湖南清水塘老工业区重金属污染特征及其在食物链的迁移富集研究OA

Heavy metal pollution in the Qingshuitang old industrial area in Hunan province poses a high risk to human health.To inves-tigate the migration and enrichment characteristics of heavy metals in the food chain of historical industrial and mining wastelands,this study collected 128 food chain samples comprising 16 groups corresponding to different populations.The contents of four heavy metals,including cadmium(Cd),mercury(Hg),lead(Pb),and arsenic(As),were tested in samples such as paddy soil,vegetable soil,rice,veg-etables,drinking water,along with human urine and blood.Then,the migration and enrichment characteristics of heavy metals in the"soil-crop-human"food chain were investigated using the pollution index,Nemerow composite pollution index,and Pearson correlation analysis.The results show that the paddy and vegetable soils both exhibited heavy Cd pollution,heavy to moderate Pb pollution,moder-ate to mild As pollution,and mild Hg pollution.Overall,the paddy soil presented higher comprehensive pollution levels than the veg-etable soil.Moreover,the rice displayed heavy pollution in Cd,Pb,and Hg and mild As pollution.In contrast,vegetables presented se-vere Cd pollution and mild pollution in Hg and As,with no Pb pollution observed.Generally,the comprehensive pollution level of rice was higher than that of vegetables.In addition,humans showed exceedances of standard limits for key biomarkers:Cd in urine(2.73 times),Cd in blood(1.73 times),and Pb in blood(2.73 times).In contrast,the As in blood and Hg in urine were generally below the clini-cal diagnostic limits.Significant correlations were determined between the Cd,Hg,Pb,and As contents in the"soil-crop(rice and vegeta-bles)"and the migration and enrichment of Cd in the"crop(rice and vegetables)-human urine".However,the enrichment of Cd and Pb in human blood followed other migration pathways.No clear enrichment patterns of As and Hg were observed in the"crop(rice and vegeta-bles)-human"transfer,indicating occasional occupational poisoning.These findings will provide a valuable reference for mitigating heavy metal pollution in industrial and mining wastelands and preventing and controlling associated human health risks.