When many Philadelphians head out the door to traverse the city, they have an option in each pocket. In one are the keys to the car; in the other, a SEPTA card. And in their head, an often tortuous debate about which method of transportation would be safer, more affordable and more dependable.
But many may not realize that this decision is also the most crucial one they can make in helping to protect the lungs of city residents from harmful pollutants.
Air quality experts say this little-considered fact is the outcome of our particular moment in time in the battle against air pollution. Since the passage of the federal Clean Air Act in 1963, air quality has significantly improved by many measures across the country, including in Philadelphia. The law established standards on six common pollutants, including lead, smog and soot (also known as particulate matter) while spurring regulations to ratchet them down and creating public alert systems during unsafe conditions.
Yet, experts say, airborne threats persist. When a typical Philadelphian walks out the door, they’re still subject to inhaling harmful pollutants generated from as nearby as the factory next door, to as far away as wildfires on the other side of the continent. Given Philadelphia’s geographic location and big city status, its residents face more air pollution than many Americans: more than one in five children in the city has asthma, compared to only about one in 20 nationwide.
The solutions to the problem change depending on the pollutant. Philadelphia residents and local officials can do painfully little to curtail wildfires and coal-burning power plants thousands of miles upwind, which contribute to particulate matter pollution.
But among local sources, there’s an obvious place to focus, experts say.
The single most important thing that every citizen can do to help alleviate air quality problems in our region is to get out of your car, to stop driving”
— Jane Clougherty, Drexel University
“The single most important thing that every citizen can do to help alleviate air quality problems in our region is to get out of your car, to stop driving,” says Jane Clougherty, a professor of Environmental and Occupational Health at the Dornsife School of Public Health at Drexel University.
Where Past Meets Present
Philadelphia sits at a critical juncture in its battle with air pollution, says Russell Zerbo, an advocate for the environmental nonprofit Clean Air Council.
Under the Clean Air Act, regions like Philadelphia can be designed as “nonattainment” areas when their air quality fails to meet national standards. Zerbo says, historically, the program works like a tightening belt loop. Every five years, the Environmental Protection Agency (EPA) is required to review the standards and often lowers the threshold considered safe for pollutants. That sets off a cascading effect where regions like Philadelphia must submit plans to meet the new, lower standards.
The Delaware Valley is still on the treadmill of this perpetual game of catch-up. Currently, the region is in violation of the standard for smog, also called ozone, last established in 2015. Primarily a product of vehicles, industry and power plants, smog can burn the lungs and lead to a host of health issues such as asthma and emphysema.
But Philadelphia and some of its collar counties are also in danger of violating a new standard for particulate matter, sometimes called PM2.5, after the EPA announced this year its intentions to lower the safe limits by 25%. And Zerbo says particulate matter — tiny particles of harmful materials that typically come from combustion of fossil fuels and wood — are even more insidious than smog.
“PM2.5 eventually makes its way into your bloodstream and brain, with all kinds of information correlating it to diseases and health outcomes,” Zerbo says. “It’s more broadly correlated to overall life expectancy.”
Zerbo is further concerned that the current regulatory safety net isn’t secure enough to protect Philadelphians from such threats. He notes the World Health Organization (WHO) already recommends a PM2.5 level nearly 50% lower than the EPA’s new proposed standard. Further, he worries that the plans that states and cities are required to submit to meet new air quality standards often aren’t robust enough to fully tackle the problem.
Clougherty sees gaps of her own. She’s particularly concerned about volatile organic compounds (VOCs), an entirely different class of air pollutants, several of which are “known carcinogens that are also associated with respiratory and cardiovascular illness,” Clougherty says.
“Because these pollutants — which primarily come from heavy industry but also tailpipe emissions — aren’t one of the EPA’s primary air pollutants, there’s not nearly the same level of monitoring,” Clougherty says. “That means they don’t trigger the orange and red air quality reports that would typically warn the public of danger.”
And, many VOCs emanate from local sources, which disproportionately impact local communities already susceptible to health harms.
“The other half of the risk equation is susceptibility. So neighborhoods where there are a lot of people with preexisting conditions due to other exposures — the elderly, children, lower-income communities — tend to be at higher risk,” Clougherty says. “One of the things that I look at a lot is chronic stress and how stress makes us more susceptible to all other exposures.”
Clearing The Air
James Garrow, communications director for the Philadelphia Department of Public Health, says the City is taking action to clean up the air. The department’s Air Management Services program has regularly updated its own local air management regulations (AMR) since the 1970s. Currently, they allow the City to regulate potential pollution sources such as construction dust, heavy fuel oil, paint spraying operations, leaky industrial pipes and harmful dry cleaning chemicals, Garrow says.
Such efforts have helped Philadelphia go from a city that, as recently as the 1990s, saw more than two months’ worth of days with “unhealthy” air quality each year, to one that now averages only a week or two. (The other 50 weeks of the year are split between about 30 weeks of “good” and 20 of “moderate” air quality.) And the City continues to create new regulations, he says.
“This past January, the City instituted a new air management regulation, AMR-VI, that vastly expanded the number of toxic air pollutants that we track and measure and work towards limiting,” Garrow added. “This is one of, if not the most, stringent air toxic regulations in the country.”
Zerbo agrees AMR-VI is a good step forward in that it gives the City the authority to “aggregate the cancer risk from multiple air toxics coming from individual facilities.”
However, he cautions that air quality data also show troubling signs for the city. Between 2014 and 2022, Philadelphia made rapid strides in the number of “good” air quality days, from 132 to 281 a year. But those numbers have since fallen backwards to the low 200s, and the 2023 wildfires gave Philadelphia its highest number of unhealthy air quality days since 2008.
Garrow says that, while the City’s regulations are well-equipped to address “stationary” sources of pollution, they do not have legal authority to regulate mobile sources such as cars, trucks and construction vehicles. That falls to the EPA, which is indeed pursuing new regulations on tailpipe emissions.
But that position doesn’t satisfy Zerbo, who says the City and State can be doing more to invest in SEPTA and to address air pollution by cutting down the number of vehicles on the road.
“The easiest and clearest solution for me is more funding for public transit,” Zerbo says.
Clougherty agrees, and also encourages people to walk and bike for short trips, adding that cutting down on vehicle pollution will reduce the hidden dangers of VOCs in the city, as well as smog and PM2.5.
But with public transit funding decisions largely out of control of the public, Clougherty is also studying even more direct action. She is currently researching communities in New York State, whose public health appears to be faring better than expected given their air quality, to see if she can determine common variables helping to inoculate them from the danger. “There are a huge range of things we’re looking at … availability of green space, playgrounds where kids exercise, schools-based interventions,” Clougherty says.
The research could result in a recipe to apply here in Philadelphia, potentially improving city health at the neighborhood level.
As Clougherty says: “We’re trying to flip our model from thinking about just stressors to thinking about resilience strategies.”
