Still, a private US environmental group has found that water in many American cities contains hexavalent chromium, The Washington Post reported last month.
The study by the Environmental Working Group — the first nationwide analysis measuring the presence of the chemical in US water systems — found hexavalent chromium in the tap water of 31 out of 35 cities sampled.
Of those, 25 had levels that exceeded the goal proposed in California, which has been aggressively trying to reduce the chemical in its water supply.
Hexavalent chromium has long been known to cause lung cancer when inhaled, and scientists recently found evidence that it causes cancer in laboratory animals when ingested. It has been linked to liver and kidney damage in animals, as well as leukemia, stomach cancer and other cancers.