Pittsburghers are all too familiar with the smell of sulfur dioxide emissions, but it’s invisible. Now, residents can get a better visual of how air pollutants float across the region on a daily basis.
Carnegie Mellon University’s CREATE Lab has launched PlumePGH, a new map from the makers of the lab’s popular app SmellPGH, which allows users to track the origin of pollution as well as how it correlates with reports of stinky air.
The map shows the four largest emitters of SO2 and other sulfur oxides in Allegheny County: U.S. Steel’s Clairton Coke Works, Irvin Works and Edgar Thomson Works, and the Cheswick Generating Station.
Each emitter is denoted by a different color. Users can follow dots that represent emissions wafting through the region over the course of 24 hours. The dots scatter as pollution becomes less dense. The plumes follow weather models from the National Oceanic and Atmospheric Administration.
Layered on top of those plumes are crowd-sourced reports from CREATE Lab’s SmellPGH app. Triangles represent individual reports with colors corresponding to the severity of smell. Users can also add data from air quality monitors to further validate the modeling and SmellPGH reports.
The brightly colored plumes correlate strongly with smell reports submitted by SmellPGH users. The map provides data stretching back to 2019.
Ana Hoffman, CREATE Lab’s director of air quality engagement, said the eye-catching design of the map allows people to feel connected to others experiencing the same air quality issues.
“It’s hard to visualize how far industrial pollution reaches, so this weaving together creates a corroboration of people’s experiences,” Hoffman said.
Respiratory irritation from sulfur dioxide exposure can cause symptoms like sneezing, sore throat, wheezing, shortness of breath, chest tightness, and a feeling of suffocation, according to the U.S. Centers for Disease Control and Prevention.
“SmellPGH offers people a way to voice something that was in the realm of conspiracy theory before. When you smell something … you’re often able to say to yourself, ‘Oh, I thought I smelled something but I didn’t really,’” Hoffman said.
PlumePGH takes that experience a step further, allowing users to see how many reports were submitted in their area and how those reports line up with NOAA models.
Looking at the map, users can see how emissions remain concentrated in the air miles from a source.
This is particularly apparent on days when the ground is colder than the upper-level atmosphere, trapping concentrated air pollution close to the ground. This is known as an inversion.
The greater Pittsburgh area sees a substantial number of inversion days; 157 per year, according to the Allegheny County Health Department.
“The alignment of these independent data sources can help us understand whose health may be impacted by this industrial pollution,” said Randy Sargent, director of visualization at the CREATE Lab.
The website provides a “Take Action” tab with resources to help users report air quality concerns in their communities. Hoffman also hopes users can also learn they aren’t alone in smelling bad air.
“I hope that this site can be a way for regulators and the community to have a shared data language to open up lines of communication,” Hoffman said. “We want this to be a technical resource — much like SmellPGH and the Breathe Cams — where someone experiencing a pollution event can go to add data to back up their concern.”