Viruses & Airborne Particulate

Environmental Filter | September 30th, 2020

Recently, there have been discussions about viruses and how they spread. Can viruses be transmitted through airborne means? In other words, can they be spread through the air or only by means of surface contact?

What is Airborne?

With the ongoing pandemic of COVID-19, the word “airborne” has been mentioned a lot lately. The word airborne by definition means “transported or carried by the air.” [1] Some viruses and bacteria are airborne, but the big debate comes into play on whether or not COVID can be transmitted through the air. Since the outbreak began, scientists and researchers have been studying the virus to inform the measures that need to be taken to prevent further spread. Because it is a new virus, more research is needed to further explore whether or not it is considered airborne. [2]

However, there are certain types of viruses and bacteria that are airborne including:

• Measles

• Chickenpox

• Tuberculosis

• Mumps

Aerosols, Droplets, and Cleaner Air

You have probably heard a lot of discussion in recent months on aerosols/droplets from viruses. What are these droplets exactly and what are aerosols? These particles, either liquid or solid, are “suspended in the air.” [3] These aerosols can be divided into small droplets or large droplets.

If you are in very close proximity of someone that has the flu for example, these droplets can come from coughing or sneezing. While sometimes you can’t see these droplets, you can become infected by them. If someone sneezes into their hand, their hand is now covered in those contagious germs. If they touch a doorknob, the doorknob now has those droplets. If you touch the doorknob and then touch your face, eyes, nose, or mouth that allows those germs to enter into your body, and next thing you know; you have the flu. It is a cycle that can allow the spread of viruses from person to person.

Viruses & Proper Filtration

Does air pollution control and filtration help in any way to fight against airborne diseases? A good way to manage aerosols and airborne diseases is to have proper ventilation. In the 1960s, a study which was conducted to find the correlation between the Influenza virus and airborne transmission. Within the study, they found that increased ventilation and high humidity “decreases the effective rate of transmission.” [4] The chances of getting an airborne infection is in a way related to the ventilation. 

You’ve probably never thought about it, but hospitals and clean rooms have to use appropriate filtration to protect patients from the spread of germs and prevent contamination.

Update 10/7/2020: The CDC recently revised their guidelines to establish that COVID-19 "can sometimes be spread by airborne transmission." [5]