Analytical challenges when sampling and characterising exhaled aerosol
Analytical challenges when sampling and characterising exhaled aerosol
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DOI：
10.1080/02786826.2021.1990207
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发表时间：
2021-10-07
影响因子：
5.2
通讯作者：
Reid, Jonathan P.
中科院分区：
文献类型：
--
作者：
Gregson, Florence K. A.;Sheikh, Sadiyah;Reid, Jonathan P.
呼吸、咳嗽、说话或医疗过程中产生的呼吸道颗粒物是疾病传播的重要途径。表征产生的颗粒数量以及它们的尺寸分布是指导感染控制政策的基础。然而，对这些颗粒进行采样带来了固有的挑战。呼吸颗粒物的大小是多分散的，时间和空间可变的，并且以非常低的浓度排放，通常低于室内环境中预先存在的气溶胶浓度。此外，它们通常以高度动态、温暖和潮湿的射流排放，导致进一步的快速过程，如分散和蒸发。在这里，我们讨论了呼吸气溶胶采样的重要考虑因素，重点是采样颗粒（直径5 μ m），这些颗粒的浓度很低，可能需要数小时的采样时间才能准确定量。我们探讨了呼气和采样仪器的流量之间的关系，并随之量化的颗粒通量。我们还讨论了呼吸射流内的液体颗粒的运输和蒸发动力学，以及它们对进行气溶胶采样研究的影响。
Respiratory particles produced by breathing, coughing, and speaking or generated during medical procedures serve as important routes for disease transmission. Characterizing the number of particles generated as well as their size distribution is fundamental for guiding policy on infection control. However, sampling such particles carries inherent challenges. Respiratory particles are polydisperse in size, temporally and spatially variable, and emitted in very low concentrations, usually lower than the preexisting aerosol concentration in indoor environments. In addition, they are typically emitted in a highly dynamic, warm and humid jet, leading to further rapid processes, such as dispersion and evaporation. Here, we discuss important considerations for sampling respiratory aerosol, focusing on sampling particles 5 mu m diameter) that are so low in concentration that they may require hours of sampling time to be accurately quantified. We explore the relationship between the flow rates of the exhalation and the sampling instrument and the consequent quantification of particle flux. We also discuss the transport and evaporation dynamics of liquid particles within respiratory jets, and their impacts on conducting aerosol sampling studies.