ChromiumVI

Rising levels of chromium^VI, or hexavalent chromium, in the water wells in Glendale may force the city to shut down those wells.

Hexavalent chromium is a corrosive form of chromium which has been showing up in ground water lately. It first came to public attention in the movie, "Erin Brokovich", and saturated the papers soon thereafter. Regulators have imposed a maximum contaminant level (MCL) of 50 parts per billion (ppb) in water, and Glendale has adopted a MCL of 5 ppb.

The Received Wisdom ^TM holds that any hexavalent chromium in groundwater is the result of industrial pollution. The problem with that is that hexavalent chromium has been found in pristine wells.

So what does hexavalent chromium do? Well, in one study with 100 rats, two of them given massive doeses of the stuff in their water developed cancer in an organ humans don't even have. One problem researchers had during the study was that the solution the rats were drinking – 500,000 ppb – was that it tasted nasty. The rats were refusing to drink it, and were resorting to cannibalism for liquids.

Well, we know stress causes cancer. Someone want to convince me that's not a high-stress environment?

At one talk, I saw a wonderful demonstration. The speaker had flask filled with a solution of 500,000 ppb chromium, as potassium chromate. It looked like orange punch. With the addition of a pinch of an antioxidant, its color changed from orange to green (with sulfites) or purple (in the case of vitamin C). (The name "chromium", by the way, comes from the variety of colors different compounds of the metal have.) A pinch of vitamin C was enough to turn all the cromium^VI into chromium^III.

Chromium^III is a lot less harmful. In fact, it's a nutrient. Health food stores sell it.

Hexavalent chromium, especially at the low levels we're seeing hereabouts, is essentially harmless. If you're worried about it, take a little extra vitamin C. (Or just drop a slice of lemon in your glass of water.) And yet, because it's new and different, and filmmakers and reporters can alarm the public over it, it's a Menace.

In reality, I suspect you're more likely to get cancer from the stress of worrying about hexavalent chromium than you are from actually drinking it.