The American Lung Association issued its annual report card on air pollution today, ranking cities most affected by three types of pollution: short-term particle pollution, year-round particle pollution and ozone pollution.

For the first time ever, a city outside California, Pittsburgh, Pennsylvania, tops one of the most polluted lists in the ninth consecutive American Lung Association State of the Air report.

Pittsburgh moved to the top of the list of cities most polluted by short-term levels of particle pollution, a deadly cocktail of ash, soot, diesel exhaust, chemicals, metals and aerosols that can spike dangerously for hours to weeks on end. The body’s natural defenses, coughing and sneezing, fail to keep these microscopic particles from burrowing deep within the lungs, triggering serious problems such as breathing, asthma and heart attacks, strokes, lung cancer and even early death.

Pittsburgh also ranks second on the list of cities with the most year-round particle pollution while Los Angeles again claims the first spot this year. Los Angeles, despite being ranked atop two of the three most-polluted lists, saw continued improvements in air quality, dropping its year-round particle pollution levels by nearly one-third during the last decade, and saw solid improvement in levels of ozone or “smog,” a gas formed most often when sunlight reacts with vapors emitted when motor vehicles, factories, power plants and other sources burn fuel.

Ozone irritates the respiratory tract and causes health problems like asthma attacks, coughing, wheezing, chest pain and even premature death.

“The air quality in several cities has improved, but in others, declines in pollution have stalled. The trends tell us loud and clear that we need to do more to protect Americans from breathing air that’s simply hazardous to their health,” said Bernadette Toomey, President and Chief Executive Officer, American Lung Association.

“We applaud the aggressive efforts of Los Angeles to control particle pollution. It’s proof that making a commitment to clean up pays off.”