Senate Barely Squelches Mercury Panic

The Senate voted this week to reject an environmental activist-inspired challenge to the Bush administration’s new rules regulating mercury emissions (search) from power plants. The vote (51-47) was a lot closer than warranted.

Last March, the Bush administration issued the first-ever rules regulating emissions of mercury from coal-burning power plants (search) — an event that itself raised doubt about the urgency or need for such regulation. The modern electric utility industry, after all, began burning coal and, thereby, emitting small amounts of mercury into the environment in the 1880s.

The Bush rules, when fully implemented are intended to reduce mercury emissions gradually over the coming years — a 29 percent reduction by 2010 and a 70 percent reduction by 2018.

Environmentalists claim, however, that the Bush plan doesn’t cut emissions rapidly enough and have been advocating a plan they claim would achieve 90 percent reductions much sooner than the Bush rules.

At the urging of environmental activists, Senate Democrats utilized a 1996 law — providing Congress with a brief window of opportunity to repeal agency rules after they have been issued ­— to force a vote on the new mercury rules.

Leading up to the vote, environmental activists did their best to scare up support for the repeal.

The U.S. Public Interest Research Group (USPIRG) released a report entitled, “Made In the USA: Power Plants and Mercury Pollution Across the Country,” which states that, “Power plants are the largest industrial sources of U.S. air emissions of mercury, a potent neurotoxin that poses serious health hazards. Mercury is particularly harmful to the developing brain; even low-level exposure can cause learning disabilities, lowered IQ, and problems with attention and memory.”

USPIRG’s scaremongering was reiterated repeatedly by Senate Democrats during the Senate floor debate immediately preceding the vote. But the closeness of the vote doesn’t square with the facts.

Most global mercury emissions are natural in origin (ocean out-gassing (search) and terrestrial flux (search) are primary sources) and most of the human-caused emissions are from Asia and Europe.

The U.S. Environmental Protection Agency has studied mercury emissions from coal-fired power plants, concluding that “regional transport of mercury emission from coal-fired power plants in the U.S. is responsible for very little of the mercury in U.S. waters.”

The EPA estimates that, “Human-caused U.S. mercury emissions are estimated to account for roughly 3 percent of the global total, and U.S. coal-fired power plants are estimated to account for only about 1 percent.”

So if we are to worry about mercury, it appears that U.S. power plants are not a terribly worthwhile starting point.

But should we be so worried about mercury emissions to the environment in the first place?

There’s no question that mercury can be toxic to humans and wildlife – but only at sufficiently high doses. A fundamental tenet of modern toxicology is that “the dose makes the poison.” Mere exposure to any level of mercury isn’t necessarily harmful.

We know that extremely high levels of exposure to mercury can be harmful – the mass poisonings that occurred at Minimata Bay (search), Japan in the 1950s and in Iraq in the 1970s provide ample evidence of mercury’s potential toxicity.

But the mercury exposure levels in these instances of poisoning were hundreds to thousands of times greater than current everyday exposures to mercury in the environment and so are of questionable relevance. Despite much research, not a single study credibly links typical exposures to mercury directly to any sort of health effect.

You don’t have to take my word for it, though. All you had to do was watch the Senate debate preceding the vote on the Bush mercury rules.

Despite all the arm-waving and hyperventilating, no Senator urging repeal of the Bush rules pointed to a single demonstrable and real-life health effect caused by typical exposures to mercury in the environment or mercury from a power plant – because no documented case exists.

Finally, the costs of the Bush rules are estimated to be $2 billion, while the costs of the environmentalists’ preferred alternative are estimated to be $358 billion.

This huge cost differential combined with the utter lack of hard evidence of health effects after more than a century of unregulated mercury emissions from power plants would seem to merit more than the four-vote margin eked out by Senate supporters of the Bush rules.

In an era when we need all the cheap energy we can get, the vote underscores the remarkable ability of environmental activists to command a substantial portion of the “world’s greatest deliberative body,” regardless of the facts.

Steven Milloy publishes and, is adjunct scholar at the Cato Institute, and is the author of Junk Science Judo: Self-defense Against Health Scares and Scams (Cato Institute, 2001).

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