Citarum, Kalimantan world’s most polluted

As for Kalimantan, the report said that much of the pollution there had come from the vast small-scale gold mining in the area that utilized mercury in the gold extraction process.

The mercury, which is burned off during the smelting process, released toxic chemicals into the air and waterways, where it might accumulate in fish and water, it said.

Greenpeace toxin-free water campaign manager Ahmad Ashov said the report showed that the government lacked in its efforts to control the use of toxic materials in industry.
http://www.thejakartapost.com/news/2013/11/06/citarum-kalimantan-world-s-most-polluted.html