By MARC LACEY

AIROBI, Kenya, Feb. 8 — Delegates attending a United Nations environmental conference here last week endorsed a global crackdown on pollution caused by mercury, although the United States blocked efforts for binding restrictions on its use.

Mercury, a highly toxic heavy metal, is particularly dangerous for infants and children, and it can be passed from pregnant women to their fetuses. Human exposure to mercury comes from a variety of sources — consumption of fish, occupational and household uses, dental fillings and some vaccines.

Advertisement

The United Nations Environment Program will begin assisting countries, particularly those in the developing world, in devising methods for cutting emissions of mercury from sources like coal-fired power stations and incinerators. Further action, possibly including a binding protocol, was put off until 2005.

The decision followed the release of a report outlining a significant global threat to humans and wildlife from mercury, a naturally occurring metal. Mercury exposure can cause development problems and can affect the brain, kidneys and liver.

The conference drew more than 1,000 delegates from 130 nations. The delegates agreed that "there is sufficient evidence of significant global adverse impacts from mercury and its compounds to warrant further international action to reduce the risks to human health and the environment."

The United Nations report found that mercury travels throughout the earth at a far greater rate than was previously known, circulating between the air, water and soil as well as in living things. Even regions without significant mercury releases of their own, such as the Arctic, were found to be adversely affected by the global spread of mercury.

Mercury has many industrial applications, although safer alternatives exist. It is used in small-scale mining of gold and silver as well as in thermometers, fluorescent lamps and some paints. The substance is also contained in many skin-lightening creams as well as in some traditional medicines.

Some European delegates had sought to begin laying the groundwork for a global protocol on mercury. But Bush administration officials, who have opposed such wide-reaching approaches to a range of environmental issues, had argued that it would take too long and be too costly to pursue such a global convention.

Instead, the American officials pressed for public awareness programs to spread the word of the risks of mercury. Such efforts would be aimed at especially vulnerable groups, like pregnant women and people living in areas with small-scale gold and silver mining operations, where mercury is a particular threat.

"We acknowledge that the case has been made for action," said an American official involved in the negotiations. "But instead of negotiating for years and spending millions of dollars on a global convention, we want quick action."

European negotiators successfully pushed for language leaving open the possibility of a global convention in the future. The issue will be revisited at a follow-up meeting in South Korea in 2005. The Europeans also wanted the effects of other heavy metals, including lead and cadmium, to be reviewed.

"No single country can resolve the mercury problem on its own," said Michael Bender, director of the Mercury Policy Project, an organization working to focus attention on the problem. "There are alternatives for mercury uses, but there is no alternative to global cooperation."

The data on global exposure to mercury remains incomplete. Many developing countries also are far less apt to notify their populations about the risks of mercury, like the dangers of too much seafood for pregnant women.

The United States is far ahead of many other countries when it comes to awareness of mercury's risks. The Food and Drug Administration and 41 states warn consumers to limit their intake of certain fish — or avoid eating them altogether — because of their mercury levels. Ten states advise pregnant women and children to limit consumption of canned tuna, the most heavily consumed fish in the United States.

Data from the Centers for Disease Control indicates that one in 12 women of childbearing age in the United States have unsafe mercury levels, translating into more than 300,000 children born each year at risk of exposure to mercury.