Don't miss a thing by getting the day's biggest stories sent direct to your inbox Metrolink's ventilation system changes the air at least 20 times an hour and bosses say this will help prevent Covid-19 infection - especially if passengers wear face-coverings.
However, according to experts hired to test Covid safety on the trams, heavy-breathing - such as after a short run or while talking loudly or shouting - could increase the risk of aerosol transmission.
Wearing a mask, meanwhile, is said to slash the risk of infection by as much as two thirds. Transport bosses shared the findings this week amid the lifting of restrictions which, despite a Government appeal to 'minimise the amount that you travel where possible', is already drawing