Philadelphia's Air Quality Reaches Dangerous Levels Amidst Wildfire Smoke and Climate Change Concerns.

Philadelphia now has the worst air quality of any major city in the world due to smoke from wildfires in Canada. The air particles are considered "hazardous" and everyone is likely to be affected. The Lehigh Valley ranks as the second worst air quality with 419, while Susquehanna Valley ranks third. Tips for dealing with smoke include avoiding extended time or strenuous activities outdoors, closing all windows and doors, and keeping pets inside as much as possible.