The air quality metric is one of many that factor into the overall Best States rankings. See the Best States methodology for a detailed look at the data behind the analysis. 50 States #1 in Air ...

Forecasters are warning that air pollution may become trapped and adversely affect humans, due to weather conditions in the U.S.

the number of days with an air quality index below a certain threshold and the number of violation points against drinking water systems in each state. Learn more about the best states for air and ...