Philadelphia’s Air Pollution Sources and steps to Attaining Federal Ambient Air Quality Standards

The Trump administration’s rollback of President Obama’s updated Corporate Average Fuel Economy (CAFE) standard is now open for public comment. In 2012, the EPA finalized new CAFE standards requiring automakers average 54.5 miles per gallon over their fleet of passenger cars and light-duty trucks by 2025.

This is a recent article about the damaging effects of losing CAFE standards: “Rolling back the CAFE standards for autos, for instance, would lead to another 5500 deaths and 140,000 cases of respiratory ailments in children.”

This press release from President Obama’s Whitehouse in 2012 is one of the best documents available on the Clean Car standards.

This is a more scientific assessment of the CAFE standards.

CAFE standards are the only way to decrease transportation pollution without changing infrastructure, like raising toll or parking costs, or increasing gas taxes.

The Ozone Transport Commission is a coalition of Mid-Atlantic and Northeastern states focused on reducing smog pollution; the coalition is established by the Clean Air Act and issued this document supporting strong vehicle emission standards.

In 2015, the U.S. Environmental Protection Agency (EPA) set a new ambient ozone (smog) standard at 70 parts per billion, firmly situating the city of Philadelphia in non-attainment of that standard.

The EPA published this document about the new standard and mentioned that Philadelphia and other cities would have a difficult time reaching attainment without significant changes:

On PDF page 456 the document says:

“Because of relatively higher ozone levels in several large urban areas (Southern California, Houston, and the Northeastern urban corridor, including New York and Philadelphia) and because of limitations associated with the data on currently identified emissions control technologies, the EPA recognized that identified and reasonably anticipated emissions controls would likely not be sufficient to bring some areas into attainment with either the existing or alternative, more stringent ozone standard level. Therefore, we designed this analysis in two stages: the first stage focused on analyzing the air quality improvements that could be achieved through application of documented, well-characterized, end-of pipe emissions controls, and the costs and benefits associated with those controls. The second stage took the emissions reductions beyond identified controls and used an average cost-per-ton method to estimate the costs and benefits of these additional emissions reductions needed to bring all areas into full attainment with the alternative standard levels analyzed.”

This paragraph addresses the fact that in order for cities to reduce smog levels, of which Nitrogen Oxides (NOx) are the main contributor, serious pollution reductions must be made outside of standard technology upgrades. Even with the most efficient automobile engines, we still need to drive less and reduce pollution from other sectors.

Mobile sources (cars and trucks) dominate Philadelphia County’s NOx pollution.

This is a recent emissions inventory tool. 

Page 31 of this document from Philadelphia’s Air Management Services mentions that “On-road mobile sources contribute the most risk from directly emitted pollutants (about 18 percent)”

The above is a national statistic that represents the emission of cancer-causing air toxics or hazardous air pollutants (HAPs). The National Air Toxics Assessment (NATA) also gave Philadelphia specific information (further down on page 31):

“Total cancer risk was 53.6 in a million. Secondary formation accounted for 36 percent of cancer risk and on-road mobile sources accounted for 32 percent. The pollutants contributing most to cancer risk were formaldehyde (42 percent), benzene (20 percent), acetaldehyde (9 percent), and 1,3-butadiene (8 percent).”

Nationally there is a bigger difference between secondarily formed air toxics and those emitted from mobile sources, but within the city their contributions are almost equal, with mobile sources contributing much more to the city’s overall cancer risk.

This is a document from the EPA discussing Philadelphia’s contribution to the region’s NOx levels.

Page 15 puts Philadelphia’s emissions in the context of other counties. Unsurprisingly, Philadelphia emits the most NOx in the area.

Starting on page 18 there is a table of stationary NOx sources and the Philadelphia Refinery is the third largest emitter of NOx in the region behind the Philadelphia airport and the Delaware City Refinery. It should be considered that the refinery makes gasoline, so theoretically if individuals consumed less gasoline via updated CAFE standards, the refinery would produce less gasoline and emit less pollution. The Delaware City Refinery also makes gasoline.

This is an informative article about the health risks of living close to a highway, even discussing the effects of time of day, wind, humidity and topography on pollution concentrations.

This is a scholarly article about the health effects of automobile pollution from a pedestrian perspective.

This article focuses on a recent misestimating of diesel nitrogen oxide emissions.

This is a scholarly article about pollution from diesel trucks involved in hydraulic fracturing in Pennsylvania.