chemicals, we’ve only scratched the surface.

What if we had the tools to splice atoms and molecules together in new and innovative ways?  What if we could go beyond text-book chemistry, and invent new molecules that behaved more like nanoscale machines?  What if we could create systems of molecules that could self-replicate – just like biological systems, only better?  All of these goals are coming within reach as scientists learn how to build new molecules atom by atom.

"Nano car" synthetic molecules, from the lab of Professor Jim Tour at Rice University

A particularly interesting example – more a proof of concept – comes from Professor Jim Tour’s lab at Rice University.  Jim was interested in how some biological molecules carry out very physical tasks – like ferrying molecules from one place to another – and wondered whether totally artificial molecules could be invented that behaved in similar ways.  The result was a molecule dubbed the nano car.  Completely artificial, it consists of four “wheels” made of carbon-60 molecules, attached together with a chassis of  organic molecules.  What is significant is that the nano cars demonstrate thermally-induced directional motion on a surface – i.e. they are able in principle to ferry a payload of other molecules from point A to point B.  Writing in Nanotechnology Law and Business in 2007, Tour noted:

The achievement with the nanocar was significant because it demonstrated for the first time structurally controlled directional movement on a surface due to rolling of the wheels rather than the common non-directional stick-slip motion of molecules on a substrate surface.  The next goal of our project was to construct a nanomachine that can convert energy-inputs into controlled motion on a surface.

The nano car attempts to achieve something that occurs all the time in nature by painstakingly controlling how the various molecules that make it up are pieced together.  But the example begs a question – if we can begin to replicate what living systems – DNA-based systems – do, through nanoscale control, how much more could be achieved by starting with DNA in the first place? The answer is – rather a lot.

One of the more interesting discoveries in biochemistry over the past several years has been that many molecules in living systems do their stuff on a physical as much as a chemical level.  For instance, while the nano cars could potentially move molecules around on a surface, naturally occurring biological molecules exist that do this every day – nature has already evolved incredibly sophisticated systems that operate at the nanoscale.  Knowing that natural “molecular motors” exist, scientists have been working hard to create their own biologically-based and biology-inspired motors.

Cartoon of an autonomous molecular motor, courtesy of Andrew Tuberfield.

One such motor is an autonomous “walker” designed and constructed by Andrew Tuberfield’s group at the University of Oxford.  The molecule – which is DNA based – is designed to walk along a track constructed from DNA for as long as there is a supply of fuel – provided by a second set of engineered molecules.  The idea is similar to that embodied in the nano car – an engineered molecule that mimics some of the features of living systems.  But in this case the building blocks used – DNA-based molecules – allow a far more sophisticated device to be constructed.  The walker consists of two asymmetric feet attached to a DNA track.  Through random thermal motion, these feet are constantly lifting up from the track.  However, because of the asymmetry of the molecule, the left foot is uniquely exposed to the surrounding environment when it becomes elevated.  at this point, the researchers who designed the system engineered in two rather clever features.  First, a purposely designed molecule – H1 in the diagram – attaches to the left foot and removes it from the track as the foot extents.  The same cannot happen to the right foot because it is not accessible.  Then, a second molecule – H2 – attaches to the H1-foot pair and removes the original H1 molecule, leaving just an unattached foot.  At this point, one of two things can happen; the foot either attaches to the left.  Or it re-attaches to the right.  The probability of either happening is random.  But as re-attaching to the left results in the molecule ending up exactly where it started, only re-attachment to the right ends up in the molecule taking a step – and the step is always in the same direction.

By using engineered biological parts and controlling their construction at the nanoscale, the researchers have created a molecule that can move along a predetermined track in a predetermined direction, for as long as track and fuel exist – a Brownian ratchet that converts random motion into directional movement.  It may not seem a lot, but it is a tremendous step towards building nanoscale systems that begin to match what biology already does.

But this research raises a yet more intriguing question:  If we can use biological parts to make non-biological motors through nanoscale engineering, can we get into the very workings of biology itself? Biology, after all, is built on nanoscale processes – from DNA to the proteins it encodes for.  If we could control biology at the atomic and molecular level (and do it well), it would quite possibly one of the most transformative technological moves since the advent of agriculture.

Thirty years ago, the notion of controlling the code of life itself would have been laughable.  Now it seems within reach.

The plummeting time to sequence the human genome

Over the past few years, the ease with which genetic code can be sequenced has plummeted.  It took 13 years for teams of scientists around the globe to first read the human genome – completing the project in 2001.  In 2007, it took 2 months to sequence the genome of DNA-co-discoverer James Watson.  And by 2013 it is likely that your personal genome could be read in the time it takes to boil an egg.

Of course, sequencing just reads the information – it doesn’t tell you how to use it.  But here’s the important thing – sequencing genomes transforms the information from the physical domain to the digital domain, where it can be experimented with and engineered in new ways.  While restricted to the physical world, there were always going to be limitations to how effectively we manipulated and controlled genetic material.  In the digital domain, those limitations are gone.  Cheap affordable sequencing is ushering in the age of digital biology.

Schematic of the "digitization" of biology

However, playing around with genetic information on computers would be little more than a novelty if it weren’t for one further advance – the plummeting cost of DNA synthesis.  This completes the loop between the physical and digital worlds.  Now, once you have uploaded your genome into the computer and digitally enhanced it, the technology exists – or soon will – to download the new genome back into reality.  It’s a technology that promises to enable an incredibly sophisticated level of genetic engineering.  It allows brand new genetic code to be written on the computer, tested out in virtual space, then downloaded back into an organism.  It even allows brand new organisms to be designed and created from scratch.

This possibility was pushed home last year when Craig Venter’s team synthesized the genome of a bacterium – Mycobacterium genitalium – from scratch.  The team has yet to insert the synthesized DNA into a cell, and thus achieve – in effect – the creation of life form laboratory chemicals.  But it seems only a matter of time before this is achieved.

January 2008 - Craig Venter's team synthesize the complete genome of a new organism from scratch

We’re not quite there yet with the technology that will allow us to manipulate biology at the nanoscale.  But it’s coming.  And when it does, the level of control we have had over matter for the past ten centuries will seem like child’s play.

Throw this level of potential control into the mix with the other two “C’s,” and you have all the ingredients for a step-change in what we can do, and what the consequences are – for good and for bad.

Next time: Confluence: Where communication, coupling and control collide.

Notes

Rethinking science and technology for the 21st century is a series of blogs drawing on a recent lecture given at the James Martin School in Oxford.  This is a bit of an experiment—the serialization of a lecture, and a prelude to a more formal academic paper.  But hopefully it will be both interesting and useful.  I’ll be posting a “rethinking science and technology” blog every week or so, interspersed with the usual eclectic mix of stuff you’ve come to expect from 2020science.

Previously: Control at the nanoscale: Smallness, strangeness and sophistication.

Next: Confluence: Where communication, coupling and control collide.

Part 5 of a series on rethinking science and technology for the 21st century

Last time in this series of occasional blogs, I made the rather bold statement that while science and technology are going to have a highly visible impact on our lives over the next few decades, progress is going to be underpinned in most cases by our increasing control over materials at the invisible nanoscale. It isn’t exactly intuitive why this should be the case though—how on earth can engineering matter on a scale a billion time smaller than the average person be so important?

In trying to answer this question, I want to take a rather unconventional approach and explore three advantages of working at this scale: Smallness, strangeness and sophistication.

Smallness. Size matters—it’s something we all understand intuitively.  There are occasions when you can do something with a small object or device that would be impossible otherwise.  This photo from Ilan Kelman for instance illustrates the idea perfectly: There are times that “smallness” gets you to places that larger objects can’t reach—like parking spaces!

It’s easy to see how making things that we can see and touch small can enhance their value.  But the utility of smallness doesn’t stop when things become invisible to the naked eye.  All the way down to the nanometer scale, there are opportunities to make things work better or work differently by making them small.

Here’s a very trivial example of smallness making a difference at the nanometer scale, but it’s a useful illustration of why size matters:

Silver is a great antimicrobial agent.  It’s been used for millennia to prevent infections from spreading and is one of the reasons why “silverware” is—or used to be—made of the metal.

But it’s not that easy to use.  Large lumps of metal aren’t always that easy to incorporate into products that you want to keep sterile or have antimicrobial properties.

One solution is convert the individual silver atoms into charged ions that can be dissolved in liquids and incorporated into other substances.  As its the ionic form of silver that is most harmful to microbes, this makes a lot of sense.  But ionic silver isn’t that easy to use either.  Say you have a silk scarf or a wound dressing you want to imbue with antimicrobial properties.  Getting those silver ions in there without changing the physical feel and nature of the material is a tough challenge.

This is where smallness comes in.  Make the silver metal into nanometer-sized particles, and it becomes relatively easy to get it into a wide range of products.  Because these are particles we are dealing with, there isn’t so much complex chemistry behind using them.  And because they are so small, they don’t unduly affect the feel and performance of the products they are used in.  As an added advantage, replacing a few large particles with millions of small ones increases the chances of microbes coming into contact with them manyfold.

Because of the advantages of smallness when it comes to using silver as an antimicrobial, there has been an explosion of products using silver nanoparticles—everything from refrigerators to socks to toothpaste.  And all because smallness gets you to new places.

It’s a trivial example, but it does illustrate an important way in which “smallness” through increased control over matter at the nanoscale leads to added value.

It’s not the only way though—there is also strangeness.

Strangeness. No two questions about it, things can get a little weird down at the nanoscale. This is good – it means that controlling matter at this scale opens up a whole new toolbox of material properties that can be put to good use.

Vicki Colvin at Rice University came up with a great analogy for strangeness a few years back.  It went something like this:  Imagine you have a cat.  It looks like a cat, sounds like a cat, smells like a cat.  Now, imagine you have a technology that allows you to make that cat smaller.  As you shrink your cat down, it gets smaller and smaller, but still retains its essential cat-ness.  But imagine reaching a point where suddenly, instead of looking, smelling, sounding like a cat, your cat becomes a dog!

