The modality of particle size distributions of environmental aerosols
The modality of particle size distributions of environmental aerosols
复制标题
DOI：
10.1016/s1352-2310(99)00217-4
复制
发表时间：
1999-11-01
影响因子：
5
通讯作者：
Johnson, G
中科院分区：
文献类型：
--
作者：
Morawska, L;Thomas, S;Johnson, G
在研究空气污染的影响时，了解空气中颗粒物的大小分布已成为一个日益关注的领域。虽然总数和质量浓度可能在暴露和风险评估分析中发挥重要作用，但对颗粒大小分布的了解往往能提供更多关于导致这些分布的大气过程类型的信息。粒径分布的模态是与气溶胶形成机制有关的一个方面。这项工作的目的是提供一个详细的模态特征的分析，在三年的时间内收集了大量的颗粒大小光谱的一系列环境气溶胶类型。使用扫描迁移率粒度仪和空气动力学粒度仪对各种环境气溶胶（包括交通影响、城市影响、植被燃烧影响、海洋影响、修改背景和郊区影响）在0.016-30 μ m范围内的6000多种粒径分布进行了测量。采用先进的数据分析程序，将两种仪器的分布结合起来计算体积尺寸分布，以便清楚地解释模态特性。可以确定的是，虽然在大多数情况下，在数量大小分布中存在明显的原子核模式，但这并不转化为体积大小分布中的原子核模式。此外，虽然所研究的每种气溶胶的许多数量大小分布不同，但体积分布是相似的。这一发现对制定大规模空气质量标准具有重要意义。1999爱思唯尔科学有限公司版权所有。
Knowledge of the distribution of airborne particulate matter into size fractions has become an increasing area of focus when examining the effects of air pollution. While total number and mass concentrations may play an important role in exposure and risk assessment analyses, often an understanding of the particle size distributions provides more information on the type of atmospheric processes resulting in the distributions. The modality of the particle size distribution is one such aspect that has been associated with the aerosol formation mechanisms. The aim of this work is to provide a detailed analysis of the modal characteristics of a large number of particle size spectra collected over a period of three years for a range of ambient aerosol types. Measurements of over 6000 size distributions in the size range 0.016-30 mu m were made using a scanning mobility particle sizer and an aerodynamic particle sizer for various ambient aerosols including: traffic influenced, urban, vegetation burning influenced, marine, modified background and suburban. Advanced data analytical procedures were adopted to combine the distributions from the two instruments for the calculation of the volume size distributions to allow clear interpretation of the modal characteristics. It was determined that, while in most cases there is a distinct nuclei mode in the number size distribution, this does not translate to a nuclei mode in the volume size distribution. Furthermore, while many of the number size distributions were different for each aerosol studied, the volume distributions were similar. This finding has serious implications for the setting of mass-based air quality standards. (C) 1999 Elsevier Science Ltd. All rights reserved.