Dietary exposure assessment for arsenic and mercury following submarine tailings placement in Ratatotok Sub-district, North Sulawesi, Indonesia

摘要

The Mesel gold mine in the Ratatotok Sub-district operated between 1996 and 2004 with tailings disposal via an engineered submarine tailings placement (STP) into Buyat Bay. This operation raised concerns of increased levels of arsenic (As) and mercury (Hg) associated disease in the local communities from consumption of seafood contaminated with anthropogenic As and Hg. This report uses the dietary exposure to As and Hg, from local fishermen and market-purchased Codex "as consumed" and environmental fish results from the pre-mining baseline (1990-1995), the mine operational (1996-2004) and post-closure monitoring (2007-2016) to examine the potential health effects. The Ratatotok Subdistrict consumers total As average daily intake from fish was between 152 and 317 mu g/day (adults) and 58 and 105 mu g/day (infants). The average daily intake of inorganic arsenic (As-i) from the dietary staples fish and rice and drinking water consumption was 77 mu g/day (adults) and 35 mu g/day (infants) at Buyat Pantai and 39 mu g/day (adults) and 19 mu g/day (infants) at Ratatotok township. Fish consumption contributed 8.2% (adults) and 6.5% (infants) to total daily As; intake. Average Hg intake from fish consumption, exceeded the FAO WHO PTWI for methylmercury (MeHg) for all age and gender groups at Buyat Pantai 4.6 mu g/kg bw/wk (adults) and 7.3 mu g/kg bw/wk (infants) and for the infants at Buyat village and Ratatotok township (2.5 and 2.8 mu g/kg bw/wk respectively). The Manado City consumers had average intakes below the MeHg PTWI. The Hg exceedances resulted from the high fish consumption in coastal communities and not elevated levels of Hg in fish. Hg exposure levels from the pre-mining baseline, Mesel STP operation and post-closure monitoring, confirmed that exceedances were unrelated to the tailings deposited into Buyat Bay. (C) 2017 The Authors. Published by Elsevier Ltd.