黄河包头段灌区玉米重金属污染及人群健康风险评价

Heavy metal pollution of corn and human health risk assessment in Baotou section of the Yellow River

【目的】对黄河包头段三大国控断面地区的土壤和玉米中重金属Cu、Zn、Pb、Cd和Mn的污染程度和人群健康风险进行评价,为当地居民食用农作物的健康风险预防提供参考。【方法】利用ICP-MS对土壤和玉米中的重金属含量进行测定,采用土壤污染负荷指数、单一金属危害商数和综合金属危害指数对当地成人和儿童食用玉米的健康风险进行评价。【结果】包头段黄河灌区三样地土壤和玉米中重金属的含量排序基本一致,其中以Zn和Mn的含量较大,Cu、Pb和Cd次之,且均未超标。土壤负荷指数(PL1)和玉米的综合危险指数(HI)排序为:画匠营子>昭君坟>磴口,Zn、Cu和Mn的贡献较大。生物富集指数BCF值Cd、Zn和Cu较大。与成人相比,儿童更易遭受因摄食玉米导致的重金属健康风险。【结论】包头段黄河灌区农田土壤受到重金属污染的程度较轻,但对当地居民造成一定的潜在健康风险,尤其以Cu、Zn和Mn对人体的健康风险较大。

[Objective]The present experiment was conducted to evaluate heavy metals（Cu, Zn, Pb, Cd and Mn） contamination in corn （Zea mays L. ） from three state-controlled Baotou section of the Yellow River, in order to provide references for health risk prevention of edible crops for local residents. [ Method ]The contents of heavy metals were determined by using ICP-MS, and the health risks of adults and children eating corn were assessed using soil pollution load index, single heavy metal hazard quotient and comprehensive heavy metal hazard index. [Result ]The results showed that, in three sampling area of Baotou section of the Yellow River, the order of different heavy metals contents in soil was consistent with that in corn. Among determined heavy metals, Zn and Mn contents were the highest, followed by Cu, Pb, and Cd.contents, while all of them didn＇t exceed limits of surface water quality standard of China. The order of soil pollution load index（PLI） and comprehensive hazard index（HI） were from the highest to the lowest as follows： Huajiangyingzi 〉 Zhaojundao 〉 Dengkou, it was mainly caused by Zn, Cu and Mn. The bio-concentration factor （BCF） of Cd, Zn and Cu were the highest. Furthermore, children were more likely to suffer potential risks of heavy metals from corn than adults. [Conclusion]The farmland soils of irrigation district in Baotou section of the Yellow River are just slightly contaminated by heavy metals. However, it can cause some potential health risks for local residents, especially Cu, Mn and Zn with the highest health risks.