Poor Air Quality Lingers in Pittsburgh

Pittsburgh circa May 1973. Photo by John L. Alexandrowicz for the EPA.

Pittsburgh, Pennsylvania has consistently been voted one of the most livable cities in the United States by the Economist Intelligence Unit. The EIU determines the winners by evaluating categories such as healthcare, culture and environment, and education. Though Pittsburgh ranks highly in every category, the rankings fail to evaluate one important category: air quality. Pittsburgh is one of the top 50 most polluted American cities, as determined by the Energy Policy Institute at the University of Chicago, and has a startlingly high rate of childhood asthma.

Air pollution (“stuff” in the air that harms humans or the environment) is created naturally or anthropogenically (by humans). The Environmental Protection Agency (EPA) sets national standards for the six most common pollutants:

  • sulfur dioxide
  • carbon monoxide
  • nitrogen dioxide
  • ozone
  • particulate matter (PM), and
  • lead

Although many of these substances occur naturally, human activities increase pollutants. Particulate matter, for example, is “a mixture of solid particles and liquid droplets found in the air;” dust and dirt are two common examples. Desert environments and forest fires are notable natural sources, while man-made sources include construction sites and power plants. PM can pose serious health problems, especially extremely small particles that are less than 10 micrometers in diameter. A strand of human hair is about 70 micrometers, which is 30 times larger than pollution that is of the utmost concern: fine particulates, which have a diameter of less than 2.5 micrometers and can be easily inhaled and enter the bloodstream. Inhaling those particulates can cause serious respiratory and cardiovascular problems.

Each year Allegheny County monitors pollutants and creates a report to detail Pittsburgh’s air quality. In 2017, the last report released, PM and ozone levels exceeded EPA standards on several days. To put these results into perspective using the Air Quality Index (AQI), a color-coded index denoting levels of pollution, Pittsburgh often falls into the yellow (moderate) air quality zone for PM and in the green (safe) zone 70 percent of the time for ozone. However, Pittsburgh still experiences unhealthy or orange air quality days every year, about nine days due to elevated levels of PM and ozone.

During the 19th century, Pittsburgh was known as “The Smoky City” and described as “hell with the lid off.” Luckily, air pollution in Pittsburgh was greatly reduced following city legislation for smoke control in the 1940s and 1950s, which primarily targeted individual coal use. Public advocacy and the Clean Air Act were able to further reduce air pollution through the 1970s. As environmental issues and advocacy groups became more visible to the public during this time, heavy industry in Pittsburgh began to decline in the late 1970s. This decline allowed the urban air in Pittsburgh to improve considerably.

Today, as Pittsburgh’s industrial past has given way to its present status as a tech hub and national player in the medical and higher education sectors, its air quality still remains below national standards. In the American Lung Association’s (ALA) 2017 “State of the Air” report, the Pittsburgh metro area is ranked 29th for high ozone days, 17th for 24-hour particle pollution, and 8th for annual particle pollution.

Even as Pittsburgh embraces its image of a high-tech city, its industrial legacy lives on and hurts its air quality. For instance, the city of Clairton, 30 miles southeast of Pittsburgh, hosts the largest coke plant in North America. Clairton Coke Works processes coke by baking metallurgical coal at high temperatures in blast ovens, producing large amounts of smoke spewing from stacks into the atmosphere. Residents and environmental groups have accused the plant of emitting toxic and hazardous substances into the air that harms residents. The Mon Valley Works, which includes Clairton Coke Works, Edgar Thomson Steel Works in Braddock and North Braddock, and Irvin Plant in West Mifflin, contributes a huge amount of dangerous pollution to Allegheny county every year. Nearby towns of Clairton and Glassport have reported high rates of cancer risk from these air pollutants. And just this year, Allegheny County gave Clairton Coke Works a $1 million fine for exceeding pollution limits. As reported by State Impact Pennsylvania, since 2014, plant emissions have increased, resulting in several violations. Employees at US Steel have also been accused of trying to hide the pollution from inspectors.

Industrial pollution in Pittsburgh is the biggest source of air pollution. It is important to recognize, however,  that the Mon Valley Works employs many people and supports the local economy. Clairton Coke Works alone employs 1,000 people. Even though it is a difficult balancing act, it is absolutely imperative for the health of all Pittsburghers to reduce air pollution. It is unacceptable for industrial players, like Clairton Coke Works, to endanger the health of the entire Pittsburgh metro area by consistently exceeding agreed-upon emissions limits.

Want to monitor the air quality in your region? Visit AirNow, a partnership among environmental agencies of the federal government, or Air Pollution in the World.


For readers interested in monitoring their indoor air quality in Pittsburgh, visit the Carnegie Library to borrow an air quality monitor.


Interested in advocating for clean air in Pittsburgh? Check out these groups:

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