云南某铅锌矿区周边农田土壤Cd、Pb分布特征及风险评价

Pollution and Health Risk Assessment of Cadmium and Lead in Cultivated Soils and Crops Surrounding a Lead-Zinc Mine in Yunnan Province

通过大田调查云南省某铅锌矿区周边农田的土壤及农作物(马铃薯和玉米)中重金属Cd、Pb含量,对该区域重金属污染现状进行评价,结果表明:该区域内土壤中Cd和Pb平均含量分别为12.93、2 246.48 mg·kg-1,总体污染程度属于重污染;马铃薯内Cd、Pb含量分别为1.41、11.45 mg·kg-1,玉米籽粒中Cd、Pb含量分别为1.18、12.50mg·kg-1。土壤重金属和土壤理化性质间的关系复杂,Cd与Pb之间呈极显著正关系,有效态Cd与总P、速效P呈极显著正相关关系;当pH≤6.5时,全量Cd和全量Pb与总P、速效P呈极显著正相关关系。该区域的土壤和食用作物已对当地居民的健康构成威胁。

Mining activities have contaminated the surrounding soils and crops. A field investigation was conducted in a lead-zinc mine in Yunnan Province to determine concentrations of Cd and Pb in cultivated soils and crops （potato and maize） and to evaluate their health risk. The average contents of Cd and Pb in soils were 12.93 mg .kg^-1 and 2 246.48 mg.kg^-1, respectively, belonging to heavy pollution. The con- tents of Cd and Pb in plants were respectively 1.41 mg.kg^-1 and 11.45 mg.kg^-1 in potato and 1.18 mg.kg-1 and 12.50 mg.kg^-l in maize. Significant positive relationship was observed between soil Cd and soil Pb contents, and between soil available Cd and soil total P content and available P contents. At soil pH ≤6.5, total Cd and Pb were significantly positively correlated with total P and available P. The present results indicate that soil and crop contamination by heavy metals from mining has threatened the health of local residents.