It's a fact of life that nanoparticles are everywhere: from sunscreen to underwear to performance wear - they are an invisible part of everyday life. Nanotechnology has made some promising inroads, but could these undetectable bits of material be harmful to our health? Recent studies however have raised serious concerns about the health impacts of nanoparticles in a plethora of consumer products and now, researchers at UCLA's Jonsson Comprehensive Cancer Center have discovered that titanium dioxide (TiO2) nanoparticles could cause genetic damage.The study is the first to find that TiO2 nanoparticles caused single- and double-strand DNA breaks, in addition to chromosomal damage and inflammation in the mice tested - all factors that increase the risk of cancer.
Though nanoparticles cannot go through skin (so that means sticking to lotion sunscreens for instance), once ingested they can accumulate in different organs since the body cannot eliminate them. Their size allows nanoparticles to go anywhere in the body, even through cells where they could wreak havoc on a sub-cellular level.
Titanium dioxide nanoparticles were once considered non-toxic because they did not trigger a chemical reaction on their own. But as Robert Schiestl, professor of pathology, radiation oncology and environmental health sciences and senior author of the study explains, it is the surface reactions of accumulated nanoparticles that is particularly worrying.
"The novel principle is that titanium by itself is chemically inert. However, when the particles become progressively smaller, their surface, in turn, becomes progressively bigger and in the interaction of this surface with the environment oxidative stress is induced," he said.
"This is the first comprehensive study of titanium dioxide nanoparticle-induced genotoxicity, possibly caused by a secondary mechanism associated with inflammation and/or oxidative stress. Given the growing use of these nanoparticles, these findings raise concern about potential health hazards associated with exposure."
Nanoparticle production is big business, with two million tons being produced per year and destined for products ranging from paint, sunscreen, vitamins, cosmetics, toothpaste, food colorants and hundreds of other consumer products.
"It could be that a certain portion of spontaneous cancers are due to this exposure," says Schiestl. "And some people could be more sensitive to nanoparticles exposure than others... I believe the toxicity of these nanoparticles has not been studied enough."
In the meantime, the study states that it's not clear if exposure increases exponentially - so it may be "prudent to limit ingestion through non-essential drug additives [and] food colors."
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