California EPA Sets Stricter Limit For Hexavalent Chromium

Made infamous by the activist Erin Brockovich and the film produced about her, the heavy metal hexavalent chromium will now be receiving a little more attention. Also, known as Chromium 6, the California EPA have set limits on the arguably cancer causing chemical found in water within the state.

On Wednesday, the California EPA imposed a statewide limit of chromium 6 of 0.02 parts per billion, the maximum amount of the chemical before it is considered to be a significant health risk. Current federal regulations limit chromium, both chromium 6 and chromium 3, to 100 ppb in water, but there are no regulations on chromium 6 itself. Chromium 3 is non-toxic and is important to glucose metabolism of the body.

Chromium 6, however, is a rather toxic substance. It is commonly discharged as waste by steel and pulp mills and also used in metal-plating and leather-tanning factories.

As the only state in the nation to require testing, California originally proposed a public health goal (PHG) for chromium 6 of 0.06 parts per billion in 2009. According to Environmental Working Group, a non profit organization in Oakland, chromium 6 is present in tap water in 31 of 35 cities tested by the group. Riverside had chromium 6 levels of 1.69 ppb and San Jose 1.34 ppb. Other cities around the U.S. of much concern include Norman, Oklahoma with 12.9 ppb, Honolulu, Hawaii with 2.00 ppb, and Madison, Wisconsin with 1.58 ppb chromium 6. The EWG also reports that more than 74 million people in 42 states drink water “most likely” tainted with chromium 6.

Limits for chromium 6 in drinking water have met many obstacles over the years. The Department of Public Health mandated a standard be set by 2004, but many demanded more credible scientific evidence that chromium 6 posed a health risk.

The new limit came after years of scientific research and efforts from activists like Brockovich. The National Toxicology Program (NTP) performed a two year study that showed water tainted with high levels chromium 6 caused malignant tumors in lab animals. The rats and mice, both male and female, were given water containing differing levels of chromium 6. The lowest of these doses contained ten times more chromium 6 than the most contaminated water recorded in California.

Scientists that conducted the study reported that the lab animals developed tumors in places they would rarely develop tumors. Rats developed numerous malignant tumors in their oral cavity and mice developed both benign and malignant tumors in the small intestine. The number of tumors increased with higher levels of chromium 6.

Arguably the most influential in bringing attention to chromium 6 was the film “Erin Brockovich”. Claiming the movie was 98% accurate, Brockovich, portrayed by Julia Roberts, stumbles upon documents about Pacific Gas and Electric (PG&E) knowingly contaminating groundwater in the town of Hinkley, California. The movie also portrays the health conditions those who worked in the contaminated water developed and suffered from. Also, the movie claims that exposure to chromium 6 will result in the development of cancer. After enough evidence was gathered, a judge ordered PG&E to pay out $333 million divided among 648 plaintiffs.

However, some people believe the film exaggerated the health risks of being exposed to chromium 6. It was reported that from 1988 to 2008, California Cancer Registry performed studies that showed cancer rates remained nearly constant throughout this time period in the cities surveyed, including Hinkley.

This new goal set by the California EPA is the first step in the battle against chromium 6 contaminating the nation’s water resources. Testing and monitoring of the chemical is largely unregulated even though it poses some health concerns. Whether or not it causes cancer, it is a little more reassuring to limit levels of chromium 6 and other pollutants in drinking water, rather than try to prove these industrial chemicals do not cause cancer. As the saying goes, better safe than sorry.

Photo credit: flickr.com/photos/publicresourceorg/494054684

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