5. Pittsburgh-New Castle, PA

Forbes: America's Dirtiest Cities

Population: 2.4 million
Year-round particulate pollution rank: 7
Short-term particulate pollution rank: 3
Ozone pollution rank: 24

(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.

More from this Slideshow

0 of 0

America's Dirtie... You don't have to live next to a coal plant to suffer the effects of air pollution. The American Lung Association figures that half the nation lives where the air is sometimes dangerous to breathe. To get these dirtiest cities we averaged the Lung Association's individual findings on ozone and particulate pollution from its report State of the Air 2011.
(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
Birmingham-Hoove... Pollution levels have improved a lot, but Birmingham suffers from being located in a valley that tends to trap stagnant summer air. Two interstate highways don't help either.

(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
7. Birmingham-Ho... Population: 1.2 million
Year-round particulate pollution rank: 8
Short-term particulate pollution rank: 8
Ozone pollution rank: 21

(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
Modesto, CA Home to E&J Gallo Winery, which also operates the largest wine bottle manufacturing plant in the world.

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
6. Modesto, CA Population: 500,000
Year-round particulate pollution rank: 10
Short-term particulate pollution rank: 12
Ozone pollution rank: 14

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
Pittsburgh-New C... This old steel town is a new boom town for natural gas drilling, and downwind of coal-fired power plants in Ohio and West Virgina.
(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
5. Pittsburgh-Ne... Population: 2.4 million
Year-round particulate pollution rank: 7
Short-term particulate pollution rank: 3
Ozone pollution rank: 24

(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
Fresno-Madera, C... San Joaquin Valley air might be getting better; last August, for the first time in recorded history, Fresno had no days with unhealthy ozone levels.
(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
4. Fresno-Madera... Population: 1.1 million
Year-round particulate pollution rank: 6
Short-term particulate pollution rank: 2
Ozone pollution rank: 4

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
Visalia-Portervi... Proximity to the giant trees of Sequoia National Park isn't enough to clean Visalia's smoggy San Joaquin Valley air.

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
3. Visalia-Porte... Population: 430,000
Year-round particulate pollution rank: 2
Short-term particulate pollution rank: 7
Ozone pollution rank: 3

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
2. Los Angeles-L... Millions of cars, a huge port in Long Beach, busy airports -- at least L.A.'s smog is better than it used to be.
(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
2. Los Angeles-L... Population: 17.8 million
Year-round particulate pollution rank: 2
Short-term particulate pollution rank: 4
Ozone pollution rank: 1

(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
Bakersfield-Dela... Hot, dusty and surrounded by California's biggest oil fields, Bakersfield has all the ingredients for the worst air in the nation.
(iStock)

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
1. Bakersfield-D... Population: 800,000
Year-round particulate pollution rank: 1
Short-term particulate pollution rank: 1
Ozone pollution rank: 2

More From Forbes:
America’s Most Dangerous Cities
America’s Dirtiest Hotels
The Most Beautiful College Campuses

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.
More From Forbes Click here to see the full list of America's dirtiest cities.