吉安县某矿山企业周边农田土壤重金属污染评价及风险评估
Assessment and Risk Evaluation of Heavy Metal Pollution in Farmland Soils Surrounding a Mining Enterprise in Ji’an County

土壤重金属污染是指农业活动中化学用品的使用、工业活动中不正规的污染物排放和自然因素等导致某种重金属物质进入陆地表层土壤后，引起土壤化学、物理、生物等方面特性改变的现象。长此以往进而影响土壤功能和有效利用，甚至危害公众健康或破坏生态环境。位于江西吉安县地区的矿山企业所遗留的废弃矿区存在一系列环境问题，重金属超标会影响周边居民的农田作物的增长和使用，因此有必要对该区域的重金属污染问题及可能存在的健康风险进行评价和评估。基于此，采取69份该矿山区周边土壤的农作物土壤样品为例，利用XRF光谱仪测定这些土壤样品中的重金属含量。针对不同环境介质中的Pb、Cu、Zn、Cr、Cd、As、Ni和Hg等重金属元素，运用单因子污染指数法、内梅罗综合污染指数法、潜在生态危害指数法分析讨论废弃矿区周边农田土壤重金属环境风险评价等问题。结果表明，以《土壤环境质量农用土壤污染风险管控标准(试行)》中国家标准限量作为参考值表明该矿山企业周边农用土壤的重金属含量都存在不同程度的超标，其中主要超标元素有Cd、Ni、Cu、Pb，其中Cd污染的情况最为严重，存在极高生态风险水平，整体上有65%的区域处于极高生态风险水平。
The phenomenon of soil heavy metal pollution refers to the alteration of soil chemical, physical, and biological properties due to the introduction of certain heavy metal substances into the surface layer of terrestrial soil, caused by the use of chemicals in agricultural activities, irregular discharge of pollutants in industrial activities, and natural factors. Over time, this affects soil functionality and effective utilization, and can even endanger public health or damage the ecological environment. The abandoned mining areas left by mining enterprises in Ji’an County, Jiangxi Province, present a series of environmental issues. Excessive levels of heavy metals can affect the growth and usability of crops in the surrounding farmlands, necessitating an evaluation and assessment of the heavy metal pollution and potential health risks in the area. Based on this, 69 soil samples from the agricultural lands around the mining area were taken, and the heavy metal content in these soil samples was measured using an XRF spectrometer. For heavy metal elements such as Pb, Cu, Zn, Cr, Cd, As, Ni, and Hg in different environmental media, the single factor pollution index method, Nemerow comprehensive pollution index method, and potential ecological risk index method were used to analyze and discuss the environmental risk assessment of heavy metals in the farmland soil around the abandoned mining area. The results indicate that, using the national standard limits from the “Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (Trial)” as reference values, the heavy metal content in the agricultural soil around the mining enterprise exceeds the standard to varying degrees, with the main excessive elements being Cd, Ni, Cu, and Pb. Cd pollution is the most severe, presenting a very high ecological risk level, with 65% of the area overall at a very high ecological risk level.