The cancer-causing chemical is best known to the general public from the 2000 movie "Erin Brockovich," starring Julia Roberts.
The film dramatized the plight of the cancer-stricken residents of Hinkley, California, who in 1996 won a $333 million settlement from Pacific Gas and Electric Co. for contaminating their tap water with hexavalent chromium.
The Environmental Working Group says, "Despite mounting evidence of the contaminant's toxic effects, including a U.S. Environmental Protection Agency draft toxicological review that classifies it as 'likely to be carcinogenic to humans' when consumed in drinking water, the agency has not set a legal limit for chromium-6 in tap water and does not require water utilities to test for it."
Hexavalent chromium is discharged from steel and pulp mills as well as metal-plating and leather-tanning facilities. It can pollute water through erosion of soil and rock, the EWG report shows.
It appears to be a simple glass of water, but... (Photo by Drita Buzuku)
The National Toxicology Program has found that hexavalent chromium in drinking water shows clear evidence of carcinogenic activity in laboratory animals, increasing the risk of otherwise rare gastrointestinal tumors.
In response to this study and others, California officials last year proposed setting a public health goal for chromium-6 in drinking water of 0.06 parts per billion. This is the first step toward establishing a statewide enforceable limit.
Levels of the carcinogen in 25 cities tested by Environmental Working Group were higher than California's proposed public health goal.
Tap water from Norman, Oklahoma, with a population of 90,000, contained more than 200 times California's proposed safe limit. Norman is home to the University of Oklahoma.
"At least 74 million Americans in 42 states drink chromium-polluted tap water, much of it likely in the form of cancer-causing hexavalent chromium," the Environmental Working Group says in its report. "Given the scope of exposure and the magnitude of the potential risk, the EPA should move expeditiously to establish a legal limit for the chemical in tap water and require water utilities to test for it."
EPA Administrator Lisa Jackson met with 10 U.S. senators Wednesday to brief them on the issue of chromium-6 in drinking water as reported by theEnvironmental Working Group.
Jackson described EPA's current chromium-6 risk assessment, a review the agency started in 2008 in response to new science showing a link between chromium-6 ingestion and cancer.
This risk assessment, which would be the first step to updating the drinking water regulations, will be finalized after an independent scientific peer review in 2011.
Jackson told the senators that based on the draft risk assessment, "EPA will likely revise drinking water regulations to account for this new science." Revisions would only take place after an independent science panel has verified the underlying science, she said.
Within days, the EPA will take action to address chromium-6 in drinking water, first assessing the extent of the problem, then issuing guidance to water system operators on monitoring and sampling programs for chromium-6.
"It is clear that the first step is to understand the prevalence of this problem," Jackson said. "While the EWG study was informative, it only provided a snapshot in time. EPA will work with local and state officials to get a better picture of exactly how widespread this problem is."
"We will also offer significant technical assistance to the communities cited in the EWG report with the highest levels of chromium-6 to help ensure they quickly develop an effective chromium-6 specific monitoring program," said Jackson.
"Strong science and the law will continue to be the backbone of our decision-making at EPA," said Jackson. "EPA takes this matter seriously and we will continue to do all that we can, using good science and the law, to protect people's health and our environment."
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