Study finds most respiratory viruses are airborne, so are masks here to stay? “Not really”, says UCSD expert

A new A research study co-led by an atmospheric chemist at the Scripps Institution of Oceanography at UC San Diego in La Jolla determined that most respiratory viruses, and not just the coronavirus that causes COVID-19, can all be spread by airway.

“We live with poor air quality,” said Professor Kimberly Prather, who is also director of the National Science Foundation Center for Aerosol Impacts on Chemistry of the Environment.

“The masks will obviously protect you against a wider range of respiratory viruses,” Prather said.

But when asked if the study implied that masks should be a permanent fixture in people’s lives, she replied, “Not really.”

Prather said she hopes the study “will raise awareness that schools – businesses too – have been poorly ventilated – for a very long time.” Improving ventilation and indoor air filtration will not only reduce the transmission of respiratory viruses, but also indoor air pollution, she said.

“Especially in schools, we come from [come] accept that the children have fallen ill, ”added Prather. “When you had kids in school, you spent your winters sick, and it didn’t have to be that way. If we invest in our schools, it will have beneficial health effects for a long, long time.

The to study, being published on Friday, August 27 in Science magazine, was edited by Prather and Chia Wang, director of the Aerosol Science Research Center and aerosol chemical physicist at Sun Yat-sen National University In Taiwan. He revealed that airborne transmission was the primary route of transmission for most respiratory illnesses, not just COVID-19.

In October, Prather and five other scientists wrote a letter urging SARS-CoV-2 coronavirus researchers to focus “on protecting against airborne transmission” rather than on the broad belief that the most likely route of transmission was surface contact or contact with large droplets produced by coughing and sneezing.

On August 26, the San Diego Unified School District, which operates five public schools in La Jolla, sent an email to parents updating its mask policy for the upcoming school year to require masks outside on campus as well as inside.

The email states that students can remove their masks outside during “mask breaks”. “During these breaks, students should maintain a distance of six feet from each other. … Masks may be removed outdoors in certain situations and with certain distancing recommendations during physical education, track and field and performing arts programs, ”as well as when students are eating.

Prather, who has advised the district since last year on its pandemic-related safety protocols, said the update was made because “there are reports that [the highly contagious] The Delta variant is transmitted to the outside.

Prather said the new study found that respiratory aerosols, formed by exhaling while breathing, speaking, singing, shouting, coughing and sneezing, remain suspended in the air still for more than five seconds. and can come from an infected person and be inhaled.

“The way that [coronavirus] sneaked around the globe – he did it in silence – [is] because more than half of the spread is from people who don’t even know they are sick, ”Prather said. “They just breathe and talk.

Referring to the common belief that the pandemic will slow down if people keep six feet among them, Prather said, “If six feet were enough, we wouldn’t be in the middle of a pandemic. If it was really just droplets falling to the ground… that doesn’t explain it. “

“I was the one who explained it to Dr. [Anthony] Fauci that [the virus] goes much further than six feet, ”said Prather. “It’s a paradigm shift for the field.

The study team looked at other viruses while looking for the spread of SARS-CoV-2. By reviewing several studies of superpropagation events during the pandemic, researchers have determined that aerosols are the most likely route of transmission rather than surface contact or contact with large droplets.

Plexiglass barriers – which protect against exposure to droplets and have been erected in many schools and businesses in an attempt to slow the pandemic – could actually hamper ventilation, Prather said, as the barriers can trap aerosols.

“What you would like is for air to circulate freely in the room so that you can bring in fresh air,” said Prather.

Prather said she was part of a recent forum to explain other protocols for keeping children safe in schools. It can be viewed at gospeakupamerica.com/deltaschools. ??