大庆市大同区土壤重金属污染及健康风险评价

发布时间：2018-03-19 00:07

本文选题：土壤　切入点：重金属　出处：《哈尔滨师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：重金属污染破坏土壤环境质量,直接或间接地危害人体健康。大庆市是我国重要的石油开采区,近年来,由于石油开采和化工业迅速发展,产生的落地油、油井漏油和集输管线泄露导致石油滴渗等,造成周围农田土壤重金属污染加剧。为更好地了解土壤重金属污染状况及土壤是否给人体健康带来危害,本研究选取大庆市大同区四个乡镇的70个样点进行采样和分析,通过实验测定重金属Cu、Pb、Cr、Hg、Zn、Ni、As、Cd的含量,描述重金属含量特征。采用单因子污染评价、内梅罗综合污染评价、地积累指数法和潜在生态风险评价法进行土壤污染评价,了解污染状况;并对非致癌因子和致癌因子进行健康风险评价,了解污染土壤给人体健康带来的危害程度,提出风险防治建议,为保护大同区土壤环境和人体健康,促进绿色农业可持续发展提供理论依据。研究结果如下:(1)8种重金属含量差异较大,所有样点均多于2种重金属超过背景值,属于复合污染。Cu、Cd、Ni均未超标,Hg、Pb出现大面积累积,污染较重。分析变异系数可知,Cu属弱变异,Cr、As和Cd为强变异。(2)单因子评价结果表明,Cu、Cd、Ni未污染,Cr、As、Zn为轻微污染,Pb、Hg的污染较重且范围广。Hg的污染贡献率最大,达55.66%,按污染贡献率由大到小排序为:HgPbCdCuNiZnCrAs。(3)内梅罗综合评价表明,全部样点都受到污染,84.29%为重污染。从四个乡镇的整体污染状况来看,四个乡镇污染等级均达到5级,污染已经相当严重,按污染程度排序:老山头乡八井子乡双榆树乡太阳升镇。(4)地积累指数表明,Cu、Cd、Cr、As、Zn、Ni未受污染,大部分样点Pb产生污染,所有样点Hg均产生污染,32.85%的样点达中度到强污染。四个乡镇的地积累指数差异不大,仅在Pb的污染上有差异。老山头乡Pb无污染,其他3个乡镇Pb处于无污染到中度污染之间。(5)从单元素潜在生态风险来看,Cu、Pb、Cd、Cr、As、Zn、Ni都属于低潜在生态危害。Hg的潜在危害较大,77.14%属于重潜在生态危害。从综合潜在危害情况分析,70%处于中等生态危害,22.86%处于强生态危害,其中Hg的污染贡献率最高,达到90.67%。大同区的四个乡镇都属于中等生态危害。(6)根据健康风险评价分析,经口摄入方式风险都比皮肤摄入大,是主要暴露途径。Cu、Pb、Cr、Hg、Zn、Ni不会造成非致癌风险,Cd不会造成致癌风险。As有27.14%的样点产生致癌风险。四乡镇非致癌风险排序:太阳升镇老山头乡双榆树乡八井子乡,致癌风险排序为:老山头乡八井子乡双榆树乡太阳升镇。老山头乡的致癌风险达到9.90E-07,已接近风险限值,需要引起注意。
[Abstract]:Heavy metal pollution destroys soil environmental quality and directly or indirectly endangers human health. Daqing City is an important oil mining area in China. In recent years, due to the rapid development of oil exploitation and chemical industry, Daqing City has produced ground oil. Oil spill from oil well and leakage of gathering pipeline lead to oil dripping, which results in the pollution of heavy metals in the surrounding farmland. In order to better understand the status of heavy metal pollution in soil and whether the soil is harmful to human health, In this study, 70 samples from four villages and towns in Datong District of Daqing City were selected for sampling and analysis, and the content of heavy metal (Cu PbPbCU / HgGZZN / NiAsAsN) was determined by experiments, and the characteristics of heavy metal content were described. The single factor pollution assessment and the comprehensive pollution evaluation of Nemelo were used to describe the characteristics of the heavy metal content. Land accumulation index method and potential ecological risk assessment method are used to evaluate soil pollution to understand the pollution status, and to evaluate the health risk of non-carcinogenic and carcinogenic factors to understand the degree of harm to human health caused by contaminated soil. The suggestions of risk control were put forward to provide theoretical basis for protecting soil environment and human health and promoting the sustainable development of green agriculture in Datong area. More than 2 heavy metals exceeded the background value in all the sample sites, and there was a large area accumulation of heavy metals in all the samples, which belonged to the compound pollution. The results of single factor evaluation showed that the single factor evaluation showed that the pollution rate of Cu / CD was higher and the range of pollution was the largest. The comprehensive evaluation of Nemero showed that 84.29% of the samples were seriously polluted according to the order of contribution rate of pollution from big to small: HgPbCdCuNiZnCrAs.0.In view of the overall pollution situation of the four villages and towns, the pollution levels of the four townships were all up to 5 levels. The pollution has already been quite serious, according to the degree of pollution: the accumulation index of the land in Shuangyusheng Town, Shuangyusheng Township, Laoshantou Township shows that there is no pollution on the ground, and most of the sample sites are polluted by Pb. In all the samples, 32.85% of the samples produced moderate to strong pollution. There was no significant difference in land accumulation index among the four villages and towns, but only in Pb pollution. There was no Pb pollution in Laoshantou Township. According to the potential ecological risk of single element, the Cu PbPbCU cdcznznzn Ni belongs to the low potential ecological hazard. The potential harm of Hg belongs to the heavy potential ecological hazard, 77.14% belongs to the heavy potential ecological hazard, according to the comprehensive potential hazard situation, the comprehensive potential hazard condition is the most important one in the other three townships where Pb is in the range of non-pollution to moderate pollution. The results show that 70% of them are in moderate ecological hazards and 22.86% are in strong ecological hazards. The pollution contribution rate of Hg is the highest, reaching 90.67.All the four towns in Datong District belong to medium ecological hazard. According to health risk assessment, the risk of oral intake is higher than that of skin intake. It is the main way of exposure. The main exposure route... The main exposure route... The main exposure route... The main exposure route... The order of carcinogenic risk is: Shuangyushu Township Shuangyushu Township, Laoshantou Township. The carcinogenic risk of Laoshantou Township is 9.90E-07, which is close to the limit value of risk and needs to be paid attention to.
【学位授予单位】：哈尔滨师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53

【相似文献】