Originally Posted by
acidfast7
Not to sound too condescending, but that's what happens (pollution) when you don't want to live in the middle of nowhere (less than 2.5M ppl, which I consider the critical mass to effective public transportation by bus and rail).
Mexico City's air is particularly dirty because of high pressure systems that move over the city and trap air in the Valley of Mexico.
Regarding effective public transport, you needn't live in a city of more than 2.5 million people in Mexico to find that. The bus system is excellent in just about any Mexican town because there is a large percentage of the population that can't afford to buy a car.