If you have been hearing about poor air quality in New York City Friday, you can breathe a deep sigh of relief (literally): ...

One possible reason for bad air quality in the city is a fire that broke out yesterday afternoon in Lancaster, Pennsylvania, ...

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This measure, based on data from the Environmental Protection Agency, evaluates states on the number of days the Air Quality Index in counties was not rated “good.” U.S. News calculated a ...

It comprises two measures: 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 ...