某镍钼矿区周边土壤重金属风险评价及种植蔬菜健康风险评估

Risk Assessment of Heavy Metals in Soil and Health Risk Assessment of Vegetable Growing around Nickel-Molybdenum Mine Area

为调查某镍钼矿区周边土壤重金属(Cd、Pb、Zn、Cu、Ni及Cr)污染情况和周边蔬菜及水稻中重金属含量对居民的影响,在矿区周边采集土壤样品,并采集其周边土壤根际的蔬菜或水稻样品。对土壤中重金属污染潜在生态风险进行评价,利用健康风险评估法对各种蔬菜或水稻判别重金属对人体健康影响程度,并采用生物富集系数法对各种蔬菜或水稻对重金属元素富集情况进行调查。结果显示,与贵州省土壤背景值相比,各个取样点重金属含量均存在超标现象,其中以Ni超标最严重。潜在生态危害趋势为Eri(Cd)>Eri(Ni)>Eri(Cu)>Eri(Pb)>Eri(Zn)>Eri(Cr),17号样点污染最严重,达到强生态危害级别。未发现可对Cd、Cr、Cu、Ni、Pb及Zn有富集能力的蔬菜及水稻,但发现辣椒和萝卜对Cd有较强吸收,水稻、萝卜及玉米对Zn具有较强吸收。结合重金属总量分析及潜在生态风险评价,研究区应注意Ni及Cd污染治理与防治,还应注意Cr及Pb造成的健康风险。

Soil samples and vegetables or rice samples around a Ni-Mo mining area were randomly collected to investigate contamination of heavy metals(Cd,Pb,Zn,Cu,Ni and Cr)in soil and influence of heavy metals content in vegetables and rice on residents.Heavy metal pollution in soil was evaluated by potential ecological risk assessment.Health risk assessment of various vegetables or rice was used to identify impact of heavy metals on human health.Accumulation of heavy metals in various vegetables or rice was investigated by Bioconcentration Coefficient Method.The results show that compared with background values of soil in Guizhou Province,contents of heavy metals in each sample point exceed the standard,of which Ni exceeds the standard to the largest extend.Trend of potential ecological hazards is E i r(Cd)>E i r(Ni)>E i r(Cu)>E i r(Pb)>E i r(Zn)>E i r(Cr).The pollution of sample 17 is the most serious,reaching the level of strong ecological hazards.Vegetables and rice which could enrich Cd,Cr,Cu,Ni,Pb and Zn are not found,but chili and radish have strong absorption on Cd,while rice,radish and maize have strong absorption on Zn.Combined with total amount analysis of heavy metals and potential ecological risk assessment,attention should be paid to control and prevention of Ni and Cd pollution in the study area,and attention should be paid to the health risks caused by Cr and Pb.