Each year in Philadelphia, an estimated 126 lives are cut short and 284 people are hospitalized due to excess air pollution, according to a report by the American Thoracic Society and New York University.
The study attributed an additional 75 deaths in the Pennsylvania suburbs and 40 in Camden County to airborne contaminants.
The first Health of the Air report, released Wednesday, examined air quality in hundreds of counties across the United States.
It attributed more than 9,300 premature deaths nationwide to the two major pollutants in smog. The number is roughly equivalent to the annual total of alcohol-related traffic fatalities, researchers said.
California accounted for more than a third of estimated deaths, 3,632. Pennsylvania (728) was in the next tier, along with Ohio (578) and Texas (604). Philadelphia was 25th out of 30 metro areas ranked.
An online tool (www.HealthOfTheAir.org) allows users to check the number of deaths and serious illnesses attributed to poor air quality for most zip codes.
"What this study should do is allow cities to think about how much they want to invest locally to reduce the impact," said lead author Kevin Cromar, director of the air-quality program at NYU's Marron Institute of Urban Management. "We're not trying to shame anyone or praise anyone but just make the data available."
The Environmental Protection Agency in October reduced the acceptable threshold for ground-level ozone, a greenhouse gas. It also set new restrictions on airborne particulate matter, which includes smoke, dust, and soot. Both ozone and particulates are linked to asthma and other chronic respiratory illnesses.
Many physicians and activists thought the EPA did not go far enough. The American Thoracic Society (ATS), a group of 15,000 physicians who specialize in breathing disorders, was among the loudest critics. The study was published in the organization's journal.
The EPA reduced the allowable amount of ozone from 75 parts per billion to 70. According to the ATS, a safe level is 60 ppb.
Government studies, however, have estimated it would cost $16 billion a year to reduce levels just to 65 ppb. And that did not include California, where the problem is most acute.
Cost estimates released last year by the National Association of Manufacturers, which opposed the EPA regulation, were much higher.
"There isn't an easy solution, but that shouldn't stop us from thinking about it and coming up with them," said Sarah Lyon, a physician who practices pulmonary and critical care medicine at the Hospital of the University of Pennsylvania and the Philadelphia Veterans Affairs Medical Center.
Ozone and particulates also exacerbate chronic obstructive lung disease, requiring more than 280 Philadelphians each year to seek hospitalization or treatment in an emergency room, according to the study.
Lyon, an ATS member, said she saw the direct effects of elevated levels of ozone and particulates on her patients, many of whom suffer from COPD and asthma.
"We don't usually think about ozone in terms of health effects outside of the sunburn issue," she said. But when levels of ozone are greater than 60 ppb, "it means many of my patients can't go outside at all and need to have central air to be comfortable in their own houses."
The problem is more severe in Pittsburgh, according to the study. Although its population is just one-fifth that of Philadelphia, estimates show more than twice as many premature deaths - 285 - could be avoided if the EPA adopted ATS standards, and 533 hospitalizations prevented.
"Clearly Pennsylvania has a long, long way to go," said Joe Minott, executive director of the Clean Air Council. "But the biggest takeaway, something we've been stating repeatedly, is the recently adopted federal standards are not protective enough of public health. That's true of both ozone and particulate matter."