Internationally, males smoke more than US males. Supposedly.
US smoking rate is 18%, China 25%, not a big difference.
Pollution levels vary significantly, but to simplify it, heavy pollution in a band from Morocco to China, with Japan, Korea nd Italy on the edges. Rest of the world is significantly cleaner, including the US.
In the US, smokers tend to be rural, away from the big cities and away from population centers ruled by nanny-state types.
In China, I suspect that smoking is far more prevalent among the city-dwelling elites, so we’d see a different demographic affected.