An investigative study released on December 20, 2010 by an environmental group reveals that 31 major cities have tap water tainted with the carcinogen hexavalent chromium.
The revelation comes just as the Environmental Protection Agency considers setting limits on hexavalent chromium in drinking water. After an exhaustive study of the chemical toxin in 2008, the National Institutes of Health's National Toxicology Program determined that hexavalent chromium is most likely carcinogenic.
The toxic substance was brought into public awareness by the film "Erin Brockovich."
Often used in industrial processes until two decades ago, hexavalent chromium's still in use within certain industries including chrome plating and plastics.
Geologists and water experts discovered the toxin can also pollute underground aquifers by leaching into water from natural ore deposits.
Currently. the federal government has mandated and regulates the total amount of chromium from any source present in tap water. That chrome includes both the important derivative "trivalent chromium"—a mineral crucial for human health, and hexavalent chromium that has been proven to create cancerous tumors in animals.
While the carcinogen is known to cause lung cancer if inhaled, cancer in laboratory animals that ate the substance was discovered relatively recently. Studies have shown the metal can cause both liver and kidney damage. Other cancers linked to it include stomach and blood cancers.
During 2009, the state of California moved to reduce the acceptable levels of the metallic toxin in tap water. Officials proposed a public health safety goal of 0.06 parts per billion. The legislature and state EPA is considering making the "goal" a law.
The eye-opening study found disturbing evidence that of the 35 cities water supplies tested, 31 contained hexavalent chromium. Worse, 25 were found to have levels present that exceeded the new California limit.
Contacted about the findings of the study by the Washington Post, Erin Brockovich declared, "This chemical has been so widely used by so many industries across the U.S. that this doesn't surprise me."
Brockovich led the fight against Pacific Gas & Electric (PG&E) for the people of Hinkley, California. The giant utility was suspected of leaking hexavalent chromium into Hinkley's groundwater for over three decades.
After a bitter court battle—that was the subject of an award-winning 2000 film—PG&E agreed to settle the claims of 600 Hinkley residents and paid damages of $333 million after promising to also clean up the damage.
"Our municipal water supplies are in danger all over the U.S.," Brockovich stated. "This is a chemical that should be regulated."