This is the very essence of strangeness—materials behaving in unexpected and sometimes radically different ways when they are engineered at a nanometer scale.  This doesn’t always happen—it depends on the material and the scale on which the material is being engineered—but in some cases the changes in behavior can be startling.

A good example is found in the metal gold.

Gold is an inert, yellowish metal—everyone knows this.  It’s lack of reactivity is why so much jewelry is made from the stuff (it doesn’t tarnish), and in part why it holds its value.  But form gold into particles just a new nanometers across, and everything changes—the metal does the equivalent of transforming from a cat into a dog.  Instead of appearing yellowish in color, the particles now appear red, and become highly chemically active.

This change in color has been exploited for millennia in glass-making (unbeknownst to the glass-makers, who had no idea they were making and using nanoparticles), with perhaps the most famous example being the Lycurgus cup from Roman times.  Illuminated from behind, the gold nanoparticle-containing dichroic glass that the cup is made from appears deep red in color.

This strange behavior has a lot to do with how the movement of electrons in materials is affected when they are engineered at a nanometer scale.  As these movements affect everything from electrical conductivity and interactions with electromagnetic radiation—including visible light—to how a material conducts heat, nanometer-scale engineering allows scientists and engineers to tap into material properties that are rarely accessible without control at this level.

But it’s not enough to have a smorgasbord of strangeness at out fingertips—we also need the ability to use these unusual properties.  And this is where sophistication comes in.

Sophistication. As humans, we are pre-programmed to build things.  As kids, we start early—usually with large blocks.  But we soon learn that there are limits to what can be made with these rather awkward building blocks, and so we progress on to finer blocks—think of it as graduating from wooden blocks to Duplo.  However, it isn’t long before we outgrow these bricks and crave something smaller with which to create increasingly sophisticated structures.  And so we discover that ultimate building medium—Lego.

It’s a rather tongue in cheek analogy, but it illustrates something we all know: The smaller the building blocks we use, the more sophisticated the products we can make.  This applies at the human scale, but it just as equally applies at the nanometer scale.  In fact, being able to build with nanometer-scale clumps of atoms and molecules gives us perhaps what is the ultimate construction set.  And before anyone interjects with “surely that’s just chemistry,” the distinction here is the ability to put these small clumps where we want them with nanometer scale precision.  This is sophistication at the nanometer scale, and opens up new possibilities in engineering materials and products with enhanced or unique properties.

It’s probably fair to say that we are just beginning to scratch the surface of what can be achieved through sophisticated nanometer-scale engineering, but already there are examples that hint at the potential that is opening up.

Here you see a schematic of an actual nanometer-scale particle developed by Raoul Kopelman and Martin Philbert at the University of Michigan.  What is particularly interesting is the sophisticated way this particle has been engineered at the nanoscale to carry out a number of tasks.

The core particle is coated with a thin layer of PolyEthylene Glycol (PEG) to make it invisible to the body’s defense systems.  It is also covered with molecules that enable it to attach to a specific target cell—a particular cancer cell in this case.  Internally, the nanoparticle has been engineered with a contrast-enhancing agent, meaning that when sufficient particles are attached to the tumor being treated, they can be seen using imaging techniques like MRI.

Then the really clever bit—the particles have been engineered with a sensitizer.  In essence, this is a component that causes the particle to do something when it receives a signal.  In this case, when the particle is illuminated with a particular wavelength of light, it releases chemicals to kill the cancer cell it is attached to.

This “smart” particle represents an incredible degree of sophistication at the nanometer scale, and does what it does—destroys cancer cells without affecting healthy cells—because of this sophistication.  And it’s only one example from an increasing number of applications that demonstrate what can be achieved when we have the sophistication to build things at close to the scale of individual atoms and molecules.

At the end of the day, smallness, strangeness and sophistication don’t tell you everything you need to know to understand why an increasing ability to control matter at the nanoscale is so important.  But they do provide a pretty good insight—dare I say, a sophisticated insight—into what can be achieved by working at this scale.

They also create a bridge between two largely separate spheres that is poised to take our control over the world in which we live to an entirely new level.  But more of that next time.

Notes

Rethinking science and technology for the 21st century is a series of blogs drawing on a recent lecture given at the James Martin School in Oxford.  This is a bit of an experiment—the serialization of a lecture, and a prelude to a more formal academic paper.  But hopefully it will be both interesting and useful.  I’ll be posting a “rethinking science and technology” blog every week or so, interspersed with the usual eclectic mix of stuff you’ve come to expect from 2020science.

Previously: Control: Gaining mastery over the world at the finest level

Next: Nanoscale control: Leveraging biology

Part 4 of a series on rethinking science and technology for the 21st century

So far in this series of occasional blogs, I’ve covered coupling and communication—two of three “C’s” which together are challenging how science and technology are best used to serve society.  Now it’s the time to delve into the third “C”—control.

Because this is a tough subject to cover in one bite, I’m going to split it between three posts.  Here, I’ll get the background stuff out of the way.  Then, in the following posts in the series, I’ll take a look at why this “C” is so transformative, and some of the more advanced directions control is taking us in.

To kick things off, I want to start big.  The image to the right is an artist’s impression of a scheme dreamt up by Roger Angel at the University of Arizona to reduce the amount of sunlight reaching the earth—a possible approach to combating (in part) global warming.  It represents the idea of suspending trillions of solar diffusers – fuzzy translucent plates—at the Lagrange point between the earth and the sun, where they can deflect a small amount of the sun’s radiation away from the planet.

If we could achieve this, it would be the largest feat of planetary control ever undertaken.

Just a few years ago, such a scheme would have been pure science fiction.  But we are getting to the point where advances in science and technology are bringing mega-engineering projects like this within our grasp.  For the first time in human history, we have both the audacity and technology to think about controlling our environment on a planetary scale.

This taking control of things on a grand scale is part of what the third “C” is about.  But it is only the tip of the iceberg.  Going back to Angel’s solar sunshade, it’s worth asking what it would take to transform this idea from fantasy to reality.  In amidst the myriad engineering challenges it represents is the issue of materials—how do you make solar diffusers (or “flyers”) light enough yet robust enough to do their job?  The reality is, the materials needed to achieve this simply don’t exist at present.

Which means that for the plan to work, new materials need to be created.

This isn’t a trivial thing to achieve.  It’s not as if we are going to discover some fancy new element that can be made into a wonder-material.  Rather, the solution is going to lie in how we put small groups of regular atoms—the building blocks of everything we use—together in different ways, to form new and better materials.

And this brings us to the area where increasing control is going to be truly transformative—control over matter at the scale of atoms and molecules—the nanoscale.

But why should controlling matter down at this miniscule level make a difference? The answer lies in what makes stuff work better, and what messes it up.

Most materials we use nowadays are not as good as they could be.  They generally function OK, but they could be better.  And the reason for this is that down at the nanoscale, they are a mess—atoms aren’t aligned properly, there are gaps in the structure where there shouldn’t be, stuff is present that should not be there, while the stuff that should be there isn’t where it ought to be.

This isn’t surprising.  Until relatively recently, we didn’t have the tools or the know-how to engineer stuff down at the atomic level, so we had to make do with rather imperfect materials.  This is changing though, and it is changing extremely rapidly.

Eighty years or so ago, scientists began to develop ways of seeing—or at least taking a good stab at visualizing—the structure of materials on an atomic scale.  Techniques like electron microscopy and X-ray diffraction opened up a brand new perspective on how stuff is put together.  More importantly, these and other tools gave scientists the feedback they needed to start tinkering systematically with materials at the nanoscale.

The age of nanometer-scale control was born.

Over the past couple of decades, near atomic-level control over matter has surged ahead, as growing awareness of its importance has combined with greater incentives for scientists to work across traditional boundaries and huge funding initiatives from government and industry.  The result has been rapid progress in engineering materials and products that work—or work better—because their structure has been controlled and manufactured at the nanometer scale.  Products as diverse as computers and cosmetics are already benefitting from the added value that comes from nanoscale control.  Already there are hundreds of consumer products out there that manufacturers claim do what they do “better” because of nanoscale engineering.  These are small fry though compared to some of the applications in the pipeline—smart drugs, new power sources, faster computers, even designer microbes.  And the indications are that we are only just beginning to flex our nano-muscles.

The bottom line here is that while science and technology are going to have a highly visible impact on our lives over the next few decades, progress is going to be underpinned in most cases by our increasing control over materials at the invisible nanoscale.

To begin to grasp how working with matter at such a small scale opens up new opportunities, it’s worth focusing on three features of nanoscale control—smallness, strangeness and sophistication.  These will be the subjects of the next blog in this series.

Notes

Rethinking science and technology for the 21st century is a series of blogs drawing on a recent lecture given at the James Martin School in Oxford.  This is a bit of an experiment—the serialization of a lecture, and a prelude to a more formal academic paper.  But hopefully it will be both interesting and useful.  I’ll be posting a “rethinking science and technology” blog every week or so, interspersed with the usual eclectic mix of stuff you’ve come to expect from 2020science.

Previously: Communication: Science and technology in a connected world

Next: Control at the nanoscale: Smallness, strangeness and sophistication

So you want to make or use carbon nanotubes, but you are worried about handling then safely.  What do you do?  The good news is that the UK Health and Safety Executive has just published an information sheet that addresses just this question.  Risk management of carbon nanotubes is (according to the blurb) “specifically about the manufacture and manipulation of carbon nanotubes, and has been prepared in response to emerging evidence about the toxicology of these materials.”

But is it any good?  Here’s my initial take:

HSE recommends a precautionary approach for managing the risks of all carbon nanotubes. This is a good move.  The evidence so far—which admittedly is sparse—points towards all forms of carbon nanotubes being more harmful in the lungs than non-nanotube forms of carbon.  Of course, it depends on how you define “precautionary,” but “looking before you leap” seems a reasonable translation in this case.

