I am not a rocket scientist...but I play one on TV!
Look, I don't know. Of course, I live and work in Glendale, right smack between Pasadena and the Valley. All I can say is, even being "above" the masses, in Glendale we call it "the Glendale grime"
the AQMD recently reported that all of the basin is "unhealthful".
Sometimes it is a matter of terms.
I'd like to share more but the Tulia mavens won't let me.