Updated: Sep 12, 2022
For the third day in a row, hydrogen sulfide (H2S) levels were so high Tuesday that an exceedance of Pennsylvania’s 24-hour average was guaranteed by 10 a.m. at Allegheny County Health Department’s air quality monitor in Liberty Borough.
Tuesday’s exceedance will mark the 43rd of the year at the Liberty monitor.
There have been 16 such exceedances at ACHD’s air quality monitor in North Braddock, the most recent of which occurred Monday.
Unfortunately, the Mon Valley grappled with more than just high levels of H2S over the past few days: It also endured an exceedance of the federal, health-based standard on Sunday for fine particulate matter, also known as PM2.5, based on preliminary data from ACHD’s Liberty Borough monitor.
For perspective on how bad air quality has been lately, the airnow.gov NowCast Air Quality Index (AQI) ranked Liberty-Clairton’s as the worst air quality in the country at times on Sunday, Monday, and today, when it soared to levels deemed “unhealthy” by the U.S. Environmental Protection Agency.
During periods of unhealthy air quality, the EPA suggests that people with heart or lung disease, older adults, children, and teens should avoid strenuous outdoor activities, keep outdoor activities short, and consider moving physical activities indoors or rescheduling them to reduce exposure to air pollutants.