Can Chromium in Drinking Water Cause Cancer?

The EPA has set total chromium in drinking water at 100 ppb as a maximum. Chromium 6 or hexavalent chromium is but a subset of total chromium and there is no limit on chromium 6. Most of the problems with hexavalent Cr are from dust and inhaled not ingested. There are known problems with Cr6 in drinking water but is usually found in ground waters as opposed to surface water. Those water supplies with a high pH (anything above 7.4) will not usually have elevated Cr.

Chromium has been implicated in some drinking water supplies as causing stomach cancers. There is a study from China in 2008 in the Journal of Epidemiology that reports such a problem. I think that the research is yet to be done to determine maximum levels in drinking water. I am not alarmed nor surprised to see it now reported. I think we have more important problems to worry about. That does not mean we should be complacent about Cr6 and we should continue to monitoring and research. Perhaps we could direct sampling and research to be more specific to Cr6 and not just total Cr. Treatment may be as simple as raising the pH for a period of time and filtering out the chrome before discharge to users. Ground water sources often to not have the infrastructure installed to modify treatment and may eventually have to spend money to get the end result yet to be determined.