Study: Probable Carcinogen Found in 31 US Cities' Water Supplies

A potentially cancer-causing metal made famous by the movie "Erin Brockovich" has turned up in the tap water of 31 out of 35 American cities tested, according to a study that urges the government to adopt tougher standards for the nation's drinking water.

The Environmental Working Group, an independent, Washington-based research organization, conducted the first nationwide analysis of hexavalent chromium, otherwise known as chromium-6, in drinking water. The substance was regularly used as an industrial chemical until the early 1990s and still appears in some plastics factories. It can also seep into groundwater from natural ores.

The metal has been shown to cause cancer in laboratory animals, and the National Institutes of Health defined it as a "probable carcinogen" in 2008. Last year, California proposed limiting the amount of chromium-6 in its drinking water to 0.06 parts per billion. It's still being debated, but if the measure passes, California would be the first state to set such a limit.

The U.S. Environmental Protection Agency hasn't set a limit and doesn't regularly test for chromium-6.

In the EWG study released today, 25 U.S. cities' water tested positive for levels of chromium-6 that are above California's proposed limit. The highest levels were found in Honolulu, Riverside, Calif., and Norman, Okla., where the water tested at 200 times the California target.

"I was expecting to find hexavalent chromium in some of the cities we checked, but I didn't expect it to be so widespread," Rebecca Sutton, a senior scientist with the EWG and the lead author of the study, told CNN.

The movie "Erin Brockovich" chronicles the true story of how the water supply of Hinkley, Calif., was poisoned with chromium-6, which was used in a nearby factory belonging to a utility company. Pacific Gas & Electric ended up paying more than $330 million in damages as part of a 1996 lawsuit.

"This chemical has been so widely used by so many industries across the U.S. that this doesn't surprise me," the real Erin Brockovich told The Washington Post, reacting to news of the EWG study. "Our municipal water supplies are in danger all over the U.S. This is a chemical that should be regulated."

In Chicago, the chromium-6 level tested at 0.18 parts per billion -- three times the proposed California limit. The same level was found in New York, with Los Angeles and Atlanta both testing at 0.20 parts per billion. Those levels could contribute to a higher risk of stomach cancer, The Chicago Tribune reported.

"For years, scientists assumed this wasn't a problem because acids in our stomachs can convert chromium-6 into chromium-3, an essential nutrient," Sutton told the Tribune. "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."

Chromium-6 can also cause lung cancer if inhaled, the Post reported. It's also been linked to liver and kidney damage as well as leukemia, the paper said.

Others call today's study alarmist and say more research is needed before people jump to conclusions about what's dangerous about their water.

"They're trying to scare people," Lon Couillard, a water quality manager in Milwaukee, told the Tribune. He said some of the chromium-6 could be coming from chrome-plated plumbing fixtures rather than passing through municipal treatment plants and contaminating a whole city's water supply.

Reacting to word of today's study, an EPA spokesman told The Salt Lake Tribune that the agency is updating its health assessment for chromium-6.

"When the assessment is complete, EPA will evaluate the results and consider the appropriate next steps," the unidentified spokesman said in an e-mail to the paper.

The American Chemistry Council, a lobby group representing chemical companies, opposes California's efforts to limit chromium-6, accusing the state of setting unrealistic goals. Some water has a naturally occurring level of chromium-6 that's above 0.06 parts per billion, it said. In a statement to the Post, the group said that "even the most sophisticated analytical methods used by EPA are not able to detect the extremely low levels that California wants to establish."

The president of the EWG, Ken Cook, responded by saying it's understandable that water utilities and chemical industrial groups are opposed to the idea of limits.

"If a limit is set, it's going to be extraordinarily expensive for them to clean this up," Cook told the Post. "The problem in all of this is that we lose sight of the water drinkers, of the people at the end of the tap. There is tremendous push-back from polluters and from water utilities. The real focus has to be on public health."