典型汞矿区周边耕地土壤重金属来源解析与农作物健康风险评价  

Sources of soil heavy metals and health risk assessment of crops in arable land at the periphery of a typical mercury mining area

作　　者：余飞 王锐 周皎 张风雷 蒋玉莲 张云逸 朱世林 YU Fei;WANG Rui;ZHOU Jiao;ZHANG Feng-Lei;JIANG Yu-Lian;ZHANG Yun-Yi;ZHU Shi-Lin(Southeast Sichuan Geological Group,Chongqing Bureau of Geology and Minerals Exploration,Chongqing 400038,China;Chongqing Key Laboratory of Land Quality Geological Survey,Chongqing 400038,China)

机构地区：[1]重庆市地质矿产勘查开发局川东南地质大队,重庆400038 [2]重庆市土地质量地质调查重点实验室,重庆400038

出　　处：《物探与化探》2024年第3期847-857,共11页Geophysical and Geochemical Exploration

基　　金：重庆市地质矿产勘查开发局川东南地质大队2023年度自立科研项目(CDNKY-2023003)。

摘　　要：为系统评价矿区周边土壤—农作物—人体系统中重金属的污染风险,为矿区生态风险的分类治理和农作物安全生产提供科学依据,以重庆市典型汞矿区周边耕地土壤和农作物(水稻、玉米和红薯)为研究对象,采用单因子污染指数(P_(i))、内梅罗综合指数(P_(综))和正定矩阵因子(PMF)模型,评估土壤重金属污染程度、生态风险,进行来源解析,并利用美国环保署(USEPA)推荐的人体健康风险评估模型评价居民食用当地主要农作物的健康风险。结果显示,研究区土壤中As、Cd、Cr、Cu、Hg、Ni、Pb和Zn平均值均高于全国和重庆市表层土壤背景值,表明重金属在耕层土壤中较为富集。单因子污染指数显示,矿区周边耕地土壤中Hg、Cd的超标率分别达96.29%和92.59%,水稻、玉米和红薯中分别有16.67%、18.75%和14.28%的样品Cd含量超过国家食品安全标准(GB 2762—2022)。内梅罗综合指数显示P_(综)为1.17~46.05,研究区整体属于轻度—重度污染,重度污染主要位于汞矿区及土法汞冶炼厂周边,以及溶溪河下游。PMF模型分析结果表明,研究区土壤重金属的来源分3种,即自然源、矿业活动源和工矿及农业活动复合源,其综合贡献率分别为47.21%、16.00%和36.79%,Cd、Cr和Ni主要受自然源影响,Hg主要受矿业活动影响,As和Pb主要受工矿及农业的混合源影响,Cu和Zn受自然源、工矿及农业复合源的共同影响。人体健康风险模型显示:无论是成人还是儿童,食用水稻、玉米和红薯均存在复合健康风险,其中食用水稻的风险指数最高,主要的风险因子是As和Cd,并且儿童高于成人。This study aims to systematically assess the pollution risk of heavy metals in the soil-crop-human body system along the periphery of mining areas,thus providing a scientific basis for the classified management of ecological risks and safe crop production in mining areas.Hence,this study examined the soil and crops(rice,corn,and sweet potato)in arable land along the periphery of a typical mercury mining area in Chongqing City.The single-factor pollution index(P_(i)),Nemero composite index(P_(综)),and positive matrix factorization(PMF)model were employed to assess the pollution degree and ecological risk of soil heavy metals for source analysis.Moreover,the human health risk assessment model recommended by the United States Environmental Protection Agency(USEPA)was applied to assess the health risks of local staple crops for residents.The results are as follows:(1)The average contents of As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn in the soil of the study area were all higher than the topsoil background values of Chongqing and China,suggesting that heavy metals are relatively enriched in topsoil;(2)The single-factor pollution index indicates that the over-limit ratios of Hg and Cd in the soil reached 96.29%and 92.59%,respectively,whereas rice,corn,and sweet potato samples with Cd content exceeding the value specified in the national food safety standard(GB 2762—2022)accounted for 16.67%,18.75%,and 14.28%,respectively;(3)The Nemero composite index(P_(综))was between 1.17 and 46.05,suggesting mild to heavy pollution in the study area,with heavy pollution primarily located around the mercury mining area and artisanal mercury smelters,as well as the lower reaches of the Rongxi River;(4)The PMF model analysis demonstrates that the heavy metals in the soil of the study area originate from three sources:natural source(47.21%),mining activities(16.00%),and a mixed source of mining and agricultural activities(36.79%).Specifically,Cd,Cr,and Ni are principally affected by the natural source,Hg by mining activities,As and Pb by the mixed

关 键 词：汞矿区 重金属 土壤—农作物 来源分析 健康风险评价 

分 类 号：X142[环境科学与工程—环境科学] X825