天津污灌区小麦和水稻重金属的含量及健康风险评价  

Contents and Health Risk Assessment of Heavy Metals in Wheat and Rice Grown in Tianjin Sewage Irrigation Area, China

作　　者：孙亚芳[1] 王祖伟[1] 孟伟庆[1] 胡蓓蓓[1] 侯迎迎[1] 王子璐[1] 张辉[1] 

机构地区：[1]天津师范大学城市与环境科学学院,天津300387

出　　处：《农业环境科学学报》2015年第4期679-685,共7页Journal of Agro-Environment Science

基　　金：国家自然科学基金(40973078;41301096)

摘　　要：以天津污灌区农作物和土壤为研究对象,采集污灌区内24个小麦和29个水稻样品及其对应的土壤样品,清灌区内10个小麦样品和14个水稻样品及相关的土壤样品,分别采用ICP-AES和原子荧光分析样品中Cd、Cu、Pb、Zn、Cr、As和Hg含量,在此基础上分析评价污灌区土壤重金属污染情况以及污灌区小麦和水稻中重金属可能产生的健康风险。研究结果表明,长期污灌导致重金属在土壤中的聚集,土壤中Cd、Zn和Hg的含量分别为0.46、129.05、0.52 mg·kg-1,超过天津土壤质量二级标准。污灌区小麦和水稻中Pb的平均含量分别为0.14、0.62 mg·kg-1,高于国家食品安全限量标准,对人类健康产生风险,其他重金属元素在小麦和水稻中的平均含量未超过国家食品安全限量标准;水稻样品中Hg、As的平均含量稍高于国家食品安全限量标准。计算结果显示Cd和Zn的转移因子值远高于其他元素,反映其具有更高的活动性,更容易从土壤转移到小麦和水稻子实中。目标风险指数(THQ)估算结果显示单一重金属的THQ值均低于1,表明当地居民对污灌区生长的水稻或小麦的消费基本不产生健康风险;小麦和水稻中As THQ值的和超过1,暗示在食用污灌区生长的水稻和小麦时As可对当地居民的健康产生风险。Sewage irrigation has caused soil heavy metal pollution. In this study, we collected 24 wheat samples and 29 rice samples and corresponding soil samples from sewage-irrigated area and 10 wheat samples and 14 rice samples and corresponding soil samples from clean water irrigation area in Tianjin sewage irrigation area. Concentrations of heavy metals such as Cd, Cu, Pb, Zn and Cr in both crops and soils were determined by inductively coupled plasma atomic emission spectrometry. Concentrations of As and Hg were measured by atomic florescence spectrometry. Results showed that continuous applications of wastewater had led to accumulation of heavy metals in soils. The concentrations of Cd, Zn and Hg in soils were 0.46 mg·kg-1, 129.05 mg·kg-1, 0.52 mg·kg-1,respectively, which exceeded the allowable limits of the second grade standards of soil environmental quality of Tianjin. The concentrations of Pb in wheat and rice were respectively 0.14 mg·kg-1,and 0.62 mg·kg-1, being higher than the safe limits for human consumption and thus having human health risk. Transfer factors of Zn and Cd were higher than those of other elements. Concentrations of heavy metals such as Cd, Zn, and As in some wheat samples and Hg and As in some rice samples exceeded the safe limits of China National Food Standard, suggesting their potential ecological risks to human health.Target hazard quotient(THQ) of individual metal was below 1, implying that heavy metals through consumption of either wheat or rice had little health risks. However, the sum of THQs of As for wheat and rice was above 1, indicating As health risk to the local residents via consumption of wheat and rice.

关 键 词：重金属污染 日摄入量 目标风险指数 健康风险 天津污灌区 

分 类 号：X53[环境科学与工程—环境工程] X82