Bałazy Anna, Toivola Mika, Adhikari Atin, Sivasubramani Satheesh K, Reponen Tiina, Grinshpun Sergey A
Center for Health-Related Aerosol Studies, Department of Environmental Health, University of Cincinnati, Cincinnati, OH, USA.
Am J Infect Control. 2006 Mar;34(2):51-7. doi: 10.1016/j.ajic.2005.08.018.
Respiratory protection devices are used to protect the wearers from inhaling particles suspended in the air. Filtering face piece respirators are usually tested utilizing nonbiologic particles, whereas their use often aims at reducing exposure to biologic aerosols, including infectious agents such as viruses and bacteria.
The performance of 2 types of N95 half-mask, filtering face piece respirators and 2 types of surgical masks were determined. The collection efficiency of these respiratory protection devices was investigated using MS2 virus (a nonharmful simulant of several pathogens). The virions were detected in the particle size range of 10 to 80 nm.
The results indicate that the penetration of virions through the National Institute for Occupational Safety and Health (NIOSH)-certified N95 respirators can exceed an expected level of 5%. As anticipated, the tested surgical masks showed a much higher particle penetration because they are known to be less efficient than the N95 respirators. The 2 surgical masks, which originated from the same manufacturer, showed tremendously different penetration levels of the MS2 virions: 20.5% and 84.5%, respectively, at an inhalation flow rate of 85 L/min.
The N95 filtering face piece respirators may not provide the expected protection level against small virions. Some surgical masks may let a significant fraction of airborne viruses penetrate through their filters, providing very low protection against aerosolized infectious agents in the size range of 10 to 80 nm. It should be noted that the surgical masks are primarily designed to protect the environment from the wearer, whereas the respirators are supposed to protect the wearer from the environment.
呼吸防护设备用于保护佩戴者免受空气中悬浮颗粒的吸入。过滤式面罩呼吸器通常使用非生物颗粒进行测试，而其使用目的往往是减少对生物气溶胶的暴露，包括病毒和细菌等感染源。
测定了2种N95半面罩过滤式面罩呼吸器和2种外科口罩的性能。使用MS2病毒（几种病原体的无害模拟物）研究了这些呼吸防护设备的收集效率。在10至80纳米的粒径范围内检测病毒粒子。
结果表明，病毒粒子透过美国国家职业安全与健康研究所（NIOSH）认证的N95呼吸器的穿透率可能超过预期的5%水平。正如预期的那样，测试的外科口罩显示出更高的颗粒穿透率，因为它们的效率低于N95呼吸器。来自同一制造商的2种外科口罩在85升/分钟的吸入流速下，MS2病毒粒子的穿透率差异极大：分别为20.5%和84.5%。
N95过滤式面罩呼吸器可能无法提供针对小病毒粒子的预期防护水平。一些外科口罩可能会让相当一部分空气传播病毒穿透其过滤器，对10至80纳米粒径范围内的气溶胶化感染源提供的防护非常低。应当注意的是，外科口罩主要设计用于保护环境免受佩戴者污染，而呼吸器则应保护佩戴者免受环境污染。
