Chromium-6 Carcinogen in Tap Water of More than 200 Million Americans

http://www.ewg.org/research/chromium-six-found-in-us-tap-water

Tuesday, September 20, 2016





By David Andrews, Senior Scientist, and Bill Walker, Managing Editor



'Erin Brockovich' Carcinogen in Tap Water of More than 200 Million Americans

In the film "Erin Brockovich," the environmental crusader confronts the lawyer of a power company that polluted the tap water of Hinkley, Calif., with a carcinogenic chemical called chromium-6. When the lawyer picks up a glass of water, Brockovich says: “We had that water brought in ‘specially for you folks. Came from a well in Hinkley.”
The lawyer sets down the glass and says, "I think this meeting’s over."
But almost 25 years after that real-life confrontation,[1] the conflict over chromium-6 is not over. A new EWG analysis of federal data from nationwide drinking water tests shows that the compound contaminates water supplies for more than 200 million Americans in all 50 states. Yet federal regulations are stalled by a chemical industry challenge that could mean no national regulation of a chemical state scientists in California and elsewhere say causes cancer when ingested at even extraordinarily low levels.

The standoff is the latest round in a tug-of-war between scientists and advocates who want regulations based strictly on the chemical’s health hazards and industry, political and economic interests who want more relaxed rules based on the cost and feasibility of cleanup. If the industry challenge prevails, it will also extend the Environmental Protection Agency’s record, since the 1996 landmark amendments to the Safe Drinking Water Act, of failing to use its authority to set a national tap water safety standard for any previously unregulated chemical.[2]
In 2008, a two-year study by the National Toxicology Program found that drinking water with chromium-6, or hexavalent chromium, caused cancer in laboratory rats and mice.[3] Based on this and other animal studies, in 2010, scientists at the respected and influential California Office of Environmental Health Hazard Assessment concluded that ingestion of tiny amounts of chromium-6 can cause cancer in people, a conclusion affirmed by state scientists in New Jersey and North Carolina.
The California scientists set a so-called public health goal of 0.02 parts per billion in tap water, the level that would pose negligible risk over a lifetime of consumption.[4] (A part per billion is about a drop of water in an Olympic-size swimming pool.) But in 2014, after aggressive lobbying by industry and water utilities, state regulators adopted a legal limit 500 times the public health goal.[5] It is the only enforceable drinking water standard at either the state or federal level.
 
Potentially unsafe concentrations for two-thirds of Americans
Spurred by a groundbreaking 2010 EWG investigation that found chromium-6 in the tap water of 31 cities[6] and a Senate hearing prompted by the findings, the EPA ordered local water utilities to begin the first nationwide tests for the unregulated contaminant. From 2013 to 2015, utilities took more than 60,000 samples of drinking water and found chromium-6 in more than 75 percent of them.[7] EWG's analysis of the test data estimates that water supplies serving 218 million Americans – more than two-thirds of the population – contain more chromium-6 than the California scientists deemed safe.
Average level of chromium-6 in U.S. drinking water

 
SOURCE: EWG, from EPA Unregulated Contaminant Monitoring Rule 3 data
The California scientists based their public health goal of 0.02 parts per billion solely on protecting people from cancer and other diseases. Public health goals are not legally enforceable, but legal limits are supposed to be set as close as possible to health goals “while considering cost and technical feasibility.”[8] But the California Department of Public Health relied on a flawed analysis that exaggerated the cost of treatment and undervalued the benefits of stricter regulation,[9] and adopted a legally enforceable limit of 10 parts per billion.

Even by that far-too-lax benchmark, EWG's analysis of EPA tests shows that more than seven million Americans are served tap water from supplies that had at least one detection of chromium-6 higher than the only legal limit in the nation. Because the EPA tests covered only a fraction of the small systems and private wells that supply water to more than a third of Americans, it is highly likely that chromium-6 contamination is even more widespread.[10]
 
12,000 Americans at risk of cancer
The EPA tests show that water tested in 1,370 U.S. counties had an average level of chromium-6 exceeding California's non-binding public health goal – the amount posing no more than a one-in-a-million risk of cancer for people who drink it daily for 70 years. (By contrast, the state's legal limit represents a cancer risk of 500 per million.) Comparing the public health goal to levels of contamination found in the EPA tests, EWG estimates that if left untreated, chromium-6 in tap water will cause more than 12,000 excess cases of cancer by the end of the century.[11]
The tests found chromium-6 in almost 90 percent of the water systems sampled. Oklahoma, Arizona and California had the highest average statewide levels and the greatest shares of detections above California's public health goal. Among major cities, Phoenix had, by far, the highest average level, at almost 400 times the California health goal, and St. Louis and Houston also had comparatively high levels.
Average level of chromium-6 in largest U.S. water systems

 
SOURCE: EWG, from EPA Unregulated Contaminant Monitoring Rule 3 data

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