What are the risks of nanoparticles in sunscreens?
The New York Times has just posted an “Ask Well” article today by Deborah Blum answering the questions
What are the risks from nanoparticles of titanium in sunscreens? and
I am curious about the dangers of nanoparticles in sunblocks
Risk Bites
As I uploaded a YouTube video recently on the risks of TiO2 nanoparticles in sunscreens, I thought this was probably an opportune time to flag it up here, as it compliments Deborah’s piece:
And just for the heck of it, here’s the 2020 science archive on sunscreens and nanoparticles.
The New York Times also posted their own video (here). It covers much of the same ground as Deborah’s piece.
The video frustratingly does refer to “titanium” in sunscreens – probably because the first of the questions above uses this terminology. It’s worth pointing out that titanium dioxide and titanium are not the same, even though they both contain atoms of titanium – just like carbon and cyanide aren’t the same. And believe me, if airplane manufacturers for instance were as cavalier about whether they were using titanium dioxide or titanium, we’d have a problem! But this may just be me nit-picking!
Titanium dioxide and cancer
Both the New York Times video and article also refer to the International Agency on Research on Cancer (IARC) classification of titanium dioxide as a potential carcinogen. This classification was solely associated with inhalation exposure, where one study showed that overloading the lungs of rats with massive amounts of titanium dioxide dust led to some cancer formation. It is not related to skin applications of the substance. It is also highly controversial, as the levels of titanium dioxide used in these studies were so massive that they utterly overwhelmed the lungs defense mechanisms, and led to a result that would probably be seen with other insoluble, inert materials.
It’s also worth noting that there are no human data that indicates titanium dioxide exposure leads to cancer, despite over 5 million tons of the material being produced and used around the world each year.
That said, there are some useful insights here.
Update July 18: Added headings