Tap water from 31 of 35 U.S. cities tested contains Hexavalent Chromium in concentrations that average three times the safety goal being proposed by the state of California, a new study says.
The highest levels were detected in Norman, OK; Honolulu, HI; and Riverside, CA. The Oklahoma sample was more than 200 times the proposed California threshold, according to the nonprofit Environmental Working Group.
‘Likely’ Human Carcinogen
California officials have proposed setting a public health goal of 0.06 parts per billion (ppb) for Chromium 6 in drinking water. This is the first step toward establishing a statewide enforceable limit, which would be the first of its kind in the nation.
The National Toxicology Program has found that Hexavalent Chromium in drinking water shows clear evidence of carcinogenic activity in laboratory animals. The compound has come under increasing regulation this year by the Occupational Safety and Health Administration.
A draft toxicological review by the Environmental Protection Agency classifies Chromium 6 as “likely to be carcinogenic to humans,” but EPA has not set a legal limit for it in tap water and does not require water utilities to test for it. However, the agency has set a legal limit in tap water for total chromium of 100 ppb to protect against “allergic dermatitis” (skin irritation or reactions).
The EPA limit is approximately 1,700 times the proposed California goal.
Pigments, Coatings Applications
Hexavalent Chromium (also known as Chromium VI, Chromium 6 or CrVI) has many industrial applications, including chromate pigments in dyes and paints; chromates added as anticorrosive agents to paints, primers and other surface coatings; and chromic acid electroplated onto metal parts to provide a decorative or protective coating.
Chromium 6 exposures are addressed in specific—and increasing—standards for general industry, rules concerning OSHA access to employee medical reports, shipyard employment, marine terminals, and the construction industry.
26+ Million People Affected
EWG calls its investigation “the broadest publicly available survey of Hexavalent Chromium to date.” The 31 cities with chromium-polluted tap water draw from utilities that collectively serve more than 26 million people.
In California, the only state that requires testing for Hexavalent Chromium, water utilities have detected the compound in tap water supplied to more than 31 million people, according to an EWG analysis of data from the state water agency.
“EWG's tests provide a one-time snapshot of Chromium 6 levels in 35 cities,” the organization said. “But chromium pollution is a continuous, ongoing problem, as shown by the annual water quality reports that utilities must produce under federal law.”
Higher Numbers Seen
The total number of Americans drinking tap water contaminated with the compound is likely to be far higher than indicated by EWG's tests, the organization says.
At least 74 million people in nearly 7,000 communities drink tap water polluted with “total chromium,” which includes hexavalent and other forms of the metal, according to EWG’s 2009 analysis of water utility tests from 48,000 communities in 42 states.
The EPA’s new analysis of Hexavalent Chromium toxicity, released in draft form in September 2010, cites significant cancer concerns linked to exposure to the contaminant in drinking water. It highlights health effects documented in animal studies, including anemia and damage to the gastrointestinal tract, lymph nodes and liver.
EWG urges EPA to “move expeditiously to establish a legal limit for the chemical in tap water and require water utilities to test for it.
“The state of California must establish a strong standard for Hexavalent Chromium in tap water immediately. A truly health-protective Hexavalent Chromium regulation will reduce the cancer risk for Californians and serve as a model for the nation.
“With an enforceable standard already six years past the statutory deadline and the health of millions of Californians at stake, the state cannot move too quickly.”