湘中某矿区地下水重金属污染特征及健康风险评估

Heavy Metal Pollution Characteristics and Health Risk Assessment of Groundwater of a Mine Area in Central Hunan

以湘中某矿区地下水为研究对象,对矿区14口监测井15项重金属指标开展监测分析。结果表明,矿区地下水中As、Sb、Co、Fe和Mn 5项重金属指标超标,超标率分别为14. 3%、64. 3%、50. 0%、10. 7%和14. 3%;最大超标倍数分别为5. 4、30. 4、0. 9、34. 0和18. 3,地下水中Sb污染最严重。污染评价结果表明研究区地下水在平水期极重污染占比达到78. 5%,丰水期污染相对较轻,极重污染占比为50%。研究区地下水污染健康风险评估确定的主要健康风险指标为As、Sb、Co,主要污染途径为饮用水。由地下水健康风险评估模型得到研究区地下水As致癌风险最大,风险值为1. 08×10-3~2. 89×10-3,远超最大可接受致癌风险限值; As、Sb和Co的最大非致癌危害商分别为1. 48×102、89. 2和69. 0,均超过可接受水平,研究区地下水饮用水途径对当地敏感人群的健康构成危害。

Taking groundwater of a mining area in central Hunan as the research object,concentrations of 15 heavy metals in 14 monitoring wells in the mining area were monitored and analyzed.The results show that As,Sb,Co,Fe and Mn concentrations in the groundwater were 14.3%,64.3%,50.0%,10.7%and 14.3%greater than the standards of GB/T 14848-2017 and GB 3838-2002 respectively,with the maximum concentrations of 5.4,30.4,0.9,34.0 and 18.3 times of the standards.The significantly greater concentrations of Sb indicated that the pollution of Sb in the groundwater is the most serious.The results of the pollution assessment show that the proportion of heavy pollution of the groundwater in the mining area was 78.5%in dry season,while the proportion of heavy pollution was 50%in the wet season.The possible health risk of the polluated groundwater to local inhabitants were assessed based on the the groundwater health risk assessment model.The results show that the health risk of the polluted groundwater was mainly from As,Sb and Co via consumption.The carcinogenic risk value of As via consumption was in the range of 1.08×10^-3-2.89×10^-3,which far exceeded the limit for acceptable maximum carcinogenic risk level.The maximum non-carcinogenic hazard quotient of As,Sb and Co were 1.48×10^2,89.2,69.0,respectively,all above the acceptable level,which can be harmful to the health of the local sensitive population through drinking groundwater.