Mercury contamination associated with artisanal gold mining on the island of Mindanao, the Philippines

摘要: The Agusan River basin of eastern Mindanao, the Philippines, hosts several centres artisanal gold mining, most important which, Diwalwal, is a significant producer in global terms. An investigation environmental impacts mining system, with particular reference to mercury contamination, was initiated 1995 following reports incidents human Hg poisoning province Davao del Norte. Results show drainage downstream Diwalwal characterised by extremely high levels both solution (maximum 2906 micrograms/l) and bottom sediments (> 20 mg/kg). Filtered surface water exceed WHO Drinking Water guideline US-EPA Quality Criteria for Protection Aquatic Life distance more than 14 km, including channel sections utilised fishing potable supply. Environment Canada sediment quality Toxic Effect Threshold exceeded km. Hair data indicate that ballmill CIP plant operators processing contaminated tailings at Mindanao's principal beneficiation centre, Apokon, may be subject enhanced occupational exposure. It appears wider population this area has not been affected.