No mention is made of possible exposure when working with carbon nanotube-containing products. HSE’s information sheet is clear that exposure to nanotubes can occur when making the stuff, when using it, and when researching its properties.  But there is no mention of what could occur when machining, grinding or cutting a product containing carbon nanotubes.  To be fair, research so far indicates that in most cases, once carbon nanotubes are embedded in a product they are unlikely to come out.  But if a precautionary approach is to be taken, it seems sensible to at least ask whether there is a chance that exposure to the material will occur while working with carbon nanotube-containing products.

The review of new evidence neglects particle-like effects in the lungs. The information sheet revolves around concerns over asbestos-like behavior and certain types of carbon nanotubes, which is understandable given the unpleasantness and latency period of diseases like mesothelioma.  But current research suggests that even clumps of carbon nanotubes that don’t look like asbestos fibers are more toxic if inhaled than might be imagined.  Last July, Anna Shvedova and colleagues published research showing that inhaling non asbestos-like single walled carbon nanotubes at concentrations currently recommended as safe by many manufacturers could be harmful.

In other words, it isn’t just asbestos-like behavior that we need to be concerned with here.

Use of carbon nanotubes appears to be discouraged in the absence of information on inhalation hazards. The information sheet states:

“HSE views CNT’s [carbon nanotubes] as being substances of very high concern.  Although the recent findings only apply to some CNTs we think a precautionary approach should be taken to the risk management of all CNTs, unless sound documented evidence is available on the hazards from breathing in CNTs.  If their use cannot be avoided, HSE expects a high level of control to be used.”

I may be reading this section wrong, but the message seems to be: If you don’t have a good handle on how harmful the substance you are using might be, don’t use it. But if you absolutely must, do everything possible to reduce exposures to a minimum. As there are no definitive data on carbon nanotube toxicity yet, this advice seems to boil down to the use of carbon nanotubes being discouraged.

Given the economic potential here, I’m interested in how this will play with industry.

Recommended qualitative risk management actions will reduce exposures… At the heart of the information sheet is advice on steps to reduce exposure to airborne carbon nanotubes when working with the substance.  These are solid, generic, good occupational hygiene practices—“use appropriate work processes,” “control exposures at source,” “make sure exposures are controlled at all times” etc.  And if followed, they should lead to fewer people being exposed to less material.  But I do wonder how practical some of them are for dealing with certain forms of carbon nanotubes—especially when it comes to working in fume cupboards and keeping material wet where possible.

…But there are few indications of “how much is enough.” Qualitative actions abound in the information sheet: “use appropriate work processes;” “provide suitable work equipment;” maintain “adequate control of exposure at all times.”  But such advice is hard to apply in the absence of any information on what processes are “appropriate,” how suitability is determined, and when “adequate control” is achieved.

I’m sure the point here is that any actions to reduce exposures are better than none.  But without quantitative benchmarks, the chances are that some people will be exposed to worryingly high levels of carbon nanotubes (under the “we tried our best” arguement), while others will struggle to obtain exposure levels that are needlessly low.

On balance, I have to commend the HSE on coming out with the information sheet on the ground that any information is better than no information, and I’m sure that some will find it helpful.  But I do worry that the information provided isn’t specific enough to either protect peoples’ health effectively, or provide nanotech businesses with the help they need to do the right thing without over-doing it.

And unfortunately, the document fails to provide links to other sources of information that may help remove some of the ambiguity (see some of the documents below for instance).

The bottom line here is that the information sheet is great for raising awareness, but seems to falls short of providing much in the way of practical advice.

Of course, I don’t actually have to make hard decisions on what exposures are acceptable for my employees, which controls to put in place, and how to assess their effectiveness.

Maybe if I did, my perspective would be different.

End Notes

I should note that I was asked to informally review a late draft of the information sheet last year.  I suspect I was too late in returning my comments though—the published document isn’t substantially different from my review copy.

For more substantive advice, I would recommend reading the document “Nanotechnologies – Part 2: Guide to safe handling and disposal of manufactured nanomaterials” from BSI Inc.  My review of it can be found here.

More detailed information on working safely with nanomaterials is also published by the US National Institute for Occupational Safety and Health.

Similar advice is available from the standards organizations ISO and ASTM International (see  Alphabet soup hides the secrets of safe nanotech! for further information)

Thoughts on applying Control Banding to working with nanomaterials can be found in this excellent paper by Sam Paik and colleagues.  While not dealing specifically with carbon nanotubes, it does develop a framework for making exposure control decisions:

Application of a Pilot Control Banding Tool for Risk Level Assessment and Control of Nanoparticle Exposures.  Paik et al. (2008) Annals of Occupational Hygiene 2008 52(6):419-428

Paik’s work forms the basis of safe handling guidelines recommended by the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), the Commission de la santé et de la sécurité du travail (CSST) and NanoQuébec.

Additional 2020 Science blogs addressing carbon nanotube safety:

• Carbon nanotubes: the new asbestos? Not if we act fast
• Resolving the carbon nanotube identity crisis
• Asbestos-like nanomaterials – should we be concerned?

]]> http://2020science.org/2009/03/17/working-safely-with-carbon-nanotubes/feed/ 1 http://2020science.org/2009/03/02/nanotechnology-risk-research-ten-years-on/ http://2020science.org/2009/03/02/nanotechnology-risk-research-ten-years-on/#comments Tue, 03 Mar 2009 02:28:21 +0000 Andrew Maynard http://2020science.org/?p=958

Ten years ago to the month, one of the first research reports detailing the challenges of ensuring the safe use of engineered nanomaterials was delivered to the UK Health and Safety Executive.  The report wasn’t for general release, and you’ll be hard pressed to find a copy of it in the public domain.  But as a co-author, I have a copy skulking around in my archives.  And given it’s ten year anniversary, I’ve been browsing through it, to find out how much has progressed—or not, as the case may be!

The report focused on ultrafine aerosols, and the Health and Safety Laboratory’s ability to respond to then-current, and future, research needs.  As such it was pretty wide ranging, and focused extensively on exposure to incidental nanoscale aerosols—such as welding fume and engine emissions—in the workplace.  But it did encompass the then-nascent field of nanotechnology and “nanophase material synthesis.”  And some of these early assessments of the field bear revisiting.

For anyone interested in what was being written about the potential health and safety issues raised by engineered nanomaterials ten years ago, I’ve extracted a few sections of the report below—for the full thing, you’ll have to go to the UK Health and Safety Executive.

My apologies that the post is so long—I’m only expecting a dedicated few to plough through it.  But at the least, you might want to skip to the end to see how the research recommendations of 1999 compare to those of today—you might be surprised!

A scoping study into ultrafine aerosol research and HSL’s ability to respond to current and future research needs.
IR/A/99/03

Kenny, Maynard et al. 1999

The introduction to the report starts:

Over the past few years a number of epidemiological studies have indicated a tentative link between ambient particulate concentrations, and morbidity and mortality rates (e.g. Dochery et al. 1993, Pope 1996, Schwartz et al. 1993, Schwartz et al. 1991).  In all studies, particles with an aerodynamic diameter less than 10 µm (the PM10 fraction) have been implicated as the key agents.  The lack of an apparent association between particles of specific composition and health effects has indicated the observed effects to be due to some physical aspect of the inhaled particles.  A further link between particle size and health has been indicated by Dochery et al. (1993) who showed a more positive correlation between ill health and particles smaller than 2.5 µm than was seen than with the PM10 fraction.  The possibility of correlations between particle size and number concentration and toxicity has been demonstrated by Oberdörster et al. (1995) by exposing rats to PTFE particles ~20 nm in diameter.  At concentrations of 106 particles cm-3 (corresponding to an equivalent mass concentration of approximately 60 µg m-3) rats exposed for 30 minutes died within 4 hours. At lower concentrations a steep dose response curve was observed between pulmonary inflammatory responses and particle number.  More recent research has begun to indicate a possible material-independent link between inhaled particle surface area and selected toxicological endpoints (e.g. Lison et al. 1997). The possibility of a relationship between fine inhaled particles and ill health is now readily accepted,  although research is still at a very early stage and most published data to date are open to a wide range of interpretations.  Tentative hypotheses concerning possible mechanisms leading to toxicity have been proposed (e.g. Schlesinger 1995, Seyton et al. 1995, Donaldson and McNee 1998), and the impact of inhaling ultrafine particles on both the respiratory and cardiovascular systems have been speculated on.  The US EPA have already acted, partially as a response to earlier epidemiological studies, and introduced the PM2.5 sampling standard for environmental particulates.  Whether the UK is to follow this lead is still under discussion.  However, despite these steps, research so far has raised more questions than answers.  There is debate over the interpretation of the epidemiological studies, and the appropriateness of chosen endpoints in toxicology tests.  Contradictory experimental results are beginning to be published regarding ultrafine particle impact on health (e.g. Pekkanen et al. 1997).  There also appear to be widely conflicting views on what constitutes an ultrafine particle, with implicit cut-off points ranging from 10 µm down to a few nm!

In amongst all the current confusion is the question of whether the alleged health implications of inhaling ultrafine aerosols are of relevance to the workplace.  Much has been made of the apparent health problems amongst vulnerable sectors of the general population following environmental exposures, and the argument is followed through to the conclusion that within a healthy workforce similar problems are unlikely to be seen (backed up by a lack of evidence of severe health problems that are clearly linked to ultrafine aerosols).  However, in part the current uncertainty over the toxicity of ultrafine particles is due to the very limited information available on the nature of so-called ultrafine particles.  Inhaled particles associated with health in epidemiology studies have been very poorly defined, and even the particles used in most well controlled in vitro and in vivo experiments have been poorly characterised.  Without basic information on particle size, morphology, composition and structure, it is clearly not feasible to make value judgements on the nature of inhaled particles, either in the general environment or in the workplace. In the light of the scarcity of information on particle characteristics, the Committee on the Medical Aspects of Air Pollutants has recommended the monitoring of such parameters at a number of environmental locations (COMEAP 1996).  Similar measurements will be essential within the workplace before further speculations on the importance of ultrafine aerosols are made.

