Hexavalent chromium, a cancer-causing chemical, is found in the tap water of 31 cities out of a total of 35 tested by the Environmental Working Group (EWG), it was reported on Monday.
The chemical was detected when EWG researchers made the first nationwide analysis of hexavalent chromium in tap water in the U.S., according to USA Today.
It is estimated that at least 74 million people in 42 states regularly drink chromium-tainted water, and a considerable proportion of it is in the carcinogenic hexavalent form, the report quoted the EWG as saying.
Analysis showed that highest levels were present in the tap water in Norman of Oklahoma, Honolulu of Hawaii, Riverside of California, Madison of Wiscosin and San Jose of California, the report said.
Hexavalent chromium, also known as chromium-6 in drinking water shows "clear evidence of carcinogenic activity" in animal studies, significantly raising the likelihood of the development of gastrointestinal tumors, according to EWG.
In 2008, the U.S. National Institutes of Health deemed chromium a "probable carcinogen." The chemical has been linked to leukemia and other cancers in animals, as well as liver and kidney damage, according to the report.
The Environmental Protection Agency (EPA) is weighing whether to set a limit on levels of hexavalent chromium in tap water, the report said.
Despite growing evidence of the dangers of hexavalent chromium in tap water, the EPA has done nothing about legal limit requirements, while water utility companies don't even have to test for levels in their tap water, scientists say.
VietNamNet/Xinhuanet
