Particulate matter analysis at elementary schools in Curitiba, Brazil
Particulate matter analysis at elementary schools in Curitiba, Brazil
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DOI：
10.1007/s00216-008-2031-y
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发表时间：
2008-06-01
影响因子：
4.3
通讯作者：
Godoi, Ricardo H. M.
中科院分区：
文献类型：
--
作者：
Avigo, Devanir, Jr.;Godoi, Ana F. L.;Godoi, Ricardo H. M.
为了评估室内空气质量，对巴西库里蒂巴两所学校教室内外的颗粒物进行了表征。有关块体成分的信息由能量色散X射线荧光(EDXRF)提供。从计算的室内外比值和富集系数可以看出，室内环境中存在S-、氯离子和锌的富集物。在本研究中，使用自动电子探针微区分析Low Z EPMA，定量地阐明了单个颗粒的化学成分，包括低Z组分，如C，N和O，以及高Z组分。进一步对样品进行了化学和形态方面的分析，确定了颗粒大小分布，并根据元素组成组合对它们进行了分类。根据主要元素浓度确定了五类：硅酸铝、烟尘、有机、碳酸钙和富铁颗粒。教室内发现的可吸入颗粒物大部分由煤烟、生物和硅酸铝颗粒组成。考虑到气溶胶颗粒的化学成分和粒度分布，计算了人体呼吸系统的局部沉积效率，揭示了烟尘在肺泡水平的沉积。结果表明，平均42%的粗颗粒沉积在胸外水平，而24%沉积在肺区。对于两种沉积水平，细小部分的沉积速率约为18%。
The particulate matter indoors and outdoors of the classrooms at two schools in Curitiba, Brazil, was characterised in order to assess the indoor air quality. Information concerning the bulk composition was provided by energy-dispersive x-ray fluorescence (EDXRF). From the calculated indoor/outdoor ratios and the enrichment factors it was observed that S-, Cl- and Zn-rich particles are of concern in the indoor environment. In the present research, the chemical compositions of individual particles were quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis low Z EPMA. Samples were further analysed for chemical and morphological aspects, determining the particle size distribution and classifying them according to elemental composition associations. Five classes were identified based on major elemental concentrations: aluminosilicate, soot, organic, calcium carbonate and iron-rich particles. The majority of the respirable particulate matter found inside of the classroom was composed of soot, biogenic and aluminosilicate particles. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the human respiratory system were calculated revealing the deposition of soot at alveolar level. The results showed that on average 42% of coarse particles are deposited at the extrathoracic level, whereas 24% are deposited at the pulmonary region. The fine fraction showed a deposition rate of approximately 18% for both deposition levels.