A cancer-causing chemical has been detected in drinking water samples from numerous U.S. cities. A study released by the Environmental Working Group released Monday found that hexavalent chromium contaminated municipal water supplies in 31 of 35 cities tested. Hexavalent chromium, also known as chromium-6, achieved notoriety in the movie “Erin Brockovich.”
Why hexavalent chromium is hazardous
Hexavalent chromium is dumped into the environment by steel and pulp mills, metal-plating and leather-tanning industries, according to the Environmental Working Group. EWG paid labs to test drinking water in 35 cities known to be contaminated by the cancer-causing chemical, which leaches into groundwater from eroding soil. An EWG scientist said evidence has been well-documented that a corollary exists between exposure to chromium-6 and stomach cancer in humans.The highest levels of hexavalent chromium were found in Norman, Okla., Honolulu, Hawaii, Riverside, Calif., Madison, Wis., and San Jose, Calif.
The chromium-6 study
The EWG study is the first nationwide assessment of hexavalent chromium in municipal water supplies. The study was made public as the Environmental Protection Agency considers a regulatory limit for chromium-6 in tap water. The National Institutes of Health classified hexavalent chromium a probable carcinogen in 2008. In 2009, California proposed a safe limit of hexavalent chromium levels in drinking water at 0.06 parts per billion. The EWG study found that in Norman public drinking water exceeded that limit by 200 times. Of the 35 cities in the study, 25 exceeded the proposed California limit.
EWG recommends reverse osmosis water filters
Hexavalent chromium is the cancer-causing chemical that starred in the movie “Erin Brockovich”. Brockovich, a real person, successfully sued Pacific Gas and Electric for contaminating the water supply of Hinckley, Calif., with chromium 6. The utility company paid more than $330 million in damages. Until the EPA regulates hexavalent chromium in drinking water, the EWG suggests a water filter. “Reverse osmosis” water filters are designed to remove heavy metals, including chromium, from drinking water. Reverse osmosis water filters can cost anywhere from about $120 to $300.