HARRISBURG, Pa., Oct. 20 -- The Pennsylvania Department of Environmental Protection issued the following news release:
The Pennsylvania Department of Environmental Protection (DEP) has declared a Code Orange Air Quality Action Day for fine particulate matter (PM 2.5) for Tuesday, October 20, 2026, in Allegheny County.
A temperature inversion will occur, and trap pollutants close to the surface for several hours in the morning on Tuesday. During this inversion, there will be hourly values in the Code Orange or higher range. Sensitive groups of the population including children, older adults, and those with respiratory conditions should avoid heavy outdoor activity during this time.
Residents are encouraged to check www.airnow.gov(http://...