Photoactivated uranyl ion produces single strand breaks in plasmid DNA.

Uranium is an important emerging toxicant whose use has outpaced the rate at which we are learning about its health effects. One unexplored pathway for uranium toxicity involves the photoactivation of uranyl ion by UV light to produce U(5+) and oxygen radicals. The purpose of this study was to provide proof of principle data by testing the hypothesis that coexposures of DNA to uranyl acetate and UVB irradiation should produce more DNA strand breaks than individual exposures. Results supported the hypothesis and suggest that investigations of uranium toxicity be expanded to include skin as a potential target organ for carcinogenesis, especially in populations with high uranium and high UV radiation exposures.