Linsey Marr weighs in on possibilities of COVID-19 transmission

Linsey Marr, the Charles P. Lunsford professor in the Charles E. Via Jr. Department of Civil and Environmental Engineering, does research on the emissions, fate, and transport of air pollutants in order to provide the scientific basis for improving air quality and health.  

“I’m passionate about doing research to protect human and environmental health and reduce threats to public health,” said Marr.

Marr began studying the airborne transmission of infectious diseases after her growing frustration watching her young children frequently catch infectious diseases from their peers at daycare. She studies factors that affect infectious disease transmission including humidity and the length of time that viruses survive in the air and on surface.

While her research primarily focuses on flu transmission, many of the concepts from her research can potentially be applied to the spread of COVID-19.

While most respiratory viruses decay rapidly when humidity is above 40 percent, there is not enough research about how this virus behaves to know whether increased humidity will have any effect on transmission.

“Airborne viruses will eventually settle on surfaces and can be picked up by someone who touches them,” she said. “The ability to survive varies with temperature, humidity, and surface material.”

Marr noted that viruses in small droplets can float around in air for many hours, but they will likely be diluted unless you’re in a small, confined space. The concentration of airborne viruses is quite high at close range, but the concentration falls off rapidly as an individual gets farther from the source.

To that end, that’s the reason why Gov. Ralph Northam and Virginia Tech President Tim Sands have joined federal officials in directing that people avoid gatherings more than 10 people and isolate as much as possible.

While there are many assumptions that can be made based on other viruses, many of them are just assumptions. “I wish we knew more,” said Marr.