渭河流域关中段地表水重金属的污染特征与健康风险评价

由于重金属的毒理性及其对水生生态系统的重要影响,水生环境的重金属污染已成为全世界关注的问题.渭河是黄河的第一大支流,近年来随着沿岸社会经济的发展,渭河的水质受到严重的威胁,但是对渭河流域地表水重金属的污染状况缺乏全面评估.以渭河流域关中段为研究区域,采集了该流域35个地表水样品,检测了12种重金属元素(Cr、Mn、Fe...

Pollution Characteristics and Health Risk Assessment of Heavy Metals in Surface Water in Guanzhong Section of the Weihe River Basin

Due to the toxicity of heavy metals and their significant impact on aquatic ecosystem,heavy metal pollution in the aquatic environment has become a worldwide issue.The Weihe River is the first major tributary of the Yellow River and its water quality has been seriously deteriorated in recent years during the socio-economic development of the basin.However,there is a lack of comprehensive assessment of heavy metal pollution in surface waters of the Weihe River Basin.In this study,35 surface water samples were collected from the Guanzhong section of the Weihe River Basin,and 12 heavy metal elements(Cr,Mn,Fe,Ni,Cu,Zn,As,Hg,Pb,Al,V and Ca)were analyzed.The pollution characteristics and health risks of heavy metals in surface waters were studied using multivariate statistical methods and health risk evaluation models.Results showed that the average concentration of 12 metals in the surface water followed this order:Ca>Fe>Cr>Al>Zn>V>Pb>Cu>As>Hg>Mn>Ni.Fe and Hg concentrations exceeded the corresponding water quality standard of China.Inverse Distance Weighted Interpolation was used to derive the spatial distribution of heavy metals in surface waters.It was found that the most serious polluted areas were Chang’an and Huazhou districts.Four principal components were obtained based on load analysis results.Cr,Mn,Cu,As,Pb,Al and V were included in the first principal component and were mainly influenced by industrial and agricultural sources.Fe,Ni and Ca appeared in the second principal component,mainly influenced by the geological environment and the soil formation process;Hg and Zn were in the third and fourth principal components,respectively.Hg was mainly influenced by urban production and living,while Zn was mainly from geochemical sources.A health risk evaluation showed that the annual average health risk of heavy metal from drinking water was higher than that via dermal exposure,indicating that drinking water was the main exposure route.The annual average health risk for adults and children due to carcinogenic elements(i.e.,Cr and As)ranged from 10^?8-10^?6 a^?1;and the risk due to non-carcinogenic elements(i.e.,Mn,Fe,Ni,Cu,Zn,Hg,Pb,Al,and V)ranged from 10^?14 to 10^?9 a^?1.The carcinogenic risk was the main factor affecting the annual average health risk for adults and children.Cr was the main element that impacted the annual average health risk for the population.The annual average health risk values caused by metal elements were in the range of 10^?13–10^?11 a^?1.The results of this study provide a scientific basis for preventing and controlling heavy metal pollution in surface waters and improving water safety of the Weihe River Basin.