重金属铅的Source-to-Effect模型构建及健康风险评价

发布时间：2018-01-21 07:01

本文关键词： 铅 Source-to-Effect模型 Monte Carlo模拟健康风险防护区域健康风险防护距离　出处：《兰州大学》2015年硕士论文　论文类型：学位论文

【摘要】：背景：工业化和城市化的快速发展使世界各地都面临着重金属污染问题,近年我国重金属污染事件,尤其是“血铅”超标事件多发,严重威胁了环境安全与人群健康。目前针对已产生风险后果的风险评价难以满足重金属铅的健康风险防范需要,应在规划阶段从源头预防控制铅排放源,合理规划布局,解决铅污染问题。目标：构建重金属铅的Source-to-Effect模型,预评估健康风险的空间分布和儿童的血铅水平,划定铅排放源健康风险防护区域和健康风险防护距离。方法：基于大气扩散模型、土壤累积模型、暴露和个体风险评估模型、儿童血铅预测模型四个子模型构建Source-to-Effect模型,通过铅排放源参数和地形、气象条件,对重金属铅的迁移过程进行模拟,考虑个体通过空气吸入、皮肤接触、土壤和食物摄入四个途径,从区域角度评估铅排放源对居民健康风险和儿童血铅的影响。采用Monte Carlo模拟,确定各模型评价参数的概率分布函数(PDF),以解决不确定性问题。通过实际案例验证建立的模型和拟合的参数的适应性和实用性。结果：案例研究预测结果显示,铅冶炼厂运营后对当地居民铅暴露风险的贡献率不足10%,各网格点健康风险贡献值远远小于非致癌风险的标准限值1,但由于大气、土壤现状浓度较高,叠加现状值后,使居民存在铅暴露风险。通过敏感性分析确定有重要影响的敏感性因素,据此分两种情景划定冶炼厂健康风险防护距离,综合大气环境、卫生防护距离和准入条件规定距离的结果,绘制外包络线,作为健康风险的防护区域,取最远距离作为健康风险防护距离,情景一健康风险防护距离为4000m,情景二健康风险防护距离为1500m。
[Abstract]:Background: with the rapid development of industrialization and urbanization, heavy metal pollution is facing all parts of the world. In recent years, heavy metal pollution events, especially "blood lead", are more frequent in China. It is difficult to meet the need of health risk prevention of heavy metal lead, so it is necessary to prevent and control the source of lead emission from the source in the planning stage. Objective: to construct Source-to-Effect model of heavy metal lead and to pre-evaluate the spatial distribution of health risk and the blood lead level of children. Methods: based on atmospheric diffusion model, soil accumulation model, exposure and individual risk assessment model. Source-to-Effect model was constructed by four sub-models of children's blood lead prediction model, and the migration process of heavy metal lead was simulated by lead emission source parameters, topography and meteorological conditions. Consider four pathways: air inhalation, skin contact, soil, and food intake. The effects of lead emission sources on health risk of residents and blood lead in children were assessed from a regional perspective. Monte Carlo simulation was used to determine the probabilistic distribution function (PDF) of the evaluation parameters of each model. In order to solve the uncertainty problem. Through the actual cases to verify the model and fitting parameters of adaptability and practicability. Results: case study prediction results show. The contribution rate of lead smelter to local residents' lead exposure risk after operation is less than 10%, and the health risk contribution value of each grid point is far less than the standard limit value of non-carcinogenic risk, but because of the atmosphere, the present soil concentration is higher. After superposition of current value, the residents are exposed to lead. By sensitivity analysis, the important sensitive factors are determined. According to these two scenarios, the distance of health risk protection of smelter is determined, and the atmospheric environment is integrated. Health protection distance and access conditions of the results of the prescribed distance, draw outsourced lines, as a health risk protection area, take the furthest distance as health risk protection distance. The distance of health risk protection for scenario one and scenario two is 4000m and 1500mrespectively.
【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】：X820.4

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