5 Smoggiest Cities in the U.S.

The top five smoggiest metropolitan areas in the U.S. in 2010 were all in California, according to a new report by Environment California. The top area, Riverside-San Bernardino, had 110 smog days, which means that the area had unhealthy air on one out of three days last year. Across California, there were 135 days in 2010 when at least part of the state had smog levels exceeding the health standard.

The top five smoggiest metropolitan areas in the U.S. in 2010, in order, were:

1. Riverside-San Bernardino, CA

2. Visalia-Tulare-Porterville, CA

3. Bakersfield, CA

4. Los Angeles-Long Beach, CA

5. Fresno, CA

Why are all the smoggiest cities in California? The answer is surprisingly simple: California is the most populous state, and a state where driving a car is of prime importance, particularly in Southern California, which has the largest population.

Even though the San Joaquin Valley is one of the least populated areas in the state, its topography (it is completely land-locked) makes it particularly vulnerable to pollution. The San Joaquin Valley is home to one of the state’s main highways, Highway 99, where trucks hauling goods to other parts of the state are a routine sight. The San Joaquin Valley is also the one of the country’s main agricultural areas, and that means loads of pesticides sprayed on crops.

The public is in danger from weak standards

The report states that the public does not always learn about unhealthy air. The air was unhealthy to breathe “many more times in 2010 and in 2011 than the public was alerted to because the 2008 air standard was not set at a level to protect public health.” In 2008, the Bush administration updated the National Ambient Air Quality Standard (NAAQS) to 75 parts per billion (ppb) from 80 ppb. However, the Clean Air Scientific Advisory Committee (CASAC), created by the Clean Air Act to provide recommendations to EPA’s periodic review of the NAAQS, unanimously recommended that the standard be set at 60 to 70 ppb.

Although current EPA Administrator Lisa Jackson decided to reconsider the 2008 standard in January 2010, the Obama administration announced earlier this month that it would not update the standard until 2013. One of the report’s policy recommendations is to update the NAAQS to 60 to 70 ppb averaged over eight hours.

The report also recommends the following:

  • Pollution from vehicles, which accounts for a third of nitrogen oxide emissions (which forms smog) in the U.S., be reduced through developing “more efficient vehicles and by improving and expanding public transportation systems.”
  • State and federal governments need to “accelerate the transition away from fossil fuels and toward a clean energy economy, by passing policies to ensure we get more of our energy from clean, renewable sources such as wind and solar power.”
  • Congress should eliminate fossil fuel subsidies.

The report highlights the need for the Obama administration to do what is necessary to clean the air. However, it is clear that Obama will not do the right thing without pressure from the American people. Put pressure on him by signing the petition, Tell Obama To Protect U.S. Citizens From Smog Pollution.

Photo: Flickr user, AnnieGreenSprings


Nikhil D
Nikhil Dutta3 years ago

Glad the Bay Area isn't on the list.

Lynn D.
Lynn D.4 years ago

I guess Californians are happy killing themselves off slowly! Too bad! Thanks for article!

Carole L.
Carole L.5 years ago

smog is ozone.

Hannah S.
Hannah Short5 years ago

wow all five top smoggiest cities are in California.

Jim Gayden
Jim Gayden5 years ago

Sorry, I almost forgot to mention that Hydrogen combusted with atmospheric air would also produce nitrogen oxides. So, basically internal combustion engines need to be eliminated. Anything that involves any type of combustion process produces some form of air pollution. Even if you used pure hydrogen with pure oxygen in the proper ratios, and had 100% combustion, there would still be a lot of heat produced. And just the heat from the exhaust would combust with the ambient atmospheric nitrogen, and still result in nitrogen oxides.

Jim Gayden
Jim Gayden5 years ago

june t
Ethanol=C(2)H(6)O. Ethane=C(2)H(6). Octane=C(8)H(18). Or the alcohol equivalent to Octane (or 8 carbon atoms in a chain. Octanol) C(8)H(18)O. In other words there is very little difference between gasoline, and alcohol. The significant difference is the additives in gasoline, which allow the combustion to be more efficient, and keep the valves, and combustion chamber cleaner. So, unless they use food grade ethanol, I would assume that they have similar additives. It is mostly these additives, in combination with innefficient combustion which produce the air pollution. If pure octane is used then the combustion end result is carbon dioxide and water if the stoichiometric ratio is correct. Otherwise there is carbon monoxide, and oxygen in the exhaust. Same with ethanol. Since the atmosphere is composed of approximately 70 something percent Nitrogen, then both gasoline, and alcohol will produce nitrogen oxides, which is far more dangerous. So, basically it is the fault of internal combustion engines, auto manufacturers, and oil companies in combination that causes air pollution. However, if pure hydrogen were used as a fuel source, the exhaust would be hot water. But hydrogen is extremely explosive. So basically we need to completely eliminate the use of internal combustion engines, unless car manufacturers can produce safe fuel cells for the use of hydrogen as a fuel. Hydrogen is the most abundant element in the universe, and very easily obtainable.

june t.
june t.5 years ago

With all the research and technology, plus knowhow to produce alternate fuels that we have in North America, why isn't California ahead of the pack in using these things? I think even Sao Paulo Brazil has cut down their gas consumption by 25% with ethanol.

Shaheen N.
Shaheen N.5 years ago

Start using Car pool system while going to school or to your work.

Grace Adams
Grace Adams5 years ago

Switching from non-tariff regulatory burden on pollution to excise taxes designed to capture external (imposed on innocent bystanders) costs would help. It would at least put a realistic price on pollution. Accepting investment in sustainable energy production as in kind payment of such a tax on fossil fuel could accelerate the switch from fossil fuel to sustainable energy. Once fossil fuel use is fully replaced by sustainable energy production and use, fossil fuel will become irrelevent as a source of pollution.

Debbie Brady
Debbie Brady5 years ago

Fossil fuels=dirty Air.
Wake up people!