Thousands die each year in Southern California from poor air quality, a new study says.

Researchers fromthe American Thoracic Society and New York University’s Marron Institute of Urban Management estimate that more than 9,000 deaths each year nationwide can be attributed to the bad air quality that routinely exceeds levels deemed safe by health professionals.

The Los Angeles-Long Beach-Glendale area is the deadliest in the nation for poor air quality, with an estimated 1,341 dying each year because of smog. In total, some 3,532 deaths in Southern California can be attributed to air pollution, according to released Wednesday.

Those numbers are conservative, researchers say, and it's believed they'll increase as thepopulation grows and wildfires continue to contribute to smog.

The researchers used air pollution data for both fine particles and ozone levels in U.S. metropolitan areas recorded in 2011, 2012 and 2013. They compared this with the number of deaths and causes of those deaths, taking into account epidemiological studies linking various health effects to air pollution exposure.

(MORE: )

They noted that the number of deaths attributed to air pollution nationwide are comparable to the number of alcohol-related traffic deaths each year.

"In addition to providing nationwide estimates, the city-specificinformation contained in this report provides a valuable tool for air quality managers," the researchers noted in the report.

Changes Could Save Thousands

They added that they did not take into account chronic illnesses associated with air pollution like cancer, new-onsetasthma and diabetes.

"Deaths from these causesand longer term nonfatal exacerbations of chronic illnesseswere not captured in this analysis but would add to the total health burden of air pollution outcomes," researchers said in the report.

The researchers concluded that lowering ozone and fine particle pollution in cities most prone to bad air – Los Angeles is worst, but New York City and Phoenix aren't far behind –would save thousands of lives each year and reduce emergency room visits and millions of missed school and work days nationwide.

MORE ON WEATHER.COM: NOAA's Best Weather Photos

First place, Professional Submissions Category: Stars behind the storm. (Brad Goddard, Orion, Ill.)

At a Glance

Researchers estimate that thousands die in Southern California from air pollution.The Los Angeles area is the most deadly with an estimated 1,341 killed each year from bad air.