Russell Zerbo has worked as an advocate for Clean Air Council in Philadelphia for 13 years.

The city, much like most major urban areas in the U.S., it doesn't attain the 2015 ground-level ozone standard, and it also is not projected to attain the EPA's updated 2024 particulate matter 2.5 standard.

The absolute largest source is transportation, but that in and of itself is very broad.

It includes the...

Philadelphia International Airport, it includes the region's marine traffic, which is fairly significant.

And obviously, cars and trucks with an emphasis on trucks, like, you know, your regular automobiles produce a certain amount of air pollution.

But your larger diesel vehicles produce much more.

In addition, Zerbo's Clean Air Council runs their own air monitoring program.