西南山地煤矿区耕地土壤-农作物重金属富集及健康风险评价

为了解西南某典型山地煤矿区周边农田土壤、农作物重金属的富集情况及对当地人群健康的影响程度,采集矿区周边农田土壤样品和对应的农作物样品,测定重金属Cr、Mn、Zn、As、Pb的含量。运用Nemero指数法、潜在风险指数法对土壤重金属的污染程度进行评价；采用靶标危害系数法(THQ)评价农作物重金属对人体的健康风险。结果显示,Cr、Mn、Zn、As、Pb分别是背景值的1.81、1.90、2.89、1.30、0.86倍,处于轻度污染级别,轻微危害程度。农作物重金属Cr、Pb和As含量的超标情况较严重,Zn的含量超标相对较小。各农作物富集的重金属对人体的健康风险大小为：高粱>玉米>白菜>葱>辣椒。农作物重金属对儿童健康的危害均达到了慢性中毒；对成人健康的影响,高粱处于慢性中毒,其它农作物重金属处于产生较大影响的危害程度。农作物重金属与土壤重金属的相关性分析表明,农作物重金属的含量与土壤重金属全量并无线性关系；各重金属在农作物中的转移能力不同；Pb,As在农作物中的转移能力较大,而Cr相对较小。鉴于矿区重金属的富集情况,应尽快采取修复治理措施,为保证当地人群健康,建议当地居民不再食用和种植富集重金属严重的高粱、玉米农作物。

Heavy metals enrichment and health risk assessment of cultivated soil-crops in mountainous coal mining areas of southwest Chinans

To understand the accumulation of heavy metals in soils and crops around a typical mountainous coal mine area in southwest China and its influence on the health of local population.Soil samples and corresponding crop samples were collected around the mining area, and the contents of Cr, Mn, Zn, As and Pb were determined. Nemero comprehensive pollution index and potential ecological risk index were used to evaluate the pollution degree of soil.Health risk assessment of heavy metal enrichment in crops was carried out by using target hazard quotient methods.The results showed that the contents of the five heavy metal elements measured were all higher than the background value of heavy metal elements in the soil of Guizhou, Cr, Mn, Zn, As and Pb were 1.81, 1.90, 2.89, 1.30 and 0.86 times of the background value respectively. The heavy metal elements in the soil were at the level of slight pollution with mild harm.In crops, the content of heavy metals Cr, Pb and As exceeds the standard, while Zn exceeds is relatively light. The evaluation results of heavy metals in crops show that the health risks of heavy metals enriched by various crops are in turn. As follows: sorghum > corn > cabbage > onion > pepper. Among the impacts of crops on adults, sorghum is at the level of chronic poisoning, while other crops are at the level of have a great impact on health.The heavy metals of all crops are at the level of chronic poisoning for children.The correlation analysis between heavy metals in crops and soil shows that the content of heavy metals in crops is not related to the total amount of heavy metals in soil.The transfer ability of heavy metals in crops is different, Pb and As have a large transfer capacity in crops, while Cr is relatively weak.For this situation of the accumulation of heavy metals in the mining area, remedial measures should be taken as soon as possible.For the sake of ensure the health of the local population, suggested that local residents no longer eat and plant sorghum and corn which are seriously enriched with heavy metals.