Heavy metal distribution in mining areas has always been a hot research topic due to the special environment of these areas. This study aims to explore the impact of heavy metal pollution on soils and crops in the study area, ensure the safety of local crops and the health of local residents, and provide a basis for the subsequent environmental restoration and the prevention and control of environmental pollution. Based on the analysis of the heavy metal concentrations in local soils and crops, the study investigated the spatial distribution, pollution degrees, and potential ecological risks of heavy metals in the farmland of a mining area in the southeastern Nanyang Basin, Henan province, China explored the sources of heavy metals and assessed the health risks caused by crop intake. The results of this study are as follows. The root soils of crops in the study area suffered heavy metal pollution to varying degrees. The degree of heavy metal pollution in maize fields is higher than that in wheat fields, and both types of fields suffer the most severe Cd pollution. Moreover, the root soils of different crops suffer compound pollution. The root soils in the maize fields suffer severe compound pollution at some sampling positions, whose distribution is similar to that of the mining area. Cd poses the highest potential ecological risks among all heavy metals, and the study area mainly suffers low and moderate comprehensive potential ecological risks. The principal component analysis (PCA) shows that the distribution of Zn, Cd, Pb, and As in soils of the study area is mainly affected by anthropogenic factors such as local mining activities; the distribution of Cr and Ni is primarily controlled by the local geological background; the distribution of Hg is mainly affected by local vehicle exhaust emissions, and the distribution of Cu is influenced by both human activities and the geological background. Different cereal crops in the study area are polluted with heavy metals dominated by Cd and Ni to varying degrees, especially wheat. As indicated by the health risk assessment results, the intake of maize in the study area does not pose significant human health risks; however, Cu has high risks to human health, and the compound heavy metal pollution caused by the intake of wheat in the study area poses risks to the health of both adults and children. Overall, the soils and crops in the study area suffer a high degree of heavy metal pollution, for which mining activities may be the main reason.
由于矿区环境的特殊性,矿区重金属分布一直是研究的热点。本研究旨在探讨重金属污染对研究区土壤和农作物的影响,保障当地农作物的安全和当地居民的健康,为后续环境修复和环境污染防治提供依据。本研究在分析当地土壤和农作物中重金属浓度的基础上,调查了河南省南阳盆地东南部某矿区农田中重金属的空间分布、污染程度和潜在生态风险,探索了重金属的来源,评估了农作物摄入重金属对健康造成的风险。研究结果如下。研究区农作物根系土壤受到不同程度的重金属污染。玉米田的重金属污染程度高于小麦田,而这两类田地的镉污染最为严重。此外,不同作物的根系土壤也受到复合污染。玉米田的根系土壤在部分采样位置受到严重的复合污染,其分布情况与矿区相似。在所有重金属中,镉的潜在生态风险最高,研究区主要遭受低度和中度的综合潜在生态风险。主成分分析表明,研究区土壤中 Zn、Cd、Pb 和 As 的分布主要受当地采矿活动等人为因素的影响,Cr 和 Ni 的分布主要受当地地质背景的控制,Hg 的分布主要受当地汽车尾气排放的影响,Cu 的分布受人类活动和地质背景的双重影响。研究区内不同的谷类作物都受到不同程度的重金属污染,其中以镉和镍为主,尤其是小麦。健康风险评估结果表明,研究区玉米的摄入量不会对人体健康造成重大风险;但铜对人体健康的风险较高,研究区小麦的摄入量造成的复合重金属污染对成人和儿童的健康都有风险。总体而言,研究区的土壤和农作物受到了严重的重金属污染,采矿活动可能是主要原因。