Penetration of fiber versus spherical particles through filter media and faceseal leakage of N95 filtering facepiece respirators with cyclic flow.
Penetration of fiber versus spherical particles through filter media and faceseal leakage of N95 filtering facepiece respirators with cyclic flow.
复制标题
纤维与球形颗粒通过过滤介质的渗透以及循环流 N95 过滤面罩呼吸器的面部密封泄漏。
DOI：
10.1080/15459624.2012.752321
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发表时间：
2013
影响因子：
2
通讯作者：
Reponen,Tiina
中科院分区：
文献类型：
--
作者：
Cho,KyungminJacob;Turkevich,Leonid;Miller,Matthew;McKay,Roy;Grinshpun,SergeyA;Ha,KwonChul;Reponen,Tiina
本研究调查了 N95 过滤式面罩呼吸器的面部密封泄漏对纤维和球形颗粒渗透的差异。生成三个循环呼吸流量，对应于 15、30 和 85 L/min 的平均吸气流量 (MIF)。纤维的平均直径为 1 μm，中值长度为 4.9 μm（计算出的空气动力学直径，dae= 1.73 μm）。使用平均物理直径为 1.01 μm (PSI) 和 1.54 μm (PSII) 的单分散聚苯乙烯球进行比较（计算出的 dae 分别 = 1.05 和 1.58 μm）。两个光学粒子计数器同时测定呼吸器内部和外部的浓度。在 MIF 为 15、30 和 85 L/min 时，纤维过滤渗透率的几何平均值 (GM) 分别为 0.06、0.09 和 0.08%。 PSI 的相应值为 0.07、0.12 和 0.12%。在 MIF 为 15、30 和 85 L/min 时，纤维面密封渗透的 GM 分别为 0.40、0.14 和 0.09%。 PSI 的相应值为 0.96、0.41 和 0.17%。对于两种类型的颗粒，随着呼吸频率的增加，面部密封件的渗透率降低 (p ≤ 0.001)。在 MIF 为 30 L/min 时，PSII 的过滤器和面部密封件渗透的 GM 分别为 0.14% 和 0.36%。纤维的过滤器渗透率和面部密封渗透率显着低于 PSI (p < 0.001) 和 PSII (p < 0.003)。这证实了 PSI 的较高渗透并不是由于空气动力学直径稍小，这表明纤维的形状而不是其计算的平均空气动力学直径是通过测试呼吸器的沉积机制的主要因素。总之，纤维和球形颗粒的面部密封渗透随着呼吸频率的增加而减少，这可以通过撞击捕获的增加来解释。与纤维相比，球形颗粒通过面密封泄漏的渗透率高 2.0–2.8 倍，通过过滤介质的渗透率高 1.1–1.5 倍，这可归因于拦截损失的差异。
This study investigated differences in penetration between fibers and spherical particles through faceseal leakage of an N95 filtering facepiece respirator. Three cyclic breathing flows were generated corresponding to mean inspiratory flow rates (MIF) of 15, 30, and 85 L/min. Fibers had a mean diameter of 1 μm and a median length of 4.9 μm (calculated aerodynamic diameter, dae= 1.73 μm). Monodisperse polystyrene spheres with a mean physical diameter of 1.01 μm (PSI) and 1.54 μm (PSII) were used for comparison (calculated dae= 1.05 and 1.58 μm, respectively). Two optical particle counters simultaneously determined concentrations inside and outside the respirator. Geometric means (GMs) for filter penetration of the fibers were 0.06, 0.09, and 0.08% at MIF of 15, 30, and 85 L/min, respectively. Corresponding values for PSI were 0.07, 0.12, and 0.12%. GMs for faceseal penetration of fibers were 0.40, 0.14, and 0.09% at MIF of 15, 30, and 85 L/min, respectively. Corresponding values for PSI were 0.96, 0.41, and 0.17%. Faceseal penetration decreased with increased breathing rate for both types of particles (p ≤ 0.001). GMs of filter and faceseal penetration of PSII at an MIF of 30 L/min were 0.14% and 0.36%, respectively. Filter penetration and faceseal penetration of fibers were significantly lower than those of PSI (p < 0.001) and PSII (p < 0.003). This confirmed that higher penetration of PSI was not due to slightly smaller aerodynamic diameter, indicating that the shape of fibers rather than their calculated mean aerodynamic diameter is a prevailing factor on deposition mechanisms through the tested respirator. In conclusion, faceseal penetration of fibers and spherical particles decreased with increasing breathing rate, which can be explained by increased capture by impaction. Spherical particles had 2.0–2.8 times higher penetration through faceseal leaks and 1.1–1.5 higher penetration through filter media than fibers, which can be attributed to differences in interception losses.