Mayor Antonio Villaraigosa strolled to the microphone, his jacket slung over his shoulder, a broad smile on his face. “What a wonderful day,” he said to the reporters and American Lung Assn. members gathered in Echo Park. “All these cameras, all these good people here to celebrate good news. Put a smile on your faces, everybody. . . .

“Today I’m proud . . . to say for the first time, it feels good to be No. 2.”

After nearly a decade at the top, the Los Angeles region has been “bested” by the Pittsburgh metropolitan area for the No. 1 spot on the “Top 10 U.S. Cities Most Polluted by Short-Term Particle Pollution.”

From 2004 to 2006, the area from Los Angeles east to Riverside and south to Long Beach had far fewer 24-hour periods of unhealthy particulate readings than the Steel City. But the region still was the worst offender in the nation for ozone levels and yearly overall particle pollution readings, according to the American Lung Assn.'s annual “State of the Air” study released Wednesday.


“But we’re still on the list,” said Villaraigosa, who mentioned that he recently suffered a bout of bronchitis, one of the ailments the Lung Assn. cited in its “F” grade for nearly all of Southern California. “Moving forward, we still have our work cut out for us,” he said.

The study tracked ozone as well as daily and annual readings for small particles in cities and counties across the country.

The rest of the state did not fare well, either: Five of the eight metropolitan areas listed as most polluted by all three measures used by the association were from California. These included Los Angeles-Long Beach-Riverside and the Central Valley areas of Bakersfield, Fresno, Visalia-Porterfield and Hanford-Corcoran. The San Diego metropolitan area made the list of top 25 most ozone-polluted cities at No. 12.

In all, 26 of the 52 counties monitored in the state received “F” grades, for having the most unhealthy high-ozone days or particle-pollution days. Nineteen counties, primarily coastal, received “A” grades. And Salinas, Redding and the San Luis Obispo region were among the top 25 cleanest U.S. cities for long-term particle pollution.


An “F” grade is equivalent to nine or more days of air quality at the level defined as “unhealthy” by the Environmental Protection Agency.

Ozone is the primary ingredient in smog and is formed when sunlight and heat react with chemicals released from tailpipes, smokestacks or other things burning fossil fuels. The effect of ozone on the lungs can be severe. “Imagine putting acid right on your eye,” said Dr. Tony Gerber, a volunteer with the lung association. “It is that corrosive.”

Particle pollution refers to a mixture of tiny solid and liquid particles in the air that get released, for example, from diesel exhaust, coal-fired power plants and burning wood, fields or forests. These particles can get trapped in the lungs.

Both ozone and particulate pollution have been linked to serious respiratory ailments and premature deaths. About 8,800 deaths in California can be tied to ozone and particle pollution, according to Dr. Sonal Patel, an allergist and pediatrician with White Memorial Medical Center in East L.A..


San Bernardino, Riverside, Los Angeles and Orange counties all received failing grades for unhealthy ozone and particle-pollution days. San Bernardino County, the worst offender in high-ozone days in the country, averaged 90 per year, followed by Kern with 83, Riverside with 77, Tulare with 68, and Los Angeles with 65. Orange County, which did not make the top 25 list, averaged seven unhealthy ozone days.

The failing grades for ozone were improvements over last year. The study did not use newly tightened EPA standards for ozone exposure, which would have added to tallies of unhealthful air days.

Over the last decade, California particle pollution levels have dropped by nearly a third. The association credited that drop primarily to tighter engine and emission standards at the state and federal level.

“As the Los Angeles metropolitan area really continues what has been our tradition -- aggressive air pollution control -- sooner or later other cities that have not been so aggressive are going to start popping up as No. 1 from time to time,” said Sam Atwood, a spokesman for the South Coast Air Quality Management District.


If the trend continues, Pittsburgh will top Los Angeles in both long- and short-term particle pollution lists next year, said Janice Nolen, assistant vice president of national policy and advocacy for the American Lung Assn.

Villaraigosa touted the Clean Air Action Plan, passed in November 2006 and which addresses port-related pollution, as key to continuing the progress, as well as a city effort to invest in renewable energy.

“In a city known for smog and sprawl, we’ve made some significant progress,” Villaraigosa said. “But we still have work to do . . . so in the coming years Los Angeles is completely off the list.”

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tami.abdollah@latimes.com

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(BEGIN TEXT OF INFOBOX)

Bragging rights?


The Los Angeles Basin dropped from the top of a list of worst offenders by one measure of pollution, but topped the list by other measures in an American Lung Assn. annual report.

Metropolitan areas with worst short-term particulate pollution (small particles):

1. Pittsburgh-New Castle, Pa.

2. Los Angeles-Long Beach-Riverside


3. Fresno-Madera

4. Bakersfield

5. Birmingham-Hoover-

Cullman, Ala.


Worst year-round small-particulate pollution:

1. Los Angeles-Long Beach-Riverside

2. Pittsburgh-New Castle, Pa.

3. Bakersfield


4. Birmingham-Hoover-

Cullman, Ala.

5. Visalia-Porterville, Calif.

Worst ozone:


1. Los Angeles-Long-Beach-Riverside

2. Bakersfield

3. Visalia-Porterville, Calif.

4. Houston-Baytown-


Huntsville, Texas

5. Fresno-Madera

Source: American Lung Assn.