某铁龙和槽对坑尾矿区酸性矿山废水中重金属污染健康风险评价

Preliminary evaluation on health risk of heavy metal contamination of Acid Mine Drainage from Tielong and Caoduikeng Tailings,Dabaoshan Mine

目的初步评价粤北某铁龙和槽对坑尾矿区酸性矿山废水(AMD)中Cd、Zn、Cu、Mn、Ni五种重金属污染的健康风险。方法采用原子吸收分光光度法测定AMD中Cd、Zn、Cu、Mn、Ni的浓度,应用美国环保局推荐的健康风险评价模型对某铁龙和槽对坑尾矿区AMD中上述五种重金属污染进行健康风险评估。结果排放口或最近排放口AMD中Cd、Zn、Cu、Mn浓度均超污染物最高允许排放浓度。两尾矿区AMD中Mn、Ni、Zn元素饮水途径危害健康平均个人年风险可忽略不计,致癌重金属Cd元素饮水途径危害健康平均个人年风险均高于国际辐射防护委员会(ICRP)推荐最大可接受风险水平(5.0×10-5/a);两尾矿区AMD经饮水途径危害健康年平均总风险为1.64×10-4/a和1.48×10-4/a,其中Cd对总风险贡献率分别为98.18%和97.3%。结论 Cd是两尾矿区主要健康风险污染物,其健康风险水平已达不容忽视水平,应将其作为首要环境健康风险管理控制指标和首要治理对象。

Objective To preliminarily evaluate the health risk of Cd,Zn,Cu,Mn and Ni contamination of acid mine drainage（ AMD） from Tielong and Caoduikeng tailings,Dabaoshan mine. Methods The concentrations of Cd,Zn,Cu,Mn and Ni in AMD from Tielong and Caoduikeng tailings,Dabaoshan mine were analyzed by atomic absorption spectrophotometry,and health risk was assessed using US EPA health risk assessment model. Results According to the quality standard of drinking water in China,the results indicated that concentrations of Cd,Zn,Cu and Mn in AMD exceeded the relevant standards. The results for health risks assessment indicated that the average health risk associated with Mn,Ni and Zn in AMD from the two tailings were negligible,and the average health risk associated with Cd was much higher than the maximum allowance levels recommended by ICRP. The total health risk per year by drinking water in AMD from the Tielong and Caoduikeng tailings was 1. 64 × 10- 4/ a and 1. 48 × 10- 4/ a,respectively.The contribution rate of Cd to the total health risk was 98. 18% and 97. 3%,respectively. Conclusion Cd should be considered as the prior pollutant to be controlled in the protection of drinking water source of Tielong and Caoduikeng tailings. The influence of Cd on public health has already reached a considerable level. Therefore,Cd in AMD should be regarded as the primary environmental health risk control index,and first improvement target.