Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, IL, USA.
Department of Biology, Illinois Institute of Technology, Chicago, IL, USA.
Indoor Air. 2017 Sep;27(5):977-987. doi: 10.1111/ina.12374. Epub 2017 Mar 17.
Understanding the bioaerosol dynamics of droplets and droplet nuclei emitted during respiratory activities is important for understanding how infectious diseases are transmitted and potentially controlled. To this end, we conducted experiments to quantify the size-resolved dynamics of indoor bioaerosol transport and control in an unoccupied apartment unit operating under four different HVAC particle filtration conditions. Two model organisms (Escherichia coli K12 and bacteriophage T4) were aerosolized under alternating low and high flow rates to roughly represent constant breathing and periodic coughing. Size-resolved aerosol sampling and settle plate swabbing were conducted in multiple locations. Samples were analyzed by DNA extraction and quantitative polymerase chain reaction (qPCR). DNA from both organisms was detected during all test conditions in all air samples up to 7 m away from the source, but decreased in magnitude with the distance from the source. A greater fraction of T4 DNA was recovered from the aerosol size fractions smaller than 1 μm than E. coli K12 at all air sampling locations. Higher efficiency HVAC filtration also reduced the amount of DNA recovered in air samples and on settle plates located 3-7 m from the source.
了解呼吸活动过程中飞沫和飞沫核的生物气溶胶动力学对于理解传染病的传播方式和潜在控制方法非常重要。为此，我们进行了实验，以量化在四种不同的 HVAC 颗粒过滤条件下运行的无人居住公寓单元中室内生物气溶胶传输和控制的尺寸分辨动力学。两种模式生物（大肠杆菌 K12 和噬菌体 T4）在低流量和高流量之间交替雾化，以大致代表恒定呼吸和周期性咳嗽。在多个位置进行了尺寸分辨气溶胶采样和沉降板擦拭。通过 DNA 提取和定量聚合酶链反应（qPCR）对样品进行分析。在所有测试条件下，在离源最远 7 m 的所有空气样本中都检测到了两种生物的 DNA，但随着与源的距离增加，DNA 的数量减少。在所有空气采样位置，从小于 1 µm 的气溶胶粒径中回收的 T4 DNA 比大肠杆菌 K12 多。更高效率的 HVAC 过滤也减少了离源 3-7 m 处空气样本和沉降板上回收的 DNA 量。
