Stay inside: Air quality last week reached dangerous levels

Air quality across the region reached unhealthy levels last week due to pervasive wildfire smoke from Canada and Minnesota. Beaver County residents were encouraged to limit outdoor activity until the pollution subsided.

More than 100 wildfire blazes in Canada as well as several in northern Minnesota caused widespread smoke across the Midwest and Northeast U.S.

On July 17, Detroit, Chicago and Washington, D.C. ranked as the world’s most polluted major cities. The dark yellow haze filling the skies of Beaver County is also present, and even more severe, across Massachusetts, New Hampshire, Vermont and Maine.

The vast majority of the fires in Canada are still out of control, due to the extremely dry conditions that followed severe drought and continual heat waves. In a July 16 statement, Breathe Project, a Pittsburgh clean air initiative, also attributed the wildfires to climate change, saying it has made extreme weather conditions and their dangerous effects “increasingly likely and more severe.”

According to a meteorologist from the National Weather Service in Moon Township, a wind shift drove smoke from the northeast into the area, causing the sudden decrease in air quality. He predicted that the highest concentration of the pollution would last July 16–17 but said a cold front on Saturday, July 18 would “scour out some of the smoke and lower air pollution.”

On July 16, for what Breathe Project states is the fourth time in Pennsylvania history, the entire state was placed under a Code Red Air Quality Alert, issued by the Department of Environmental Protection (DEP). A Code Red alert identifies the air quality as “unhealthy.” But in Allegheny County, the air quality was classified as Code Maroon, meaning it had reached “hazardous” levels on the Air Quality Index (AQI) scale.

Breathe Project posted on Facebook about the air quality level, saying it was “as bad as it gets.” They strongly recommended that everyone avoid outdoor activities. However, due to severe high temperatures in the region, the post included another warning: “If you don’t have AC, staying inside with windows shut can be dangerous in this heat — find a cooling center or AC if you’re overheating.” 

Also on July 16, the Allegheny County Health Department (ACHD) invoked the Mon Valley rule, requiring certain corporations to reduce their emissions, abiding by plans approved by the ACHD. The rule applies to facilities like steel plants, chemical manufacturers, landfills and construction materials companies. 

The DEP also prompted individuals to limit emissions that may contribute to fine particulate matter pollution. They encouraged limiting the use of lawn and garden equipment powered by gas, reducing the use of wood stoves and fireplaces and avoiding the open burning of materials such as leaves and trash. 

By July 17, the air quality alert had changed to Code Purple, classified as “very unhealthy,” rather than “hazardous.” However, most people were still told to limit outdoor activities, and the DEP recommended people keep doors and windows closed, keep medications for respiratory issues handy as necessary and wear an N95 while outside.

On July 18, the smoke began to clear. The cold front seemed to “scour out” some of the pollution as predicted, and rain showers throughout the morning and afternoon also helped clean up the smog. Thunderstorms Saturday night, which prompted flash flood warnings in Beaver County, also played a role in removing particulate matter from the sky — washing the air, so to speak.

By Sunday, the air quality was classified as Code Red, still “unhealthy,” but on its way to normal. On Monday, July 20, a Code Yellow alert was issued, labeling the air quality “moderate,” just one level away from “good.”