Owner Sarah Celek (red leggings) teaches a class at Pure Barre Cincinnati West, while gyms and gyms in Ohio are back in operation after the COVID-19 pandemic in Cincinnati, Ohio.
Jason Whitman | NurPhoto via Getty Images
The World Health Organization released new guidelines on Thursday that cannot rule out the possibility that the coronavirus can be transmitted by airborne particles in enclosed spaces, including gyms and restaurants.
The WHO previously acknowledged that the virus can get into the air in certain environments, such as "medical processes that produce aerosols". The new guidelines recognize some research that suggests that the virus may spread through "airborne particles" through particles in the air. "Choir exercises, in restaurants or in fitness courses" were mentioned as possible areas of air transmission.
"In these events, short-range aerosol transmission, especially in certain indoor areas, such as overcrowded and under-ventilated rooms with infected people over a long period of time, cannot be ruled out," says the new guidelines from the United Nations Health Department.
The WHO said in its guidelines that early evidence may indicate airborne transmission in such environments, but the spread through droplets and surfaces could also explain transmission in these cases.
"However, the detailed studies of these clusters suggest that the transmission of droplets and fomites could also explain the transmission from person to person within these clusters," says the guidelines.
The WHO added that more research is needed to further examine the preliminary results. The agency said the main mode of transmission should still be through airborne droplets.
Airborne transmission of the coronavirus could occur when evaporation-containing droplets "produce microscopic aerosols" by evaporation, the WHO said, or "when normal breathing and speech lead to exhaled aerosols". Theoretically, the WHO said that someone could inhale the aerosols and become infected. However, it is not known whether such aerosols actually contain enough viable viruses to cause infection.
"So far, the transmission of SARS-CoV-2 via this type of aerosol route has not been demonstrated. Given the potential impact of such a route, further research is needed," the WHO guidelines said.
The WHO said it is continuing to investigate the role of different types of spread, including by air, how much virus is required to potentially infect someone, and what types of environments pose a higher risk of spread.
If airborne transmission turns out to be a major factor in the spread of the virus, this could have far-reaching political consequences. Masks can prove even more important for reducing infections, especially indoors and even in areas where physical distance is possible. And more specific masks for blocking microscopic particles can become more important. Specially equipped ventilation devices that are supposed to kill the virus in the ambient air could prove to be critical to prevent the spreading indoors and in gatherings.
The new guidelines come after 239 scientists from 32 different countries published an open letter earlier this week asking WHO and other health authorities to update their information about the coronavirus.
In an article titled "It's Time to Address the Transmission of COVID-19 in the Air," the group of scientists claims that WHO needs to give more weight to the role of Covid-19 in the air.
On Tuesday, senior WHO officials told reporters that they were reviewing the latest findings and working with the wider scientific community to publish new guidelines on what is currently known about whether and how easily the virus spreads by air.
"The evidence continues to grow and we are adjusting," said Dr. Soumya Swaminathan, chief scientist at WHO, on Tuesday. "We take this very seriously. Of course, we focus on public health advice."
Some scientists have criticized the WHO for being slow to issue guidelines for the latest research on coronavirus that emerged in Wuhan, China, just over six months ago. WHO has defended its guidelines and stated that it is transparent about its review process and applies healthy skepticism to research that has not been reviewed by experts.
In a few days, WHO reviews up to 1,000 publications, Swaminathan said on Tuesday. A typical day could mean WHO researchers combing around 500 new studies on topics ranging from the spread of the virus to medicines to treat Covid-19.