广州某农场土壤和植物重金属含量及健康风险评估

摘要

以广州某农场中的植物和土壤为研究对象,采用火焰原子吸收分光光度法对植物和土壤中的6种重金属(Pb、Cu、Ni、Zn、Cr、Cd)含量进行分析,对蔬菜中重金属的人体健康风险进行了评估.结果表明:与国家土壤质量Ⅱ级标准GB 15618-1995 (6.5＜pH＜7.5)相比,所有土壤样品都超过土壤环境质量一级标准.用单因子指数法、内梅罗污染指数法评价了广州某农场中植物、土壤重金属污染程度,单因子评价结果表明,香蕉土中的Cd和Zn为轻微污染;从内梅罗指数评价中可看出芋头土和豆角土为清洁,小白菜土、毛豆土、番薯土为尚清洁,而香蕉土轻度污染.土壤中Zn元素含量最高,Cd元素含量最低,且土壤重金属含量基本上都高于植物.运用THQ(Target Hazard Quotients)靶标危害系数方法进行健康风险评估,结果表明Cr元素对人体健康造成的影响不明显,Pb、Cu对几类人群健康都存在最大的风险.%On the basis of the vegetable and soil in a farm in Guangzhou,the contents of six heavy metals (Pb,Cu,Ni,Zn,Cr,Cd) in plants and soil were analyzed by flame atomic absorption spectrometry.The human health risks of heavy metals in vegetables were assessed.The results showed that compared with the national soil quality standard Ⅱ GB15618-1995 (6.5＜pH＜7.5),all soil samples exceeded the first grade standard of soil environmental quality.Pollution levels of heavy metal of the plant and soil in the farm were evaluated by the single factor index and Nemerow pollution index.The result of the single factor index showed that Cd and Zn in Musa balbisiana Colla soil were slightly polluted.Nemerow index showed that Colocasia esculenta (L.) Schoot.and Vigna unguiculata soil was clean,Brassica chinensis Linn,Glycine max Merr.and Ipomoea batatas (L.) Lam.soil were relatively clean.While Musa balbisiana Colla soil was slightly polluted.The content of Zn in the soil was the highest,the content of Cd was the lowest and the content of heavy metal in the soil was higher than that in the plant.Health risk assessment was evaluated by THQ (Target Hazard Quotients).The results showed that the effects of Cr on human health were not obvious,Pb and Cu had the greatest risk to the health of several groups.