By BRYAN WALSH, Time, Sept. 29, 2011
10. Pittsburgh/San Diego
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During its industrial heyday, Pittsburgh was an environmental catastrophe, a steel-mill city where the soot was visible on residents’ windowsills. Over the years, Pittsburgh has gone from a city of steel workers to one of middle managers — though, thankfully, the Steelers haven’t gone away — and the air has improved. But pollution is still a major problem — an estimated 47,000 children in the greater Pittsburgh area suffer from asthma. Meanwhile, most Americans probably think of San Diego as a Southern California paradise. But heavy traffic on its highways — as well as localized pollution from the city’s busy port — can turn the air brown, especially during rush hour. San Diego averages nearly 30 days of unhealthy ozone levels each year — though like Pittsburgh, its air has improved in recent years.
8. Hanford-Corcoran, Calif.
Really, you could make all of Southern California one big bad air zone, but this metropolitan space does manage to stand out. The Hanford-Corcoran area, in the southern San Joaquin Valley, has major air-pollution problems, with industry and traffic congestion amplified by high temperatures. It doesn’t help that even if Hanford reduces its own pollution, it will still get particulates drifting over from its neighbors
7. Visalia-Porterville, Calif./Hilo, Hawaii/Modesto, Calif./Fairbanks, Alaska
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Which of these cities doesn’t belong? Visalia and Modesto are both Central Valley California towns that suffer from the same congestion-created, hot-weather air pollution as their neighbors. But Hilo and Fairbanks are in Hawaii and Alaska — two states most Americans would associate with fresh, clean air. However, Hilo — on the Big Island — experiences volcanic ash that can darken the sky, creating what’s known as “vog.” In Fairbanks, meanwhile, local air pollution is worsened by the use of outdoor wood-fired boilers called hydronic heaters. They may be on the way out, though — the city council is considering outlawing them.
3. Riverside/San Bernardino/Ontario, Calif.
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Welcome to life in the smog belt. Riverside not only has to deal with its own pollution but also takes the leftover pollution from the L.A. basin as well as particulates that drift over from the port of Los Angeles — the busiest container port in the U.S. Last year, Riverside had 105 days of unhealthy ozone levels — pollution that can exacerbate asthma and other respiratory conditions.
2. Fresno, Calif.
CRAIG KOHLRUSS / THE FRESNO BEE / AP
Fresno may be known as the “Raisin Capital,” but the city is also regularly near the top of air-pollution lists. Traffic congestion and industry contribute to the pollution problems throughout the city. More than 75,000 of the city’s 900,000 people suffer from asthma, and another 25,000 suffer from chronic bronchitis.
1. Bakersfield, Calif.
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It makes sense that Bakersfield owes its early boom years in the 19th century to the oil industry, because it’s oil that has enabled the suburban sprawl and congestion that has caused the city to have perhaps the worst air pollution in the U.S. It’s not all bad — high-ozone days in Bakersfield have dropped over the past decade (the economic slowdown may have played a role). But if the residents of Bakersfield and the rest of Southern California ever want to experience truly clean air, they’re going to need to look to innovative solutions: electric cars, public transit and maybe even the occasional walk.