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The 10 worst pollution problems in the world

Oct. 16, 2009, 11:21 p.m.
Smelting

Photo: Graham Heywood/iStockphoto

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Metal processing and smelting

Lax regulations on metal smelting and processing contribute to severe pollution problems in nearby communities. The process of extracting metals from ore releases lead, arsenic and cadmium into the air, where they can travel for miles.