摘要
[目的]叶面尘中重金属污染情况对区域重金属污染具有指示作用,研究区域叶面尘中重金属分布特征、来源及风险对区域重金属防治具有重要意义.[方法]以晋中市太谷区不同环境功能区、粒径和生活型树种叶面尘为研究对象,采用ICP-MS(等离子体-质谱仪)方法测定叶面尘中重金属的含量,通过相关性及主成分分析方法分析该区叶面尘中重金属的来源,并利用生态风险与健康风险评估模型评估太谷区叶面尘中重金属的风险.[结果]重金属平均含量由高到低分别为 101.52±164.46(锌Zn)、20.60±22.53(铬Cr)、15.70±20.01(铅Pb)、7.06±3.54(砷As)、4.45±3.22(铜Cu)、3.11±2.48(镍Ni)、0.98±1.38(镉Cd)mg/kg,Cd的含量为山西省土壤元素背景值的 9.8倍.叶面尘中重金属含量总体趋势为交通干道>文教区>工业区,PM2.5>PM10,灌木>常绿乔木>落叶乔木.Pb、As和Cd主要来源于汽车尾气的排放,Ni和Cu主要来源于岩石风化和土壤母质,Cr和Zn主要来源于工业废气的排放.重金属的潜在生态危害指数(RI)为281.35,具有中等程度的生态风险.重金属的非致癌和致癌风险值分别为5.68×10-1(成人)和9.19×10-1(儿童)、2.94×10-4和4.84×10-4,无非致癌风险,但具有致癌风险.[结论]镉(Cd)为晋中市太谷区叶面尘中主要污染重金属,由叶面尘重金属引起的生态风险和致癌风险需引起重视.
Abstract
[Objective]The heavy metal pollution in foliar dust serves as an indicator of regional heavy metal pollution,and inves-tigating the distribution characteristics,sources,and risks of heavy metals in foliar dust is of great significance for regional heavy metal pollution control and prevention.[Methods]This study analyzed foliar dust from different environmental functional areas,particle sizes,and tree species in Taigu District of Jinzhong City.ICP-MS(plasma mass spectrometer)method was used to determine the content of heavy metals in foliar dust.The sources of heavy metals in leaf dust of Taigu District were in-vestigated using correlation and principal component analysis.Ecological and health risk assessment models were used to assess the associated risk.[Results]The main findings of this study were as follows:the average heavy metal concentrations,in de-scending order,were 101.52±164.46(Zn),20.60±22.53(Cr),15.70±20.01(Pb),7.06±3.54(As),4.45±3.22(Cu),and 3.11±2.48(Ni)mg/kg.The Cd concentration(0.98±1.38 mg/kg)was 9.8 times higher than the background value of soil elements in Shanxi Province.The overall distribution trend of heavy metal content in foliar dust was:traffic road>cultural and educational area>industrial area;PM2.5>PM10;shrub>evergreen tree>deciduous tree.Pb,As,and Cd were mainly derived from vehicle exhaust emissions;Ni and Cu originated mainly from rock weathering and soil parent material;Cr and Zn were largely contributed to industrial exhaust emissions.The potential ecological hazard index(RI)for heavy metals was 281.35,indicating a moderate ecological risk.The non-carcinogenic and carcinogenic risk values of heavy metals were 5.68×10-1(adults)and 9.19×10-1(children),and 2.94×10-4and4.84×10-4,respectively,which indicated no non-carcinogenic risk but with a carcinogenic risk.[Conclusion]Cd is the main heavy metal contaminant in foliar dust in Taigu District,Jinzhong City.The ecological and carcinogenic risks associated with heavy metals in foliar dust warrant significant attention.
维普
万方数据