CHICAGO TRIBUNE UPDATE

Exported mercury returns to haunt U.S.

Recycled toxin goes overseas, but ends up in atmosphere

By Michael Hawthorne
Tribune staff reporter
Published August 8, 2006

Tons of toxic mercury from U.S. recycling programs are funneled each year to loosely regulated industries in developing countries, where much of the hazardous metal is released into the atmosphere.

Scientists say some of that air pollution can drift back to this country and contaminate lakes and rivers, undercutting aggressive efforts to keep mercury out of the environment.


Tainted seafood


The mercury menace

The federal government estimates that U.S. firms exported at least 276 tons of mercury last year. It moves overseas through a little-known network of purifiers and brokers that operates without government oversight and faces few questions about what happens to the silvery metal once it is sold.

Environmental regulators acknowledge they know more about used motor oil and scrap tires than they do about the mercury trade, in part because it is considered a commodity and isn't subject to the same handling and tracking laws as hazardous waste.

But as policymakers become more aware of the dangers of mercury exposure, particularly for young children and women of childbearing age, they are focusing more attention on curbing sources of mercury pollution. Last month, U.S. Sen. Barack Obama (D-Ill.) introduced legislation that would bar American mercury exports.

"This is a problem that is impacted by things happening all over the world," Obama said in a recent interview. "But we can make an enormous difference."

Combined with a European Union proposal to block mercury exports, the U.S. effort could shrink global supplies of the metal and drive up the cost enough to encourage alternatives, Obama said.

The number of U.S. companies that use mercury in industrial processes or products is declining, a trend driven by concerns that once the metal gets into the atmosphere it can pose serious threats to public health.

Mercury pollution that falls into oceans, lakes and rivers is converted into a neurotoxin that becomes more dangerous as it moves up the food chain from fish to people. The federal government estimated last year that 410,000 babies are born each year at risk for mercury poisoning because of high levels in their mothers' bodies.

Illinois and other states have encouraged the move away from mercury with laws phasing it out in thermometers, school laboratories and industrial scrap. States also are taking steps to discourage mercury-laden garbage from being disposed of in landfills.

But there still is robust demand for mercury in developing countries, where it is used by small-scale gold-mining operations, thermometer manufacturers and chemical plants.

The demand is great enough that most mercury collected through U.S. recycling programs is sold instead of stored away. The U.S. Geological Survey estimates that most of the 276 tons exported by American companies went to Brazil, Mexico, Peru and Vietnam.

Total exports likely are much higher because U.S. metal mines aren't required to report what happens to mercury dug out of the ground in the same places as gold, silver, copper and lead, said William Brooks, who follows the mercury trade for the Geological Survey.

The world market soon will be flooded with even more mercury. Two American chemical plants that use large amounts of mercury to create chlorine are shutting down. Obama is pushing a second bill that would require six other chlorine plants to close or switch to mercury-free technology by 2012.

Those plants turn salt, or sodium chloride, into chlorine gas and caustic soda by pumping a briny solution through electrified vats of mercury. The industry had more than 2,600 tons of mercury on hand at the end of 2005, according to the Chlorine Institute, a trade group.

Environmental groups and a coalition of state officials are urging the federal government to store the metal safely instead of allowing it to be sold to other countries. The government already stores about 4,400 tons that had been stockpiled by the Defense Department.

The U.S. Environmental Protection Agency has agreed only to study whether the nation's commodity-grade mercury should be taken off the market.

"Outside of a handful of people, our role in this international trade has been completely off the radar screen for people in Washington," said Linda Greer, director of the environment and health program for the Natural Resources Defense Council. "We should be part of the solution, not part of the problem."

In recent years the federal government's policies have focused largely on a Bush administration proposal to limit mercury emissions from coal-fired power plants, the world's largest manmade source of the metal. Coal plants are responsible for about half of the 3,000 tons of mercury churned into the atmosphere each year, according to the United Nations Environment Program.

The next-largest source is gold mining in developing countries, which releases about 1,000 tons. UN officials say much of the mercury used to extract gold from ore comes from the U.S. and Europe.

U.S. mines long ago switched to mercury alternatives. But it still is used in other countries as an inexpensive method to remove gold from ore.

Lured by rising gold prices, some 15 million people across the world are engaged in small-scale mining, the UN says. The most common extraction process is to mix an amalgam of mercury and gold-laden ore. Mercury is released into the atmosphere when the mixture is heated to separate the gold.

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