龙江河水体重金属污染状况及健康风险评价

Assessment on the Status and Health Risks of Heavy Metal Pollutions of Longjiang River

关键词:  龙江河  重金属  内梅罗指数法  健康风险评价

Key words:  Longjiang River  heavy metals  Nemero comprehensive index method  health risks

摘要:

[目的]以广西龙江河水体为研究对象,对龙江河地表水体中As、Cd、Zn、Pb、Cu等重金属污染物含量进行分析测定,以阐明龙江河水体重金属污染物的分布特征和风险水平。[方法]运用内梅罗综合指数法、健康风险评价模型对龙江河水质等级和水体中重金属引起的健康风险水平进行评价。[结果]各采样点的重金属含量均符合Ⅱ类水质标准,龙江河13个采样点水质均属重金属未污染状态,水质清洁。龙江河重金属As和Zn的健康风险值大于Cd、Pb、Cu的健康风险值,但均低于最大可接受风险水平5.0×10^-5 a^-1。[结论]龙江河水体重金属综合污染指数与健康风险值所反映的水质状况规律一致,均表现为中下游较上游的结果要稍高一些。As是龙江河水环境产生健康风险的主要污染物质,应该作为龙江河水环境风险管理的重点对象。

Abstract:

[Objective] The purpose of this research is to investigate the quality of the water body of the Longjiang River in Guangxi.Concentrations of heavy metals As,Cd,Zn,Pb and Cu in the water surface of Longjiang River were analyzed to figure out the distribution characteristics of heavy metal pollutants in this area.[Methods] The Nemero comprehensive index method and the health risk assessment model were adopted to evaluate the grade of water quality of Longjiang River and the health risk level imposed by heavy metals in the water.[Results] The concentrations of heavy metals in each sampling point conform to grade Ⅱ according to water quality standards.The water samples collected on 13 sampling points of the Longjiang River are clean and not polluted by heavy metals.The health risk values of heavy metals As and Zn are greater than that of Cd,Pb,and Cu in the Longjiang River,but still lower than the maximum acceptable risk level of 5.0×10^-5 a^-1.[Conclusion] The disciplinarian of the heavy metals distribution in the Longjiang River reveals that the downstream of the river possessed slightly higher values than the upstream,which is consistent per the comprehensive pollution index and the health risk value.As is the major pollutant of the health risk of Longjiang River,and it should be regarded as the key object of environmental risk management of Longjiang River.