Regarding #2, I was in Shanghai and Beijing in late 2019. I had a lot of discomfort first landing in Beijing; Shanghai's haze was not as bad but it still shows

Regarding #2, I was in Shanghai and Beijing in late 2019. I had a lot of discomfort first landing in Beijing; Shanghai's haze was not as bad but it still shows up in pictures. I imagine this is what the USA's coal country used to feel like when it was in active swing.