Covid-19: How many windows to keep open to cut virus build-up

Regularly opening car windows for 10 seconds can cut the build-up of Covid-19 particles by 97%, a study has found.

Swansea University found the difference in air pressure between the inside and outside of a moving vehicle creates a through-draught to suck out the virus.

For driving below 30mph (48kph), opening all four windows is most beneficial, but on faster roads, opening two on a diagonal can have an even bigger impact.

The team's research, done on behalf of the Welsh government's Covid-19 Technical Advisory Group, also discovered that sitting in the front seats was far safer than being in the back, owing to the prevailing direction of the airflow through the car.