São Paulo, Brazil is the most populated city in the Western Hemisphere, with a population of over 22 million people.
The city of Bakersfield, California is the most polluted city as of 2014. The second most polluted city in the state is Merced.
Western
Most of the US is in the western hemisphere, with only a small portion of Alaska extending into the eastern hemisphere.
western
Western Hemisphere
from my research the most polluted city in china is Linfen.
Most of Europe is in the Eastern Hemisphere.
The largest metropolitan area in the western hemisphere is Mexico City with 21.2 million
Milwaukee is the most polluted city because of the industry.
Los Angeles Greater area is the most polluted city in the United States.
Western Hemisphere