da Eira Silva Vinicius, Abele Meagan, Bercovitz Ian, Ferguson Sherri
Department of Biomedical Physiology and Kinesiology, Simon Fraser University.
Environmental Medicine and Physiology Unit, Simon Fraser University.
Workplace Health Saf. 2025 Apr 17;73(7):21650799241230039. doi: 10.1177/21650799241230039.
The use of the N95 respirator outside work environments calls for a deeper understanding of the factors that interfere with its fitting, thus effectiveness. Here we determined how beard length influences N95 effectiveness. This research will improve guidance for individuals that use N95s in public spaces but cannot shave due to personal reasons.
Bearded males ( = 28) participated in this study. Participants' beard length was measured at the chin, mid jawline, and corner of the mouth, and a respirator fit tester was used to conduct a quantitative fit test. Participants then shaved and re-took the test. Fisher's exact test was conducted to determine the association between bearded (BEA) and clean-shaven (CLE) conditions and test passing rate. A mixed effects model was conducted with participants as a random factor to determine the differences in fit factor (FF) scores between conditions. Finally, a regression analysis was completed to determine if there was a linear relationship between the FF response and beard length at the three locations.
No statistically significant difference in passing rate (-value = .79) and mean FF scores between BEA and CLE ( = 0.75, -value = .39) was found. Although the regression analysis failed to detect a statistically significant relationship between the FF and beard length at the chin, mid jawline, and corner of the mouth (-values = .07, .27, and .11, respectively), the results showed a decrease in FF scores when beard length increased.
CONCLUSION/APPLICATION TO PRACTICE: Individuals who cannot shave completely should be encouraged to keep their beard as short as possible since beard length negatively impacts N95 effectiveness.
在工作环境之外使用N95口罩需要更深入地了解那些会干扰其贴合度进而影响其有效性的因素。在此，我们确定了胡须长度如何影响N95口罩的有效性。这项研究将为那些因个人原因无法剃须却在公共场所使用N95口罩的人提供更好的指导。
28名留胡须的男性参与了本研究。在参与者的下巴、下颌中线和嘴角测量胡须长度，并使用呼吸器贴合度测试仪进行定量贴合度测试。然后参与者刮掉胡须并重新进行测试。采用Fisher精确检验来确定留胡须（BEA）和剃须后（CLE）两种情况与测试通过率之间的关联。以参与者作为随机因素进行混合效应模型分析，以确定两种情况之间的贴合因子（FF）得分差异。最后，完成回归分析以确定FF反应与三个部位胡须长度之间是否存在线性关系。
未发现BEA和CLE两种情况在通过率（P值 = 0.79）和平均FF得分方面有统计学上的显著差异（P = 0.75，P值 = 0.39）。尽管回归分析未能检测到下巴、下颌中线和嘴角处的FF与胡须长度之间存在统计学上的显著关系（P值分别为0.07、0.27和0.11），但结果显示随着胡须长度增加，FF得分会降低。
结论/实际应用：对于无法完全剃须的人，应鼓励他们尽可能留短胡须，因为胡须长度会对N95口罩的有效性产生负面影响。
