Prolonged Use of Surgical Masks and Respirators Affects the Protection and Comfort for Healthcare Workers.

This study explored the ideal period for wearing masks to prevent the physiological and psychological problems associated with long-term face mask use during respiratory infections by healthcare workers. Breathing simulators, surgical masks (SM) and medical respirators (PM) were prepared for two to eight hours. Changes in the comfort of masks (facial skin temperature, breathing resistance, and moisture permeability) and protection (filtration efficiency, resistance to blood penetration, and colony count) were assessed. The results demonstrated that the masks offered efficient liquid-particle filtering even after eight hours of use. However, the number of bacterial colonies using PM and SM grew significantly after two and four hours, respectively. Concerning comfort, the inspiratory resistance of masks rose dramatically after two hours, whereas the moisture permeability declined considerably after four hours. In addition, skin temperature had a significant increase within two hours, which may result in facial discomfort. When conditions permitted, the hospital staff was instructed to replace their masks every two hours.

Research on efficacy of masks under different simulated wearing modes

OBJECTIVE: To study the relationship between the comfort and protection of masks under different simulated wearing methods, so as to provide reasonable suggestions for medical staff on how to wear masks. METHODS: The N95 mask and disposable mask commonly used by medical staff were choose to design five wearing methods are designed: Single layer disposable mask(Single-D), Double layer disposable mask(Double-DD), Single layer N95 mask(Single-N), N95 mask inside + Disposable mask outside(Double-ND), Disposable mask inside + N95 mask outside(Double-DN). According to the mask standard GB 19083-2010, the filter efficiency, moisture permeability, respiratory resistance, resistance to synthetic blood penetration and moisture resistance of masks under different wearing modes were tested. RESULTS: Compared with Single-N methods, the filtration efficiency, moisture resistance and anti-synthetic blood penetration of the Double-ND and Double-DN methods had no significant difference, the moisture permeability was significantly lower than that of Single-N mode(P<0.05), and the respiratory resistance was significantly higher than that of Single-N mode(P<0.05). Compared with Single-D modes, the moisture resistance and synthetic blood penetration of Double-DD had no significant difference, the filtration efficiency was significantly higher than that of Single-D mode(P<0.05), the moisture permeability was significantly lower than that of Single-D mode(P<0.05), and the respiratory resistance was significantly higher than that of Single-D mode(P<0.05). CONCLUSION: The Single-layer N95 wearing mode(Single-N) is sufficient to meet the protection requirements. The double-layer wearing mode(Double-ND, Double-DN, Double-DD) seriously affects the wearing comfort and increases the risk of infection and leakage, which is not recommended for use.