The research in relation to face masks and respirators comes from the Chinese University of Hong Kong, and it is based on an assessment of 42 countries across 6 continents. The research identifies a negative correlation between wearing a face mask and infection rates. This is based on airborne transmission via respiratory aerosols representing the dominant route for the spread of COVID-19.
Such findings are unsurprising. Research from a decade ago found that the use of face masks and hand hygiene may reduce respiratory illnesses in community settings and lessen the impact of season influenza (“Mask Use, Hand Hygiene, and Seasonal Influenza-Like Illness among Young Adults: A Randomized Intervention Trial.”)
While government policy is a key measure, cultural factors also influence the wearing of masks. For instance, in many Asian countries, the use of face masks ubiquitous and the donning of a mask part of overall hygiene etiquette. This is in contrast to many western countries, where there is often greater resistance.
This is evidenced with data relating to Hong Kong, which is in close proximity to mainland China. The infection rate in Hong Kong is considered modest (around 1,110 cases to-date). In Hong Kong 98.8 percent of people surveyed said they wear face masks in public. In contrast, the U.S. where face mask wearing rates are relatively low, there have been over two million cases.
Masks do have some limitations, however. While face ,asks trap the droplets the virus often remains infectious (a fact that makes used face masks hazardous waste. Face masks can be improved with the addition of chemicals like salt, which can inactivate many viruses.
The study is published in the American Journal of Respiratory and Critical Care Medicine. The research paper is titled : “COVID-19 and Public Interest in Face Mask Use.”