Perchlorate in the water

Perchlorate is turning up in water supplies.

The chemical, used in rocketry, is generated by the military, the space program, and their contractors, and it seeps into ground water.

Now there's an argument over what amount in the water is safe.

Proposed standards range from 200 parts per billion (recommended by industry) to 1 part per billion (recommended by many environmentalist groups). A National Academy of Sciences panel has set a recommended maximum dose of 700 picograms per kilogram of body weight, 23 times higher than the EPA's recommendation of 30. Those who specialize in this subject believe this will work out to a standard of 6 parts per billion.

The reaction from environmental groups has been mixed. The Environmental Working Group supports the findings, but others believe the panel was pressured to recommend a high level.

But the Natural Resources Defense Council said the panel's findings will "threaten the health of millions of American children." The group said the report "was likely shaped by a covert campaign by the White House, Pentagon and defense contractors to twist the science and strong-arm the academy."

And there was no pressure from environmental groups pushing for as low a standard as possible?

I figure the number the panel came up with is higher than some want, and lower than others want, so it's probably not too far from the Goldilocks number.

See also reports at Tech News World, Fox News, and Pasadena Star News.

The Pasadena Star News and Fox News both named the National Academy of Sciences as hosting the panel, and Fox News offers a statement from the NAS rebutting charges that their findings were influenced by industry and/or the Bush Administration. Fox also mentions that perchlorate is found in nature.

One interesting quote from the Fox News piece:

But environmentalists contended such a high standard could endanger children's health while letting defense contractors off the hook for cleanup costs.

As I mentioned here, the quest for perfect safety is not without costs. Phrasing the issue as "letting defense contractors off the hook for cleanup costs" biases the argument toward the notion that perfect safety (in this case, an arbitrarily low level of perchlorate) can be achieved without cost. The problem is, every dollar spent cleaning up contamination that is already below harmful levels is a dollar that won't be spent on something we might actually need more.