How do scientists study about smog and air pollution?

Answer 1

well a lot of it was theory. about the effects of air traffic on air pollution.

then in the days after the twin towers, air traffic was grounded.

And air quality improved by an every greater level than the scientists thought possible.

there are various ways of collecting air samples, from ones on buildings, on motorways to weather balloons, and now satellites that can scan the gases in clouds

Answer 2

Uh, well they collect samples. Refine your questions.

Answer 3

with instruments