Keeping Windows Down, Wearing Masks Reduces COVID-19 Risk in Cars

For individuals driving with groups outside their households or using ride-share services, keeping the windows rolled down and wearing masks can decrease the risk of spreading COVID-19, according to research results from the University of Surrey in the United Kingdom.

A team at the university’s Global Centre for Clean Air Research (GCARE) used sensors to monitor the concentration of pollution particles to map how those particles varied during different settings in the vehicle and to evaluate exposure doses for 3 different ventilation settings. They evaluated scenarios with the air conditioning on and using fresh air, with air conditioning on and using air recirculation, and the windows open.

The team found that maintaining a continuous intake of fresh air by keeping the windows open while also wearing a mask is the best way to guard against the transmission of COVID-19, according to a statement.

However, this scenario also increases occupants’ exposure to toxic air pollution particles.

This creates a dilemma because guarding against air pollution in turn increases the risk of COVID-19. The study results showed that the probability of transmission increased by 28.5% when windows were closed and air recirculation was switched on.

To balance both these issues, the team found that the best chance of remaining safe from both air pollution and COVID-19 was to keep the windows closed while running the air conditioning on ambient mode, in which it draws in fresh air from outside. This approach avoids external air pollution while minimizing exposure to COVID-19.

Lead author Prashant Kumar, PhD, founding director of GCARE at the University of Surrey, said in the statement research like this is essential to end the COVID-19 pandemic.

“It’s vital that the scientific community provides society with the data it needs so we can learn from the painful experience of the past 2 years,” he said. “Our research found that if your priority is to reduce the risk of contracting COVID-19, wearing a mask and keeping car windows open is the ideal approach.”

Reference

The combination of mask wearing and keeping windows open is best for reducing COVID-19 risk in cars, finds a new study. University of Surrey. News release. August 24, 2021. Accessed August 27, 2021. https://www.surrey.ac.uk/news/combination-mask-wearing-and-keeping-windows-open-best-reducing-covid-19-risk-cars-finds-new-study