Code Orange air quality warning declared for Mon Valley

An air quality action day has been issued for Allegheny County’s Mon Valley because of a spike in particulate matter pollution.

The Pennsylvania Department of Environmental Protection declared a Code Orange Air Quality Action Day on Tuesday, which was caused by a strong temperature inversion in the morning and light winds that will keep concentrated levels of pollution near the surface.

Inversions are created when air on the ground is quite warm, but cold air masses move above the warm air mass and trap pollutants near the surface.

According to the Allegheny County Health Department, the inversion is expected to break later Tuesday morning, but even lower air quality readings in the afternoon won’t be enough to keep the 24-hour daily average out of the Code Orange range.

An Air Pollution Warning has been issued for the Mon Valley for today, April 11. The 24-hour PM2.5 standard for the Mon Valley has been exceeded at an official monitoring station in the Mon Valley. pic.twitter.com/tswLQdE5bB

— Allegheny County Health Department (@HealthAllegheny) April 11, 2023

The Liberty-Clairton area of Allegheny County is affected by the Code Orange action, according to the DEP. The area includes Clairton City, Glassport Borough, Liberty Borough, Lincoln Borough, and Port Vue Borough.

The DEP said that young children, seniors, and those with respiratory problems, such as asthma, emphysema, and bronchitis, are especially vulnerable to the effects of air pollution and should limit outdoor activities during this time.

Residents and businesses within the Code Orange area are strongly encouraged to help reduce fine particulate matter air pollution by reducing or eliminating fireplace and wood stove use; avoiding the open burning of leaves, trash, and other materials; and avoiding the use of gas-powered lawn and garden equipment.

The county health department also said that companies most significantly contributing to particulate pollution in the Mon Valley region are required to temporarily reduce particulate emissions, because of the Code Orange action.

The biggest source of air pollution in Allegheny County comes from industrial facilities, which are concentrated in the Mon Valley. Air pollution has decreased dramatically over the last decade, but the region is still among the worst in the nation.

For more information, visit the DEP air quality monitoring website at www.ahs.dep.pa.gov/AQPartnersWeb and the Allegheny County Health Department air quality website at www.alleghenycounty.us/airquality.