Hexavalent chromium. The term sounds high-tech and slightly ominous to those unfamiliar with it -- and apparently few people are familiar with it. Hexavelent chromium is currently piquing online readers' curiosity.
The highly publicized specter of potentially toxic water can do that.
So here are some basics.... Hexavelent chromium is, quite obviously, a form of the element chromium. The heavy metal is more commonly called chromium 6 and it's used in the production of stainless steel, pigments and protective coatings.
Here's related chromium-6 information from the Center for Disease Control and Prevention's occupational-health overview. It states: "[The National Institute for Occupational Safety and Health] considers all Cr(VI) [hexavalent chromium] compounds to be potential occupational carcinogens. An increased risk of lung cancer has been demonstrated in workers exposed to Cr(VI) compounds. Other adverse health effects associated with Cr(VI) exposure include dermal irritation, skin ulceration, allergic contact dermatitis, occupational asthma, nasal irritation and ulceration, perforated nasal septa, rhinitis, nosebleed, respiratory irritation, nasal cancer, sinus cancer, eye irritation and damage, perforated eardrums, kidney damage, liver damage, pulmonary congestion and edema, epigastric pain, and erosion and discoloration of the teeth."
Here's a more comprehensible chromium-6 fact sheet from California's Office of Environmental Health Hazard Assessment, complete with an explanation of the difference between chromium 6 and chromium 3. Even if you didn't ace high school chemistry, give it a shot.
In short, the ill effects from inhaling hexavalent chromium are well-known; the effects of drinking it aren't, as yet, quite as clear. But suffice to say it's done lab mice little good.
The advocacy organization Environmental Working Group is on the case, however, sparking the latest round of Internet searches and consternation with its report on tap-water analysis.
Here's the take on that report from the Chicago Tribune, concerned about the presence of hexavalent chromium in drinking water in that city: High levels of chromium found in Chicago-area tap water.
You don't have to live in Chicago to find the article relevant. It explains that the metal was found in the water of 31 of 35 cities tested, with notably high levels in Madison, Wis.; Norman, Okla.; Honolulu; and Riverside. The full list of cities can be found in the original report from the Environmental Working Group.
Here's the alarmed reaction of Illinois' elected officials: Durbin and Kirk raise alarm on chromium 6. Plus the response from the L.A. Times' Greenspace blog: Chromium-tainted drinking water: Time for a federal crackdown?
Of note, many residents of one California town recently became convinced that what seemed to be a rash of local cancer cases could be traced to chromium-6-tainted groundwater. They were recently informed otherwise: Fewer cancers found in Hinkley than expected
One more thing about hexavalent chromium: There's no federal standard for it in drinking water.
And yes, it was the subject of considerable debate in the "Erin Brockovich" movie.