Smog in China reaches very high levels. At such times motor vehicles are restricted from the cities and factories shut down for some time.
Cyclists, pedestrians, everyone in the cities has to wear a mask to protect their vulnerable lungs. Some smog particles are large enough to get to the lungs and cause respiratory problems over time.
A government official in the south-western city of Dazhou in Sichuan Province once said that the lingering smog was caused by smoking bacon. Funny at the wrong time.
In Kenya some month or two ago some Indians were discovered to have polluted land and caused serious health problems among the locale's folks-barrenness, mental problems(some kind of upumbavu) in children...and the Indians escaped scot free.
Seems as long as there's profits to be enjoyed, humans will mess up the environment and not worry about the environment and the poor.