This was revealed by a study by an environmental group, reported The Washington Post.
The Environmental Working Group study, the first nationwide that measures the presence of hexavalent chromium in U.S. water systems, will be published in full on Monday, the newspaper said.
The organization found hexavalent chromium in the water from the tap in 31 of the 35 cities examined. Twenty of them had levels that exceeded the target set by California, which has an intense campaign to reduce chemicals in the water supply.
The federal agency Environmental Protection discussed the possibility of establishing a limit for hexavalent chromium in drinking water. The authorities are reviewing the chemical after the National Health Institute, called it “a likely carcinogen” in 2008.
Hexavalent chromium is long thought to cause lung cancer when inhaled, and scientists recently found that it can cause cancer in laboratory animals when ingested. In animals it has been linked to liver and kidney damage as well as leukemia and stomach cancer.
Widely used as an industrial chemical to the 90’s, hexavalent chromium is still used in some industries such as chrome and plastics and dyes. The substance can also seep into groundwater through natural minerals.