北京可吸入颗粒物中元素地球化学特征与健康风险评价

发布时间：2018-01-13 11:08

本文关键词：北京可吸入颗粒物中元素地球化学特征与健康风险评价　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：北京雾霾天气频发,并且大气可吸入颗粒物中重金属元素浓度过高会引发一系列的人体健康问题,因此掌握大气颗粒物中重金属元素的地球化学特征及其时空分布规律具有重要的意义。本研究于2013年1~4月(冬/春两季)期间,使用TH1500C智能中流量(80~120L/min)大气采样器在北京市区和郊区,进行了大气颗粒物(TSP/PM10/PM2.5)的采样工作,采集的样品利用电感耦合等离子体质谱仪和原子荧光谱仪分析,测试了Al、Fe、Mn、As、Hg、Cd、和Cr等21种元素。本文主要研究了北京春季与冬季的颗粒物浓度超标幅度及元素浓度分布特征,解析了元素来源,对儿童和成人进行了健康风险评价。获得的主要结果如下:北京市冬季大气颗粒物浓度超标幅度远远高于春季,尤其在雾霾天气情况下,超标幅度更高;北京市区各功能区及郊区均表现为,冬季浓度远高于春季;北京市区建材厂区的浓度最高,其次是商业区(属于人口密集区)。Cd、Cr、As、Hg四种重金属在冬季大气颗粒物PM10中的浓度比春季的增幅分别为233%、306%、298%、141%;在PM2.5中的增幅分别为442%、309%、310%、256%。与春季相比,冬季各元素在颗粒物中的富集程度高,有毒有害元素的表现尤为明显,并且在PM2.5中的富集程度显著高于PM10的,表明有毒有害元素易于富集在PM2.5中。北京市大气污染来源较为复杂,人为污染源主要是车辆排放、工业排放和燃煤。冬季PM2.5中三种污染源的贡献率占64.53%,春季PM2.5中占64.25%;冬季PM10中贡献率在53.95%~66.71%之间,春季PM10中占58.94%;冬季与春季人为污染源贡献率差异不显著。北京市区冬季的健康风险高于春季,郊区则相反;北京市区和郊区非致癌风险均较高,会增加发生疾病的概率;冬季,大气中的Cr和As元素的存在,造成北京市区存在一定的致癌风险,其数量级为10-6,即每100万人口会增加1个致癌患者,春季仅有Cr存在致癌风险;北京郊区在冬季与春季均未存在致癌风险。和成人相比,儿童的健康风险更大。
[Abstract]:Smog is frequent in Beijing, and high concentrations of heavy metals in inhalable particulates in the atmosphere can lead to a series of human health problems. Therefore, it is of great significance to understand the geochemical characteristics of heavy metal elements and their temporal and spatial distribution in atmospheric particulates. This study was conducted during the period of 1 ~ April (winter / spring) from 2013 to April. Use the TH1500C Intelligent medium flow rate 80L / min Atmospheric Sampler in Beijing's urban and suburban areas. Samples of atmospheric particulate matter (TSP / PM10 / PM2.5) were measured by inductively coupled plasma mass spectrometer and atomic fluorescence spectrometer. In this paper, the characteristics of the concentration of particulates in Beijing in spring and winter were studied, and the distribution of elements and the origin of the elements were analyzed. The health risk assessment of children and adults was carried out. The main results were as follows: the concentration of atmospheric particulates in winter in Beijing was much higher than that in spring, especially in smog weather; The concentration in winter is much higher than that in spring. The concentration of building materials factory in Beijing is the highest, followed by commercial district (belonging to the densely populated area). The concentrations of four heavy metals in PM10 in winter were 233306 and 29881, respectively, which were higher than those in spring. The increase in PM2.5 was respectively 442 / 3099 and 31010 / 2566.Compared with that in spring, the enrichment degree of each element in winter was higher than that in spring, especially in toxic and harmful elements. The enrichment degree in PM2.5 was significantly higher than that in PM10, indicating that toxic and harmful elements were easily enriched in PM2.5, and the sources of air pollution in Beijing were more complex. The main sources of anthropogenic pollution were vehicle emissions, industrial emissions and coal combustion. The contribution rate of the three sources of PM2.5 in winter was 64.53, and that of PM2.5 in spring was 64.25. The contribution rate of PM10 in winter was between 53.95% and 66.71%, and in spring PM10 was 58.94%. There was no significant difference between winter and spring in the contribution rate of anthropogenic pollution sources. The health risk in winter in Beijing urban area was higher than that in spring, but in suburb was opposite. The non-carcinogenic risk is higher in urban and suburban areas of Beijing, which will increase the probability of disease. In winter, the presence of Cr and as in the atmosphere results in a certain risk of carcinogenesis in the urban area of Beijing, whose order of magnitude is 10-6, that is, an increase of one cancer patient per 1 million population. Only Cr had carcinogenic risk in spring. There is no risk of cancer in winter or spring in the suburbs of Beijing. Children's health risks are higher than those of adults.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513;X823

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