In reading this, it is important to remember that the state of the science is ten years on from when this was written—there are now a wealth of publications on the potentially health-relevant behavior of nanometer-scale particles.  Yet the framework of questions set out largely remains as relevant now as it did then.

Perhaps more interestingly, in 1999 the discussion was focused on understanding and managing the health impacts of inhaled particles, NOT whether those particles could be classified as arising from nanotechnology or not.  As a result, the document tends to be more grounded in the science of how fine particles potentially impact on health, rather than how the poorly defined field of “nanotechnology” might lead to health effects.

The report goes on to consider the generation of ultrafine aerosols in the workplace:

In general, very little is known about any aspect of ultrafine aerosols in the workplace.  There are a number of processes such as welding and soldering where intuitively one would expect large numbers of sub-µm particles.  However even in these areas, detailed measurements of particle size do not appear to have been made.  There is a general feeling that in situations where large concentrations of particles are generated, agglomeration will remove ultrafine particles from the aerosol before it is inhaled, thus removing the need to consider ultrafines. However this has not been verified, and evidence exists for significant mass concentrations of ultrafines existing close to generation sources.  Interestingly, researchers are currently speculating that agglomerates with ultrafine primary particles may have the equivalent impact on the lungs as the individual primary particles.  More is known about the products of internal combustion engines, although mainly from the view point of monitoring and reducing environmental emissions.  However very little information on the nature of individual particles in the workplace exists.

Ultrafine aerosols tend to be formed either through nucleation (in particular homogeneous nucleation), gas to particle reactions or through the evaporation of liquid droplets.  The majority of workplace ultrafine particles are likely to arise from the nucleation route, either as combustion products, or within saturated vapours arising from other sources (e.g. welding, smelting, laser ablation).  Evaporation of sub-micron and even micron sized droplets of relatively high purity solvents will result in very small particles.  Where the initial particles are highly charged, there is the possibility of any resulting fine particles exceeding the Rayleigh charge limit and fragmenting into even finer particles.  This is a recognised method of generating ultrafine particles through electrospraying.  To what extent this generation route is present in the workplace is unknown, although it is used for the specific generation of ultrafine particles during nanofabrication.  Gas to particle generation of ultrafine aerosols accounts for the majority of non-combustion particles in the environment, although again the significance of this route within the workplace is unclear.

Following current interest in nanophase technology, and the use of ultrafine particles as precursors in nanophase materials, it is likely that the next few years will see an increase in the industrial generation and use of ultrafine particles.  At present the planned generation of particles tends to be isolated to the production of ultrafine metal oxides such as TiO2, ZnO and fumed silica.  Ultrafine carbon black is also currently generated on a commercial scale. Although the full extent to which ultrafine aerosols are generated as an unwanted by-product within industry is still largely unknown, there are clear cases where the generation rate is high, such as in welding and from internal combustion engines.  Even so, data on the nature of generated aerosols in these areas are sparse.

There follows an assessment of different sources of nanoscale particles in the workplace, from welding to plastic fumes from laser cutting, and a range of other sources.  This is all interesting information, but here I want to focus on the section on ultrafine aerosol precursors in nanophase technology:

Over the last ten years, interest in the unique properties associated with materials having structures on a nanometer scale has been increasing at something approaching an exponential rate.  By restricting ordered atomic arrangements to increasingly small volumes, materials begin to be dominated by the atoms and molecules at the surfaces of these ‘domains’, often leading to properties that are startlingly different from the bulk material.  As the domains become smaller, and hence more dominated by surface atoms and surface energies, so the properties become increasingly unique from either the bulk material or the constituent atoms. So for instance, a relatively inert metal or metal oxide may become a highly effective catalyst when manufactured as ultrafine particles; opaque materials may become transparent when composed of nanoparticles, or vice versa; conductors may become insulators, and insulators conductors; nanophase materials may have many times the strength of the bulk material.  All of these effects and many more have been observed with various materials.  Such material properties that are unique to nanostructured materials that have excited both the scientific and industrial communities in recent years.

Most nanophase materials are fabricated either from the liquid state, or the aerosol state, although some routes combine the two.  The liquid route perhaps gives more control over the process in some cases.  However there is a general feeling at the present that using aerosols is an inexpensive and versatile route to constructing these materials.  Although there are many different production methods being explored, the general approach is to generate, capture and process an aerosol of particles with the dimensions of the final nanostructure.  Typically this requires the generation of particles from 1 to 2 nm in diameter up to around 20 – 30 nm in diameter, depending on the required properties of the final material.  Generation rates in research laboratories tend to be low (of the order of mg/hour), although where industrial production of nanoparticles has commenced, production rates of the order of tonnes per hour are seen.

At present, nanophase materials are an emerging technology, with the emphasis most definitely still on the research lab.  However, there is considerable commercial commitment to the field, and it is certain that as scale-up problems are overcome, the mass production of both nanoparticles and nanophase materials will increase rapidly world-wide.  When this occurs, the unique health problems associated with a unique product that can neither be treated as a bulk material or on a molecular level will have to be fully addressed.  In the meantime, there is a clear need to keep up to date with both developments in the technology, and any health concerns that may be associated with it.

Over the past ten years, commercial-scale production of nanoscale materials has moved on significantly, although perhaps not as much as some would have predicted.  Yet the issues surrounding their safety still reflect (by on large) the issues raised here.

The report summarizes the state of nanotechnology research in 1999—which I’ll skip over—and goes on to consider where the rather quaintly termed nanophase technology was heading:

The indication from the scientific press is that there are as many potential applications for nanophase technology as there are groups working in the field.  However a relatively small number of areas can be identified where commercial production of materials is most likely to be seen in the next 5 – 10 years.  To understand the commercial pressure behind the progress of nanophase technology and its likely integration into industry, you only have to consider the potential market for successful applications.  In the electronics industry in particular, the revenue arising from nanotechnology is likely to be well in excess of hundreds of billions of dollars.  In other areas, such as coatings and catalysts, similar markets exist for successful applications.  The market for ‘intelligent’ drug delivery systems, if successful, is likely to be immense.  Reflecting this, the pharmaceutical industry is currently investing in excess of $14B per annum into advanced delivery systems.

Electronic applications

The reduction in particle size has a profound effect on electronic structure as nanometre dimensions are reached, leading to a number of unique electronic properties seen in individual and groups of nanoparticles.  As an illustration, Si, which is semiconducting in the bulk solid, may be used to form nanometre sized pseudo-crystals with one of two types of atomic structure dominating its faces.  Particles with one structure are fully conducting. Those with the other are good insulators. What does this mean/what are the general implications?

Perhaps the most widely recognised electronic property of nanoparticles is their ability to act as quantum dots.  In arrays of such particles, the overall electronic characteristics are dominated by quantum effects within the particles, leading to novel applications.  For instance, quantum dot devices can be used to create high efficiency LED’s and electroluminescent plastics.  High frequency solid state lasers based on quantum dot technology are expected to form the basis of a major breakthrough in telecommunications, leading to significantly higher communication bandwidths.  High speed and high capacity computer memory will also be possible using quantum dot technology.  Success in fabricating viable quantum dot devices will bring about a major technological step within the electronics industry, leading to a $B production industry, although progress at present is limited by the need to fabricate very precise arrays of well characterised particles.  Current approaches include the use of colloids, nanolithography and aerosols.

Porous nanostructured semiconductors such as silicon have recently been shown to have electroluminescent properties.  If this can be fabricated into integrated circuits, the basis for the next generation of high speed optoelectronic computers will be laid.  Nanoparticles are also being found to lead to improved properties in resistors and capacitors.  Ultrafine conducting particles embedded in an insulating matrix have been shown to give a great range of resistances as well as showing very high temperature stability.  Similarly, the use of nanoparticles in capacitors has been shown to give a high dielectric permitivity and a low dissipation factor, making them ideal for high speed computer memory.

A particularly interesting phenomenon seen in nanophase materials is that of electrochromism; the modification of optical properties by the application of an electric field. Windows or mirrors coated with thin layers of these materials show variable light transmittance or reflection based on the magnitude of an applied electric field.  It has also been found that nanophase materials may be used to form thin transparent films with high conductivity.

A number of other important areas relating to electronics are increasingly relying on the use of nanostructured materials.  Solid state gas sensors show improved sensitivity when using films of sintered nanometre particles; high temperature superconductors have a higher performance when formed of nanostructured materials; thermocouples benefit from nanostructure and the magnetic properties of some nanostructured materials is already exploited to the full in magnetic storage media.

Coatings

Using nanophase materials to coat a wide range of substrates is being explored, and has been exploited in a wide range of applications.  Hard nanophase coatings are important in the construction industry.  The use of coatings with specific optical properties is of interest within the glass and photographic film industries.  Dry coating technology is also benefiting from nanophase materials.  It has been shown that the transport properties of large particles may be radically altered by the addition of a thin coating of fine particles of a suitable material.  For instance, coating starch grains with fumed silica results in a highly flowable powder.  In many cases, this coating need only be of the order of nanometres thick, and the use of nanoparticles in dry coating processes is already under investigation.

Chemical-mechanical polishing using nanoparticle slurries.

Surface polishing is a critical step in the processing of silicon wafers prior to semiconductor chip fabrication.  Surface blemishes are a major source of both wafer and chip rejection in the electronics industry.  By using polishing slurries consisting of nanoparticles, planarisation of wafer surfaces with fewer blemishes is possible.

Drug delivery systems.

