The same type of cancer-causing metal featured in the movie "Erin Brockovich" is turning up in tap water around Chicago and two dozen other nearby cities, according to a study that urges federal regulators to adopt tougher standards.
Even after scientists at the U.S. Environmental Protection Agency and National Toxicology Program linked the ingestion of hexavalent chromium to cancer, the EPA still doesn't require Chicago or other cities to test for the toxic metal in its drinking water. Nor does the EPA limit the dangerous form of chromium in drinking water.
In a study, the Environmental Working Group hired an independent laboratory who found the toxic metal in treated drinking water from 31 cities. The amount in Lake Michigan Chicago water pumped to 7 million people in Chicago and its suburbs was 0.18 parts per billion, more three times higher than a safety limit California officials put forth last year.
Other cities found significantly above the proposed California limit, included Norman, Okla.; Honolulu; Riverside, Calif., and Madison, Wis., according to a report to be released Monday. Milwaukee toxin water levels were reportedly found to be the same as in Chicago.
In other major cities, hexavalent chromium levels ranged from 0.20 parts per billion in Los Angeles and Atlanta to 0.18 in New York and 0.03 in Boston.
The reports findings could pose another challenge for utilities that are detecting dozens of unregulated substances in treated drinking water, including pharmaceutical drugs and industrial chemicals that can pass unfiltered through conventional treatment methods. Chromium can be found naturally in the environment but also is released by industry into waterways.
While the potential health threats of many pollutants are still being studied, researchers say there is a clear risk of stomach cancer from drinking water contaminated with hexavalent chromium, also known as chromium-6.
"For years scientists assumed this wasn't a problem because acids in our stomachs can convert chromium-6 into chromium-3, an essential nutrient," said Rebecca Sutton, a senior scientist with the Environmental Working Group, a Washington, D.C.-based research and advocacy organization. "Newer science is showing our stomachs can't take care of everything, which means the dangerous form of chromium is getting into our bodies and can cause damage."
