Mercury Pollution: An End in Sight?
Work continues on a global treaty to solve the world's mercury pollution problem.
Mercury is a potent neurotoxin and a pollutant that knows no borders. Mercury pollution from industrial activities halfway across the globe can end up in your local lake or the fish in your grocery store, where it poses a serious health hazard, especially for children and pregnant women.
Mercury moves around the world in three key ways. First, it is actively traded as a global commodity, often for uses like artisanal and small-scale gold mining in the developing world, where substantial releases to the environment are routine. Second, airborne mercury released by industrial activities can travel great distances before being deposited in waterways. So mercury released in Asia, for example, can circle the globe and enter American waterways when it rains. Third, once mercury enters a waterway, naturally occurring bacteria absorb it and convert it to its most toxic form, methyl mercury, which then moves up the food chain into fish – and the fish we eat comes from all over the world. Stopping mercury pollution in the United States isn’t enough to protect the health of our kids and future generations. Mercury pollution is a global problem that needs a global solution.
Mercury Poses Serious Health Hazards
The U.S. Environmental Protection Agency estimates that every year hundreds of thousands of American newborns are at risk for problems with fine motor skills and learning difficulties as a result of their mothers' fish consumption during pregnancy. Emerging research also links mercury exposure with cardiovascular disease in adult men, and scientists continue to raise flags about additional health threats posed by mercury exposure.
Where Mercury Comes From
Coal-burning power plants and industrial processes are important sources of mercury pollution, both nationally and globally. Coal is naturally contaminated with mercury, and when it is burned, the mercury simply goes up the smokestack and into the air if not effectively controlled.
Another significant source of mercury pollution is metallic mercury, used in a number of commercial products and industrial processes. The largest uses of metallic mercury globally are artisanal and small-scale gold mining, the production of chlorine and/or caustic soda at chlor-alkali facilities and PVC production where mercury is used as a catalyst. Other significant uses include the manufacture of various products such as switches and relays, button cell batteries, measuring devices (such as thermometers and blood pressure cuffs) and lamps.
In most of these processes and products, equivalent or better non-mercury alternatives can be used. A recent study prepared for the United Nations Environment Program (UNEP) identifies those alternatives and their global availability.
According to UN experts, between 3,100 and 3,900 metric tonnes of mercury are purchased around the world each year for various products and processes. In recent decades, developed nations have substantially reduced their use of this highly toxic metal. However, the surpluses created by declining industrial use of mercury have too often been allowed to flood the global marketplace. The resulting cheap mercury has fueled a sharp increase in the use of mercury in developing nations.
Most developing nations have no effective regulations to protect exposed workers and the environment. And since mercury travels so easily, mercury pollution in the developing world is a problem the world over. Simply put, the current laissez-faire global market in this toxic substance is a dangerous threat to the world's children. It endangers this generation and will threaten future generations.
The Major Mercury Suppliers and Buyers
There are four main pathways by which mercury arrives on the global market: "virgin" mercury mining; "by-product" mercury recovered from mining and smelting other metals such as zinc and lead, and oil/gas production; "recovered/recycled" mercury removed from wastes and used products; and "inventory mercury" from preexisting stockpiles and closed or converting mercury cell chlor-alkali plants. Virgin or primary mercury mining is the worst source of mercury since it introduces new mercury into the global pollution pool and the mining process itself releases significant quantities of mercury into the environment.
Key players in global mercury supply and demand include these countries:
Kyrgyzstan is the only country that mines mercury in significant quantities for export. The Kyrgyzstan mine is heavily subsidized by the central government, and efforts to privatize it have failed. International bodies are encouraging Kyrgyzstan to close the mine in favor of alternative development projects for the region.
China is the largest consumer of mercury in the world, accounting for about one-third of global mercury demand. The biggest uses of mercury in China are for the production of PVC and medical devices (fever thermometers and blood pressure cuffs). China mines produce about 1,000 tons of mercury annually to supply these sectors and other domestic uses.
Japan and the United States export significant quantities of mercury to the global marketplace. Japan exported more than 200 tonnes in 2006 and 2007, and more than 150 tonnes in 2008. The United States exported a net average of 296 tonnes annually from 2006 to 2008. However, new legislation will prohibit the U.S. export of commodity mercury beginning in 2013.
Historically, the European Union used to account for approximately 30 percent of the global mercury supply and was involved in more than half the global trade in mercury, even though it accounted for only 10 percent of the world's demand for mercury. However, the E.U. has recently committed to keeping this surplus mercury out of the global marketplace through an export ban that began in 2011.
A diverse group of countries in Asia, Africa and South America use a large and still growing amount of mercury in artisinal and small-scale gold mining, a particularly polluting source.
An International Solution for an International Problem
In February 2009, at a meeting of the UNEP Governing Council, an agreement was reached to pursue a global treaty to reduce mercury pollution. This treaty is expected to include measures that will reduce global mercury use, supply, and trade, as well as mercury emissions from sources such as coal burning power plants. An Intergovernmental Negotiating Committee (INC) convened in June 2010 and is expected to meet five times before completing the draft treaty in early 2013.
While the treaty discussions are underway, governments can exercise leadership and take immediate action to reduce the global supply of mercury. As noted above, the EU enacted an export ban beginning in 2011. And in 2008, the U.S. Congress enacted a similar export ban beginning in 2013. Other governments, such as Japan, should take similar action.
The world's nations can also reduce their use of mercury wherever possible, focusing first on the largest uses for which there are readily available non-mercury alternatives. In the United States, this means building upon the excellent leadership of state governments in restricting the manufacture and sale of many mercury products, and phasing out the use of mercury at the two remaining chlor-alkali plants using this antiquated technology.
In addition, mercury air emissions from the largest pollution sources, including coal burning, lead and zinc smelting, and cement plants, must be effectively controlled as soon as possible.
NRDC, in conjunction with a global coalition of NGOs called the Zero Mercury Working Group, will be proposing treaty measures which would phase out mercury mining and the use of mercury in products and processes where non-mercury alternatives are available. The proposed measures would also prohibit most global trading of mercury and substantially reduce global emissions of mercury from coal combustion, zinc and lead smelters, and other important air emission sources.
last revised 10/27/2014
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