摘要:
为调查与评价包头市南部旧工业区周边农田土壤和农作物的镉、铅和锌元素特征,分析测试了土壤及农作物根系土和籽实重金属含量,参照相应标准进行了污染评价,运用污染指数法、生物富集系数和人体健康风险指数等方法开展了重金属元素风险评估及来源解析。结果表明:区内土壤环境质量以清洁土壤为主,污染土壤主要分布于旧排污渠两侧;根系土超标点位也主要分布在旧排污渠周边;重金属元素形态中碳酸盐结合态、铁锰结合态和残渣态占比较高,可交换态(水溶态、离子交换态)占比较低,大部分农作物籽实样品呈正常和低富集特征;与其他农作物比较,向日葵籽实对镉、铅和锌具有超强吸附性,对儿童和成人均存在明显的非致癌和致癌健康风险。
Abstract:
To investigate and assess the characteristics of cadmium, lead, and zinc in the soil and crops in the farmland around the old industrial area in the south of Baotou City, this study analyzed and tested the heavy metal content in soil, crop root soil, and seeds, assess the pollution according to relevant standards, and conducted the risk assessment and source analysis of heavy metals using the pollution index, the bioconcentration factor, and human health risk index. The results are as follows:Regarding the soil environmental quality, the soils in the study area are dominated by clean soils, with the polluted soils distributed primarily on both sides of the old sewage canals.The sites of over-limit root soils are also primarily distributed around the old sewage canals.Among the heavy metal morphologies, carbonate-bound, Fe-Mn-bound, and residue heavy metals account for relatively high proportions, while exchangeable heavy metals (water-soluble and ion-exchange) account for relatively low proportions. Most of the seed samples exhibited normal and low enrichment of heavy metals. Compared with other crops, sunflower seeds showed super adsorptivity of cadmium, lead, and zinc, posing significant non-carcinogenic and carcinogenic health risks to children and adults.
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