There have been a lot of studies over the past 10 years showing how bad air pollution is for people. In the short term it reduces cognitive abilities on top of all the physical maladies. In the long term it can have major mental and psychological impacts.
Regarding politics, we can discuss cause-effect, risk, and technical solutions without getting political. But at some point the science has to be implemented to see wide-ranging benefits, and there are certainly cases where science can't be implemented without legislation.