The Brockovich Story, Part 2

By George Johnson | March 25, 2013 9:57 am

Human lung cells damaged by chronic exposure to particles of a chromium compound. Wise Laboratory

Chromium, an element in the periodic table, occurs naturally in the earth, and when dissolved in the water it migrates between two states. Chromium 3 is essential to human metabolism and is supplied in multivitamin pills. Chromium 6, in high enough concentrations, can be harmful and even carcinogenic. The difference lies in what chemists call the oxidation state, which indicates how reactive a substance is.

The E.P.A. sets a standard for how much chromium is safe in drinking water, whether occurring naturally or as the result of industrial pollution: no more than 0.1 parts per million for both types combined. The number is based on the worst-case assumption that all of the chromium might be the poisonous kind.

Chromium 6 was the contaminant in the Erin Brockovich case, which was featured in the PBS NewsHour report I criticized in my previous post. The second part of the broadcast, which was better than the first, focused on whether a much lower standard should be set, as has already happened in California.

As noted here before, chromium 6 (also called hexavalent chromium) has been shown to cause lung cancer when inhaled by workers. What happens when you drink the stuff has been harder to figure out. In the stomach it quickly reverts to its more stable state, the beneficial chromium 3. The question is how much of the bad chromium it takes to overwhelm our biological barriers. A review of the science in 2003 suggested that concentrations 20 times higher than the federal standard are rapidly reduced to the harmless kind, and that the body can handle doses as high as 100 times the limit.

When chromium 6 does come into contact with cells, it can mutate their chromosomes. PBS showed some stunning images of the process, and there is an excellent explanation of the research on a web page for the Wise Laboratory of Environmental and Genetic Toxicology. What remains at issue is whether there is enough of the metal in even very contaminated water to damage living cells.

“There’s a lot that we don’t know,” John Wise, the director of the laboratory told O’Brien. “I don’t think we have enough studies to tell us whether — clearly whether it’s a drinking water carcinogen or not.”

But that point gets lost in the story, and I suspect that the image that will stay in most viewer’s minds is another clip spliced from the movie Erin Brockovich, in which Julia Roberts is berating a local water official.

People are dying, Scott. You have got document after document here. Right under your nose, it says why, and you haven’t said one word about it. I want to know how the hell you sleep at night.

In the real world there is no evidence that chromium 6 in drinking water has killed anyone in this country. The PBS story mentions a study of Chinese villagers whose water was so laden with the metal — far beyond what happened in the Brockovich case — that it turned yellow. An epidemiological report in 1987 showed that there had been an elevated rate of stomach cancer. But 10 years later, under suspect circumstances, the data were reanalyzed and no excess was found.

So what, if it is even possible to know at this point, is the truth of the matter? It is a twisted tale, which I’ll write more about soon. Meanwhile, here is a story that appeared in Salon back in 2000. It makes you wonder whether Brockovich and the lawyers she worked for were really such heroes after all. Not everyone in Hinkley thought so.

CATEGORIZED UNDER: Cancer, select, top-posts
  • JonFrum

    There are two issues here – one scientific, one legal/social. Given what we know about the former, the latter shouldn’t even come up. The Salon article focuses on the rights of plaintiffs to collect more money than they got. The science says none of them should have been awarded a penny. Brockovich was just a symptom, and certainly no hero under any rational understanding of the word.

  • Alan Cooper

    “I don’t think we have enough studies to tell us whether — clearly whether it’s a drinking water carcinogen or not.”

    Oh well then let’s just keep dumping it in the drinking water until we do then eh?

  • CandleForex

    To error on the side of caution, is there some sort of water filter that will filter out the hexavalent chromium?

    • Rick Wilson

      No. Hexavalent chromium is water soluble and can’t be filtered out. The water can be treated, but it’s a fairly complicated (industrial) process of lowering the pH, adding a reducing agent to convert the chromium to trivalent, then raising the pH back up to filter or precipitate out the trivalent chromium. Not practical for a homeowner. A city or water district would have to do it.

      • CandleForex

        Oh I see. I asked because already some water filter companies are claiming with Reverse osmosis filtering that Hexavalent chromium can be largely removed from the water.

        As far as I know when consumed by a person, Hexavalent chromium breaks down to trivalent chromium which is actually a trace mineral required by the human body. Not entirely though and there remains the problem.

        I cannot see a city or water district filtering it out either because chlorination of water that contains Hexavalent chromium, will oxidise the Hexavalent chromium to quadvalent chromium . In my opinion there should not be any forms of chromium in drinking water, because any forms of chromium can convert back and forth (eg chromium 3 to chromium 4 back to chromium 3) in water (as they are water souble as you pointed out) and in the human body, depending on environmental conditions.
        Will be highly interested to see another article based on further research by you.

  • Stephen Green

    PBS aside, naturally occurring elements, in their natural state and used by life forms, all fit a pattern do they not? Only mankind seems to mess this stuff. And once in a while the Earth does too..

  • Ce Gzz

    same happens with gmo crops. Lots of saying that goes into the media, and lots of research that finds nothing. Once the patents die, 3rd world countries will bring their own gmo crops regardless of the whole environmentalist agenda that wants to live on precautionary principles.

  • Roger Faulkner

    There were lots of other contaminants in that water that Erin Brockovitch was fighting about. Maybe she picked the wrong contaminant. For me, I feel that elements that have no known biological function (lead, mercury, cadmium especially) should be regulated the most tightly.

  • Roger J

    Some things we take for granted, like this, often turn out to be not so, but that doesn’t help ratings for news stations and the big-buck rewards for the plaintiff’s bar . We are now learning that high cholesterol in our bodies may not be the cardiological bug-a-boo we’ve been led to believe (and the statins we take to fix it may, in fact, be more dangerous, particularly for women). Another pseudo-scientific “truth” is that living down wind from nuclear powered electrical generating plants is also dangerous. There is a study done many years ago in the Pacific Northwest that indicated that cancer levels began to rise in certain areas near the nuke plants before they even had nuclear material installed or went on line. The culprit: viral infections from foreigners (workers coming from other parts of the country) in indigenous populations (local residents who had lived pretty much isolated in that area and had no anti-bodies in their immune systems against the new viral strains). It wasn’t nuclear material causing the cancer, but the common cold (or similar viral infections). As Gomer Pyle used to say, “Well, gah-ah-ah-leee!!!” Of course, no-one can sue a virus for millions of dollars


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About George Johnson

George Johnson writes about science for the New York Times, National Geographic Magazine, Slate, and other publications. His nine books include The Cancer Chronicles: Unlocking Medicine's Deepest Mystery (August 2013), The Ten Most Beautiful Experiments, A Shortcut Through Time, and Fire in the Mind. He is a winner of the AAAS Science Journalism Award and has twice been a finalist for the Royal Society science book prize. Co-founder and director of the Santa Fe Science Writing Workshop, he can be found on the Web at Twitter @byGeorgeJohnson.


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