World's Dirtiest Citites

Forbes recently published a list of the dirtiest cities in the world and the U.S. Interestingly, the dirtiest cities in the world were mostly due to heavy metal pollution, especially lead, and were concentrated in the former Soviet Bloc. The dirtiest cities in the U.S. are right in our backyard: California! For more information and some pictures of the polluted cities visit: FORBES.