Since its 1968 debut, CBS’ "60 Minutes" has been a staple news broadcast for millions of Americans. In its most recent season, an average of 9 million viewers tuned in each week to watch in-depth interviews featuring special guests like Nicolas Cage, Prince Harry, and Charles Barkley. 

On Sunday night, Oct. 29, Virginia Tech aerosol expert Linsey Marr will join the ranks of those noteworthy guests.

The transmission of infectious diseases via airborne particles is a topic that Marr’s used to speaking about. In fact, since the outbreak of COVID-19 in 2020, the civil and environmental engineering expert has done more than 500 interviews with local, national, and international news outlets. Today, she is considered one of the world’s leading experts on airborne transmission of viruses.

A long-awaited meeting

When Marr was identified as an expert early on in the pandemic through her Twitter threads and exchange of ideas with other scientists related to airborne disease transmission, news outlets took note. CBS’ award-winning chief medical correspondent, Jon LaPook, reached out to Marr and her research team in spring 2020 to ensure that the network was promoting correct information about how the coronavirus was spreading. The two were in regular contact during the unprecedented COVID-19 outbreak. After three years of phone and email interviews, the "60 Minutes" piece finally brought LaPook and Marr together in the same room.

“I was thrilled to finally meet LaPook in person when he came to Virginia Tech to interview me because it felt like we had been through a war together,” said Marr, the Charles P. Lunsford Professor and University Distinguished Professor. “We immediately hugged when we saw each other.”  

Marr sat down with LaPook for an hour-long conversation while the cameras rolled. They discussed the difference between droplets and aerosols and set the stage for the live demonstration that would take place after the interview. 

It’s all smoke and mannequins

Marr’s research has demonstrated that viruses can be transported in respiratory aerosol particles similar to the way cigarette smoke travels through a room. That evidence supported the practice of wearing masks in indoor spaces and showed that improving ventilation indoors could slow the virus from spreading between individuals.

The crew from "60 Minutes" visited Virginia Tech’s Blacksburg campus and spent nearly a day and a half with Marr and her research team. While there, they captured an inside look at how ventilation can impact the risk of transmission by filming a demonstration using mannequins and a smoke generator. 

The demo was the brainchild of Aaron Prussin, a research scientist at Virginia Tech who has worked in Marr’s research group for 10 years and manages the Environmental and Water Resources labs in the Charles E. Via, Jr. Department of Civil and Environmental Engineering.

When Prussin learned that the "60 Minutes" team wanted to demonstrate how outbreaks like the one experienced by the Skagit Valley Chorale were possible, he developed the ventilation-focused show-and-tell featuring mannequins. 

Research Scientist Aaron Prussin demonstrates exhalations containing viral particles with smoke and mannequins during filming. Photo by Lee Friesland for Virginia Tech.

“I learned from our facilities team that we have a few rooms on campus where we can dial in whatever air exchange rate [ventilation] we want from a tablet,” said Prussin. “It dawned on me that if we could get some mannequins from the Department of Apparel, Housing, and Resource Management, set them up in one of those rooms where ventilation was easily controlled, and use our smoke generator to show smoke coming out of one of the mannequin’s mouths, viewers could easily visualize the effect of ventilation.” 

When airflow was poor, the ventilation exhibit showed more visible smoke coming from the mannequins’ mouths. This smoke resembled exhalations containing viral particles from someone who was sick. 

“We saw the smoke or ‘cough’ linger around the other mannequins [healthy people], leading to longer exposure to viral particles and increased risk of infection,” said Prussin. “We also showed that when ventilation is good, the smoke [viral particles] is quickly removed from the space and virus exposure to healthy people is minimized.”

The "60 Minutes" crew captures footage of the air ventilation exhibit while Linsey Marr (at back left) and Jon LaPook prepare to discuss the impact of ventilation on particle transmission. Photo by Lee Friesland for Virginia Tech.

Marr said the demonstration was a great educational tool for her students and for the public moving forward. 

“As we head into another COVID-19 and flu season, good ventilation and filtration continue to be a key aspect of reducing the risk of infection," said Marr. “This can be done by opening a window, turning on exhaust fans, or running a portable air filtration unit, or some combination of these.”

The future of flu research

Marr’s research on the transmission of illnesses through the air doesn’t end with the "60 Minutes" interview. She’s tackling a project that ties back to something that originally sparked her interest in this area of research: the health of young children in day care and specifically, her own son. MITIGATE FLU is part of an $8.8 million grant from Flu Lab with collaborative research from the University of Michigan, University of Pittsburgh, Emory University, and Georgetown University.

“Our goals are to figure out how behavioral and environmental factors affect flu transmission and to identify effective interventions that can be used in day care centers to mitigate transmission,” said Marr. “Along the way, we hope to figure out how much transmission occurs by breathing in the virus from the air versus being sprayed by large droplets carrying the virus versus touching contaminated surfaces.”

Watch the "60 Minutes" promo.

Written by Chelsea Seeber