Dyspnoea and lung function with certified masks, home-made masks and optimized masks-a risk-benefit evaluation in patients with chronic lung diseases (BIO-PROTECT-Mask)

Because of the outbreak of COVID-19, many countries have recently regulated by law or strongly advice that face masks should be worn in distinct public environments in order to prevent further spreading of SARS-CoV-2. While there is a vivid discussion on the different types of certified or home-made masks and possible shortages in the supply chains, previous studies in other virus epidemics (influenza) indicate that compliance with wearing face masks and wearing time are the strongest predictors with respect a successful public healthcare intervention. One explanation for low wearing time might be the high pressure loss of most certified face masks that makes breathing difficult and wearing uncomfortable. Especially high-risk patients with chronic lung diseases may suffer from additional breathlessness while requiring a particularly high level of protection. Shortness of certified masks results in low-evidence recommendations for the use of home-made masks, however, it remains unclear whether the used materials provide reasonable protection against the transmission. In-depth studies that identify the best materials and layering are lacking, although experiments that would identify innovative materials with an optimal relationship of bioaerosol deposition and pressure loss might be a solution to improve the real-world effectiveness of mask wearing in public. In BIO-PROTECT we investigate filtration efficacy, pressure characteristics and effects on the load of breathing for different kinds of face masks in high- and low-risk populations and in relation to wearing time.