Case Study: How PurpleAir is Helping With Pennsylvania Air Quality

Pennsylvania Air Quality
  • Topic: Lehigh Valley PurpleAir Air Quality Network 
  • Industry: Air Quality, Community Development 
  • Author: Adrian Dybwad 
  • Website: 


Air pollution isn’t just a global problem. It’s also a local one. While it’s easy to think that air pollution belongs to big countries, like China, or big cities, like New York, small counties and neighborhoods also experience air pollution. That’s because air pollution is a hyper-local problem that also needs hyper-local solutions. One such instance is Lehigh Valley, Pennsylvania.  

Unlike most of Pennsylvania, Lehigh Valley’s major air quality concerns aren’t limited to power plants and industrial facilities. Rather, they’re also concerned about the impact of the emissions from mobile sources, like trucking and warehousing.  

So, to better understand Pennsylvania's air quality, a Lehigh University student started an air quality network. With this network, they can collect hyper-local air quality data that can shape and inform air quality initiatives and policies. 

The State of Pennsylvania Air Quality 

Lehigh Valley has a long history of struggle with air pollution. In the 20th century, it was the hotbed for steel and heavy manufacturing. It was also the location of Bethlehem Steel, the second-largest steel company in the world. Although these industrial activities helped Lehigh flourish, they also deteriorated the health of residents.  

According to an air quality study published by Cambridge University Press, Pennsylvania air quality was bad enough to cause higher mortality rates from 1916 to 1927. This was because steel mills emit toxic air pollutants, including Particulate Matter (PM).

Although many of these industrial facilities have shut down, modern sources of air pollution are still prevalent. During the eCommerce boom in recent years, Lehigh has grown into a logistics and warehousing hub. In fact, it’s now the home of big companies like Crayola and Peeps, which have further deteriorated Lehigh’s air quality.

In 2023, the Lehigh Valley Planning Commission reported that transportation and mobile sources account for 26.6% of Lehigh’s air pollution. This makes it the second major source of poor air quality after electricity and natural gas.   

Not only that, the PennEnvironment ranked Lehigh as the seventh worst air quality urban area in Pennsylvania. Plus, Asthma Capitals ranks Allentown, a city in Lehigh County, as the worst place to live for people with asthma.  

Despite this knowledge, Lehigh has only two official air quality monitoring stations for the entire county. Currently, there isn’t enough air quality data to give insight into how residents are affected by these air pollution sources.  

Thankfully, one resident is taking matters into her own hands. Local university student, Madison Hernandez, started an air quality monitoring network with PurpleAir monitors to better understand Lehigh's air quality. 

The Lehigh Valley and PurpleAir Case Study 

As a Lehigh University student, Madison Hernandez focused on environmental sciences. During her studies, she became interested in solutions to the current air pollution situation in Lehigh County. Wanting to learn more about the air quality in Lehigh Valley, she started conducting an air quality study. 

Once she started comparing various devices, she chose to use PurpleAir air quality monitors since they are regularly used by academic researchers. First, she placed an air quality monitor in her professor’s home as a control variable, since the home was located in an area with low population density and good air quality.  

After this, she placed five air quality monitors in North Bethlehem. Then, she placed five additional ones in South Bethlehem. Now, all ten monitors are reporting air quality in the county thanks to her hard work. 

By the end of the study, Madison aims to:  

  • Gain hyper-local insight into the air quality of Lehigh communities 
  • Understand how air quality impacts low-income communities 
  • Help spread awareness on issues regarding air pollution 
  • Develop solutions that mitigate the sources of air pollution 

How Lehigh Valley is Promoting Better Air Quality with PurpleAir 

Madison’s project was just the beginning of Lehigh’s air quality monitoring. Now, about a year after the project, Lehigh University professors are collaborating with the local county for the Lehigh Valley Breathes community science project.  

Lehigh Valley Breathes plans to install 40 PurpleAir air quality monitors across the county, especially in areas with high pollution activities and high population density. You can already see the air quality monitors on the Lehigh Valley Breathes air quality map and the PurpleAir Map.  

With the data collected from this community project, Lehigh County seeks to propose informed policies that promote air quality for all. They also hope to implement data-driven traffic regulations that will reduce mobile emissions. Most of all, they hope to provide healthy, breathable air for everyone in Lehigh.  

According to Lamont McClure, Northampton County Executive, “The reason we're going to do that is we are data-driven. We believe in solutions that are directed by science, not merely by emotion and rhetoric.” 

About PurpleAir 

Since being founded in 2018, PurpleAir has dedicated itself to providing highly precise air quality monitors that track hyper-local air quality levels in real time. In doing this, PurpleAir is empowering community scientists and helping to facilitate social change through accessible air quality data for all. By working together, everyone is more informed and able to make changes in their local communities to improve air quality.