A key goal in current drug delivery system research is the development of ‘intelligent’ systems that will deliver doses to specific sites within the body.  One approach being actively considered is the use of coated nanoparticles.  These would be capable of penetrating capillaries and being transported directly to the target site.  The coating would include the drug to be delivered, components to prevent an immune response from the body and components to achieve site-specific or condition-specific delivery.

Nanoparticle catalysts

The modified surface chemistry of nanoparticles is well recognised for its catalytic properties in many materials.  This, together with the associated surface area to mass ratio for such particles, has led to intense interest in nanostructured catalysis within many fields.

After laying out the state of the science regarding the potential risks of inhaling nanoscale particles (which has advanced considerably over the past ten years), the report summarises (on the health impacts):

There has been little work in this field to date, so it is difficult to draw meaningful general conclusions from the published data. One of the reasons for this lack of data appears to be the difficulty in generating particles of standard and known size for use in in vitro studies. Particles used in both in vitro and in vivo studies have also tended to be relatively poorly characterised. Different effects both in vitro and in vivo have been observed with different sources of ultrafine particles, so the responses measured may be a function of the particle constituents rather than the particles per se. The differences observed have been attributed to the ability of particles with a particular composition to have different levels of free radical activity at their surface. Whilst there has been some work investigating synergy between acid aerosols and ultrafine particles (see below), there has been no work investigating the synergy between ultrafine particles and other potential airborne contaminants, e.g. allergens, VOC’s and bacteria. Some of the animal models used to demonstrate toxicological endpoints require exposure regimes which are far in excess of any possible exposure in humans (e.g.  6 hours a day, 5 days a week for 3 months). Therefore, the extrapolation of such health effect data to humans should be treated with some caution.
…
Interest in possible health effects following inhalation of ultrafine particles is high at present, and research is beginning to follow this interest.  Inhalation toxicology has taken over from epidemiology over the past few years, and dominates the field at present.  Dose response relationships in rodents are being seen that indicate particle number or surface area to be more appropriate metrics than mass.  The possibility of ultrafine particles acting as vectors to transport  acids and metals to the alveolar region of the lung is also being explored.  However it is recognised that many of the current approaches being taken are lacking in various aspects, particularly regarding the significance of chosen endpoints and the characterisation of particle exposure, and a number of groups are now beginning to address these issues.  This is an area that is particularly ripe for good research proposals to sympathetic funding bodies. The need to fully characterise the particles used in exposure and inhalation tests, as well as those that people are exposed to in the workplace and environment, is well understood, although the right combination of technical skills to achieve this seems to be lacking in many establishments.  In particular there would appear to be significant scope for transferring analytical electron microscopy skills used in materials science and nanostructure analysis to the analysis of ultrafine aerosol particles.  There is also a recognised need for in-vitro test systems that allow cell cultures to be exposed to the aerosol, rather than a particulate suspension.  A small number of research groups are currently developing test systems allowing direct aerosol deposition.  Funding for fine particle research (PM2.5 sampling, and mass-based aerosol sampling) still dominates, but all aspects of ultrafine particle research are on the increase, and it is likely that the next few years will see significant funding opportunities and research in this area.  Driven by concerns over environmental exposure, together with the need to address exposure limits for nuisance dusts, there is increasing interest in examining the impact of ultrafine particle exposure in the workplace.

The report covers a lot of ground on exposure measurement and control, which I won’t duplicate here (although a lot of the information remains highly pertinent).  Instead, I’ll jump right to the end of the report, where a number of research recommendations are made.  Remembering that these are focused specifically on inhalation exposure in the workplace, they sound surprisingly contemporary, being written 10 years ago:

Full quantification of ultrafine aerosol exposure in the workplace:

• Measurement of number, size, surface area, composition, morphology, structure
• Investigation of the surface properties of workplace particles.
• Investigation of surface enrichment, role of modified surface activity below 10 nm, relevance of internal structure.
• Development of instrumentation and analytical techniques for surface area
• measurement and individual particle characterisation (Analytical Electron Microscopy)

Targeted epidemiology and toxicology studies.

• Epidemiological evidence for ultrafine particle toxicity in the workplace
• Toxicity of well defined particles, and of particles characteristic of those found in the workplace.
• Investigation of mechanisms resulting in toxic responses, in relation to the known physical and chemical attributes of workplace particles.

Instrumentation

• Identification of deficiencies in instrumentation and monitoring requirements, and development of new technologies and methods.

Control

• Reassessment of  the applicability of conventional control systems (including RPE) to reduce exposure to ultrafine particles, and the development of new approaches to exposure control.

Exposure Limits

• Assessment of current exposure limits in the light of available data on ultrafine particle toxicity, and the development of more appropriate approaches to exposure limits.

Ten years on, it is surprising how relevant this document still is.  The major issues facing the safe use of nanomaterials were reasonably clear ten years back.  And many of the research needs raised then remain today.  Progress certainly has been made since then, and an understanding of the types of nanomaterials of greater concern has increased—the 1999 report doesn’t mention carbon nanotubes for instance.  But on the flip side, this is a report that was clearly unencumbered by the politics of nanotechnology that seem to have diffused through things today

Perhaps most surprisingly though, is that governments and others are still talking about the same issues – often as if they have discovered them for the first time – without doing that much about them.  It would be churlish to ask where we might have been now if some of those 1999 recommendations were listened to.  But at least I can ask where we might be in 2019, if only we can break out of this endless cycle of re-inventing the nanotech risk report!

Endnote

Because this was an internal report, I have been careful to extract only parts of it that are of general interest and are not in any sense proprietary.  That said, there is a lot of information in the full report that would be helpful to anyone grappling with addressing and managing potential occupational risks arising from nanoscale particle exposure in the workplace.  It would be great if the UK Health and Safety Executive could release it for public use!

References

COMEAP (1996).  Non-biological particles and health.   HMSO Publications.

Dochery, D. W., Pope, C. A., Xu, X., Spengler, J. D., Ware, J. H., Fay, M. E., Ferris, B. G. and Speizer, F. E. (1993).  An association between air pollution and mortality in six U.S. cities.  N. Engl. J. Med, 329, 24, 1753-1759.

Donaldson, K. and McNee, W. (1998).  The mechanics of lung injury caused by PM10.  In: Air Pollution and Pealth.  Eds:  Hester and Harrison.  Royal Society of Chemistry.  ISBN 0-85404-245-8.  pp21-32.

Lison, D., Lardot, C., Huaux, F., Zanetti, G. and Fubini, B. (1997).  Influence of particle surface area on the toxicity of insoluble manganese dioxide dusts. Arch. Toxicol. 71, 725-729

Oberdörster, G., Gelein, R. M., Ferin, J. and Weiss, B. (1995).  Association of particulate air pollution and acute mortality:  involvement of ultrafine particles?  Inhal. Toxicol., 7, 111-124.

Pekkanen J, Timonen KL, Ruuskanen J, Reponen A, Mirme A (1997) Effects of ultrafine and fine particles in urban air on peak expiratory flow among children with asthmatic symptoms. Environ Res 74: 24-33

Pope, C. A. (1996).  Adverse health effects of air pollutants in a nonsmoking population.  Toxicology, 111, 149-155.

Schlesinger, R. B. (1995).  Toxicological evidence for health effects from inhaled particulate pollution:  does it support the human experience?  Inhal. Toxicol., 7, 99-109.

Schwartz, J., Spix, C., Wichmann, H. E. and Malin, E. (1991).  Air pollution and acute respiratory illnessin five German communities.  Environ. Res., 56, 1-4.

Schwartz, J., Slater, D., Larson, T. V., Pierson, W. E. and Koenig, J. Q. (1993).  Particulate air pollution and hospital emergency room visits for asthma in Seattle.  Am. Rev. Respir. Dis., 147, 826-831.

Seyton, A., MacNee, W., Donaldson, K. and Godden, D. (1995).  Particulate air pollution and acute health effects.  The Lancet, 345, 176-178.

Explaining nanotechnology to people is tough—as anyone working in the field will tell you.  Clever stuff that’s too small to see with the naked eye doesn’t slot easily into most people’s human-scale view of the world.  So it’s not surprising that many non-experts (and even some “experts”) end up with a rather mangled idea of what the technology is, and what it is not!

And this begs the question: if people are to be empowered to make informed decisions on nanotechnology, how do you un-mangle the misconceptions?

One approach is to tap into the latent creativity of researchers and science-enthusiasts, and get them to make educational video-shorts.  The American Chemical Society is doing just this in its “What is Nano?” video contest.  The challenge: submit an original creative video no more than 3 minutes long before March 12 2009 on “what is ‘nano’?” “how is ‘nano’ best visualized?” or “where is ‘nano’ headed?” And get the chance to win $500in cash!

You can browse the entries and vote for your favorite on the ACS NanoTube website—highly recommended for an entertaining diversion when the pressures of work get too much!

My favorite so far: “Small can be big – a French cheesy perspective” from Irene Suarez-Martinez and Chris Ewels.  Not sure how great the educational value is, but it made me laugh:

[Add your vote here]

The top contender at present though is “The Nano Song” from Patrick Bennett and fellow researchers at UC Berkeley… – seen at the top of this blog [you can vote for the video here].

I’m still not sure whether to cringe or grin at this one—but you have to admit, the production values are pretty high.  And the video does have the distinction of hitting the big time on the Wired Science blog.

I should also mention out of familial loyalty, my eleven year old son’s entry:

[Add your vote here - no pressure!]

This is a repackaging of some legomation shorts he made for me a couple of years back. It stretches the boundaries of the competition rather (to say it explains anything about nanotechnology is a bit of a stretch).  But I still think it’s a lot of fun—and it demonstrates a level of skill in stop frame animation that’s way beyond anything I could do!

To be honest, there are plenty of turkeys amongst the gems in the current offerings—including videos that will leave your head spinning, even if you thought you knew a thing about nanotechnology.  But as a start, the competition is a great way of getting people to think more imaginatively about the work they do, and how to make it accessible.

