贵州铅锌矿区土壤和作物重金属生态风险与迁移特征

土壤中积累高含量的重金属对生态环境和人体健康存在潜在风险.以贵州省某铅锌矿区农田土壤和作物为研究对象，运用GIS空间制图分析了重金属的分布与来源，采用潜在生态风险指数(RI)评价了重金属的潜在生态风险，利用美国环保署(USEPA)推荐的人体健康风险评估方法量化了居民暴露于铅锌矿周围土壤重金属的健康风险.结果表明，土壤中ω(As)、ω(Cd)、ω(Cr)、ω(Cu)、ω(Hg)、ω(Ni)、ω(Pb)和ω(Zn)平均值分别为：58、7.9、175、64、0.461、65、1 539和2 513 mg·kg^-1,均显著高于贵州省表层土壤元素背景值.土壤As、Cd、Cu、Hg、Pb和Zn含量在空间分布上极不均匀，其受到了强烈的铅锌矿冶炼等人为扰动.RI评价显示，土壤重金属存在极强、较强等级为主的综合潜在生态风险，Cd为主要的生态风险因子. 22%和10%的玉米籽实样品中Pb和As分别超过了食品安全国家标准中的重金属污染阈值.人体健康风险评价显示，暴露于土壤重金属对成人和儿童存在非致癌健康风险，对儿童存在一定的致癌健康风险.土壤pH值是影响Cd生物有效性和土壤-作物系统C...

Ecological Risk and Migration Patterns of Heavy Metals in Soil and Crops in the Lead-Zinc Mining Area in Guizhou, China

An accumulation of heavy metals in soil poses a risk to the ecological environment and human health. In this study, the concentrations of heavy metals in soil and crops were examined in a lead-zinc mining area in Guizhou Province, China. The distribution and sources of heavy metals were analyzed using GIS spatial mapping. The potential ecological risks of heavy metals were assessed using the potential ecological risk index (RI), and the human health risk assessment method recommended by the United States Environmental Protection Agency (USEPA) was used to quantify the health risk of residents exposed to heavy metals in the soil around lead-zinc mines. According to the results, the average of concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the soil were 58, 7.9, 175, 64, 0.461, 65, 1539, and 2513 mg·kg^-1, respectively, which were significantly higher than the background values in Guizhou Province. It was found that the As, Cd, Cu, Hg, Pb, and Zn concentrations were extremely irregular in the soil and that the concentrations decreased significantly with the distance to the smelters, which were greatly disturbed by human activities. Comprehensive evaluation of soil heavy metals using the potential ecological risk index revealed that the risks of soil heavy metals were pole-strength and strong levels, and Cd constituted the primary ecological risk factor. A total of 22% and 10% of the corn samples contained Pb and As above the heavy metal pollution thresholds in the national food safety standards. According to human health risk assessments, heavy metals in the soil present potential non-carcinogenic risks to adults or children, and pose a potential carcinogenic risk to children. Soil pH was an important controlling factor affecting the bioavailability, migration, and accumulation of Cd in soil-crop systems. This study provides data and theoretical support for the prevention and control of soil pollution in lead-zine mining areas.