By Dr. Randall Pozdena,
Pozdena is a Senior Economist with ECONorthwest,
When the Coronavirus arrived in the US, there was a rush by the public to acquire face masks. After all, the Coronavirus was a pathogen that caused disease by getting into the lungs by inhalation or by touching contaminated hands to the mouth, nose or eyes. Face masks have the potential to filter particles and to deter touching one’s hands to the face. Wearing face masks thus seemed a natural thing to do.
Rather than thanking the public for their efforts, however, health policy officials chastised them and told them to stop buying masks. For example, the US Surgeon General tweeted on February 29, 2020, saying:
“Seriously people – STOP BUYING MASKS! They are NOT effective in preventing the general public from catching Corona virus, but if healthcare providers can’t get them to care for the sick patients, it puts them and our communities at risk!”
Apparently, health officials believed that transmission to others only involved symptomatic individuals with viral particles in their sneezes and coughs. The resulting sharp bursts of droplets then contaminate the hands and belongings of the affected individual and collect on surfaces. Hence, initially the US and Oregon public was only advised to wash hands and avoid or disinfect contaminated surfaces.
The snag in this logic is that virus transmissions from asymptomatic, but infected individuals, have been identified in the case of Coronavirus (Rothe et al. 2020), and found to be as much as 80 percent of all infections of others (Li et al. 2020). In March 2020, a summary of research on the mobility and characteristics of flu particles was published in the journal Aerosol Science and Technology. That literature makes it clear that the Coronavirus particles of symptomatic and asymptomatic people were of the appropriate small size and persistence in the air to be inhaled deep into the respiratory tract of an uninfected individual.
This is precisely the set of circumstances, of course, that wearing a mask to protect the wearer could have great benefit. The virus particles (or an important share of them) can then be kept from entering the respiratory tract of the wearer. The benefits of masks do not stop there; by keeping a new infection from occurring, they also keep the infection from being passed to wearers’ contacts. In so doing, masks arrest the process that causes a pandemic to exhibit rapid growth of infections.
Indeed, the greater the number of secondary contacts a person has (the “reproduction number”), the greater is the potential for the pandemic to spread exponentially. Conversely, the blocking of infections by masks has the potential to rapidly reduce spreading. It has been estimated that if 60 percent of the community wore masks that were 60 percent effective at blocking the virus, the pandemic would cease (Howard, et al. 2020). Of course, in-migration of infected individuals would have to be limited through testing and quarantine procedures.
Unfortunately, health officials elected to discourage the use of masks and chose to rely almost exclusively on “social distancing” methods such as sheltering-in-place. Like the use of masks, social distancing reduces the probability of infected individuals encountering uninfected individuals. Where the two approaches differ significantly, is the cost of compliance. There was no official recognition of the utility of masking policy even as late as April 2020. Thus it is hard to know how the spread of Coronavirus might have evolved differently under that policy. What is clear, however, is that the physical distancing policies imposed a tremendous burden on the economy, households, and businesses. The ultimate burden is currently unknowable as Congressional and Federal Reserve actions to ameliorate the direct distortions is far from complete, and a comparative reckoning of impacts on morbidity and mortality is speculative.
It is worthwhile, however, to examine how the greater reliance on face masks seems to be playing out in Japan. First, Japan encountered the Coronavirus at approximately the same time as the United States. Second, with a population of 120 million people in an area the size of California, Japan’s cities are densely populated, which should encourage pandemic spreading. Finally, it is in close proximity of other nations that have encountered the Coronavirus.
There are some distinct differences in policy, however. For example, the Japanese public has a tradition of wearing masks during allergy and influenza seasons. In fact, Japan manufactures 4.3 billion masks per year for consumers, mostly in the form of disposable surgical masks. Also, Japan has not relied significantly on social distancing and contact tracing in the current outbreak. Thus, it is interesting to compare current Coronavirus cases and death rates of Oregon and the US with Japan on a population-adjusted basis.
As of this writing, both confirmed infections and deaths are much rarer in Japan than in either the US or Oregon. Japan currently has only one Coronavirus case for every 9,600 persons. By comparison, the US ratio is one per every 336 persons and one per every 1,872 in Oregon. Japan has only one death per 364,000 persons versus one death per 59,000 persons in the US and one per 48,000 in Oregon. By these metrics, whatever the Japanese have been doing is more effective than either the US or Oregon approach. Perhaps most importantly of all, Japan has not borne the huge economic burden associated with social distancing.
What would our experience have been if we had been encouraged sooner and more urgently to follow strict masking rules? And how should we go forward from here? Perhaps a combination of comprehensive use of masks, periodic random testing of the level of infection, and border screening may obviate the need for costly social distance policies going forward.
– Asadi, Sima, N. Bouvier, A. S. Wexler, W. D. Ristenpart . 2020. The coronavirus pandemic and aerosols: Does COVID-19 transmit via expiratory particles? The Journal of Aerosol Science and Technology.
– Howard, Jeremy, et al. Face Masks Against COVID-19: An Evidence-Based Review . Preprints (www.preprints.org) 12 April 2020
– Li,R.,S.Pei,B.Chen,Y.Song,T.Zhang,W.Yang,andJ.Shaman.2020. Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (covid-19). Science :eabb3221. doi:10.1126/science.abb3221.
– Rothe,C.,M.Schunk,P.Sothmann,G.Bretzel,G.Froeschl,C.Wallrauch,T. Zimmer, V. Thiel, C. Janke, W. Guggemos, et al. 2020. Transmission of 2019-ncov infection from an asymptomatic contact in Germany. The New England Journal of Medicine 382 (10):970–1. doi:10.1056/NEJMc2001468.