Cho Kyungmin Jacob, Reponen Tiina, McKay Roy, Shukla Rakesh, Haruta Hiroki, Sekar Padmini, Grinshpun Sergey A
Center for Health-Related Aerosol Studies, University of Cincinnati, Cincinnati, OH 45267, USA.
Ann Occup Hyg. 2010 Jan;54(1):68-77. doi: 10.1093/annhyg/mep062. Epub 2009 Aug 21.
The aim of this study was to investigate respirator filter and faceseal penetration of particles representing bacterial and fungal spore size ranges (0.7-4 mum). First, field experiments were conducted to determine workplace protection factors (WPFs) for a typical N95 filtering facepiece respirator (FFR). These data (average WPF = 515) were then used to position the FFR on a manikin to simulate realistic donning conditions for laboratory experiments. Filter penetration was also measured after the FFR was fully sealed on the manikin face. This value was deducted from the total penetration (obtained from tests with the partially sealed FFR) to determine the faceseal penetration. All manikin experiments were repeated using three sinusoidal breathing flow patterns corresponding to mean inspiratory flow rates of 15, 30, and 85 l min(-1). The faceseal penetration varied from 0.1 to 1.1% and decreased with increasing particle size (P < 0.001) and breathing rate (P < 0.001). The fractions of aerosols penetrating through the faceseal leakage varied from 0.66 to 0.94. In conclusion, even for a well-fitting FFR respirator, most particle penetration occurs through faceseal leakage, which varies with breathing flow rate and particle size.
本研究的目的是调查代表细菌和真菌孢子大小范围（0.7 - 4微米）的颗粒在呼吸器过滤器和面罩处的穿透情况。首先，进行现场实验以确定典型N95过滤式面罩呼吸器（FFR）的工作场所防护因数（WPF）。然后利用这些数据（平均WPF = 515）将FFR放置在人体模型上，以模拟实验室实验中的实际佩戴条件。在FFR完全密封在人体模型面部后，还测量了过滤器的穿透情况。从总穿透率（通过部分密封的FFR测试获得）中减去该值，以确定面罩穿透率。使用三种对应于平均吸气流量为15、30和85升/分钟的正弦呼吸流模式重复进行所有人体模型实验。面罩穿透率在0.1%至1.1%之间变化，并随颗粒大小（P < 0.001）和呼吸速率（P < 0.001）的增加而降低。通过面罩泄漏穿透的气溶胶比例在0.66至0.94之间变化。总之，即使对于贴合良好的FFR呼吸器，大多数颗粒穿透也是通过面罩泄漏发生的，其随呼吸流率和颗粒大小而变化。
