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If You're in a Car, This is the "Worst Scenario" for Catching COVID, Study Shows

“Driving around with the windows up and the air conditioning or heat on is definitely the worst scenario.”
woman taxi driver in a black protective medical mask with white hair and a gray T-shirt is sitting in a left-hand drive car

With COVID often transferred from person to person, you may think of your car as a safe place. It isn't always. If you have a passenger, "driving around with the windows up and the air conditioning or heat on is definitely the worst scenario, according to our computer simulations," says Asimanshu Das, a graduate student in Brown's School of Engineering, and co-lead author of a new study in Science Advances. "The best scenario we found was having all four windows open, but even having one or two open was far better than having them all closed." Read on to find out why, and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had Coronavirus

The Authors Ran Simulations to Find the Safest Way to Drive

The authors started by running a simulation. "Transmission of highly infectious respiratory diseases, including SARS-CoV-2, is facilitated by the transport of exhaled droplets and aerosols that can remain suspended in air for extended periods of time," report the authors. "A passenger car cabin represents one such situation with an elevated risk of pathogen transmission." In their study, they "present results from numerical simulations to assess how the in-cabin microclimate of a car can potentially spread pathogenic species between occupants, for a variety of open and closed window configurations." Their conclusion? "An air flow pattern that travels across the cabin, farthest from the occupants can potentially reduce the transmission risk. Our findings reveal the complex fluid dynamics during everyday commutes, and non-intuitive ways in which open windows can either increase or suppress airborne transmission."

In other words: keep "all four windows open, but even having one or two open was far better than having them all closed."

RELATED: 7 Tips You Must Follow to Avoid COVID, Say Doctors

The CDC and Dr. Fauci Have Warned Against Automobile Travel

The risk of catching COVID from a driver or passenger in a poorly-ventilated car is why the CDC and Dr. Anthony Fauci, the nation's top infectious disease doctor, have warned about travel. "As warm and pleasant as they are during the holiday season, [try] to keep the gatherings to people within the immediate household," Fauci has said. "And if you have other people come in, be very careful. Hopefully they may have been tested. So you know, that very recently there were negative or they have their own bubble where they're very, very careful in themselves, protecting themselves so that when you get together is much less of a risk [than when] someone who just gets from an airport or a train station gets in an Uber, but comes to your house, sits down. And then you have a social setting. You have no idea who they were exposed to. Those are the things you avoid."

"Consider limiting the number of passengers in the vehicle to only those necessary (for example, choose one or two family members who are not at higher risk for severe illness to run the essential errands)," says the CDC. "Improve the ventilation in the vehicle if possible (for example, open the windows or set the air ventilation/air conditioning on non-recirculation mode)."

As for rideshares, the CDC says the same, and also advises: "Don't ride in a vehicle if the driver or other passengers who don't live with you are not properly wearing face masks." So avoid riding in poorly-ventilated cars with other people, and to protect your life and the lives of others, and don't visit any of these 35 Places You're Most Likely to Catch COVID.