Ah, yes, the infamous reports that Pittsburgh is the sootiest city. Quite surprising when you actually live here and see very little in the way of smog downtown.
The State of the Air report, if I recall correctly, is comprised of readings from an array of air sensors in the area, and the highest measurement dictates the city's pollution level. One of the Pittsburgh area sensors is in a valley with the largest coke works in the nation in Clairton (~15mi SE of the city). Hardly representative of the city, but it gets lumped in with us.
The State of the Air report, if I recall correctly, is comprised of readings from an array of air sensors in the area, and the highest measurement dictates the city's pollution level. One of the Pittsburgh area sensors is in a valley with the largest coke works in the nation in Clairton (~15mi SE of the city). Hardly representative of the city, but it gets lumped in with us.