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Tuesday, July 22, 2014

Ask Well: Nanoparticles in Sunscreens

Today's post is shared from Workers' in an outdoor environment are exposed the the sun's rays. The question arises as to whether present protective measures, ie. sunscreens are more harmful than helpful.

Titanium dioxide nanoparticles have been used increasingly in sunscreens in the last decade to protect the skin because the tiny particles directly absorb the radiation from sunlight, especially in the UVB range. But because the articles are so tiny — generally about 100 nanometers across, compared with about 3,000 to 9,000 nanometers for a speck of dust — some scientists have raised concerns about whether they might do harm by seeping through the skin and into the bloodstream.

Concerns grew when studies in mice showed that when injected under the skin, titanium dioxide caused inflammation . In addition, the International Agency on Cancer Research, part of the World Health Organization, decided in 2006 to classify titanium dioxide as a potential human carcinogen, based mostly on inhalation studies in animals, though the group called the evidence “conflicting at best.”

But research has largely dismissed such concerns about absorption, and most experts say that sunscreens containing nanoparticles can be safely used.

More recently, concerns have focused on the possibility that these nanoparticles could promote skin aging....

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