摘要
从新疆喀什市城乡交错带采集20个耕地土壤样品,测定其中Cd、Cr、Ni和Pb等4种重金属元素的含量。采用内梅罗污染指数(NPI)、潜在生态风险指数(RI)、生态风险预警指数(IER)以及健康风险评价模型,对耕地土壤重金属的污染及生态、健康风险进行评估。结果表明:1)研究区耕地土壤Cd、Cr、Ni和Pb平均含量分别超出新疆灌耕土背景值的3.25,1.55,1.1,1.29倍,Cd呈现中度污染,Pb、Cr和Ni呈现轻度污染,NPI呈现重度污染。2)各重金属元素单项生态风险指数平均值从大到小依次为:Cd>Pb>Cr>Ni,均处于轻微风险水平。耕地土壤RI呈现轻微生态风险,IER呈现中等预警态势,Cd对NPI和RI的贡献较大,是耕地土壤主要的污染因子。3)耕地土壤4种重金属通过3种暴露途径的非致癌风险熵(HQ)与非致癌风险指数(HI)均小于安全阈值范围,属于可接受风险水平。Cr是最主要的非致癌风险因子,研究区耕地土壤中Cr对人体的健康风险应当引起重视。
A total of 20 soil samples from farmlands were collected from urban-rural ecotone of Kashgar City,Xinjiang,and the contents of four heavy metal elements（Cd,Cr,Ni and Pb） were determined by standard methods. The pollution and ecological,human risks were analyzed based on Nemerow pollution index（NPI）,potential ecological risk index（RI）,ecological risk warning index（IER） and health risk assessment model. The results indicated that： 1） The average contents of Cd,Cr,Ni and Pb in farmland soils exceeded the background values for irrigation soils in Xinjiang by 3. 25,1. 55,1. 1,1. 29 times,respectively. Cd in farmland soils fell into moderate pollution level,whereas Cr,Ni and Pb fell into light pollution level,and NPI showed a heavy pollution level. 2） The average value of the individual ecological risk index for each heavy metal elements of farmland soils was following as： Cd Pb Cr Ni,which showed light ecological risks. The average value of RI fell into light ecological risk situation,the average value of IERfell into moderate warning situation. Cd had strong influences on NPI and RI of farmland soils in study area,which was the main pollution factor. 3） The non-carcinogenic risk quotient（HQ） and non-carcinogenic risk index（HI） of four metal elements by three exposure pathways were lower than their threshold values,within the limit of the acceptable risk level. Cr was the main non-carcinogenic risk factor. Great attentions should be paid to the health risks of Cr in farmland soils of the study area.
作者
阿吉古丽.马木提
麦麦提吐尔逊.艾则孜
艾尼瓦尔.买买提
AJIGUL Mamut;MAMATTURSUN Eziz;ANWAR Mohammad(College of Geographical Science and Tourism, Xinjiang Normal University, Urumqi 830054, China;College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, China)
出处
《环境工程》
CAS
CSCD
北大核心
2018年第4期160-164,共5页
Environmental Engineering
基金
国家自然科学基金项目(41561073)
关键词
耕地
重金属污染
生态风险
健康风险
城乡交错带
farmland
heavy metal pollution
ecological risk
health risk
urban-rural ecotone
