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What the Smoggiest Cities in the U.S. Can Do To Improve Air Quality

By Jihan Lee Los Angeles is notorious not only for its glitz, glam, and movie stars, but also for the hazy smog that even the best dressed must tolerate. When you look out at the skyline during sunset from a high vantage point in the Hollywood Hills, what becomes strikingly clear is that the blurry...

Smog shrouds downtown Los Angeles, one of the most polluted cities in the country. Photo by Jodi Cobb, National Geographic

By Jihan Lee

Los Angeles is notorious not only for its glitz, glam, and movie stars, but also for the hazy smog that even the best dressed must tolerate. When you look out at the skyline during sunset from a high vantage point in the Hollywood Hills, what becomes strikingly clear is that the blurry and sometimes colorful line above the city isn’t a mirage; it’s a thick envelope of air pollution, one that its residents breathe every day.

While walking the streets of a polluted city, it might not be so easy to notice the harmful effects of air pollution (unless you’re in Beijing, then it’d be impossible not to notice). But over time, regular exposure to high levels of particle pollutants and ground-level ozone, the major component in smog, may eventually lead to respiratory diseases, asthma, and reduced lung function, especially among infants, young children, and the elderly. It can also be a contributing factor to heart disease, stroke, and cancer.

The top five smoggiest cities in the U.S. are all suspiciously located in California, most likely due to the sheer number of people, the prevalence of cars on the road, heavy industrial emissions, and the bowl-like topography of certain areas, where gases get trapped. Still, the American Lung Association found in 2011 that roughly half of the United States population lives in counties that experience regular, unhealthy levels of particle or ozone pollution. Baltimore, Washington, D.C., Philadelphia, Houston and Atlanta all ranked poorly, just below California.

According to Environment America’s Clean Air Report, these are the smoggiest metropolitan areas in the nation, ranked by number of smog days in 2010. A smog day is characterized by unhealthy air.

Metropolitan AreaNumber of Smog Days in 2010Number of Red Alert Days in 2010
1. Riverside-San Bernadino, CA11024
2. Visalia-Tulare-Porterville, CA786
3. Bakersfield, CA6910
4. Los Angeles-Long Beach, CA693
5. Fresno, CA426


What Causes Air Pollution?

Smog is comprised of a mixture of ozone, oxides of nitrogen, and volatile organic compounds. These chemical compounds are released from exhaust pipes, factories, and gasoline and chemical vapors, as well as some natural sources. They combine forces in the presence of heat and sunlight, which is why smog days usually occur in the summer.

Particle pollution is another form of air pollution made up of very small particulate matter and liquids, like acids, chemicals, metals, and dust particles. California once again swept the competition for highest particulate pollution in 2011, with Bakersfield, Los Angeles, Visalia, and Hansford claiming four out of the top five spots on the American Lung Association’s list. Phoenix, AZ came in at number three.

What Counties, States, and the Federal Government Can Do To Improve Air Quality

While Los Angeles has improved a great deal since the 1970s when smog alerts would often recommend that people stay completely indoors, it’s still no Mount Shasta. The City of Angels was the most polluted city in the middle of the 20th century, but it was also the first one to initiate the country’s first air pollution control program in 1947. This was monumental in addressing decades of air pollution, which was only getting worse, but what can be done now?

Cars, people, and factories aren’t disappearing any time soon, so in an increasingly industrialized world, is smog just becoming a regular part of life or can the detriments of air pollution be tempered? Here are some ways that the authorities can continue to innovate and mediate the problem of air pollution. Note that complacency or adopting the status quo is not on the list.

  1. Develop more efficient and less gas-guzzling vehicles: They’re doing it in Europe, so why not start amping it up here? Because air pollution is largely caused by the amount of exhaust-producing vehicles on the road, making a mass switch to either electric, hybrid, or other gasoline alternative cars would help ease congestion in automobile-dependent cities. Making these vehicles affordable and competitive would be the key to any scalable change, and could also benefit the economy, if effective.
  2. Improve public transportation: This may seem like an obvious solution, but it’s much harder to implement than to visualize. Southern California is a jungle of highways, a hugely populated area that grew to its current size largely through the boom of the automobile industry in the 1920s. Many people would scoff at the suggestion of taking public transportation in L.A., but if it were widespread, fast and reliable, it could mean a huge shift toward more manageable emissions levels, especially if buses and trains are held to high emissions standards.
  3. Build air quality monitors near freeways and other congested areas: Because people living near freeways experience higher levels of particulate pollution, one coalition in L.A. is advocating for air quality monitors to be built near highly traveled roads. They argue that children’s centers and apartments are continuing to be built near freeways against EPA guidelines, so this move hopes to bring awareness to government officials about where not to place buildings for sensitive populations. Public air quality monitors could also help raise awareness about the respiratory dangers of smog.
  4. Increase public awareness of smog days: Some may remember the foghorn alerts in L.A. during the 1970s; whereas Midwest foghorns signify an incoming tornado, Southern California’s loud alarms would signify air that is too dangerous to breathe. Though it’s a good thing that dire smog alerts are fairly rare these days, largely due to the Clean Air Act and vigorous environmental policy, a lack of these sorts of alerts may mean that people are less aware of the danger they are in when bad smog hits. Issuing smog warnings on the news or through social media outlets can serve to both protect people with respiratory care needs, as well as encourage average citizens to consider air pollution a serious problem, possibly spurring some into action.
  5. Enforce the Clean Air Act and Introduce Higher Standards: The Clean Air Act was implemented in 1970 as a way of setting government standards to reduce air pollution. It set emissions guidelines to regulate the amount of particles allowed into the air, but it is not enforced as stringently as it could be. Oftentimes, polluters like oil companies challenge the validity of the Clean Air Act, attempting to find loopholes or undo laws, but clean air initiatives need to be consistently upheld and enforced despite lobbyists’ interests. The EPA estimates that the Clean Air Act alone saved 160,000 lives in 2010 and prevented 100,000 hospital visits. Continuing to improve and enforce this important piece of legislation may be one of the most widely effective ways of improving air quality in the U.S.

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