四川省Y县稻谷和农田土壤中重金属含量测定及致癌风险评价  

Determination and Carcinogenic Risk Assessment of Heavy Metals in Rice Grain and Paddy Soil in Y County,Sichuan Province

作　　者：任婷[1] 钟文思 赵丽娇[1] 曾毅[1] REN Ting;ZHONG Wen-si;ZHAO Li-jiao;ZENG Yi(Beijing Key Laboratory of Environmental&Viral Oncology,The Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China;School of Chemical and Biomolecular Engineering,Georgia Institute of Technology,Atlanta GA 30332,USA)

机构地区：[1]北京工业大学环境与生命学部环境与病毒肿瘤学北京市重点实验室,北京100124 [2]佐治亚理工学院化学与分子生物工程系,美国亚特兰大GA 30332

出　　处：《化学试剂》2020年第9期1073-1077,共5页Chemical Reagents

基　　金：国家自然科学基金资助项目(21778011);北京市长城学者支持计划项目(CIT&TCD20180308);北京市百千万人才工程培养项目(2019A16)。

摘　　要：建立并优化了高分辨连续光源原子吸收光谱法(HR-CS AAS)测定稻田土壤及水稻可食用籽粒中铬(Cr)、镉(Cd)、铅(Pb)和砷(As)含量的测定方法。4种重金属的方法检出限(LOD)分别为0.025、0.011、0.012和0.006μg/L;土壤标准品回收率98.3%~99.3%,大米粉标准物质回收率为98.4%~99.6%。应用该方法对四川省Y县稻田土壤和稻粒样品中4种重金属元素进行了定量分析,结果表明,土壤样品中重金属平均含量均小于国标农用地土壤风险筛选值,有3.7%土壤样品中Cd超标;稻粒样品中重金属含量平均值都在国标食品中污染物的限量范围内,有15%的稻粒样品中Cr含量超标。采用美国环境保护署(USEPA)建议的致癌风险模型分别对土壤和稻粒中重金属暴露进行了致癌风险评价。结果表明,稻田土壤中重金属经各种途径暴露对人类的致癌风险均在可接受范围内。稻粒中重金属经口摄入对人类的总致癌风险指数为1.48×10-3,潜在致癌风险超出可接受范围。稻谷可食用部分的经口摄入是当地居民暴露于重金属的主要途径;可能是导致当地胃癌高发病率的重要影响因素之一。A method for the determination of chromium(Cr),cadmium(Cd),lead(Pb) and arsenic(As) in paddy soil and edible rice grains by high resolution continuum source atomic absorption spectrometry(HR-CS AAS) was established and optimized.The LOD of four heavy metals were 0.025,0.011,0.012 and 0.006 μg/L,respectively.The recovery of soil standard was 98.3%~99.3%,and that of rice flour standard was 98.4%~99.6%.The method was applied to the quantitative analysis of four heavy metals in the paddy soil and rice grain samples of Y county,Sichuan province.The results showed that the average contents of heavy metals in the soil samples were lower than the national standard agricultural soil risk screening values,while 3.7% of the contents of Cd in soil samples exceeded the standard value.The average contents of heavy metals in the rice grain samples were within the national food pollutants standard limitation,and 15% of contents of Cr in the rice grain samples exceeded the limitation.The carcinogenic risk model proposed by the United States Environmental Protection Agency(USEPA) was used to evaluate the carcinogenic risk of heavy metals in soil and rice grain.The results showed that the carcinogenic risk of heavy metals in paddy soil which were exposed by various ways to human beings was acceptable.The total carcinogenic risk index of heavy metals in rice grains was 1.48×10-3,and the potential carcinogenic risk was beyond the acceptable range.Oral intake of edible parts of rice was the main exposure way of heavy metals for local residents,which may be one of the important factors that cause high incidence rate of gastric cancer in the local area.

关 键 词：重金属 农田土壤 稻谷 致癌风险评价 原子吸收光谱法 

分 类 号：X503[环境科学与工程—环境工程]