The treaty was approved by 147 governments Saturday at a forum in Geneva, Switzerland, bringing praise from the European Union, Ireland, Switzerland and other European supporters.
The Minamata Convention on Mercury -- named after the Japanese city where the Chisso Corp. discharged mercury-tainted water into the ocean over several decades causing serious health problems -- calls for new controls and reductions across a range of products, processes and industries where mercury is used, released or emitted.
Under its terms, the countries agreed to ban mercury in thermometers, batteries and energy-saving light bulbs by 2020, the U.N. Environment Program said.
Particularly affected is the artisanal and small-scale gold mining and refining industry, which is the largest source of mercury pollution worldwide and is booming in such countries as Thailand, Peru and Senegal due to high gold prices.
The Minamata Convention requires governments to develop national action plans to ban the most harmful forms of mercury use, promote mercury-free mining methods, protect children and women of childbearing age and seek to improve the health of miners.
Children employed in small-scale gold mining are at serious risk as they work with mercury or are present during the burning of the mercury-gold amalgam, the non-governmental advocacy group Human Rights Watch said.
Switzerland, which along with Norway initiated a push for the treaty in 2002, praised its passage. It has a particular interest because most of the world's raw gold passes through Swiss refineries, including 2,600 metric tons in 2011, Swissinfo.ch reported.
Franz Perrez, head of the Swiss negotiating delegation in Geneva, said the adoption of the Minamata Convention "demonstrates the vitality of the U.N. system and the willingness of states to work together to find solutions to global problems."
Switzerland, Norway and Japan have pledged to fund the start of the convention, including $1.1 million from Switzerland, Federal Councilor Doris Leuthard announced.
"We have reached a robust, balanced and dynamic environmental agreement," added European Commissioner for Environment Janez Potocnik.
"While the EU has an overarching strategy for controlling mercury at all stages of the mercury life cycle, such controls are unfortunately lacking in many parts of the world," he said. "This new treaty will bring benefits to all populations around the world, including the citizens of the EU given the long distances that mercury can travel in the air."
"The treaty which has now been agreed (upon) will improve the lives of many across the world, as well as protecting our precious environment," agreed Irish Environment Minister Phil Hogan, whose country holds the rotating EU Council presidency.
"Mercury has long-since been recognized as a dangerous substance that is particularly hazardous to vulnerable populations like pregnant women, children and indigenous communities that depend on local fish sources."
The new convention will be submitted for ratification by the states late this year.
"Everyone in the world stands to benefit from the decisions taken this week in Geneva -- in particular the workers and families of small-scale gold miners, the peoples of the Arctic and this generation of mothers and babies and the generations to come," UNEP Executive Director Achim Steiner declared.
"I look forward to swift ratification of the Minamata Convention so that it comes into force as soon as possible."