The dos and don’ts of wearing a face mask
People need clear advice on face-coverings during the coronavirus pandemic
Austria, the Czech Republic, Slovakia and Bosnia-Herzegovina have all made wearing face masks compulsory in some public places; many other EU countries advise against. Citizens of many Asian countries are donning them routinely. In the US, the Centers for Disease Control and Prevention recently issued new advice for people to wear cloth-based mouth coverings, even bandannas or T-shirts, in crowded areas. President Donald Trump has opted out. “I don’t think I’m going to be doing it,” he said.
In few areas of the Covid-19 pandemic has advice appeared so inconsistent as that related to face masks. The World Health Organization has revised its guidance but still insists that the wide use of masks by healthy people in everyday life “is not supported by current evidence and carries uncertainties and critical risks”.
Caution towards mask-wearing has been dictated in part by the need to prevent panic buying and ensure sufficient medical-grade protection for healthcare staff, amid shortages.
The advice has, nonetheless, been largely based on scientific evidence — or the lack of it. Few proper clinical trials have taken place of how mask-wearing affects viral infection rates. A review by the University of East Anglia of all published research on masks’ effectiveness in respiratory viruses concluded that wearing them in crowded places such as shops or buses could help to protect the most vulnerable from Covid-19. Yet while masks had a consistent but small protective effect, this was not strong enough to recommend widespread use.
Experts fear masks can create a false sense of security, tempting wearers to ignore social distancing, or may be seen as a substitute for other measures such as handwashing. Since the outer surface can become contaminated, wearers risk infecting themselves if they remove them clumsily. Homemade covers such as scarves can become damp, turning them into a potential transmission route.
Masks can also cause skin damage through sweating and rubbing, leading to other forms of infection. Some homemade masks carry particular dangers; consumers have tried adapting vacuum cleaner filters that may contain dangerous particles.
In weighing the pros and cons, much emphasis has been placed on the limited ability of anything short of medical-grade respirators to protect wearers from infection through inhalation; viruses are so tiny they can pass between the fibres of many materials. Yet the evolving understanding of Covid-19 suggests there may be strong arguments for donning masks to reduce infection risks to others.
The main virus transmission route is through droplets, which some evidence now suggests can be propelled further than previously thought by sneezing. Infected individuals may be contagious before suffering symptoms. Masks can catch some droplets expelled by sneezes, coughs or exhalation, reducing contamination of surfaces.
Health authorities, even if they stop short of recommending masks, should recognise many consumers are taking matters into their own hands; in parts of New York, the barefaced are already frowned upon. Authorities should continue to stress that surgical masks must be reserved for professionals, and that handwashing and social distancing are most vital. For individuals who may opt for facial protection, however, officials should issue clear dos and don’ts on what to use, and how. In a world where consumers can easily see what other countries are doing, inconsistent advice is not just unhelpful. It risks undermining trust in those giving it.