矿山湿地表层水中颗粒态和溶解态Pb,Cr影响因子分析及环境风险评价

On Environmental Risk Assessment and Factors Influencing for Dissolved and Particulate Pb,Cr in Surface Water of Mine Wetland

通过1年的监测分析,结果表明,矿山湿地表层水中颗粒态Pb(SPb)、溶解态Pb(DPb)、颗粒态Cr(SCr)和溶解态Cr(DCr)含量空间差异显著.其中MW-1中溶解态、颗粒态Pb含量分别为:0.44μg/L和1.12μg/L,溶解态、颗粒态Cr含量分别为:1.40μg/L和1.96μg/L;MW-2中溶解态、颗粒态Pb含量分别为:0.89μg/L和2.24μg/L,溶解态、颗粒态Cr含量分别为:3.51μg/L和4.91μg/L;且均以颗粒态为主;矿山湿地表层水中颗粒态Pb,Cr季节性变化显著(p<0.05),而季节对溶解态Pb,Cr无显著性影响(p>0.05);溶解态Pb含量冬季最高,夏季最低,颗粒态Pb含量夏季最高,秋季最小.溶解态Cr冬季最低,颗粒态Cr夏季最高.主成分分析表明,前2个主成分累计解释了总因子的55.575%,82.824%,其主要受人类活动污染和自然地球化学因素共同影响.聚类分析表明,各元素可归为三类:其中,pH,DO,BOD5,COD和TSS为一类;DCr,SCr,SPb,TN和DPb为一类;TP单独为一类.采用单因子指数法评价分析,矿山湿地表层水中各水期溶解态铅、铬均未污染;同一水期MW-2的溶解态Pb,Cr的P值均大于MW-1.应用健康风险评价表明,鱼肉中铅、铬食入途径所产生的个人健康危害年风险均低于国际辐射防护委员会(ICRP)推荐的最大可接受水平5×10-5 a-1,不会对暴露人群构成危害.

Surface water samples have been collected from two mine wetland.The results indicate that the charac-teristics of heavy metal species in spatially cause significant differences （p〈0.05）.Dissolved and Particulate Pb （DPb and SPb）average concentrations are 0.44μg/L and 1.12μg/L,Dissolved and Particulate Cr （DCr and SCr）average concentrations are 1.40μg/L and1.9 6μg/L respectively in MW-1 ,while the average concen-trations of DPb and SPb,DCr and SCr in MW-2 were 0.89μg/L,2.24μg/L,3.51μg/L,4.91μg/L,re-spectively.SPb and SCr in seasonally cause significant differences （p＆lt;0.05）.However,season did not cause significant differences （p〉0.05）on DPb and DCr.The average concentrations of DPb and SPb are higher in winter than in summer,higher in summer than in fall respectively.The minimum of DCr average concentrations is in winter.The maximum of SCr average concentrations is in summer.Principal Compo-nent Analysis （PCA）reveals that the cumulative rates of the top two principal components are 55.575%and 82.824%,indicating that the two main sources of heavy metals are human activities and natural geo-chemical.These elements can be classified into three clusters,i.e.,cluster one （pH,DO,BOD5,COD and TSS）,cluster two （DCr,SCr,SPb,TN and DPb）,cluster three （TP）.Analysis of single factor in-dex method,surface water of mine wetland is not contaminated;P value of DPb,DCr in same water peri-od：MW-2 ＆gt; MW-1 .Application of health risk assessment for Pb,Cr in three fish muscle,the total con-sumption risk of the heavy metal is lower than 5.0×10-5 ,as recommended by ICRP.Three fishes are ac-ceptable for people’s consumption.