When Erin Brockovich, an environmental activist, shook down Pacific Gas & Electric for $333 million for allegedly poisoning a community with hexavalent chromium and causing cancer and all sorts of other health problems, Julia Roberts portrayed the protagonist in a sensationalized blockbuster movie. It is unlikely, however, that Hollywood will be filming a sequel.
Why? Because not only was Ms. Brockovich wrong, but the State of California has now partially repudiated what she fought for.
|Not Erin Brokovich, but she plays her in the movie|
I doubt that Erin is a deliberate fraud, but it is certainly true that she pursued and won a crusade which based on extremely weak science, and an abundance of emotions.
We've known for a long time that Ms. Brockovich used junk science to score a jackpot settlement. She used a common rhetorical trick, known as the Texas sharpshooter fallacy, to claim that a cluster of cancer and other diseases in the small town of Hinkley, California was the result of groundwater contamination by hexavalent chromium.I worked on the toxicity of hexavalent chromium once upon a time, at least for algae and marine animals. If you dig deep, you may even find a reviewed scientific paper or three with my name on it. It's toxic, but its not super scary, unless you breathe it, or play with chromic acid.
There were multiple problems with this argument. First, as hinted above, a cluster of cases is not necessarily indicative of anything. By sheer chance alone, patients with particular diseases -- even rare ones -- can occasionally be found in close proximity to one another. Second, an epidemiological survey found no extra cases of cancer in Hinkley than what normally would be expected. Third, while inhaled hexavalent chromium is linked to lung cancer, there is no evidence that ingesting tiny amounts of hexavalent chromium is harmful. Fourth, Ms. Brockovich's case did not make biomedical sense, because she not only blamed hexavalent chromium for causing cancer but a myriad of unrelated conditions. As Joe Schwarcz wrote for Quackwatch back in 2004:
Whether it's a miscarriage, a rash, bone deterioration, Crohn's disease, lupus, or any sort of cancer, Brockovich points the finger at chromium-6. In all probability she is wrong. Single toxins do not cause such a wide array of conditions.
|But I see the resemblance|
Now, the Sacramento Bee reports that California water regulators have decided against implementing a rule that would have capped hexavalent chromium in drinking water at 10 parts per billion (ppb). A judge said the rule was invalid because economic feasibility was not considered.Given that it's California, hoping for reason to triumph is a trifle optimistic.
That's not a complete victory; indeed, California could very well implement the 10 ppb rule anyway. And the rule was deemed invalid based on economics, not science. But let's hope that reason ultimately will prevail in this momentary triumph of sanity.
According to the EPA, hexavalent chromium can be found in drinking water from both natural and manmade sources. The federal limit for total chromium (i.e., chromium-3 and chromium-6) is 100 ppb, and this has been the agency's policy for many years. California's desire to decrease the limit to 10 ppb lacks scientific justification, and as to be expected, its biggest champion is the thoroughly unscientific Environmental Working Group.Hexavalent Cr is the stable state of chromium in neutral to basic oxygentated water. It is, however, rarely found in high concentrations, as it tends to oxidize any organic material present. It reduces to trivalent Cr, which is not very soluble and strongly attracted to particles, and is usually removed to very low concentrations.