汞矿区周边土壤重金属空间分布特征、污染与生态风险评价

为探明汞矿开采对周边土壤环境及人体健康的影响，在重庆市酉阳县某汞矿聚集区周边采集表层土壤组合样42件，分析了土壤中重金属（Cd、Hg、Pb、As、Cr、Cu、Zn和Ni）的含量及pH，对土壤重金属含量的空间分布特征、污染程度和生态风险进行了研究.结果显示，研究区土壤重金属表层富集明显，参照《土壤环境质量农用地土壤污染风险管控标准（试行）》（GB15618-2018）发现，土壤Cd、Hg、Pb、As和Zn存在不同程度的超标现象.土壤存在一定程度的污染和生态风险，土壤重金属中度-重度污染和强生态风险区均分布在矿点周围，说明矿业活动对土壤环境的影响.土壤Cr、Cu和Ni含量可能受到母岩的风化和成土作用的影响，土壤Hg、Pb和Zn可能受到矿产开采等人为活动的影响，土壤Cd和As同时受到地质背景和人为活动的影响.重金属对成人的健康影响较小，对儿童造成健康风险的概率较大，土壤As是造成人体健康风险的主要贡献因子，8种重金属均以经口摄入途径的贡献率最高.汞矿的开采是造成研究区土壤污染及生态风险的主要原因.

Spatial Distribution Characteristics, Pollution, and Ecological Risk Assessment of Soil Heavy Metals Around Mercury Mining Areas

To ascertain the impact of mercury mining on the surrounding soil environment and human health, 42 surface soil composite samples were collected around a mercury mining area in Youyang County, Chongqing, and the heavy metals (Cd, Hg, Pb, As, Cr, Cu, Zn, and Ni) contents and pH of the soil, the spatial distribution of heavy metals, pollution degree, and ecological risk were studied. The results show that the surface soil layer in the study area is significantly enriched in heavy metals. According to the soil environmental quality risk control standard for soil contamination of agricultural land (GB15618-2018), soil Cd, Hg, Pb, As, and Zn showed different degrees of excess. A certain degree of pollution and ecological risk was also identified in the studied soil. Moderate-to-severe pollution and strong ecological risk areas are distributed around the mining sites, indicating the impact of mining activities on the soil environment. The content of Cr, Cu, and Ni in the soil may be affected by weathering and soil formation from the parent rock; Hg, Pb, and Zn content may be affected by human activities such as mineral mining; and Cd and As content may be affected by both geological processes and human activities. Heavy metals pose less of a health risk for adults but have a greater probability of causing health risks for children. Soil As is the main contributor to human health risks, and the oral intake of the eight heavy metals has the highest contribution rate. The mining of mercury is the main cause of soil pollution and ecological risk in the study area.