可挥发性致癌物污染场地周边人群健康风险研究

发布时间：2018-05-03 17:53

本文选题：挥发性有机物 + 污染场地　；参考：《兰州大学》2015年硕士论文

【摘要】：众所周知的“4.11”兰州自来水局部苯超标事件与化工污染场地密切相关,为全方位保护兰州市饮用水安全,避免再次发生局部渗漏时污染物进入自流沟内,甘肃省政府启动实施了自来水管线周边污染场地修复治理工程。工程对受污染的土壤和地下水进行修复治理,工作重心全部集中在降低污染物浓度上,使修复后场地环境中污染物的浓度满足国家标准要求,这是基于环境安全方面的考量,能极大地降低环境风险。然而,这里有一个未加重视的问题,那就是在工程施工期间,污染土壤开挖时挥发以苯为主的有机物,这种可挥发性有机物会对环境空气、施工人员和场地周边居民身体健康产生较大影响。为了定量评估挥发性有机物对人体的健康风险水平以及周边环境空气质量,本文从人体健康和大气污染的角度,以苯污染物为研究对象,主要开展了以下几方面的研究：(1)通过查阅相关文献资料,估算土壤开挖时无组织排放源强；运用大气估算模式(Screen 3 System),预测土壤中苯挥发物的最大落地浓度和最大地面浓度占标率,定量分析其对环境空气的影响。(2)收集与场地修复治理工程相关的资料,通过危害识别等手段,分析土壤中苯挥发物的毒性效应以及到达人体的暴露途径,应用国内外较为完善和成熟的污染场地健康风险评价体系,分析土壤开挖过程中苯挥发物对场地周边居民身体健康的致癌风险和非致癌危害商,并进行暴露风险贡献率分析,进而判断何种暴露途径对人体健康产生的风险影响程度最大。研究结果显示：(1)分层开挖时,重度污染区苯的挥发量较大,土壤第一层重、中污染区域苯的排放源强为121.00g/h,其他区域的排放源强为3.86g/h；第二层重、中污染区域苯的排放源强为6063.00g/h,其他区域的排放源强为3.92g/h；第三层重、中污染区域苯的排放源强为222.90g/h,208.80g/h,其他区域的排放源强为32.07g/h。(2)土壤开挖过程中无组织排放的苯的最大落地浓度为4.86mg/m3,最大浓度占标率分别为202.5%。场地分段开挖过程中苯污染物对桃源村的影响浓度范围为0.03mg/m3-2.85mg/m3,贾家堡预测浓度范围为0.04mg/m3-2.85mg/m3。(3)土壤开挖过程中苯挥发物对场地周边居民人体健康的总致癌风险水平为2.20x 10-4,远远大于可接受的致癌风险水平(10-6)；非致癌危害指数为26.1,远大于可接受的非致癌风险水平(1.0)。(4)吸入土壤颗粒物、吸入室外来自表层土壤挥发物2种暴露途径下的总致癌风险均超标,其中吸入土壤颗粒物暴露途径下的致癌风险水平最大(1.97×10.4)。经口摄入土壤、吸入土壤颗粒物、吸入室外来自表层土壤挥发物3种暴露途径下的危害指数均超标,其中吸入土壤颗粒物暴露途径下的危害商最大,高达13.7。(5)土壤表层、中层、下层苯挥发物所造成的致癌风险贡献率和危害商贡献率分别为27.91%、48.64%、23.45%和37.74%、54.19%、8.07%。(6)从致癌效应的角度看,贡献率最高的暴露途径是吸入土壤颗粒物,贡献率高达89.55%；其次是吸入室外表层挥发物,贡献率为9.86%;其余所有暴露途径下的致癌风险贡献率不足0.59%。从非致癌效应的角度看,贡献率最高的暴露途径是吸入土壤颗粒物,贡献率高达52.49%；其次是吸入室外表层挥发物,贡献率为21.03%；其余所有暴露途径下的危害商贡献率为26.48%。
[Abstract]:It is known that the "4.11" Lanzhou tap water local benzene superstandard event is closely related to the chemical pollution site. In order to protect the safety of drinking water in Lanzhou and avoid the contamination into the self flow ditch, the Gansu provincial government started to implement the remediation and treatment project of the pollution site of the tap water pipeline. The project is polluted. The soil and groundwater are repaired and treated. The focus of the work is focused on reducing the concentration of pollutants, and the concentration of pollutants in the environment after restoration meets the national standard. This is based on environmental safety considerations and can greatly reduce environmental risk. However, there is a problem that is not paid attention to, that is, engineering application. During the process of excavation, the contaminated soil volatilized with benzene - based organic matter. This volatile organic substance would have a great impact on the health of the environment air, the builders and the residents around the site. In order to quantitatively assess the health risk level of the volatile organic compounds and the ambient air quality in the surrounding environment, this article from the human health and atmosphere From the point of view of pollution, taking benzene pollutants as the research object, the following research is carried out in the following aspects: (1) to estimate the intensity of unorganized emission in soil excavation by consulting relevant literature and data, and to predict the maximum ground concentration and the maximum ground concentration of the benzene volatiles in the soil by using the atmospheric estimation model (Screen 3). Analysis of its influence on environmental