The biggest polluters on earth are China and India, both which are inexplicably exempt from most of the economic restraints that the international scientific community wants to impose on the U.S. In 100 years they may (but probably won’t) improve their production facilities and processes to benefit the environment. In the meantime, they are laughing their a**es off and collecting untold wealth from activities denied businesses in this country.
Lots of maps out there give real values of how much countries are outputting (India doesn't seem to report so much). Also, Malta? http://aqicn.org/map/world/