House Votes to Ban Mercury Exports - AP

[Eugene]

Source: Associated Press

House Votes to Ban Mercury Exports

Tuesday November 13, 2007 11:46 PM

By JIM ABRAMS

Associated Press Writer

WASHINGTON (AP) - The export of highly toxic mercury
would be banned and federal agencies prohibited from
selling or distributing mercury under legislation the
House passed Tuesday.

The United States currently exports mercury for use in
thousands of small-scale gold mines, often in developing
countries. Environmental and health groups warn that
mercury toxins from those sites can return to this country,
either through the atmosphere or contaminated fish,
posing particular danger to young children and the
fetuses of pregnant women.

Rep. Tom Allen, D-Maine, a sponsor of the bill, cited
estimates that up to one-third of U.S. mercury air pollution
travels into the country from Asia, where mercury pollution
is extensive. He said that much of the fish Americans eat,
including tuna, is imported from off the coasts of Asia and
South America where the use of mercury in small-scale gold
mining is widespread.

The export ban would go into effect in 2010. The bill, H.R.
1534, also directs the Energy Department to provide
permanent storage for domestic stocks of mercury,
allowing for the safe disposition of some 1,500 tons of
mercury still in use at plants in this country.

-snip-

Read more: http://www.guardian.co.uk/worldlatest/story/0,,-7075195,00.html

[eppur_se_muova]

1. Mercury is also released into the Amazon by this kind of mining.

Mercury Rising

Deforestation and gold mining in the Amazon basin cause the release of toxic metal.

One of the less well known effects of soaring gold prices in the late 1970s was the creation of a gold rush in the Amazon basin. While price fluctuations from $100/oz to more than $800/oz literally enriched the lives of many people, the downstream environmental and health effects of gold mining in South America has potentially impoverished the lives of thousands of locals.

Part of the problem stems from how the gold is pulled from the ore. Across Brazil, thousands of garimpieros, itinerant gold miners, remove ore by washing a rock face with a high-pressure stream of water. The ore is then broken down in a hammer crusher, and the gold-bearing ore is sluiced with mercury in a process known as amalgamation. The amalgam is filtered manually and then retorted to release the mercury from the gold. The mercury vapor that results is distilled and reused, although a small fraction remains bound to the gold, to be released by the gold dealers during processing.

Although much of the mercury is recovered in the amalgamation process, it has long been believed that losses due to dumping or evaporation, about 100–150 tons/yr, were the main cause of environmental mercury contamination. Numerous studies supported this theory, showing astronomical levels of mercury in the soils and rivers surrounding the mining districts. There was also the medical evidence of mercury contamination in the garimpieros (see box, “The Mercurial Tea Party”).

Curses, Soiled Again
Marucia Amorim, a cytogeneticist at the Federal University of Pará (Belem, Brazil), was interested in the high mercury levels that she was finding in Brazilian garimpieros and grew concerned when she found similar levels in natives living kilometers from the mines. In 1992, Amorim contacted Donna Mergler, a neurotoxicologist at the University of Québec at Montréal (UQAM) who studied the effects of occupational exposure to environmental contaminants and, together with Marc Lucotte, director of UQAM’s Institute of Environmental Sciences, established a joint project to study the Brazilian mercury situation.
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more: http://pubs.acs.org/subscribe/journals/tcaw/10/i03/html/03willis.html