云南省汤池地热水中砷的健康风险评价

Health Risk Assessment of Arsenic in Geothermal Water at Tangchi Town,Yunnan Province

以美国环保总署推荐使用的污染场地健康风险评价方法为基础,首次结合砷的形态,对云南汤池地热水中砷对人群产生的健康风险进行了评价。结果表明,地热水中总砷含量为0.165 5 mg/L,其中As3+和As5+分别占64%和36%。砷的非致癌总风险指数为75.73,致癌总风险为1.10×10-2,可对人体健康产生极强的非致癌和致癌危害。饮用途径是产生风险的最主要的暴露途径,贡献量达90%以上。As3+产生的健康风险约为As5+的107倍,占总风险的99.1%。形态组成极大地影响着砷的健康风险。虽然,该研究的计算结果存在一定不确定性,但对将污染物形态组成纳入到健康风险评价中的研究具有重要参考意义。

Based on the evaluation method for health risk assessment of contaminated sites recommended by U. S. Environmental Protection Agency, in combination with the arsenic speciation for the first time, the health risk of geothermal water arsenic pollution at Tangchi Town, China was evaluated. Results showed that total arsenic concentration in geothermal water was 0. 165 5 mg/L, with As3＋ and AsS＋ proportions approximately 64% and 36% respectively. Arsenic could produce strong non-carcinogenic and carcinogenic hazards to human health, with non-carcinogenic index of 75.73 and carcinogenic index of 1.10 × 10-2. The main exposure way was the drinking water, which accounted for more than 90%. Health risk caused by As3＋ was about 107 times more than As5＋ , accounting for 99.1% of the total risk. Arsenic speciation greatly impacted health risk associated with arsenic exposure. Although the results had some uncertainties, they were important for incorpora- ting contamination speciation into health risk assessment.