44% of Americans breathe dangerously polluted air. In California, it's 82%

Greater Los Angeles remained the astir ozone-polluted metro country successful the nation, according to the American Lung Assn.’s 2026 State of the Air report, which recovered that Southern California continues to look immoderate of the country’s dirtiest air.

The report, released connected Wednesday, ranked Los Angeles-Long Beach arsenic the worst U.S. metro country for ozone pollution, with an mean of 159.2 unhealthy ozone days a year. The portion besides ranked seventh worst nationally for yearly particle contamination and seventh worst for short-term particle pollution.

The American Lung Assn., oregon ALA, assigns grades based connected the fig of unhealthy aerial days and the severity of contamination levels, utilizing national aerial prime standards. Los Angeles County received failing grades crossed each 3 categories measured successful the report: ozone, short-term particle contamination and yearly particle pollution.

Riverside and San Bernardino counties besides failed each 3 measures.

Orange County received an F for ozone, a failing people for yearly particle contamination and a C for short-term particle pollution.

Ground-level ozone, often called “smog,” is simply a corrosive state that forms erstwhile contamination from vehicles and different sources reacts successful vigor and sunlight. It tin irritate the lungs and trigger superior breathing problems.

Short-term and yearly particle contamination notation to good particulate matter, known arsenic PM2.5. These microscopic particles travel from sources specified arsenic conveyance exhaust, concern emissions and wildfires. Because they are tiny capable to participate the bloodstream, they are linked to asthma attacks, bosom disease, strokes and lung cancer, according to Will Barrett, adjunct vice president for Nationwide Clean Air Policy astatine the ALA.

The study did find immoderate signs of progress. Los Angeles posted its lowest yearly particle contamination level successful the past of the report, adjacent though the portion inactive ranked among the nation’s worst overall.

On the different hand, ozone contamination successful Los Angeles worsened from past year’s report, keeping the metro country successful the apical spot nationally for smog. The study says Los Angeles has ranked worst for ozone successful 26 of the 27 years the ALA has issued the study.

Speaking to the property Tuesday, Barrett said the region’s contamination comes mostly from proscription sources “primarily burning gasoline and diesel,” on with refineries and different section emissions sources. He said those pressures are compounded by clime and coastal conditions that propulsion contamination inland, particularly into the Inland Empire, wherever unhealthy ozone days are adjacent much severe.

Nationally, the study recovered that successful the U.S., 152.3 cardinal people, oregon 44% of the population, unrecorded successful places that received a failing people for astatine slightest 1 measurement of ozone oregon particle pollution. That includes 33.5 cardinal children, oregon 46% of radical nether 18. In California, the ALA said 82% of residents unrecorded successful counties affected by unhealthy air.

Of the 15 U.S. counties with the astir atrocious smog days past year, 8 were successful California.

When it came to atrocious PM2.5 contamination days, California had 7 of the 15 worst counties.

And of the 15 counties with the worst year-round PM2.5 pollution, 9 were successful California.

In the report, the ALA said caller national actions could undermine California’s efforts to amended aerial quality. Those see missed deadlines for stronger particle contamination standards, rollbacks of clean-vehicle and fuel-economy rules, exemptions from toxic aerial contamination regulations, and a Congressional Review Act situation targeting 3 of California’s clean-vehicle standards.

“This [Environmental Protection Agency] is making important rollbacks to life-saving cleanable aerial rules,” Diana Van Vleet, the report’s pb writer and the ALA’s manager of nationwide cleanable aerial advocacy, said during Tuesday’s property call. “Federal actions person weakened, delayed and repealed galore contamination limits.”

She referenced the EPA’s February revocation of a longstanding technological decision that man-made clime alteration threatens the wellness of Americans.

“The caller actions by the national authorities to interfere with California’s authorities rights to support residents’ wellness are a large situation to the ongoing occurrence of our section aerial districts and authorities Air Board,” said Barrett. He added that authorities estimates amusement national actions weakening California’s clean-air authorization could pb to much than 14,000 deaths, thousands of exigency country visits and hospitalizations, and $145 cardinal successful cumulative wellness impacts done 2050.

Children are particularly susceptible to polluted aerial due to the fact that their lungs are inactive developing, they respire much aerial comparative to their assemblage size, and they often walk much clip outdoors, the study said.

“In my regular enactment life, I dainty children with asthma that is often made worse due to the fact that of the dense doses of contamination they breathe,” said Afif El-Hasan, physician-in-charge astatine Kaiser Permanente San Juan Capistrano Medical Offices.

El-Hasan added that aerial contamination “also inhibits lung improvement successful children, which tin pb to reduced lung capableness arsenic adults. This is not reversible. Once it happens, it’s done.”

Southern California’s aerial contamination load has agelong been shaped by a premix of traffic, freight movement, industry, geography and climate.

The region rankings amusement the attraction of that burden. San Bernardino County ranked arsenic the astir ozone-polluted region successful the nation, with 159.2 weighted mean unhealthy ozone days, followed by Riverside County astatine 126.7 and Los Angeles County astatine 119.0.

The study besides highlighted cleaner-air successes elsewhere successful California. Sacramento recorded its lowest yearly particle contamination levels and fewest unhealthy ozone days successful the report’s history.

Four California cities besides ranked among the nation’s cleanest successful astatine slightest 1 category: Salinas and Chico for having zero high-ozone days, and Santa Barbara and San Luis Obispo for signaling zero days of unhealthy particle pollution.

The ALA urged authorities lawmakers to support backing programs aimed astatine cutting emissions from the biggest sources. “The Lung Association is calling for the California Legislature to put successful zero-emission motortruck programs,” Barrett said, arsenic good arsenic for backing for cleaner cultivation instrumentality and user cars.

The wellness and biology arguments for these governmental positions person been argued to death, but Barrett says that the economical consequences of soiled aerial are often overlooked. “What is often missing is this interaction of the outgo of aerial contamination connected household budgets, connected kids missing school, their parents staying location from work, connected and connected and on,” helium said. “Air contamination is simply a costly societal occupation that needs to beryllium addressed.”