Chromium-6 scare hits Oregon

Some Oregonians are apparently fretting over chromium-6 (Cr-6) in drinking water. Here’s why they (and you) shouldn’t.

The current round of Cr-6 scaremongering began last December with headlines like this from the Washington Post: “Group finds ‘Erin Brockvich’ chemical in D.C., Bethesda Water“.

The comrades at the Environmental Working Group reportedly found hexavalent chromium (Cr-6) in drinking water across the country at levels up to 200 times greater than the goal proposed by California (0.06 ppb). Cr-6 reportedly is associated with increased cancer risk in laboratory mice.

But before you swear off tap water, run to your doctor, join a class action lawsuit or do anything other than simply roll on the floor laughing at Ken Kook and his fellow EWG Krazies, here’s a few things to consider:

  1. Outside of a hotly disputed study of a 1970s-era Chinese population, epidemiologic studies have not associated Cr-6 exposure with increased risk of cancer. Even the EPA acknowledges this (See p. 207 of April 2010 EPA review document). Then there’s this comment from a review of the Cr-6 epidemiology:

    The weight of scientific evidence supports that Cr-6 is not carcinogenic in humans via the oral route of exposure at permissible drinking-water concentrations. [J Toxicol Environ Health A. 2002 May 24;65(10):701-46.]

  2. Mice are not little people. So who cares whether lab mice poisoned with Cr-6 got cancer or did cartwheels?
  3. No violations of the EPA drinking water standard for chromium were reported. While there are no specific drinking water standards for Cr-6, the EPA oral reference dose (RfD) for Cr-6, which includes a monster safety factor of 300, is way above the levels of Cr-6 detected by EWG.
  4. The proposed California standard for Cr-6 is not science-based.
  5. Research shows that Cr-6 is safe in water at a level of 100 ppb.
  6. The EWG specializes in efforts to scare people about the mere presence of chemicals and metals in drinking water. The group seems to be impervious to Paracelsus’ 450-year-old basic toxicology principle that “the dose makes the poison.”

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