The Allegheny County Health Department announced this week that the Liberty air monitor measured its lowest levels of PM 2.5 pollution to date last year. PM 2.5 refers to pollution particles of 2.5 micrometers in diameter or smaller.
“We are pleased that for the first time the PM 2.5 at the Liberty monitor has met the EPA standard,” said County Executive Rich Fitzgerald in the press release, referring to the Environmental Protection Agency.
The 2018 annual PM 2.5 value for the Liberty monitor was 11.5 micrograms per cubic meter, slightly lower than the EPA standard of 12. Last year’s number represents a 14 percent drop from the 2017 value of 13.4. All other county monitors are also in compliance, according to the release.
The 24-hour value for PM 2.5 was 28 micrograms per cubic meter, lower than the EPA standards of 35 and below the 2017 value of 36.5. The 24-hour a value is a three-year average of annual 98 percentile 24-hour PM 2.5 concentrations.
“We have worked diligently to address the issues at the Liberty monitor, and the 2018 data is showing that significant progress is being made,” said Dr. Karen Hacker, director of the health department, in the press release. “In addition to meteorological influences, we believe these improvements at the Liberty monitor are a result of strong enforcement actions, fines and penalties, and consequent improvements made at U.S. Steel’s Clairton Coke Works.”
The announcements follow months of bad news on air quality in the county.
Last week, the county received a failing air quality grade from the American Lung Association, based on pollution measurements from 2015 to 2017. And on Monday, environmental organizations sued U.S. Steel over emissions since a Dec. 24 fire at its Clairton Coke Works, which also affected operations at its Edgar Thompson Works and Irvin mill.