Assessment of Human Health Risks for Arsenic Bioaccumulation in Tilapia ( Oreochromis mossambicus ) and Large-Scale Mullet ( Liza macrolepis ) from Blackfoot Disease Area in Taiwan

This paper carries out probabilistic risk analysis methods to quantify arsenic (As) bioaccumulation in cultured fish of tilapia (Orechromis mossambicus) and large-scale mullet (Liza macrolepis) at blackfoot disease (BFD) area in Taiwan and to assess the range of exposures for the people who eat the contaminated fish. The models implemented include a probabilistic bioaccumulation model to account for As accumulation in fish and a human health exposure and risk model that accounts for hazard quotient and lifetime risk for humans consuming contaminated fish. Results demonstrate that the ninety-fifth percentile of hazard quotient for inorganic As ranged from 0.77-2.35 for Taipei city residents with fish consumption rates of 10-70 g/d, whereas it ranged 1.86-6.09 for subsistence fishers in the BFD area with 48-143 g/d, consumption rates. The highest ninety-fifth percentile of potential health risk for inorganic As ranged from 1.92 x 10(-4)-5.25 x 10(-4) for Taipei city residents eating tilapia harvested from Hsuehchia fish farms, with consumption rates of 10-70 g/d, whereas for subsistence fishers it was 7.36 x 10(-4)-1.12 x 10(-3) with 48-143 g/d consumption rates. These findings indicate that As exposure poses risks to residents and subsistence fishers, yet these results occur under highly conservative conditions. We calculate the maximum allowable inorganic As residues associated to a standard unit risk, resulting in the maximum target residues, are 0.0019-0.0175 and 0.0023-0.0053 microg/g dry weight for tilapia and large-scale mullet, respectively, with consumption rates of 70-10 g/d, or 0.0009-0.0029 and 0.0011-0.0013 microg/g dry weight for consumption rates of 169-48 g/d.