So do look through the competition entries, and PLEASE add your votes—the more attention the videos get, the higher the quality of submissions here and in subsequent contests is likely to be.

And if you feel inspired, there’s still time to get your 3-minute masterpiece out there for all to see.

Best of luck!

I spend quite a bit of my time talking to different groups about nanotechnology, including its potential and its challenges. And as a result, I’m constantly on the prowl for new ways of illustrating why nanotechnology is important. In particular, I’ve been keeping my eyes peeled for a quick and dirty (and fun) demonstration to show that size matters.

Which is why I finally cracked this weekend and started messing around with packs of Mentos Mints and bottles of Coke.

One of the important ideas underpinning nanotechnology is that, as stuff gets smaller, things change. It may be that the smaller stuff can get to new places or be used in new ways. It may just be that the stuff is able to do more of its “stuff” when it’s smaller. Or it may be that the original stuff starts behaving like completely different stuff when it gets really small.

Whatever, when it comes to nanotechnology, size matters.

But how do you convince someone of this when they can’t see or experience what is happening at the nanoscale? After all, we are all endowed with brains that have evolved to handle things we can see and touch—not stuff that is invisible to the naked eye.

One approach is to use analogies between stuff that can be seen and touched, and nanoscale materials that cannot be experienced so readily. Along these lines, I’ve been wondering for some time whether the notorious reaction between Mentos and Coke could be exploited in some way to demonstrate aspects of nanotechnology.

Dropping Mentos into a bottle of coke causes a rapid release of carbon dioxide from the liquid, and a frothy geyser to erupt from the container. (For those of you who have no idea of what I’m talking about, just check out the videos at Eepybird.com). If it’s particle surface that drives the reaction between the Mentos and the Coke, grinding the candy up into smaller bits before adding it to should lead to more vigorous “eruption.”

The result—if it works—lots of fun, and a great illustration of one way in which size matters.

Having nothing better to do this weekend, I drafted my kids and an unwitting friend of my daughters into testing the idea. The concept—crush a couple of Mentos into medium and small bits, add to a 2 liter bottle of Coke, and watch what happens.

Saved for posterity, here’s the video of the great event:

Unfortunately, the finely crushed Mentos didn’t create as stunningly superior a geyser as I had hoped. Lesson number one—there’s often a yawning chasm between hypothesis and reality. However, there was a clear size-effect: The medium sized chunks of candy gave the highest geyser, while the finest chunks led to the longest reaction.

Clearly size mattered—just not in the way that might have been predicted…

Despite the disappointing performance of the fine stuff in this instance, the experience has convinced me there’s considerable mileage in using Mentos to explore some of the ideas underpinning nanotechnology. The experiment clearly demonstrates to those involved that making something into smaller pieces changes how it behaves—that’s a pretty important concept.

But that’s just the beginning. Mentos are a great example of a particle with a core-shell structure—the outside of each Mento is different to the inside. Many engineered nanoparticles have a similar structure, so we’re on good analogy ground here.

It’s likely that the Mentos’ outer shell has something to do with the vigor of the reaction with Coke—as New Scientist reported last year, surface roughness and chemistry probably play a role in making the whole Mentos-Coke thing work. So just crushing the candy up wouldn’t necessarily make the reaction go that much faster, as you’re not adding any more of the outer coating to the mix.

However, what if that outer coating was removed? I haven’t tried this, but it would be a cool experiment to wash (or suck perpahs) the outer coating off the Mentos, and see how it affects their geyser-forming properties. You could even go one step further, and see how crushing the denuded Mentos into increasingly finer particles changed things.

This could have the makings of a fun experiment for exploring the importance of size and surfaces—and all with a pack of mints and a bottle of Coke. How much simpler could things get?

Of course, the down-side is that someone needs to clear the mess up afterwards!

Introducing MINChar—a new community initiative to support effective material characterization in nanotoxicity studies.

Here’s a tough one:  Imagine you have a new substance—call it substance X—and you run some tests to see how toxic it is.  But you’re not quite sure what substance X is.

You know that it is a powder, and it is supposed to have chemicals x y and z somewhere in it.  But you don’t know how small the particles are, what shape they are, whether chemical z is on the surface of the particles or inside them, whether the particles all clump together when shoved into the test system or whether they can’t get far enough away from each other after being administered, or whether there is something else present in substance X that really shouldn’t be there.

Now imagine your tests show that substance X looks like it could be rather dangerous.  How do identify which aspect of the material is causing the problem, so you can go about fixing it?

Or imagine someone else wants to repeat your work.  Or they want to compare your data with another study.  How do you know that the substance being used in other studies is the same as substance X, and not simply a crude approximation?

The scenario is somewhat hypothetical, but the issues are very real.  And they have dogged the field of nanotoxicology for over a decade.

The problem is, toxicologists are used to working with substances where chemical identity and mass of material are all that are needed to establish the concentration at which the material becomes harmful.  These folks aren’t used to dealing with materials that “do what they do” because of a complex set of physical and chemical characteristics, and that may change from one environment to another.

But the toxicology community is becoming increasingly aware of the new challenges of studying the harmfulness of engineered nanomaterials.  Which is why a new grass-roots initiative has just been launched to try and change things for the better.

The Minimum Information on Nanomaterial Characterization initiative—MINChar for short—has its roots in a workshop held in Florida back in 2004.  At the time, materials scientists and toxicologists were well aware of the disconnect between conventional toxicology and the new challenges presented by engineered nanomaterials.  But they weren’t clear what to do about it.  And it rapidly became apparent that the research community wasn’t ready to take radical action to change the habits of a lifetime—the ideas were there, but the timing wasn’t right.

Four years on though, the landscape has changed—an increasing amount of nanotoxicology research is being funded and published, and more people are realizing that for the work to be useful, the materials being tested need to be characterized appropriately.

But there is a problem: what constitutes “appropriate.”  Or rather, to the toxicologist who is easily scared by long lists of incomprehensible parameters that require fancy (and expensive) instruments to measure—what is the minimum material characterization that is achievable in practice.

This is what the MINChar initiative set out to address.  Over the course of two days in October, a group of people involved with generating, assessing and using toxicology data got together and hashed out a minimum set of information they thought was necessary for effective studies.  The idea was to put something in place as a community that would compliment initiatives from more august bodies—and start to improve the quality of nanotoxicology studies from the laboratory outward.

The result was a list of nine physical and chemical parameters, and three overarching considerations—available on the MINChar website.

But just as importantly, the meeting spawned a community of people interested in improving the state of material characterization in nanotoxicology studies.

And if you are involved in any way with nanotoxicology—as a researcher, a reviewer, a program manager, a data-user—you can sign up as a member of MINChar Community.  This is something that is being strongly recommended by the organizers of the October workshop—because the more people there are involved in improving the quality of nanotoxicology research, the more likely it is that approaches to using new and potentially useful nanomaterials safety will be developed.

And understanding how to use substance X safely will no longer be like groping in the dark.

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Endnotes

• Further information on the MINChar initiative can be found at http://characterizationmatters.org
• If you are interested in being a part of the MINChar community, you can sign up at http://characterizationmatters.org/community/
• This week’s copy of Chemical & Engineering News has a great article on MINChar [accessible from here]

]]> http://2020science.org/2008/12/15/getting-to-grips-with-nanomaterial-toxicity/feed/ 1 http://2020science.org/2008/11/11/taking-a-fresh-look-at-nanomaterials/ http://2020science.org/2008/11/11/taking-a-fresh-look-at-nanomaterials/#comments Tue, 11 Nov 2008 23:23:28 +0000 Andrew Maynard http://2020science.wordpress.com/?p=450

The Royal Commission on Environmental Pollution report on Novel Materials

Imagine for one naïve moment that we have a pretty good handle on managing the environmental impact of existing manufactured “stuff”.  Then someone comes along and invents some “new stuff” that behaves very differently from the “old stuff.”

How can we be sure that the frameworks and mechanisms in place for preventing harm to the environment will work for the new stuff?  And where they are strained to breaking point, how do we go about fixing the system?

These are two questions addressed in a new report from the Royal Commission on Environmental Pollution—an independent British standing body established in 1970 to advise the Queen, government, Parliament and the public on environmental issues… Of course, because this is for the Her Majesty The Queen, phrases like “old stuff” and “new stuff” are conspicuous by their absence in the report—which instead addressed the rather more sophisticated-sounding issue of “Novel Materials in the Environment.”

This is, in effect, a report on the challenges of avoiding adverse environmental impacts of engineered nanomaterials.  Coming four years after the seminal report from the Royal Society and Royal Academy of Engineering on nanoscience and nanotechnologies, it reflects both how thinking on the challenges and opportunities presented by engineered nanomaterials has advanced, and actions to ensure their safe use have not!

The report itself draws on extensive interviews with experts around the world, and the depth and quality of the writing reflects this.  Perhaps not surprisingly, many of the recommendations arising from this process will be familiar to readers—the challenges haven’t changed that much over the years, and solutions still seem few and far between in many cases.

But familiar as many (not all) of the recommendations are, they are still important to the sustainable development of emerging nanotechnologies, and bear re-iterating.

And there are three in particular that are worth calling out:

Functionality: we need to focus on the properties and functionalities of specific nanomaterials as the key driver rather than treat all materials in the size range as one single class.

To my mind, this is the single most important conclusion to arise from the report.  It moves the debate on environmental impact away from generic nanomaterials—an ill-defined class of materials that have no unifying impact-relevant characteristics—towards materials that present unconventional risks due to novel behaviour.  This is a smart move, as it opens the door to addressing materials that have the potential to cause harm in ways that are not covered by conventional understanding, and avoids endless (and usually fruitless) discussions on what defines a nanomaterial.

Essentially, the Royal Commission have stated that it is not what you call a material that is important, but what it does.

