Early Data: Airborne SARS-CoV-2 Not Detected in Florida Gym

Both the World Health Organization (WHO) and U.S. Centers for Disease Control and Prevention (CDC) say that COVID-19 is primarily transmitted via respiratory droplets from the nose and mouth—often during close contact—and fomites. Respiratory droplets refer to particles greater than 5-10 micrometers in size, while fomites are infected droplets left on surfaces.

Since early spring, scientists have hypothesized that SARS-CoV-2, the virus causing COVID-19 can also spread via aerosols, or very small airborne particles—less than 5 micrometers in size—which can linger in the air longer than denser respiratory droplets.

Aerosols & Gyms: What We Currently Know

The WHO currently states that transmission via aerosols in closed indoor spaces with poor ventilation cannot be ruled out, and that “more studies are urgently needed to investigate such instances and assess their significance for transmission of COVID-19.” On October 5, 2020, the CDC updated their “How COVID is Spread” page to acknowledge the existence of uncommon circumstances in which airborne particles have potentially transmitted COVID-19, noting these instances occurred in enclosed, poorly ventilated spaces and often involved activities causing heavier breathing. The CDC has not changed any recommendations based on this update.

Several studies have demonstrated that SARS-CoV-2 forms aerosols that can linger in the air. However, scientists do not know what proportion of exhaled droplets from speaking, breathing, or singing evaporate to form aerosols, nor what dose of infected aerosol particles would result in a COVID-19 infection.

For example, in studies published in the journal Aerosol and Air Quality Research and the International Journal of Infectious Disease, scientists sampled the air and found SARS-CoV-2 in the Student Healthcare Center (SHCC) at the University of Florida (UF) and in a COVID-19 patient’s hospital room.

A Device to Test the Air for SARS-CoV-2

The studies used a device, developed by Chang-Yu Wu, Ph.D., and John Lednicky, Ph.D., along with Aerosol Dynamics Inc., that is capable of efficiently sampling airborne particles of the virus that causes COVID-19. It works by gently collecting airborne viruses and preserving their viability using water vapor condensation-based technology, something that is not possible using other devices. You can see the air sampling device in action in the cardio area at IHRSA member club Gainesville Health & Fitness Center, one of the sites from which researchers collected air samples.

"Aerosol sampling is a noninvasive and effective technique for collecting airborne respiratory viruses, and thus has many important and practical uses,” Wu said.

Preliminary Findings Promising for Florida Health Club

A new study used the same methodology to look at the levels of the SARS-CoV-2 virus in the air in various locations in the community, including GHF.

In an email to members, Joe Ciriulli, GHF owner, shared that a team led by Wu, professor in the Department of Environmental Engineering Sciences, Engineering School of Sustainable Infrastructure and Environment at UF, tested the air quality in the club using a unique virus aerosol sampler.

The researchers brought the device to main GHF location on three separate—typically busy—days to test the air for SARS-CoV-2, and here’s what they found:

• August 31: no SARS-CoV-2 virus was detected,
• September 8: no SARS-CoV-2 virus was detected, and
• September 14: no SARS-CoV-2 virus was detected.

Safety Protocols Could Make a Difference

GHF has implemented several key safety protocols following CDC guidelines, which Wu agrees could have contributed to absence of detectable SARS-CoV-2 in the club. Four of these safety protocols include:

1. Establishing a mask-wearing policy. GHF requires all staff to wear masks, and that all members wear masks entering and exiting the club, and when walking around the club when they cannot maintain 6 feet of distance.
2. Leveraging UV sanitizing techniques. GHF installed Air Pear fans with a sanitizing UV light that kills 99% of all airborne germs and added UV light features to major AC ducts to kill germs and viruses.
3. Continuing social distancing practices. GHF maintains social distancing between machines and encourages members to practice social distancing while in the club.
4. Implementing enhanced cleaning and sanitizing procedures. This is especially important given the fact that fomites can become re-aerosolized in certain situations.

Additionally, GHF had already implemented an AC system that circulated in and exchanged outdoor air multiple times per hour. For more information on HVAC systems and ventilation, see “The Role of Your Health Club’s HVAC System in COVID-19 Safety.”

While these findings would support previous data suggesting clubs are not a primary transmission site for COVID-19, indicated by contact tracing in Louisiana and Colorado and early findings from Oslo, Norway, and the CDC, these unpublished, non-peer reviewed findings are limited by the fact that they represent only one health club in one city.

Thus, it is far too early to draw conclusions. Researchers are still collecting data as part of this ongoing study which can hopefully inform key practices to prevent the spread of COVID-19 in public spaces, and help inform future policy decisions.

If you are interested in participating in third-party air quality sampling, please email ab@ihrsa.org for more information.