The impact of wearing powered air purifying respirators or N95 masks on the olfactory function in healthcare workers: A randomized controlled trial.

Background: With the Coronavirus disease 2019 epidemic, wearing a mask has become routine to prevent and control the virus's spread, especially for healthcare workers. However, the impact of long-term mask wear on the human body has not been adequately investigated. This study aimed to investigate whether Powered Air Purifying Respirators and N95 masks impact the olfaction in healthcare workers.

Methods: We recruited fifty-six healthcare workers and randomly divided them into 2 groups, wearing a powered air purifying respirator (PAPR) (experiment group, N = 28) and an N95 mask (control group, N = 28). Olfactory discrimination and threshold tests were performed before and after wearing the masks. SPSS 26.0 (SPSS Inc., Chicago, Illinois) software was used for the statistical analyses.

Results: There was a statistical difference in the olfactory threshold test after wearing the mask in both PAPR Group (Z = -2.595, P = .009) and N95 Group (Z = -2.120, P = .034), with no significant difference between the 2 (χ2 = 0.29, P = .589). There was no statistical difference in the discrimination test scores in both 2 groups after wearing the masks.

Conclusion: Wearing a mask affects the healthcare workers' olfaction, especially odor sensitivity. Healthcare workers have a higher olfactory threshold after long-term mask wear, whether wearing PAPRs or N95 masks.