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California Cities Top List of Most Polluted Areas in American Lung Association Report

California Cities Top List of Most Polluted Areas in American Lung Association Report

The American Lung Association State of the Air 2015 report, released last week, showed that while progress has been made, California continues to have some of the worst air pollution in the country. In fact, 28 million Californians live in counties where ozone or particle pollution levels can make the air unhealthy to breathe. (Click on the map to enlarge.)

Covering air pollution data from 2011-2013, State of the Air 2015 shows that California cities still dominate lists for the most polluted areas in the nation for ozone (smog) as well as short-term and annual particle pollution (soot). Several cities had both higher year round averages and unhealthy days on average of particle pollution driven largely by drought weather conditions.

Specifically, of the top ten cities in the nation with the worst air pollution, California metropolitan areas rank as follows:

Ozone Pollution
6 out of the Top 10

Short-Term Particle Pollution
6 out of the Top 10

Annual Particle Pollution
7 out of the Top 10

#1 Los Angeles-Long Beach-Riverside

#1 Fresno-Madera

#1 Fresno-Madera

#2 Visalia-Porterville-Hanford

#2 Bakersfield

#2 Bakersfield

#3 Bakersfield

#3 Visalia-Porterville, Hanford

#3 Visalia-Porterville-Hanford

#4 Fresno-Madera

#4 Modesto-Merced

#4 Modesto-Merced

#5 Sacramento-Roseville

#5 Los Angeles-Long Beach-Riverside

#5 Los Angeles-Long Beach-Riverside

#8 Modesto-Merced

#6 San Jose-San Francisco-Oakland-Stockton

#6 El Centro



# 7 San Jose-San Francisco-Oakland-Stockton

Despite these rankings, many California cities have seen significant reductions in unhealthy ozone and particle pollution over the 16-year history of the report. Major regions of the state have seen reductions in unhealthy ozone days of approximately 40% or more since the 2000 report, led by 80% or more reductions in bad air days in the Bay Area and San Diego regions. Five cities reached their lowest levels (Los Angeles, Visalia, Bakersfield, Sacramento, and San Diego) of ozone pollution in the 2015 report.

For unhealthy particle pollution days, major reductions have occurred in the Bay Area (-74%), Sacramento (-73%), San Diego (-92%) and Southern California (-69%) since State of the Air 2004. The Los Angeles area achieved its lowest level of year-round particle pollution to date.

Salinas was once again named one of the cleanest cities in the nation, one of only six cities to make all three cleanest city rankings.

For too many people, air pollution remains a pervasive public health threat, contributing to thousands of hospitalizations, emergency room visits, and deaths every year to our most vulnerable citizens  –  children, seniors, and those with lung disease such as lung cancer, chronic bronchitis, or emphysema.

While many communities are at risk due to unhealthy air, some communities face higher risks due to their proximity to freeways, rail yards, freight corridors, and other local pollution sources. Lower income communities and communities of color often bear the burdens caused by these local air pollution sources. “All communities deserve cleaner air,” said Bonnie Holmes-Gen, Senior Director, Air Quality and Climate. “The Lung Association supports investments and clean up in vulnerable communities to ensure that all communities in California can breathe healthy air.”

Drought and stagnant weather conditions linked to climate change contributed to higher pollution levels and point to the need for greater actions to continue our clean air progress.

Going forward, California must redouble its efforts to transition off of fossil fuels for transportation and energy generation by investing in the rapid development of zero emissions solutions. Key solutions to help improve air quality across the state are to invest in sustainable zero- and near-zero emission freight technologies, deploy zero emission vehicles and fuels, maintain and enhance wood burning controls, and focus community planning on walking, biking, and transit alternatives to driving.

The American Lung Association in California calls for several steps to advance the fight for a healthier, clean air future for all Californians and safeguard the air everyone breathes:

  • Support California’s healthy air and climate leadership (SB 350 and SB 32). SB 350 (de Leon and Leno) sets important new targets for petroleum reduction, clean, renewable power and energy efficiency. SB 32 (Pavley) sets mid-term and long-term greenhouse gas reduction goals to continue California’s leadership in cutting harmful pollutants that threaten public health, delay air quality progress and contribute to climate change.
  • Expand cap and trade investments to reduce traffic and freight pollution. California is currently investing cap and trade funding to promote zero emission and near-zero emission solutions for cars, trucks, buses, freight transport, and other mobile sources in all communities, but more is needed. Given the additional funding available this year, the legislature should increase funding for low-carbon transportation, cleaner freight, and healthier communities that support transit and active transportation.
  • EPA must adopt strong final carbon pollution standards. The EPA needs to issue tough final standards to reduce carbon pollution from power plants, and strengthen the limits on the ozone and particle pollution that blow across state lines.
  • Protect the Clean Air Act. Congress needs to ensure that the protections under the Clean Air Act remain effective and enforced. The Clean Air Act is a critical public health law.
  • Strengthen the outdated ozone standards. The EPA must adopt an up-to-date ozone limit that follows the current health science and the law to protect human health. Stronger standards will drive much needed cleanup of ozone pollution across the nation and support the need for faster clean air progress in California.

To see how your community ranks in “State of the Air 2015,” to learn how to protect yourself and your family from air pollution, and to join the fight for healthy air, visit:

Trend charts, rankings, regional fact sheets, and maps of California grades are available at

Michael Ong, MD, PhD, is Associate Professor in Residence at the David Geffen School of Medicine, UCLA, and a volunteer physician of the American Lung Association in California.

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