Covid can remain active on a mask, depending on the fabric for between 2 and 7 days. The worst thing you can do with a virus like this is touch things then touch your face. But with people constantly adjusting their masks, taking them on and off to eat and drink, they are increasing their chances of being exposed to covid. Washing your hands frequently and not touching your face, along with social distancing is your best defense against exposure to the virus. If you choose to wear a mask, have a CLEAN, unused mask that you put on for a specific outing, don't fuck with it, and then throw it out or wash it. The way most people are using masks is increasing their chances of coming in contact with covid.