Which Means the Coronavirus Can Be Airborne
The CDC recently updated information on the coronavirus to highlight the “potential for the spread of coronavirus through airborne droplets.” This marks some subtle changes in the precautions we need to take.
It is known that COVID-19 is transmitted mainly by airborne droplets. This is the reason for the physical distance, as it is difficult for these droplets to move more than a few feet. For the past several months, scientists have debated whether very small droplets – small enough to float in the air – are common and infectious enough to pose a serious risk.
Ordinary droplets that fall to the ground from a distance of about six feet are still considered the primary means of transmission. But if aerosols can also be contagious, that means indoor spaces can be dangerous, even if you’re careful and stay away from others.
Here’s what the CDC has to say about the update:
The CDC continues to believe, based on modern science, that people are more likely to become infected the longer and closer they are to a person with COVID-19. Today’s update confirms the existence of some published reports showing limited, unusual circumstances in which people with COVID-19 infected others who were more than six feet away or shortly after the person with positive COVID-19 left the area. In these cases, transmission took place in poorly ventilated and enclosed areas, often accompanied by activities that cause breathing difficulties, such as singing or exercise. This environment and activities can facilitate the accumulation of virus-carrying particles.
The CDC recommendations remain unchanged based on existing scientific evidence and after careful technical review of the guidelines.
If it is true that small floating droplets are a significant source of transmission, this does not mean that everything we thought we knew was wrong. It just means that some things are even more important than we thought.
Physical distancing is still important
If coronavirus is commonly transmitted through aerosols, distancing may not protect us as much as we thought. Staying six feet away from someone only means that we avoid the larger respiratory droplets that form when we breathe and cough.
If the smaller droplets can move and infect people, that means being in the immediate vicinity of that six feet of radius could still put you at risk. Again, this is a change of emphasis , not a complete change. Nobody ever said that the six-foot rule was a guarantee. But it may turn out that this rule provides less protection than we thought.
We need to be even more careful about indoor spaces.
Outside, fresh air circulates, and these tiny droplets can fly away in the wind. Indoors, they hover in the air with no obvious escape route.
Ventilation helps. This means opening windows or starting an air circulation system, ideally with a filter. But the main takeaway is that indoor spaces can be risky in nature. Aerosols can be the reason singing and screaming meetings like church services can be so problematic.
The need for N95 masks is even more pressing
We already know that medical masks provide better protection than cloth masks, and N95 protects best.
If the virus is transmitted through these tiny droplets, cloth and treatment masks are even less effective than we thought. If so, perhaps we should all be wearing the N95. Unfortunately, stocks are still scarce. The recommendation to wear “cloth face masks” (and surgical masks, if any) is based in part on the need to free these N95s for healthcare professionals. This is still a problem, but the lack of an N95 will become even more of a problem if it turns out that our homemade masks don’t work as well as we thought.
This post was originally published in July 2020 under the headline “What would it mean if the coronavirus is airborne?” and was updated in October 2020 to note that CDC now recognizes transmission over the air.