大气细颗粒物(PM2.5)已经成为影响我国大气环境质量和人们身体健康的首要污染物. 作为青少年集中学习和生活的校园环境的空气质量状况已经成为多方关注的热点. 为研究校园环境大气细颗粒物的空间分布状况及其物理化学特征, 在不同高度(5, 40 m)设立采样点, 同步采集大气PM2.5样品, 利用高分辨扫描电子显微镜-X射线能谱仪(scanning electron microscope-energy dispersive spectrometer, SEM-EDS)分析了不同高度和不同时间段校园大气环境中PM2.5的微观组成、化学组分, 得出如下主要结论: 校园环境PM2.5的微观组分主要有燃煤飞灰颗粒、矿物颗粒(原生的和新生的矿物颗粒)、烟尘集合体以及无法鉴定的颗粒物; 5 m高度处采集的颗粒物的质量浓度和数浓度均高于40 m高度处, 5 m高度处PM2.5的矿物颗粒相对较多, 而40 m高度处PM2.5的烟尘集合体相对较多; 晚上样品中颗粒物数量和种类都比白天要多.
PM2.5 has become a major air pollutant. Air quality in campus has close relationship with the health of young people. This study focuses on mass concentration and physicochemical characterization of PM2.5 collected at different heights above a campus. Ambient PM2.5 particles were sampled synchronously at two heights (5 m and 40 m). Microscopic character and its chemical composition of the fine particles were characterized using scanning electron microscope-energy dispersive spectrometer (SEM-EDS). The following results are obtained. Mineral particles, soot aggregates and fly ash are ubiquitous in the campus PM2.5, and gypsum particles, unknown particles can also be found. Mass and number concentrations at 5 m are higher than that of PM2.5 collected at 40 m. The numbers of mineral particles in PM2.5 collected at 5 m are more than that of fine particles sampled at 40 m. Soot aggregates in the PM2.5 at 40 m are more abundant than that at 5 m. Both the particle types and the number of mineral particles collected during daytime are less than that sampled at night.
[1] Koch M. Airborne fine particulates in the environment: a review of health effect studies, monitoring data and emission inventories [R]. Laxengurg: International Institute for Applied Systems Analysis, 2000.
[2] 谢鸣捷, 王格慧, 胡淑圆, 等. 南京夏秋季大气颗粒物和PAHs组成的粒径分布特征[J]. 中国环境科学, 2008, 28(10): 867-871.
[3] 杨仪方, 钱枫, 张慧峰, 等. 北京市交通干线周围可吸入大气颗粒物的污染特性[J]. 中国环境科学, 2010, 30(7): 962-966.
[4] Uematsu M, Hattori H, Nakamura T, et al. Atmospheric transport and deposition of anthropogenic substances from the Asia to the East China Sea [J]. Marine Chemistry, 2010,
120: 108-115.
[5] Mage D, Wilson W, Hasselblad V, et al. Assessment of human exposure to ambient particulate matter [J]. Journal of Air & Waste Management Association, 1999, 49(11): 1280-l291.
[6] Baulig A, Sourdeval M, Meyer M, et al. Biological effects of atmospheric particles on human bronchial epithelial cells: comparison with diesel exhaust particles [J]. Toxicology in Vitro, 2003, 17(5/6): 567-573.
[7] Obot C J, Morandi M T, Beebe T P, et al. Surface components of airborne particulate matter induce macrophage apoptosis through scavenger receptors [J]. Toxicology and Applied
Pharmacology, 2002, 184(2): 98-106.
[8] Kijnzli N, Kaiser R, Studnicka M, et al. Public health impact of outdoor traffic-related air pollution: a European assessment [J]. The Lancet, 2000, 356(9232): 795-801.
[9] Zanobetti A, Schwartz J. The effect of particulate air pollution on emergency admissions for myocardial infarction: a multi-city case-crossover analysis [J]. Environ Health Perspect, 2005, 113: 978-982.
[10] Li S, Batterman S, Wasilevich E. Association of daily asthma emergency department visits and hospital admissions with ambient air pollutants among the pediatric medicaid population in Detroit: time-series and time-stratified case-crossover analyses with threshold effects [J]. Environment Research, 2011, 111(8): 1137-1147.
[11] 胡伟, 魏复盛. 儿童呼吸健康与颗粒物中元素浓度的关联分析[J]. 安全与环境学报, 2003, 3(1): 8-12.
[12] 时宗波, 邵龙义, 李红, 等. 北京市西北城区取暖期环境大气中PM10的物理化学特征[J]. 环境科学, 2002, 23(1): 30-34.
[13] 肖致美, 毕晓辉, 冯银厂, 等. 宁波市环境空气中PM10和PM2.5来源解析[J]. 环境科学研究, 2012, 25(5): 549-555.
[14] 姚振坤, 冯满, 吕森林, 等. 上海城区和临安本底站PM2.5的物化特征及来源解析[J]. 中国环境科学, 2010, 30(3): 289-295.
[15] Yin H, Mu S Y, Zhao L, et al. Microscopic morphology and elemental composition of size distributed atmospheric particulate matter in Urumqi, China [J]. Environ Earth Sci, 2013, 69: 2139-2150.
[16] 刘田, 裴宗平. 枣庄市大气颗粒物扫描电镜分析和来源识别[J]. 环境科学与管理, 2009, 34(2): 151-155.
[17] 董树屏, 刘涛, 孙大勇, 等. 用扫描电镜技术识别广州市大气颗粒物主要种类[J]. 岩矿测试, 2001, 20(3): 202-207.
[18] 董树屏, 李金香, 李琭. 应用扫描电镜-能谱系统对大气颗粒物中单颗粒的观测和识别[J]. 电子显微学报, 2006, 25: 328-329.
[19] 宋晓焱, 邵龙义, 宋建军, 等. 煤矿区城市PM10单颗粒微观形貌及粒径分布特征[J]. 中国矿业大学学报, 2011, 40(2): 292-296.
[20] 邵龙义, 杨书申, 时宗波, 等. 城市大气可吸入颗粒物物理化学特征及生物活性研究[M]. 北京: 气象出版社, 2008: 34-47.
[21] 杨书申, 邵龙义, 李卫军, 等. 上海市冬季可吸入颗粒物微观形貌和粒度分布[J]. 环境科学, 2007, 28(1): 20-25.
