Hourly Update

Arizona researcher: Depleted uranium can still make people sick

PHOENIX - Uranium's heavy-metal properties can make people sick, independently of the element's radiation and radon gas, according to a research project led by a Northern Arizona University biochemist. "People assume that if the uranium is not radioactive, it's harmless. We're finding that's not the case," said NAU biochemist Diane Stearns. Heavy metals are metallic elements with high atomic weights, such as mercury, cadmium, arsenic and lead. If they get into the bloodstream, they can bind with DNA particles to interrupt cellular communication and cause diseases. The Environmental Protection Agency and the Nuclear Regulatory Commission treat depleted, or "non-radioactive," uranium as a hazardous material, but the Department of Defense continues to use it for anti-tank weapons, tank armor and ammunition rounds. The department also has declined to clean it up from military sites. While the harmful effects of heavy metals such as mercury and lead are well known, Stearns and her team are the first to identify this trait in uranium and to show that when it binds with DNA, the cells acquire mutations. Stearns is optimistic the research could lead to new rules for handling depleted uranium. It also could lead to tests for exposure to the heavy-metal properties of uranium as well as the radiation and radon gas it emits as it decays. The program, funded by the Native American Cancer Research Project, is also having other effects. A number of Navajo researchers are working on Stearns' team, gaining knowledge they can take back to the reservation. Widespread and largely unregulated uranium mining on the Navajo's vast reservation from the 1940s through 1960 left the Navajos with a legacy of disease and death. The reservation, which sprawls across northeastern Arizona and northwestern New Mexico, has about 1,300 abandoned uranium mines. Blocks from the mines have been used as building materials and groundwater has been contaminated in some areas. Hertha Woody, a research assistant in Stearns' laboratory, believes her work enables her to help other Navajos better understand the health hazards of uranium and take precautions. "I want to stay in research and go back to the reservation to work," she said. "There are so many issues there." Woody grew up in Shiprock, N.M., not far from a huge mound of uranium tailings left by an abandoned mill. "I grew up seeing this pile, and I knew it could make people sick," Woody said. "But I didn't know why." A federal cleanup is under way at Shiprock, where the air and groundwater are being carefully monitored for contamination.