[thkim]

This is probably before the virus was better understood. Some argue that the virus can be spread by the host 48 hours before a symptom is developed. Whether true or not, what's so difficult about everyone wearing a mask just to be on the safe side? Is it because there isn't enough masks to wear every day? It's fine with wearing same mask every day as long as it can contain droplets from spreading outside of virus host.

[stubish]

Given the lifespan of the virus on various surfaces, reuse seems fine in any case. If you need to go out every day, cycle between 3. Weekly shopping, just one.