14. San Jose, CA
Major Causes of Pollution: 2 (Traffic Congestion, Computer Industry)
Life is good at San Jose despite the heavy traffic the city experiences from time to time. However, one of the biggest pollutants in the city is caused by the thriving computer industry. Various solvents have been leaked in the soil, and because the city is enclosed by water, blockages often occur due to dumping in water. Many organizations have made an effort to lessen and prevent these problems.
