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Heavy metal emissions from the pyrite ore roasting for sulfuric acid production can be considerable in some area.A new frontier method of using bulk metal and mineralogical determinations,sequential extractions combined with Zn and Cd isotopic analyses by high-precision MC-ICP-MS is proposed here for tracking pollutant sources in surface sediments from a riverine system,which drains an industrial site of the Yunfu sulfur refining plant,the Western of Guangdong Province,China.The highest metal concentrations were observed 4-6 km downstream from the sulfur refining plant(Tl: 16.73 mg/kg,Cd: 3.84 mg/kg,Pb: 1789mg/kg and Zn: 22809 mg/kg).For most of the studied sediments,metals of Tl,Cd and Zn was mainly retained in the reducible fraction,with Pb in the residual fraction.The isotopic data showed significant fractionations of Zn and Cd isotopes during the production of sulfuric acid.The fluidized-bed furnace bottom slag was characterized by exceptionally heavier delta 114/110Cd(1.71‰)and delta 66/64Zn(0.78‰)than the raw pyrite ore(delta 114Cd: 0.59‰,delta 66Zn: 0.21‰).A strong positive correlation(r2 = 0.97)is found between delta 66Zn and delta 114Cd values preserved in the reducible fractions of the sediments and the pyrite(slag).Sediments proximal to the plant bear remarkably heavier delta 114/110Cd and delta 66/64Zn signatures than the distal background sediment.A binary mixing model shows a quantitative anthropogenic Zn and Cd pollution of 0-75%on sediments by the open-air disposal of pyrite slag from the plant.