江苏某市水稻籽粒重金属富集特征及健康风险评价

Heavy metals accumulation characteristics and health risk assessment of rice grain produced in Jiangsu area

为评估食用重金属污染土壤所产水稻对人体健康产生的风险,选取江苏省某市16个乡镇393组水稻籽粒-根际土为研究对象,考察As、Cd、Cr、Hg、Pb的质量浓度和富集特征;利用单因子污染指数法分析水稻籽粒的重金属污染特征,并用健康风险指数(HQ)评估重金属对人体健康的潜在风险。结果表明:Cd的富集系数远高于其他重金属,说明Cd具有更强的迁移性,易从土壤转移至水稻籽粒中。部分水稻籽粒中Cd质量浓度超过《食品安全国家标准食品中污染物限量》(GB 2762-2017)中的标准限值。5项重金属中,仅Cd对暴露人群产生的HQ大于1,是影响人体健康的主要因子。其中,食用无污染和轻微Cd污染土壤所产水稻的HQ小于1,没有健康风险;>2~18岁男性人群食用轻度Cd污染土壤所产水稻的HQ大于1,会产生一定的风险;食用中度及重度Cd污染土壤所产水稻对所有人群的HQ均超过1,HQ最高可达6.32,对当地人群具有较大健康风险,且水稻籽粒重金属摄入对儿童造成的健康风险高于成人。

393 rice grain samples and corresponding rhizosphere soil samples were collected from 16 towns of Jiangsu area to assess the health risk of eating rice grain produced in heavy metal polluted soil.The contents and enrichment characteristic of As,Cd,Cr,Hg and Pb in rice grain and soil samples were analyzed.The single factor pollution index was used to analyze the pollution character of rice grain and hazard quotient(HQ)was calculated to assess potential human health risk.Results showed that bioaccumulation factor of Cd was higher than those of other elements,suggesting the strong mobility in soil and transfer from soil to rice.Concentrations of Cd in some rice samples exceeded“National food safety standard:limits of pollutants in food”(GB 2762-2017).Among the studied heavy metals,the HQ of Cd was predominant risk factor for human and higher than 1.0.The HQ of Cd for rice from uncontaminated-slightly contaminated soil was below 1 for all resident.The HQ of Cd for rice produced from mild contaminated soil was above 1 for male of>2-18 years old and causing ceratin health risk.The HQ of Cd for rice grain produced from moderately-heavily contaminated soil was above 1 for all resident and causing higher health risk.The highest HQ could reach to 6.32 indicating heavy health risk to the local residents via consumption of rice grains.The health risk for children was higher than adults.