石家庄污灌区小麦玉米重金属污染现状及其健康风险评价

发布时间：2018-01-28 13:28

本文关键词： 污水灌溉重金属小麦玉米健康风险主成分分析　出处：《河北医科大学》2015年硕士论文　论文类型：学位论文

【摘要】：目的:探讨污水灌溉、清水灌溉和清水污水混合灌溉对农作物重金属含量的影响;分析和评价石家庄污灌区小麦玉米中重金属Cu、Zn、Cr、As、Cd、Pb和Hg的污染程度及对人群健康的风险大小,为减少污水灌溉对农作物的污染和进行安全性评价提供科学依据。方法:1样品收集以总退水渠两岸5公里内栾城县的自然村为对象,收集各户农民家小麦和玉米,询问灌溉水类型并编号。2样品前处理经粉碎机粉碎后,分装于样品袋,贴上标签,备用;小麦和玉米均通过HNO3-HCl O4湿解消化,待测。3样品测定ICP-MS测定Cu、Zn、Cr、As、Cd和Pb的含量,全自动测Hg仪测定Hg的含量。4样品分析将农作物灌溉方式分为污水灌溉、清水灌溉和清污混灌,应用方差分析评价不同灌溉方式对农作物重金属含量的影响;采用单因子和综合污染指数评价法分析小麦玉米重金属污染程度;借鉴美国国家环境保护局(USEPA)推荐的风险评价模型评估重金属的成人和儿童健康风险;并运用主成分分析对灌溉方式进行综合评价。结果:1农作物重金属超标率分析小麦中Cr和Pb的超标率为100%,Zn、As和Cd的超标率分别为96.23%、92.59%和24.07%,Cu和Hg未超标;玉米中Cr、Pb、As和Zn的超标率分别为96%、92%、66.67%和12.50%,Cu、Cd和Hg未超标。2不同灌溉方式下小麦和玉米重金属含量分析污水灌溉的小麦重金属Zn和Cd的含量高于清污混灌和清水灌溉(P0.05),而不同灌溉方式的其它重金属Cu、Cr、As、Pb和Hg的含量差异不明显(P0.05);清水灌溉的玉米重金属Zn的含量低于清污混灌和污水灌溉(P0.05),其它重金属的含量差异亦不明显(P0.05)。3单因子和综合污染指数评价小麦单因子污染指数排序为PbCrZnAsCdCuHg,分别为3.32、2.08、1.61、1.27、0.78、0.71和0.08。玉米排序为PbCrAsZnCdCuHg,指数分别为2.28、2.14、1.20、0.82、0.38、0.25和0.12。其中,小麦Pb单因子污染指数大于3,属重度污染;小麦和玉米综合污染指数是2.59和1.54,分别属中度和轻度污染。4人群健康风险评价成人与儿童日均暴露量均为Zn最大,Cu次之,Hg最小。只有小麦的致癌重金属Cd和As日均总暴露量为成人大于儿童,其它均为成人小于儿童。致癌重金属As和Cd健康风险大于其它非致癌重金属的风险;非致癌风险儿童高于成人,致癌风险则是成人高于儿童,但其风险水平都在最大风险可接受范围内(非致癌:7?10-5;致癌:3.5?10-3)。5灌溉方式的综合评价不同灌溉方式小麦重金属污染程度为污水灌溉清污混灌清水灌溉,玉米为清污混灌清水灌溉污水灌溉。结论:1小麦重金属污染较玉米严重,分别为中度和轻度污染,主要受Cr和Pb污染。2小麦Zn、Cd和玉米Zn含量均为污水灌溉高于清污混灌和清水灌溉。3小麦健康风险高于玉米,As、Cd健康风险高于Cu、Zn、Cr、Pb和Hg,非致癌风险儿童高于成人,致癌风险成人高于儿童。4小麦重金属污染程度为污水灌溉清污混灌清水灌溉,玉米受影响不明显。
[Abstract]:Objective: to study the effects of sewage irrigation, water irrigation and mixed irrigation with clean water on the heavy metal content of crops. To analyze and evaluate the pollution degree of the heavy metal Cu ~ (2 +) Zn ~ (2 +) Cr ~ (2 +) ~ (2 +) in wheat and maize in Shijiazhuang sewage irrigation area and the risk to the health of the population. In order to reduce the pollution caused by sewage irrigation and to evaluate the safety of crops, methods: 1 sample was collected from the natural village of Luancheng County within 5 kilometers of the total backwater channel. To collect wheat and corn from farmers, ask about irrigation water type and number .2 sample pretreatment after pulverized by pulverizer, pack it in sample bag, label it, and reserve it; Wheat and maize were digested by HNO3-HCl O _ 4, and the contents of CD and Pb were determined by ICP-MS. The method of crop irrigation was divided into sewage irrigation, clean water irrigation and sewage mixed irrigation. Variance analysis was used to evaluate the effects of different irrigation methods on crop heavy metal content. The degree of heavy metal pollution in wheat and maize was analyzed by single factor and comprehensive pollution index evaluation method. The risk assessment model recommended by USEPA was used to assess the health risks of heavy metals in adults and children. The principal component analysis (PCA) was used to evaluate the irrigation methods. Results the excess rate of heavy metals in wheat was 100%. The exceeding rates of as and CD were 96.23% and 24.07%, respectively. The exceeding rates of CrPbAs and Zn in maize were 960.92and 66.67% and 12.50%, respectively. Analysis of heavy Metals content in Wheat and Maize under different Irrigation modes of CD and Hg the contents of Zn and CD in sewage irrigated wheat were higher than those in sewage mixed irrigation and clean water irrigation (P0.05). However, there was no significant difference in the contents of Pb and Hg in other heavy metals (Cu ~ (2 +) Cr ~ (2 +)) and Hg (P ~ (0.05)) in different irrigation methods. The content of Zn in corn irrigated with clean water was lower than that of mixed irrigation and sewage irrigation (P0.05). There was no significant difference in the content of other heavy metals in wheat. The order of single factor pollution index of wheat was PbCrZnAsCdCuHg, which was 3.32, respectively. The order of maize is PbCrAsZnCdCuHg, and the index is 2.28 ~ 2.14 ~ 1.20, respectively. The Pb single factor pollution index of wheat is more than 3, which belongs to severe pollution. The comprehensive pollution index of wheat and maize were 2.59 and 1.54, respectively. The health risk assessment of moderate and mild pollution groups was followed by the average daily exposure of Zn to adults and children. Hg was the smallest. The average daily exposure of CD and as in wheat was higher than that in children. The health risks of carcinogenic heavy metals as and CD were higher than those of other non-carcinogenic heavy metals. Non-carcinogenic risk children are higher than adults, carcinogenic risks are higher in adults than children, but their risk levels are within the maximum risk acceptable range (non-carcinogenic: 7? 10-5; carcinogenic 3. 5? Comprehensive Evaluation of 10-3 ~ (5) Irrigation methods the degree of heavy Metal pollution in different Irrigation methods is sewage Irrigation and cleaning mixed Irrigation with clear Water Irrigation. ConclusionThe heavy metal pollution of W1 wheat is more serious than that of maize, which is moderate and light pollution respectively, and is mainly polluted by Cr and Pb. 2 wheat Zn. The contents of CD and Zn in sewage irrigation were higher than those in mixed irrigation and clean water irrigation. 3. The health risk of wheat was higher than that of AsC, CD, Pb and Hg. The degree of heavy metal pollution in non-carcinogenic children was higher than that in adults, and the degree of heavy metal pollution in wheat was polluted by sewage irrigation and mixed irrigation with clean water, and maize was not affected significantly.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X82

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