Sunday, 28 April 2013

Mercury in the environment

Why is mercury hazardous? In the US, the neurotoxin has caused billions of dollars of expenditure on healthcare, causing up to an estimated 6000 heart attacks and 130,000 asthma attacks annually. It’s particularly acute in communities and cultures where there is a large consumption of fish – mercury bioaccumulates in fish and their predators as they move through the food chain. So close to source areas like Japan, eastern India and Uruguay are particularly at risk.
How does it get into the environment?
According to UNEP, in 2010 alone nearly 3000 tonnes of mercury were released into the atmosphere and water systems. Mercury enters the environment by all sorts of pathways – from chemical effluent, as in the case of Chisso, to its inclusion in household items like thermometers, cosmetics, antiseptics, skin lightening creams....
But two of the biggest sources are coal fired power plants and artisanal mining, together emitting around 1100 tonnes per year. Coal itself contains mercury, which is released when the coal is burned. Artisanal gold mining involves using mercury to separate the gold from its ore. This forms a gold-mercury amalgam which is burned off with a torch. It’s simple, requires no training, and is relatively cheap. Mercury is tasteless and odourless, so when it does get into the environment it’s not easy to spot.
Read more.

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