Very little is known about the elemental composition and possible sources of fine aerosol particles from Mediterranean megacities. Fine aerosol particles were collected at a residential-industrial area in Greater Cairo, Egypt, during the period from October 2010 to May 2011. The elemental compositions of the collected samples were quantified by using a homemade energy dispersive x-ray fluorescence spectrometer, whereas black carbon was quantified by a black smoke detector. Fifteen elements have been quantified. Of these constituents, Ca, C, Cl, S, and Fe had the highest concentrations: greater than 1 µg m-3. The overall mean mass concentration of the collected samples equals 70 µg m-3; this value exceeds the European Union annual Air Quality Standard levels. The individual elemental concentrations of the fine particles were found to be dominated by elements linked to mineral dust. Most of the monthly variations of elemental concentrations can be attributed to seasonal meteorological conditions. Other possible sources were vehicle-exhaust and industrial activities. The results pinpoint the problem of identifying different sources when one source, in this case, the nearby deserts, is dominant. The results from this study contribute to the growing knowledge of concentrations, composition, and possible sources of ambient fine particulate matter.

中文翻译：

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地中海大都市住宅区中PM2.5气溶胶的元素组成。

关于地中海大城市细小气溶胶颗粒的元素组成和可能来源知之甚少。在2010年10月至2011年5月期间，在埃及大开罗的一个居民区收集了精细的气溶胶颗粒。使用自制的能量色散X射线荧光光谱仪对收集的样品的元素组成进行了定量，而黑色用黑色烟雾探测器对碳进行定量。量化了15种元素。在这些成分中，Ca，C，Cl，S和Fe的浓度最高：大于1 µg m-3。所收集样品的总平均质量浓度等于70 µg m-3；该值超过了欧盟年度空气质量标准水平。发现细颗粒的单个元素浓度主要与矿物粉尘相关。元素浓度每月的大部分变化都可归因于季节性气象条件。其他可能的来源是车辆排气和工业活动。结果确定了当一个来源（在本例中为附近的沙漠）占主导地位时识别不同来源的问题。这项研究的结果有助于人们逐渐了解浓度，组成和周围细颗粒物的可能来源。结果确定了当一个来源（在这种情况下为附近的沙漠）占主导地位时识别不同来源的问题。这项研究的结果有助于人们逐渐了解浓度，组成和周围细颗粒物的可能来源。结果确定了当一个来源（在这种情况下为附近的沙漠）占主导地位时识别不同来源的问题。这项研究的结果有助于人们逐渐了解浓度，组成和周围细颗粒物的可能来源。