Nanoparticles cause genetic damage in mice

LOS ANGELES, Nov. 17 (UPI) -- A U.S. study has shown titanium dioxide nanoparticles found in numerous household items can cause systemic genetic damage in mice.

Scientists at UCLA's Jonsson Comprehensive Cancer Center said they found the titanium nanoparticles induced single- and double-strand DNA breaks and also caused chromosomal damage as well as inflammation -- all of which increase the risk for cancer.

The UCLA scientists, led by Professor Robert Schiestl, said their study is the first to show titanium nanoparticles have such an effect.

The researchers said they found that once in the system, the nanoparticles accumulate in different organs because the body has no way to eliminate them. Because they are so small, they can go everywhere in the body, even through cells, and may interfere with sub-cellular mechanisms.

In the past, titanium nanoparticles have been considered non-toxic since they don't incite a chemical reaction. Instead, it is surface interactions that the nanoparticles have within their environment -- in this case inside a mouse -- that causes the genetic damage, Schiestl said. They wander throughout the body causing oxidative stress, which can lead to cell death.

"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," Schiestl said. "Given the growing use of these nanoparticles, these findings raise concern about potential health hazards associated with exposure."

The study appears in the journal Cancer Research.