Chemical and morphological properties of particulate matter (PM10, PM2.5) in school classrooms and outdoor air
Chemical and morphological properties of particulate matter (PM10, PM2.5) in school classrooms and outdoor air
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DOI：
10.1016/j.atmosenv.2008.04.047
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发表时间：
2008-09-01
影响因子：
5
通讯作者：
Twardella, D.
中科院分区：
文献类型：
--
作者：
Fromme, H.;Diemer, J.;Twardella, D.
研究表明，高浓度的颗粒物（PM）对学校有害。需要进一步了解这些粒子的来源和组成。在为期6周的上课时间内，对室外空气和两间教室的空气进行了采样。用重量分析法测量PM，PM过滤器用于测定元素和有机碳、吸光度和10种水溶性离子。用扫描电子显微镜（SEM）和能谱仪（EDX）对部分过滤器进行了进一步分析，PM10浓度的中位数室内为118.2 μ g m（-3），室外为24.2 μ g m（-3）; PM2.5的相应结果室内为37.4 μ g m（-3），室外为17.0 μ g m（-3）。使用PM10和PM2.5数据，我们计算出以下室内外比值：0.3和0.4（硫酸盐），0.1和0.2（硝酸盐），0.1和0.3（铵），1.4和1.6（钙）。使用PM过滤器上测得的硫酸盐含量作为环境PM来源的指标，我们估计PM2.5和PM10分别占43%和24%。都是环境因素造成的教室PM的组成（例如。高钙浓度）和SEM/EDX分析结果表明，室内PM主要由地壳物质、建筑材料和白垩的沉淀物组成，学生的体育活动导致室内主要粗颗粒物的再悬浮，对教室PM 10的增加有很大贡献。室内和室外燃烧过程引起的细颗粒物浓度相当。我们的结论是，PM在教室测量的主要来源以外的室外颗粒。假设燃烧相关的颗粒和地壳材料的毒性不同，我们的研究结果支持的假设，室内产生的PM可能是有毒的PM相比，在环境空气中。(C)2008爱思唯尔有限公司保留所有权利。
Studies have shown high concentrations of particulate matter (PM) ill schools. Further insights into the Sources and the composition of these particles are needed. During school hours for a period Of 6 Weeks, Outdoor air and the air ill two classrooms were sampled. PM was measured gravimetrically, and PM filters Were used for the determination of the elemental and organic carbon, light absorbance, and 10 water-soluble ions. Some filters Were further analyzed by scanning electron microscopy (SEM) and energy dispersive microanalysis (EDX).The median PM10 concentrations were 118.2 mu g m(-3) indoors and 24.2 mu g m(-3) outdoors: corresponding results for PM2.5 were 37.4 mu g m(-3) indoors and 17.0 mu g m(-3) outdoors. Using PM10 and PM2.5 data, We calculated the following indoor/outdoor ratios: 0.3 and 0.4 (sulfate), 0.1 and 0.2 (nitrate), 0.1 and 0.3 (ammonium), and 1.4 and 1.6 (calcium). Using the Measured Sulfate content on PM filters as an indicator for ambient PM Sources, we estimated that 43% of PM2.5 and 24% of PM10 respectively. were of ambient origin. The composition of the classrooms' PM (e.g.. high Calcium concentrations) and the findings from SEM/EDX suggest that the indoor PM consists mainly of earth crustal materials, detrition of the building materials and chalk.Physical activity of the pupils leads to resuspension of mainly indoor coarse particles and greatly contributes to increased PM10 in classrooms. The concentration of fine particles caused by combustion processes indoors and Outdoors is comparable. We conclude that PM measured in classrooms has major sources other than outdoor particles. Assuming that combustion-related particles and crustal materials vary in toxicity, our results support the hypothesis that indoor-generated PM may be less toxic compared to PM in ambient air. (C) 2008 Elsevier Ltd. All rights reserved.