[Da Coyote]

Hmmmm, seems like this CA place (whatever that is...I believe it used to be a place that was envied) is really polluted.

What those folks need to do is to elect lots of liberal dim-bulb-crats who will most certainly clean things up, make businesses better, and give all a qualilty education.

/s

[Vigilanteman]

Plus eight of the top ten are in the southwest where naturally occurring dust is a big, if not bigger, factor than industrialization. Of the remaining two, both St. Louis and Pittsburgh are dominated by massive rivers which cause chronic flooding in low lying areas (producing mold) as well as an abundance of flora (producing pollen).

Blaming the Homer City power plant for Pittsburgh's relatively mild air pollution is idiotic as well since Homer City is mostly to the east and north whereas the worst pollution cited is mostly to the west. FWIW, our prevailing winds are mostly from the west.

[Mariner]

Actually they include plain old dust in the particle counts and this is an arid farming area.

The tractors stir up a LOT of dust, but it's generally not toxic.

The valley also has it's fair share of plain old smog.