Most Polluted Cities in the United States

Polluted Cities

Smog encircles the Los Angeles skyline in 2015. L.A. is one of the most polluted cities in the United States. | Mark Ralston/AFP/Getty Images

Most Polluted Cities in the United States

Some Americans breathe easier thanِ others.
Although overall air quality inِ the United States hasِ improved inِ recent years, 4 out ofِ 10 people inِ the country stillِ live inِ counties withِ unhealthy levels ofِ pollution, according toِ theِ American Lung Association’s 2017 State ofِ the Air report.
Climate change, according toِ theِ Lung Association.

14. Anchorage (tie)

Alaska mightِ beِ America’s lastِ great wilderness, butِ the air inِ the state’s largest city isn’t alwaysِ pristine.
From 2013 toِ 2015, theِ Anchorage metro area experienced a weighted average ofِ eightِ days a year whenِ levels ofِ short-term particle pollution reached unhealthy levels.
Many Alaskans rely onِ wood-burning devices forِ heat duringِ long, cold winters, theِ Lung Association said.

Sled dogs walk on a street in Anchorage. | Jim Watson/AFP/Getty Images

14. Sacramento, California (tie)

Sacramento tied withِ Anchorage forِ 14th place inِ the Lung Association’s list ofِ the cities withِ theِ worst short-term particle pollution.
The city experienced a weighted average ofِ eightِ days ofِ alarmingly dirty air perِ year.
Those periodic dips inِ air quality mightِ not seemِ likeِ something people needِ to beِ worried about, butِ even briefِ exposure toِ high levels ofِ particle pollution canِ beِ deadly, according toِ theِ American Lung Association.

13. Missoula, Montana

Missoula experienced fewerِ spikes inِ short-term particle pollution from 2013 to 2015 thanِ from 2012 to 2014, according toِ theِ Lung Association.
But itِ still wasn’t enoughِ to knock itِ out ofِ the list ofِ mostِ polluted cities, withِ air quality hitting exceptionally bad levels onِ 8½ days perِ year, onِ average.
Although theِ number ofِ days withِ spikes inِ short-term pollution wasِ high, theِ city hadِ zero high ozone days.

12. Lancaster, Pennsylvania

The Sacramento skyline is seen from the window of Amtrak’s California Zephyr. | Joe Raedle/Getty Images

Lancaster isِ known forِ its large Amish population.
But despiteِ the Amish’s reliance onِ horse-and-buggy transportation, thisِ city stillِ experiences occasional spikes inِ short-term particle pollution, whichِ occurred nineِ times perِ year, according toِ theِ Lung Association’s weighted average.
Fortunately, theِ city  experienced 47 fewerِ high ozone days thanِ itِ didِ in 1996.

11. El Centro, California

The number ofِ unhealthy air days inِ El Centro hasِ reached a newِ high, according toِ heِ American Lung Association.
There wereِ a littleِ more thanِ nineِ days everyِ year withِ high levels ofِ short-term particle pollution.
The city, whichِ isِ inِ the farِ southern part ofِ the state nearِ the border withِ Mexico, alsoِ had moreِ than 20 high ozone days perِ year.

10. Reno, Nevada

Smoke from wildfires fills valleys near Missoula in 2000. | Don Emmert/AFP/Getty Images

In 2000, Reno experienced aboutِ 2½ days a year withِ high levels ofِ short-term particle pollution.
From 2013 to 2015, theِ average number ofِ dirty air days hadِ increased byِ almost 11.
Few willِ beِ surprised toِ seeِ the nextِ city inِ the top 10 forِ worst air pollution.

9. Los Angeles

Los Angeles hasِ long hadِ a reputation forِ dirty, smog-choked air.
While theِ city hasِ made strides inِ reducing pollution levels inِ recent decades, problems stillِ remain.
Short-term particle pollution isِ alsoِ a seriousِ problem inِ the region, particularlyِ inِ Los Angeles andِ Riverside Counties.

8. Logan, Utah

An Amish horse-drawn buggy travels on a road near Lancaster, Pennsylvania. | Stan Honda/AFP/Getty Images

Logan, Utah, isِ one ofِ the smaller cities onِ the Lung Association’s list, butِ it hasِ the sameِ dirty air problems asِ some bigger U.S.
Short-term pollution levels wereِ inِ the unhealthy range forِ a weighted average ofِ 20 days perِ year.
Reliance onِ wood-burning sources ofِ heat contributed toِ someِ ofِ the spikes inِ short-term particle pollution, according toِ theِ report.

7. Salt Lake City

Like Los Angeles, Salt Lake City’s unique geography contributes toِ itsِ air quality problems.
The mountains surrounding theِ city trap pollution, especiallyِ in theِ winter.
From 2013 to 2015, thereِ were moreِ than 20 days perِ year withِ seriousِ short-term particle pollution.

6. San Francisco

The Bay Area cities ofِ San Francisco, San Jose, andِ Oakland areِ among theِ mostِ polluted inِ the country, according toِ theِ American Lung Association.
In addition toِ falling inِ the top 10 forِ short-term particle pollution, theِ region wasِ theِ fourth-worst inِ the country forِ year-round particle pollution andِ ranked 18th for theِ number ofِ high ozone days.
California’s extreme drought (which eased upِ thisِ year) andِ the accompanying wildfires wasِ partly toِ blame forِ the region’s high pollution levels.

5. Fairbanks, Alaska

Fairbanks, theِ second-largest city inِ Alaska, hadِ the fifth-worst short-term particle pollution inِ the country, according toِ theِ Lung Association.
From 2013 to 2014, theِ city averaged 25 days withِ unhealthy levels ofِ short-term particle pollution, upِ significantly fromِ just a handful ofِ days a decade earlier.
But theِ city alsoِ had theِ lowest levels ofِ ozone pollution inِ the country.

4. Modesto, California

Modesto, likeِ the otherِ California cities thatِ top thisِ list, isِ inِ the San Joaquin valley, a notorious hot spot forِ air pollution. The area’s geography, combined withِ drought andِ wildfires duringِ the years measured, contributed toِ high levels ofِ soot inِ the region. Modesto wasِ inِ the top fiveِ cities forِ bothِ short-term andِ year-round particle pollution, andِ it ranked sixth forِ ozone pollution.

2. Visalia, California (tie)

As inِ the rest ofِ the San Joaquin Valley, drought, oil drilling, intense agriculture, andِ traffic allِ contribute toِ dirty air. Short-term particle pollution wasِ high forِ anِ average ofِ 40 days perِ year, theِ report found, whileِ thereِ were nearlyِ 100 high-ozone days annually. But someِ ofِ the area’s pollution comesِ from farِ away.

2. Fresno, California (tie)

The air inِ Fresno isِ bad, anyِ way youِ lookِ atِ it. The city wasِ inِ the top threeِ inِ the country forِ ozone days, year-round particle pollution, andِ short-term particle pollution. “These tiny particles, knownِ asِ soot, canِ lodge deep inِ the lungs andِ trigger asthma attacks, heart attacks andِ strokes.

1. Bakersfield, California

When itِ comesِ to short-term particle pollution, youِ can’t getِ worse thanِ Bakersfield. The city hadِ the highest average number ofِ days withِ spikes inِ unhealthy air. “The hardest days areِ when weِ haveِ to tellِ the boys theyِ can’t goِ outside toِ ride theirِ bikes orِ play soccer becauseِ of theِ bad air.”