This week, coronavirus infection in big cats, how new diseases emerge in the first place, whether face masks work against coronavirus, can Covid-19 spread through the air, can you catch Covid from urine, and is previous TB a risk factor for severe coronavirus disease? Also, will wearing a face mask protect other people from you, is 5G a risk for Covid-19, and can coronaviruses be carried in semen? Join Dr Chris and Azania as they Ask the Naked Scientist... Like this podcast? Please help us by supporting the Naked Scientists