5. Modesto – Merced, CA
No improvements for this area either, as the air is even worse in 2017 than in 2016. The cities in this area rank 5th on our list of cities with the worst air pollution in the US. They were ranked 9th in 2016 and 6th in 2017 for particle-pollution, and they moved from 7th to 6th position in the same period on the list of most ozone-polluted metro areas in the US. Radical changes need to be done as 806,843 citizens are breathing this low-quality air.
Pixabay/Public Domain
