curiousKC: Is COVID-19 Airborne? Definitive Answer Up in the Air

Images of people walking down the street in hazmat suits are common in movies like “Contagion,” where a deadly virus sweeps the globe. In those films there is a fear that even going outside could cause you to become infected. 

That fictional fear has seeped into the real world as COVID-19 cases spike, and mask wearing has become a political debate rather than a public health consensus. 

To make matters worse, confusion over how the virus can actually be spread is starting to become a real problem for those who are trying to live their lives during a pandemic.

One Kansas City resident turned to curiousKC for help. Valerie Messigner asked: “Is coronavirus airborne? Is it floating in the air so even on a walk do we need to wear a mask?”

Scientists are still trying to reach consensus on that question.

Droplets cause infection

The conversation around airborne transmission of coronavirus took a turn recently when an article in “Clinical Infectious Diseases” said that 239 scientists believe the World Health Organization (WHO) should reconsider its stance that the virus is only transmitted through large respiratory droplets from something like a sneeze, a cough or someone yelling.

Three days later, the WHO did just that. 

On July 9, the WHO released a scientific brief that said the airborne spread of coronavirus in spaces with poor ventilation or that are crowded indoors “cannot be ruled out.”

“Outside of medical facilities, some outbreak reports related to indoor crowded spaces have suggested the possibility of aerosol transmission, combined with droplet transmission, for example, during choir practice, in restaurants, or in fitness classes,” the brief said. “In these events, short-range aerosol transmission, particularly in specific indoor locations, such as crowded and inadequately ventilated spaces over a prolonged period of time with infected persons cannot be ruled out.”

But what is aerosol transmission? It goes hand in hand with airborne transmission.

Airborne transmission happens when tiny droplets called aerosols remain infectious in the air over longer distances and for a longer amount of time.

Primarily this has been a worry in hospitals where aerosol generating procedures like positive pressure ventilation (BiPAP and CPAP) and nebulizer treatments, which deliver medication as a mist, take place. 

The droplet transmission that has been mentioned frequently with COVID, and according to the WHO is the most common way the virus spreads, is via large droplets. These droplets typically come from a cough or sneeze and are heavy enough to drop to a surface instead of lingering in the air, which is why wiping down surfaces and washing your hands is so important.

The WHO has two theories as to how aerosols are being generated outside of a medical setting.

“These theories suggest that 1) a number of respiratory droplets generate microscopic aerosols (<5 µm) by evaporating, and 2) normal breathing and talking results in exhaled aerosols. Thus, a susceptible person could inhale aerosols, and could become infected if the aerosols contain the virus in sufficient quantity to cause infection within the recipient.”

But the WHO acknowledges that more research needs to be done, especially in areas with poor ventilation where people are in close proximity.

Interactive COVID-19 Case Mapper

Masks and distance

Although there is not scientific consensus on whether or not aerosol transmission is infecting people with coronavirus, it is best to keep following recommended practices to slow the spread.

“There is more research needed to identify the airborne nature (of the virus),” said Dr. Reem Mustafa, associate professor in the Department of Internal Medicine at the University of Kansas. “If there is accuracy to this airborne idea, still wearing a mask will protect a majority of people.”

Wearing face masks help keep large droplets that could be containing COVID-19 from getting out and infecting other people.

Kansas City’s mask order includes wearing face coverings indoors in public areas such as the grocery store. 

If you are looking for silver linings in the pandemic, one is that you can go for a walk in the park or around your neighborhood without wearing a mask (or the aforementioned hazmat suit) without worrying about contracting the virus. But remember to keep six feet of social distance!

Jacob Douglas reports for Kansas City PBS in cooperation with Report For America.