It really depends where you live. What's the pm 2.5 in your city? Mine isn't high enough to worry about outdoor pollution, and if it was I would move. But peop

It really depends where you live. What's the pm 2.5 in your city? Mine isn't high enough to worry about outdoor pollution, and if it was I would move. But people in high smog cities do wear masks. They have regular smog warnings too; people treat it like the weather. See this pre-pandemic article showing people wearing masks during a smog outbreak: https://www.ctvnews.ca/lifestyle/beijing-locals-don-colourful-face-masks-as-smog-hovers-over-city-1.2691234?cache= https://www.ctvnews.ca/lifestyle/beijing-locals-don-colourfu... For cars, I think the biggest factor is choosing a good filter and making sure it remains in good working order.