Of course, there is still the issue of what defines a “novel material.”  While I’m sure this will be debated to death in certain quarters, here are some pointers from the report.  Novel materials are:

• New materials hitherto unused or rarely used on an industrial scale, such as certain metallic elements (e.g. rhodium, yttrium, etc.) and compounds derived from them;
• new forms of existing materials with characteristics that differ significantly from familiar or naturally-occurring forms (e.g. nanoforms of silver and gold that exhibit significant chemical reactivity, enhanced biocidal properties or other properties not manifest in the bulk form);
• new applications for existing materials or existing technological products formulated in a new way, which may lead to substantially different exposures and hazards from those encountered in past uses (e.g. the use of cerium oxide as a fuel additive); and
• new pathways and destinations for familiar materials that may enter the environment in forms different from their manufacture and envisaged use (e.g. microscopic plastic particles arising from mechanical action in marine ecosystems).

Information: we need to establish directed research programme on the properties and functionalities of materials in order to inform risk assessment and risk management strategies.

There’s nothing new here.  The Royal Society and Royal Academy of Engineering said as much in 2004, and I have gone on record repeatedly stressing the need for strategic research programmes.  But the fact that the Royal Commission on Environmental Pollution pulled this out as one of their three main priorities highlights how little is still being achieved in this area.

Maybe this time, someone will listen.

Adaptive management: we need to recognise the degree of ignorance and uncertainty and the time it will take to address these (insofar as they can be addressed). We also need to develop flexible and resilient forms of adaptive management to allow us to handle such difficult situations and emergent technologies.

Whichever way you look at things, conventional approaches to risk assessment and management are unlikely to work in the short term for novel materials.

Materials that behave in unconventional ways will always be developed faster than a deep knowledge of how they interact with and impact on human health and the environment.  And any attempt to avoid managing risks until a full and complete conventional risk assessment has been conducted will jeopardize innovation, people’s health and the environment.  This doesn’t mean that quantitative risk assessment needs to be abandoned—it is still the best tool we have for making evidence-based decisions on reducing and managing potential harm.  But in the short term, novel approaches are needed to managing risks, to avoid undue harm without stifling innovation.

For instance, if you are manufacturing carbon nanotubes, you cannot wait ten years for government agencies to set hard and fast exposure limits—you need guidance now on effective ways to reduce potential risks if you are to have a hope of getting viable products out of the door.  And that means taking unconventional approaches to establishing pragmatic, flexible acceptable exposure levels that are based on the best available information.

The results may not be as robust as what regulators will come up with in several years’ time.  But I can guarantee that they will help the manufacturer protect the workforce without being crippled by unnecessary investment in control and containment technologies.

This is just one example of where flexible and resilient forms of adaptive management can both protect people and the environment while enabling the sustainable use of novel materials—there are many more.

And as the Royal Commission recognizes, the increasing pace of innovation means that such innovative approaches to risk management are going to become more and more important.

We recommend that it is desirable to move beyond one-off public engagement ‘projects’ to recognise the importance of continual ‘social intelligence’ gathering and the provision of ongoing opportunities for public and expert reflection and debate. We see these functions as crucial if, as a society, we are to proceed to develop new technologies in the face of many unknowns.

This is a specific recommendation in the report rather than an overarching recommendation (as the first three points were).  But it is worth highlighting, because the interplay between society, science and technology is only going to get more complex over the coming years.  And the sustainable development of any new technology is going to have to factor in new directions in the “democratization of science and technology.”

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Overall, this is an important report, and one that should be taken seriously.  It represents an evolution in thinking rather than a step-change (with perhaps the exception of re-framing the debate over nanomaterials in terms of novel materials).  But nevertheless it makes clear recommendations that are essential to the safe and successful use of engineered nanomaterials.

But back to the “stuff.”  ‘New stuff” (novel materials) is essential to solving global challenges that the “old stuff” we have to hand simply cannot handle.  And these are big challenges that include renewable energy, global warming, water purification and disease treatment.  But as the Royal Commission on Environmental Pollution implies, new stuff requires new ways of doing business if we are going to see the benefits while avoiding potential pit-falls.

And at the end of the day, this means thinking innovatively about research, risk management and reaching out to citizens and other stakeholders.

Amidst the cacophony of debate swirling around the true meaning of nanotechnology, I head a voice or reason last week.  The voice was that of Dr. Bernd Sachweh of BASF, speaking at the European Aerosol Conference in Thessoloniki.

I paraphrase, but the essence of Bernd’s point was this:

‘Nano’ is not a thing or a product.  It has no intrinsic value.  Rather, ‘nano’ adds value; it changes the properties and the worth of something that already exists.

I must confess, I rather like the idea of ‘nano’ as adding value, rather than being an entity in and of itself.  It’s hard to come up with of an example where engineering something at the nanoscale leads to behaviour or functionality that is independent of the starting material.  Rather, the great potential of nanotechnology would seem to be in taking raw materials and engineering them in ways that lead to the emergence of novel scale-related properties, which can then be used in new and innovative ways. 

But what I really like about the concept of added-value is that it provides insight into how nanotechnology might be approached from an oversight perspective.  

Just as ‘nano’ adds value to products and processes, it can also be seen as changing the potential of something to cause harm; an “added-risk” to counterbalance the “added-value.”

As soon as ‘nano’ is seen in terms of both added-value and added-risk, it becomes easier to think through some of the more knotty questions associated with using nanomaterials and nano-products safely.  

First off is the question of whether all products of nanotechnology are uniquely harmful.  

Unique nanoscale-related functionality features in many definitions of nanotechnology—this is where the added value comes from.  And it is often assumed that this unique functionality will always equate to unique risks.  Yet unlike added-value, added-risk is not intentionally built into the products of nanotechnology.  Rather, it is a by-product of the technology.  

As a result, added-risk may be significant in some cases, while in others it may be negligible.  It is even conceivable that engineering a material at the nanoscale could reduce the risk it presents to human health and the environment—leading to negative added-risk.  From an oversight perspective, functionality and potential to cause harm sometimes need to be disentangled—something that the concepts of added-value and added-risk might help to achieve.

Following this line of thought, effective nanotechnology oversight will depend on identifying whether engineering a material at the nanoscale results in added-risk.  And implementing such oversight will mean identifying, measuring and controlling those aspects of a new product or material that add to the risk—whether they are related to particle size, material surface area, surface chemistry, or other nano-relevant characteristics. 

But does nanotechnology demand a brand new set of regulations, or can the existing ones cope?  Where existing regulations work for conventional materials and products, the concept of added-risk would seem to support developing new rules on applying current regs to nanotech materials and products, rather than formulating a new set of nanotechnology regulations.  After all, if ‘nano’ has no intrinsic value or risk, what will a brand new set of regulations actually regulate?

The caveat here of course is that the existing regulations need to be sufficiently robust yet flexible to address the added-risk that some nanotechnology applications will embody.  And the evidence is that this isn’t the case for every material or product out there! (See for instance, “Managing the effects of Nanotechnology” by J. Clarence Davies)

Sticking with existing regulations, the concept of added-risk is useful when it comes to defining what is ‘nano’ and what is not from an oversight perspective.  

If the aim is for regulations (in the broadest sense) to address the added-risk rather than the added-value of nanotech materials and products, should definitions of nanotechnology be used that emphasize added-value?  Probably not.  Definitions that depend on the uniqueness and “added-value” of nanotechnology are great for guiding and inspiring research and investment that will lead to new nanotechnology-based products.  But where they do not embody the concept of “added-risk,” they are at best inadequate and at worst seriously misleading when it comes to ensuring the safety of new nanotechnologies.  For instance, gold nanoparticles can bring significant added-value to products when incorporated into heterogeneous catalysts, but if release and exposure are low, added-risk is likely to be minimal.  On the other hand, reducing the size of silver particles to 20 nanometers brings only marginal added-value from a nanotechnology perspective (the physical and chemical properties of the silver do not alter appreciably from the bulk material at this size), yet the increased possibility for release, dispersion and exposure most likely leads to significant added-risk in some cases.

For regulatory purposes, something else is needed—a point hammered home by Mike Taylor in his 2006 assessment of the US Food and Drug Administration’s ability to regulate the products of nanotechnology.  In this respect, it would be far more useful to have a definition of nanotechnology that incorporates the idea that nanoscale engineering can lead to significant changes in the potential risks associated with a material.  Something like: 

For regulatory and oversight purposes, nanotechnology is the control of matter at dimensions between approximately 1 and 100 nm, where the behaviour of the resulting material or product differs sufficiently from the component materials to lead to significant changes in potential risks to human health and the environment.

This is a definition that is based on added-risk, not added-value.  And unlike the more commonly used definitions of nanotechnology, it would encompass engineered nanomaterials where the predominant change in moving from the macroscale (or molecular scale) to the nanoscale is an increased potential for release, transport, accumulation, exposure dose, and biological impact.  

Developing an added-risk based definition along these lines (and this is just an example of what a definition might look like) would include a broad range of materials and products that have an altered risk profile because of how they have been engineered; not just those that lie within the somewhat artificial boundaries of 1 to 100 nm.  In effect, there would be no more need for lengthy arguments about whether a 99 nm particle is a nanoparticle for regulatory purposes but a 101 is not; or whether large molecules should be treated as nanomaterials.  Under such a definition, the determiner of relevance would be added-risk, NOT size.

This all sounds great.  But I do have one niggling concern about this idea of added-risk.  And that is how will it apply to the more esoteric products of nanotechnology that are coming along—the increasingly complex second, third and even fourth generation materials that have multiple components, multiple functionalities, and can respond and adapt to their environments and other stimuli.  Here we are moving from adding value to existing materials and technologies, to building brand new materials and technologies.  Will we still be able to think of oversight in terms of added-risk, or will we need to go back to the drawing board?  

