Updated: Sep 13, 2022
Allegheny County experienced two more air quality exceedances last week when the midnight-to-midnight 24-hour average concentration of hydrogen sulfide (H2S) exceeded Pennsylvania’s air quality standard of 0.005 ppm.
Those exceedances occurred at Allegheny County Health Department’s (ACHD’s) North Braddock air quality monitor on both Dec. 23 and Dec. 24, with 24-hour concentrations of 0.007 ppm and 0.008 ppm, respectively.
For those keeping track: The latest H2S exceedances bring the total to 28 so far this year, according to preliminary data from ACHD.
When it comes to H2S, Allegheny County saw the highest one-hour concentration (across all ACHD monitors for the entire year) between midnight and 1 a.m. today at the North Braddock monitor – 0.060 ppm. During that same hour, data show sulfur dioxide concentration at the North Braddock monitor was 0.070 ppm, close to the federal health-based standard of 0.075 ppm.
We know that air quality data can be confusing and that sometimes visuals help – so check this out: