广州市农村菜地土壤镉污染状况及健康风险评价

Cadmium pollution in vegetable soils in rural areas of Guangzhou City and health risk assessment

目的检测广州市农村菜地土壤镉含量,评价镉污染状况和人群暴露健康风险。方法2015-2018年,采集367份菜地土壤样品,检测镉和p H值,评价镉污染状况,用美国环境保护所(USPEA)健康风险评价模型评价镉污染对不同人群暴露的健康风险。结果土壤样品多呈酸性,pH值平均值为6.36。镉总合格率为80.65%,平均含量为0.27 mg/kg。pH值与镉呈正相关性。瓜果类土壤的镉含量水平最高,叶菜类土壤pH值高于瓜果类。各类人群的非致癌风险和致癌风险均在可接受范围内。成年男性经呼吸摄入途径的单污染物的非致癌危害指数(HI值)和致癌风险(CR值)最高,儿童经皮肤接触和口摄入途径的HI值最高。结论广州市各区菜地土壤镉污染状况与其经济发展程度有关,菜地土壤的pH值和镉可能与施肥方式关系密切。

[Objective]T o detect the cadmium(Cd)content in vegetable soils in rural areas of Guangzhou City,evaluate Cd pollution status and its potential risk to human health.[Methods]From 2015-2018,totally 367 samples of vegetable soil were collect,to detect the Cd content and pH value,and evaluate Cd pollution status.The health risk assessment model recommended by the United States Environmental Protection Agency(USEPA)was used to evaluate the exposure risk to different populations.[Results]Soil samples were mostly acidic,the average pH value of soil was 6.36.The total qualified rate of Cd was 80.65%,and the average content was 0.27 mg/kg.There was a positive correlation between the pH value and Cd content.The Cd content in the soil of cucurbits vegetables was the highest,and the pH value of the soil of leafy vegetables was higher than that of cucurbits vegetables.Non-carcinogenic risks and carcinogenic risks of various populations were in the recommended maximum acceptable level.The HI and CR values of adult males through the respiratory intake pathway were highest.The HI values of children through skin contact and oral intake were highest.[Conclusion]Cd pollution of vegetable soil in each district of Guangzhou City is related to its economic development,and the pH value and Cd content of vegetable soil may be closely related to fertilization mode.