The Two Bees in the Fillmen

There is just so much talk about two bees in this movie. Most people we see outside at any point are wearing masks, which was keno strange to watch this year. I don't think they're wearing masks for any disease control reason. My best guess is that so it's part of the setting, that the world they live in is after a nuclear war has taken place. So my guess is it's supposed to be that there are radio nucleides everywhere,. and that the masks are to help prevent people from inhaling radioactive particles.