RODALE NEWS, EMMAUS, PA—According to a new report released just before the holidays, there could be an infamous Hollywood villain lurking in your supposedly clean drinking water. The report, released by the nonprofit Environmental Working Group (EWG), revealed that 89 percent of city water supplies tested had detectable levels of the cancer-causing chemical chromium-6, the same chemical Pacific Gas & Electric Co. released into the water supply of Hinkley, CA, an action that ultimately resulted in a $333 million settlement to residents and inspired the movie Erin Brokovich. "This is the first national-scale testing of chromium-6," says EWG senior scientist David Andrews, PhD. "And it really highlights the need for more chromium-6 testing."
THE DETAILS: EWG drew water samples from 35 large U.S. cities and tested them for chromium-6, also called hexavalent chromium. Thirty-one of the samples showed detectable levels, and just 10 cities had levels that fell under California's proposed public health limit of 0.06 parts per billion (ppb). The cities with the highest levels were Norman, OK (12.9 ppb); Honolulu (2 ppb); Riverside, CA (1.69 ppb) Madison, WI (1.58 ppb); and San Jose, CA (1.34 ppb). (This past Tuesday, California revised its proposed limit downward to 0.02 ppb.)
The Environmental Protection Agency (EPA) currently has no guidelines for chromium-6 in drinking water; they require only that water utilities test and keep total chromium levels under 100 ppb. But that figure is misleading, as it includes chromium-3, which our bodies need to regulate glucose metabolism.
The EPA was quick to respond to EWG's report. Two days after it was released, EPA administrator Linda Jackson met with 10 senators and said that the agency will work to see how serious and widespread chromium-6 contamination is in other areas of the country. Based on the results of their assessment, they'll revise their drinking-water regulations for the chemical. In the meantime, she added, the EPA will "issue guidance" to water utilities instructing them how to test for chromium-6 and will offer assistance to the communities that had the highest levels in EWG's study.
WHAT IT MEANS: Aside from California's proposed public health limit, there is no hard evidence of how much chromium-6 is bad, or how much one would need to be exposed to before harm occurs, says Andrews. "But we want to make sure that, for known carcinogens, we're at levels that are safe for long-term exposures."
Published on: January 6, 2011
Updated on: January 7, 2011