air. (2) collect data related to site remediation projects, analyze the toxic effects of benzene volatiles in soil and the way to reach human exposure through hazard identification and other means, and apply a more perfect and mature health risk assessment system at home and abroad to analyze the volatilization of benzene in the process of soil excavation. The research results show that: (1) the volatilization of benzene in severely polluted areas is larger, the first and middle pollution areas of the soil are heavy, the first and middle pollution areas are in the soil. The source of the emission of benzene is strong 121.00g/h, the emission source of other regions is strong 3.86g/h, second layer heavy, the emission source of benzene in the middle polluted area is 6063.00g/h, the emission source of other regions is strong 3.92g/h; the emission source of the benzene in the middle polluted area is 222.90g/h, 208.80g/h, and the source of the other region is strongly 32.07g/h. (2) soil excavation. The maximum ground concentration of benzene in the process of unorganized emission is 4.86mg/m3, and the maximum concentration ratio is 202.5%. site subsection excavation process, the influence concentration range of benzene pollutant to Taoyuan village is 0.03mg/m3-2.85mg/m3. The predicted concentration range of Jia Jiabao is 0.04mg/m3-2.85mg/m3. (3) soil excavation process of the benzene volatiles to the surrounding area. The total cancer risk level of human health was 2.20x 10-4, far greater than the acceptable level of carcinogenic risk (10-6); the non carcinogenic risk index was 26.1, far greater than the acceptable non carcinogenic risk level (1). (4) inhalation of soil particulate matter, and the total carcinogenic risk under the 2 exposure pathways of the external self surface soil of the inhalation chamber exceeded the standard. The risk of carcinogenic risk was the largest (1.97 * 10.4) under the exposure of soil particulate matter exposure. Through oral intake of soil, inhaled soil particulate matter, and the hazard index under 3 exposure routes from surface soil volatiles inhaled outdoors was above the standard, among which the highest risk merchants were exposed to soil particulate matter exposure, up to 13.7. (5) soil surface, middle layer, The rate of contribution to the risk of carcinogenesis and the contribution rate of harmful commercial contribution were 27.91%, 48.64%, 23.45% and 37.74%, 54.19%, and 8.07%. (6), from the point of view of the carcinogenic effect, the highest contribution rate was inhaled soil particulate matter, the contribution rate was up to 89.55%; the second was the volatiles of the outer layer of the inhalation room, the contribution rate was 9.86%; the rest were the rest. The contribution rate of cancer risk under exposure is less than 0.59%.. From the point of view of non carcinogenic effect, the highest contribution rate of exposure is inhaled soil particulate matter, the contribution rate is up to 52.49%, followed by the outward volatiles of the inhalation room, the contribution rate is 21.03%, and the contribution rate of the other exposure routes is 26.48%..

【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X503.1;X820.4

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