14. San Jose-San Francisco-Oakland, CA
On the 18th place on our list of the most polluted cities in the US in 2017 is the area of San Jose-San Francisco and Oakland. It is ranked 6th for 24-hour particle pollution out of 186 metropolitan area, while for annual particle pollution out of 184 metropolitan areas it is 4th. A number of people dealing with lung cancer is 3,778.

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