Sunday, July 22, 2012

Research Shows Coal Burning Responsible For Arctic's Heavy Metal Pollution

The heavy metals polluting the Arctic have primarily come from the burning of coal in North America and Western Europe, according to a study conducted by researchers from the Desert Research Institute in Reno, Nev., and published in the Proceedings of the National Academy of Sciences. Researchers took an ice core sample from Greenland and analyzed it to determine levels of heavy metal deposits over time. They looked specifically for the metals cadmium, lead and thallium, and were able to measure monthly levels of the contaminants as far back as 1772. The levels of all three pollutants surged between the years of 1850 and 1900, coinciding with the growth of rapid industrialism in North America and Europe. By the early 1900s, all three toxic metals were being deposited at a rate 10 times higher than before the Industrial Revolution. During the worldwide depression of the 1930s, global industrial production slowed, with a corresponding decrease in the rate of heavy metal deposition in the ice. Levels quickly rose again as production increased after the depression. In the 1950s, levels of lead began to rise more rapidly than levels of the other two metals, likely due to growing use of automobiles. By the 1970s, levels of all three pollutants had begun to drop again as Europe and North America adopted clean air laws. Like many organic pollutants, heavy metals bio-accumulate - that is, they build up in the tissues of animals and steadily move up the food chain. Because the diets of Arctic peoples are high in fatty animals such as seals and certain fish, many inhabitants of the Arctic Circle carry bodily pollutant loads many times higher than the global average. Some Arctic people, for example, ingest high enough levels of cadmium to be a risk of kidney damage. Their diets also contain high concentrations of mercury, also emitted during the burning of coal. Mercury and lead are neurotoxins, while thallium was once used in rat poisons. Source -

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