【摘要】 为研究西南地区典型磷矿区土壤中的重金属对人体健康的影响,采集四川省什邡市工业区(穿心店、宏达、双盛)和非工业区(马井)4个采样区的农田土壤,测定了Pb、Zn的全量,研究了Zn的分布特征。采用改进BCR法研究Pb、Zn的形态,采用体外仿生实验研究Pb、Zn的生物可给性,并对土壤中的Pb、Zn进行人体健康风险评估。根据《土壤环境质量农用地土壤污染风险管控标准》(GB15618-2018)中的筛选值,Pb在整体水平上未引起污染,Zn在工业区引起了轻度污染,且工业区Pb、Zn全量较非工业区高。距磷肥厂烟筒排污口下风向距离的分布特征表明,Zn全量在300～400 m达到最大。马井、穿心店、宏达和双盛采样区Pb的生物可给性分别为8.9%、28.8%、18.0%、77.3%,Zn的生物可给性分别为5.1%、7.1%、6.7%、24.5%,工业区Pb、Zn的生物可给性高于非工业区。Pb、Zn均以残渣态为主,Pb的生物可给性与各形态含量无定量相关,但Zn的生物可给性与其酸提取态含量呈显著正相关。采用Pb、Zn全量和生物可给性分析,成人和儿童的健康风险均在可接受范围内,但儿童潜在的健康风险不容忽视。基于重金属全量和生物可给性,工业区土壤中Pb、Zn对成人和儿童潜在的健康风险均高于非工业区,并且Pb对总非致癌风险的贡献分别为96.5%和98.6%,Zn分别为3.5%和1.4%。与用全量相比,用生物可给性修正的模型评估Pb、Zn潜在的健康风险大幅度降低。更多还原

【Abstract】 The possible health risk owing to soil contamination with Pb and Zn for the local populations by the oral intake of the contaminants in Shifang City, Sichuan Province, southwest China was investigated. Farmlands around phosphate fertilizer plants in Chuanxindian and Hongda, and around the industrial park in Shuangsheng were selected as sampling areas. A farmland in Majing was selected as the control area. Total concentrations of Pb and Zn, and the distribution of Zn were determined. The fractions and bioaccessibility of Pb and Zn were studied by the modified method proposed by the Community Bureau of Reference(BCR)and the simple bioavailability extraction test(SBET), respectively. Additionally, the health risk models recommended by United States Environmental Protection Agency(USEPA)were used to assess the health risk owing to Pb and Zn exposure. According to the screening values of Risk Control Standard for Soil Contamination of Agricultural Land in Soil Environment Quality(GB15618-2018), Pb did not cause pollution in the study area, whereas Zn caused slight pollution. The total concentrations of Pb and Zn in the industrial areas were higher than those in the non-industrial area. The highest concentration of Zn was observed at a distance of 300～400 m from the chimney in the direction of the flow of effluents from the chim.ney outlet. In Majing, Chuanxindian, Hongda, and Shuangsheng, the bioaccessibility of Pb was 8.9%, 28.8%, 18.0%, and 77.3%, respectively, and the corresponding values for Zn were 5.1%, 7.1%, 6.7%, and 24.5%, respectively. The bioaccessibility of Pb and Zn in the industrial areas was higher than that in the non-industrial area. Pb and Zn existed mainly in the residual fraction in the sampling areas. There was a significant positive correlation(R~2=0.999 3)between the bioaccessible and the acid-extractable fractions of Zn. However, no such correlation was noted for Pb. Based on both the total concentrations and the bioaccessibility, the health risks of Pb and Zn for both adults and children were within the tolerable limit, but the potential health risk for children could not be overlooked. Moreover, based on the total concentrations and the bioaccessibility, the contributions of Pb for the total non-carcinogenic risk(HI)were 96.5% and 98.6%, respectively.Through the modified models by the bioaccessibility replacing the total concentrations of Pb and Zn, the potential health risks were significantly reduced.更多还原