top of page

Liberty-Clairton Again Tops U.S. List of Places with Worst Air Quality; H2S Standard Again Exceeded

Updated: Sep 14, 2022

Folks in the Liberty-Clairton area on Monday again endured some of the worst air quality in the nation, according to, a U.S. Environmental Protection Agency website that tracks the Air Quality Index (AQI) throughout the United States.

According to initial data from the Allegheny County Health Department (ACHD), the 24-hour average concentration of hydrogen sulfide (H2S) at the Liberty monitor ended Monday at 0.007 ppm, exceeding the state’s limit of 0.005 ppm.

While concentrations of sulfur dioxide (SO2) and fine particulate matter (PM2.5) in Allegheny County Monday were less-than-ideal, they did not cross any regulatory lines.

Editor’s Note: We prepped some graphs for those who would like to take a deeper dive into the data.

bottom of page