That’s a tricky one and I’m not sure the answer is clear yet.  But given the current rate of progress being made in nanotechnology, we could do with some answers sooner rather than later.  In the meantime, seeing nanotechnology in terms of the added-value and added-risk it brings to materials, processes and products might just help deal with the nanotech which is out there now.

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This post first appeared on the SAFENANO blog in September 2008

Why nano?  Why care?  For non-nanotech initiates, an obsession with nanotechnology must sometimes seem a bizarre occupation of the sad and lonely.  And even within the nanotechnology community, who hasn’t had occasional doubts over the legitimacy of singling out “nano” as something special?  Yet occasionally a piece of work comes along that helps put things back into perspective.  For me, a paper just published on-line in the journal Nano Letters did exactly that.

To be quite frank, the paper’s title is not what I would call inspirational.  But dig below the surface, and you unearth an object lesson in what makes nano so intriguing, and why taking a fresh look at possible health and environmental impacts is so important.  First the science though.

The Science

The paper in question is “Controlled Manipulation of Giant Hybrid Inorganic Nanowire Assemblies” by Fung Suong Ou, Manikoth M. Shaijumon, and Pulickel M. Ajayan, published on-line in Nano Letters, May 29 2008.  Unfortunately, a subscription to the journal is needed to view the paper, but the supplemental information is freely available (here), and well worth looking at.  

In brief, the authors used a nanoscale fabrication technique to construct long, straight, carbon nanotubes capped with gold nanowires.  Think “magician’s wand” with the nanotube as the stem and the gold as the white tip, and you will get the idea.  The nano-wands (for want of a better description) were between 100 nm and 150 nm wide, and over 100 mircometres (100,000 nm) long.  Micrographs in the paper show rafts of uniform-length nano-wands stacked side by side, with individual wands fraying off at the edges.

But this is where things get interesting.  These long, straight artificial rods were designed to have one end that was hydrophobic (water-repelling; the carbon end), and one end that was hydrophilic (water-seeking; the gold).  When dispersed in water, these wands formed a uniform suspension.  But when an organic solvent—dichloromethane (DCM)—was added to the mix, the nano-wands assembled into shells around the DCM, with the black carbon nanotubes facing in and the gold tips facing out.  With a bit of shaking and ultrasonic agitation, one large gold-coloured sphere was formed, separating the DCM from the water.  Reversing the process by suspending the nano-wands in DCM and adding water, a large black sphere assembled; separating the water from the organic solvent.  Black, because in this case the carbon nanotube “tails” were pointing outward.

Using the same fabrication technique, the researchers demonstrated a couple of other tricks.  By adding a band of the metal nickel below the gold tip, the nano-wands could be made magnetic—so now the spheres separating the two liquids could be moved around using a magnetic field.  And by adding an ultraviolet light-degradable hydrophobic chemical to the gold end of nano-wands, spheres were constructed that quite literally turned inside-out under UV irradiation.

The Promise

Nanotechnology is all about functionality—making materials and products that behave in new and unusual waysbecause they have been engineered at an incredibly fine scale.  This new and unusual behaviour might in some cases be due to the unusual physics and chemistry of small clusters of atoms (such as the size-related fluorescence of quantum dots).  But it can just as easily arise from engineering a material at such a fine scale that it can be used in new ways (such as making antimicrobial silver particles small enough to be incorporated into a miscellany of products); or constructing materials at the nanoscale with such sophistication that new properties emerge (multi-functional nano-therapeutics for instance).  The nano-wands are most definitely in the latter categories—their functionality arises from their smallness and sophistication.  

The important point here is that, while size matters, performance matters more.  And so while these nano-wands are technically larger than the 100 nm limit usually (and somewhat arbitrarily) imposed on nanotechnology, they nevertheless represent an ability to create a novel functional material through sophisticated engineering at a very fine scale.

And what functionality!  This is a crude material compared to what could be achieved using similar construction techniques, but even so the nano-wands behave in a most unusual way.  Functionally, they are reminiscent of polar molecules, and the spheres they form are analogous to micelles—“capsules” formed by organic molecules with opposing hydrophobic and hydrophilic ends.  But by engineering them at the nanoscale out of inorganic materials, structural and functional possibilities open up that are way beyond the realm of chemistry alone.  

It is easy to imagine how this material could be used to encapsulate and collect chemical spills in the environment.  Or deliver drugs to where they are needed in a very targeted way (only releasing their payload by disassembling when the right signal is received).  Yet the work of Fung Suong Ou and colleagues hints at much greater things.  Using the same basic technology, there is nothing to prevent the construction of multi-component nanomaterials that can assemble and re-assemble in many different ways, depending on their environment and the stimuli they receive.  As the paper’s authors’ conclude, 

“This controlled engineering feat at the nanoscale that allows well-controlled assembly and manipulation could lead to the creation of smart materials that are a cornerstone for the development of nanotechnology-based applications.”

The challenge

But stimulating as the science is, this paper is also an object lesson in why new thinking is needed on possible risks to human health and the environment, if such technologies are to succeed.

First and foremost, the paper comes hot on the heels of Poland et al.’s study linking some forms of multi-walled carbon nanotubes to precursors of mesothelioma—a disease more usually associated with asbestos exposure.  Poland’s research suggests that carbon nanotubes which are thin, longer than 15 – 20 micrometres, straight, and dispersible, could lead to the disease if inhaled.  The nano-wands in the Ou et al. paper are around 150 nm in diameter, something over 100 micrometres long, straight, and apparently dispersible—in other words, exactly the types of fibres which Poland’s work suggests more research is needed on before the possible health implications are understood.

It’s too early to tell whether Ou’s nano-wands will have their own unique risk-profile.  But their inevitable comparison with the nanotubes used in Poland’s study and the possibilities of dispersive use hinted at in the accompanying press release do raise important questions about their safety.  The important point here is not that this particular material might show harmful behaviour, but that there is always the chance that novel behaviour can lead to unanticipated harm—unless the right questions are asked early on.  And this most definitely requires new thinking on what those questions are, and how they might best be answered.

The second object lesson in new challenges concerns regulations.  Unless used as a drug or pesticide, substances are typically regulated according to their chemical makeup.  It’s an approach that was developed at a time when the terms “chemical” and “substance” were interchangeable.  But Ou’s nano-wands challenge this paradigm.  

These nano-wands and other hybrid substances have no unique chemical identity, and so potentially slip through the net of many existing regulations.  Yet they display a functionality that depends on their physical form and complex makeup, which is not predictable from their chemical components.  And regulations are needed that recognize this.  If effective approaches are to be developed to ensure the safe use of this emerging class of material, new thinking is needed on how substances are classified and regulated.

The bottom line

Why nano? As Ou’s work shows, we can potentially do things with nano that are way beyond any other technology at our disposal.  And when nano is combined with other technologies like biotech and information tech, the possibilities become endless.

Why care?  Because nano will change your life, whether you like it or not.  And you might want to make sure that it is a change for the better, not for the worse.

And the nano-wands?  These have tremendous potential as an innovative new material.  Lets hope that their development is matched by equally innovative thinking on using them safely.

Further resources

Paper: Controlled Manipulation of Giant Hybrid Inorganic Nanowire Assemblies

Supplemental Material to the paper

Managing the Effects of Nanotechnology.  J. Clarence Davies

Paper: Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study

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This post first appeared on the SAFENANO blog in May 2008

The author Neal Stephenson got it wrong—at least, if this week’s nano-news is anything to go by!   In his landmark 1995 novel “The Diamond Age,” Stephenson described a future built on nano-innovation.  But thirteen years later, nanotechnology seems to be ushering in “The Silver Age.”  And to some it’s looking a little tarnished.

First we had Cal Baier-Anderson’s entry on the Environmental Defence Fund nanotech blog, calling claims that bacteria cannot develop resistance to silver “not only false, but dangerous.”  Two days later, the International Center for Technology Assessment (CTA) filed a petition with the USEPA requesting the agency regulate nano-silver products as pesticides.  And to top it all, Washington Post science writer Rick Weiss completed the hat trick with a story on nano-silver in Friday’s edition of the paper.

Silver is currently topping the charts in the Project on Emerging Nanotechnologies consumer products inventory—136 entries out of 610 as of May 2nd.  Nano-silver is clearly a technology of the moment, and manufacturers are flocking to use the antimicrobial nanoscopic particles in anything they can—from socks to toothpastes to fluffy toys.  CTA claim the sole reason for using nano-silver in these products is as an agent for killing microbes and as such, it should be classed as a pesticide. But that would make life difficult for opportunistic manufacturers looking to get onto the nano bandwagon.  Perhaps this is why some companies are using the technology, but being circumspect about who they tell (check out “Benny the bear, and the case of the disappearing nano”).

Silver is a powerful antimicrobial.  Yet widespread and indiscriminate use of silver nanoparticles raises clear concerns: is it harmful to people, will it be released and accumulate in the environment, will it harm environmental organisms, and will it lead to silver-resistant strains of bacteria?  The jury’s still out on most of these questions, which suggests more research is needed—and fast.  A recent study by Paul Westerhoff and Troy M. Benn of Arizona State University demonstrated that ordinary laundering of silver nanoparticle-laden socks can wash the particles out.  But where these particles go and what they do, once out in the environment, is largely unknown.  

And what about microbes building up resistance to nano silver over time?  In a recent article Lucian Lucia, an associate professor of chemistry at North Carolina State University, suggested that bacteria cannot build up resistance to silver nanoparticles as they can to antibiotics: “That’s the beauty of silver… [t]here’s no way to develop a resistance to it.”  Yet Cal Baier-Anderson’s cites a series of convincing studies that challenge this claim.

Silver is a useful weapon in the fight against infection, and nano-silver extends its reach in this arena.  But using it without caution would seem unwise.  Surely it’s time to discover the rules of safe use, and to avoid applications where the benefits are dubious and the risks uncertain.  At least; if we want a nanotechnology age without tarnish.

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This post first appeared on the SAFENANO blog in May 2008