Respiratory Droplets vs Aerosols: Understanding The Difference

From the get-go, experts have made it clear that the novel coronavirus that causes COVID-19 is transmitted through respiratory droplets. But alongside the latest spike in cases in the U.S., health officials have discovered that COVID-19 can be transmitted by aerosol too. Two research studies came out recently describing how the two methods differ in terms of how they spread the virus. There are still no solid data to determine which spreads the virus more.

The first study, published in the Journal of the American Medical Association, says that exhaled respiratory droplets are larger or equal to 5 microns (µm). Aerosol particles are smaller than 5 µm,  so they tend to rapidly evaporate in the air and can remain suspended for hours.

The second study published in the National Center for Biotechnology Information compared the transmission of droplets and aerosols in different environmental settings and found that it is still difficult to ascertain which caused more transmissions between the two. The researchers advised that people should practice safety precautions in various settings, including airplane cabins, passenger cars, health care centers and other enclosed spaces since the behavior of the virus has been "unprecedentedly unique."

People can reduce the transmission of the novel coronavirus from respiratory droplets by wearing face coverings and practicing social distancing. But, prevention of the aerosol transmission is trickier since  face shields provide partial protection and the aerosols could spread beyond the 6-foot social distancing limit. People with COVID-19 and asymptomatic carriers can both produce both droplets and aerosols.

Both studies concluded that even though more research needs to be done to find out if respiratory droplets lead to more infections than aerosols and vice-versa, for now, available information suggests that airborne transmission of COVID-19 through aerosols is not more predominant than transmission via respiratory droplets.

COVID-19 An artist's representation of the novel coronavirus that causes COVID-19. Pixabay

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