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UTSA study shows airborne coronavirus particles could travel more than a mile

Study does not show for how long the plumes of virus particles could remain concentrated enough to infect someone

SAN ANTONIO – Airborne coronavirus particles could travel for more than a mile, depending on weather conditions, according to a new study authored by a UTSA associate professor of mechanical engineering.

The peer-reviewed study, authored by Kiran Bhaganagar and her graduate student, Sudheer Bhimireddy, used meteorological data from New York City in March and April to run computer simulations on how the weather patterns would affect the airborne plumes of virus particles -- hundreds of thousands of which could be expelled in a single cough.

“From the initial time of release, the virus can spread up to 30 min in the air, covering a 200-m radius at a time, moving 1–2 km from the original source,” according to the study.

The study does not indicate how much of the virus must be present to infect someone, though. So it does not reflect at what point the plume may no longer be a danger to bystanders.

However, Bhaganagar still sees the results as evidence of the role airborne transmission could have played in the COVID-19 pandemic.

“For most of the cases, we found around a kilometer was where they were significantly present,” she told KSAT Tuesday. “And so, even though we don’t know how many numbers are needed to get infected, there is a fair amount of chance that they can be the cause of the transmission -- as one of the pathways.”

Though prevention efforts have focused on avoiding close contact with infected people, there has also been discussion over the possibility of airborne spread of the coronavirus.

The Centers for Disease Control and Prevention published, then retracted, statements on its website earlier this month that seemed to indicate it believed the virus could hang around in the air and spread over an extended distance, according to an Associated Press report.

The CDC website currently states a draft version of changes to its recommendations had been mistakenly posted, and that it is updating its recommendations regarding airborne transmission.

For now, the website says the virus is thought to be spread between people who are within six feet of one another through respiratory droplets.

The UTSA study is expected to be published in the December issue of the journal Environmental Research. It was funded through a grant from NASA MIRO Center for Advanced Measurements in Extreme Environments.

Bhaganagar is a co-principal investigator at the NASA MIRO CAMEE at UTSA.


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