NAIROBI, Kenya -- The Obama administration reversed years of U.S. policy Monday by calling for a treaty to cut mercury pollution, which it described as the world's gravest chemical problem.
Some 6,000 tons of mercury enter the environment each year, about a third generated by power stations and coal fires. Much settles into the oceans, where it enters the food chain and is concentrated in predatory fish like tuna.
Children and fetuses are particularly vulnerable to poisoning by the toxic metal, which can cause birth defects, brain damage and peeling skin.
Daniel Reifsnyder, the deputy assistant secretary of state for environment and sustainable development, told a global gathering of environmental ministers in Nairobi, Kenya, that the United States wants negotiations on limiting mercury to begin this year and conclude within three.
"We're prepared to help lead in developing a globally legally binding instrument," he said. "It is clear mercury is the most important global chemical issue facing us today that calls for immediate action."
The statement represented a "180-degree turnaround" from policy under the Bush administration, said Michael Bender, co-coordinator of the Zero Mercury Working Group, a global coalition of 75 environmental organizations working to reduce mercury exposure.
"The change is like night and day. The Bush administration opposed any international legal agreements on mercury, and President Obama is in office less than one month and is already supporting a global agreement," he said.
Bender said his group has had more discussions over mercury control in the past two weeks than it has in the last eight years and that the U.S. government included many of his group's ideas in the proposal being presented in Nairobi.
Mercury is also widely used in chemical production and small-scale mining. The toxin can travel thousands of miles through the air or water.
Substitutes exist for almost all industrial processes that require mercury, but more than 50 percent of mercury emissions come from coal-fueled power plants, complicating efforts to regulate it in countries that rely on coal for power.
A proposal drafted by the United States obtained by the Associated Press would form a negotiating committee in conjunction with the U.N. environment program to help countries reduce their mercury use, clean up contaminated sites and find environmentally sound ways to store mercury. The European Union has banned mercury exports starting in 2011. The United States has a similar ban that will be effective in 2013, legislation that was sponsored by Obama when he was a U.S. senator.