Air Pollution Plagues Many US Cities
Air quality should be a concern for everyone - after all, the air you breathe can have a major effect on your health - but people in some cities may be in more trouble than others. The American Lung Association's "State of the Air" report ranks the worst cities in the U.S. for air pollution, based on ozone and airborne particle levels.
Common Air Pollutants
People are used to thinking of ozone as a good thing. In the upper atmosphere, ozone can protect people from harmful ultraviolet radiation, but at ground level, it's actually a pollutant. According to the National Institute of Environmental and Health Sciences, exposure to ozone over long periods can make people more susceptible to respiratory ailments and cause the lungs to work less effectively. Exhaust from cars and factories can create ozone when they're exposed to sunlight.
That exhaust is also a pollutant on its own, known as particle pollution. Although these particles are too small to see on their own, when masses of them come together, they form the clouds of dust and smoke that you can see coming from cars on city streets and from factories on the skyline. Since these particles are so small, they can easily make their way into the lungs, and some can even enter the bloodstream directly. HEPA-type air purifiers can trap all but the smallest particles inside, but those living in the most polluted areas may still feel their impact.
Despite all the qualities that make California a desirable place to live, many places in the state made the ALA's list of the 25 most-polluted cities in the country. Fresno was the top city for both short- and long-term particle pollution, while Los Angeles topped the list for ozone levels. Bakersfield, Modesto and Visalia also appeared near the top of each list.
Given that vehicles and manufacturing centers are major sources of air pollution, cities that are known for their factories often have poor air quality as well. For instance, Pittsburgh, sometimes known as Steel City, was a major producer of steel until the late 20th century, and that legacy has led to poor air quality. The city is No. 6 for particle pollution and No. 21 for ground ozone levels. The Cleveland-Akron-Canton, Ohio, area, also a former manufacturing hub, placed 16th for long-term particle pollution and 24th for ozone levels.