News Coverage
Who'll stop the mercury rain?
Published March 29, 2004
These days your favorite fish may come with a side of toxic mercury. It's a tough reality for Lake Michi-gan fishing boat captain Duane Nadolski, who says that after asking, "How's the fishing?" his customers often inquire: "Are these fish safe to eat?" Now, people who do their fishing at food stores have similar fears. Swordfish, shark, and several other fish are off limits for young children and women who are pregnant, nursing, or planning to conceive. And two weeks ago, the Environmental Protection Agency and the Food and Drug Administration warned that these consumers should also cut back on some canned tuna, eating no more than one 6-ounce can of albacore per week.
There's little relief in sight. Efforts to limit mercury from the 1,100 coal-burning power plants that are the main uncontrolled source of the pollutant in the United States have slipped into a political and technical morass. Last December, the Bush administration moved to ease planned mercury regulations and extend a federal emissions deadline by 10 years. The result was an outcry--and now the EPA is rethinking the scheme. But proposals for faster reductions face other hurdles: Technologies for reducing mercury emissions from power plants have a long way to go, and even the best U.S. controls won't touch the clouds of mercury coming from natural sources and from industry abroad.
In fact, mercury pollution could get worse before new controls kick in. About half the nation's electricity already comes from burning coal, and dozens more plants may come online in the next decade. As coal burns, it releases traces of mercury that waft out of smokestacks. Much of the mercury stays airborne for up to two years and spreads around the globe. But some is emitted as a water-soluble compound formed when mercury reacts with chlorine, an element often found in coal from eastern states, says Praveen Amar, an engineer with the Northeast States for Coordinated Air Use Management.
Precipitation quickly washes this form of mercury into lakes, rivers, and oceans, where microorganisms take it up and convert it into toxic methylmercury. The mercury passes up the food chain into fish--reaching the highest levels in large predatory species like swordfish and tuna--and on into people. High levels can cause learning problems or retardation in children and neurological damage in developing fetuses. One recent study found fetus-harming levels of mercury in about 8 percent of U.S. women of childbearing age.
Backing off.
After years of study, the Clinton administration announced in 2000 that it would regulate mercury as a hazardous air pollutant. Under the Clean Air Act, that designation would have forced utilities to install top-notch pollution controls on virtually all smokestacks. Current emissions were slated to fall by 90 percent over four years. But late last year, when the EPA unveiled a long-awaited plan for controlling mercury, it proposed shifting it to a more lenient section of the law. The shift would allow utilities to use a flexible pollution trading program, require an overall cut of 70 percent rather than 90 percent, and give them 15 years to do it.
Many experts, including members of an EPA working group that had spent more than a year developing mercury regulations, were dismayed. "It was an exercise in futility," says Martha Keating, a former EPA scientist who sat on the panel and works for the nonprofit Clear the Air. Keating was also one of the first to notice that the EPA's proposed trading rule borrows wording, sometimes verbatim, from utility memos on mercury control. The EPA has dismissed these echoes as anomalies.
Industry groups certainly like the flexibility of the EPA's proposed regulations, which would set a nationwide emissions cap and give each plant a limited number of pollution allowances. Utilities could either install equipment to cut emissions below the allowed level and sell unused allowances or exceed the level and buy extra allowances from other sources. The total number of allowances would fall each year as the cap tightened.
Such "cap and trade" approaches are at the core of President Bush's Clear Skies Initiative, a suite of clean-air legislation that's currently stalled in Congress. This strategy proved cheap and effective when introduced in 1990 to stem acid-rain-causing emissions from power plants. What's more, lumping mercury and acid rain together under one trading system would save more than $1 billion in annual compliance costs, says the Edison Electric Institute, which represents most U.S. electricity companies.
But critics say that while trading worked well for the pollutants that cause acid rain, it is the wrong approach for a toxic substance like mercury. Because much mercury falls within 100 miles of its source, utilities that buy credits instead of installing controls could worsen local mercury deposition--so-called hot spots--says Lynn Goldman, a pediatrician at Johns Hopkins University and former EPA official. "I don't think it makes sense," she says.
The administration has now backpedaled, extending the time for public comment and analysis. EPA chief Mike Leavitt told U.S. News that the December proposal was just a "starting point," and he expects "significant changes" in the final rule, to be issued at the end of this year. Leavitt says the agency is still studying a "range of different alternatives" for quick, efficient mercury cuts.
Smoking it out.
Technology, however, could stymie faster timetables. Controls for other pollutants remove some mercury. But the Energy Department and industry are trying to develop technologies specifically aimed at mercury, such as sorbent injection--for example, shooting carbon dust into smokestacks, where it binds to the mercury, forming particles that can be sifted from the exhaust. Leavitt says he is "highly optimistic" about the method but believes "it will not be widely deployable until 2010 or after."
And even the best technologies won't choke off all sources of mercury. About one third of U.S. atmospheric mercury emanates from natural sources, such as volcanoes around the world, according to Christian Seigneur of Atmospheric & Environmental Research Inc., which recently did an industry-funded study of mercury deposition. An additional 21 percent drifts over from power plants in Asia, mostly China. Much of the mercury in oceangoing fish also hails from sources abroad. That's why many utilities say they're not entirely to blame. "Reducing mercury emissions from U.S. power plants makes very little difference," says Vicky Sullivan, environmental issues manager for Southern Co., which operates 21 coal-burning plants in the South.
Not so, says Harvard University atmospheric chemist Daniel Jacob. Mercury hot spots downwind of power plants show that local emissions matter, he says. "Reducing emissions from local plants will not eliminate the problem, but if it is a large local source, it will help."
With all sides in the mercury debate gearing up for a long fight, there are sure to be more questions for fishermen like Nadolski and more quandaries at the fish counter.