When Langston Verdin noticed high rates of emergency department visits and hospitalizations for asthma in many of Milwaukee’s North Side neighborhoods, he wanted to learn why.
“What I found was that there was no way for us to know what the air quality was like at the neighborhood level,” Verdin said.
The uncertainty led Verdin to start the MKE FreshAir Collective, a passion project to monitor local air quality in 2019. It became a nonprofit in 2023, and Verdin and Danika Hill-Paulus are co-executive directors.
In the fall, the collective released the 2024 Milwaukee Air Quality Report, which uses data from 21 air quality sensors. The report was created in collaboration with Data You Can Use, a nonprofit that helps people access data and make it useful in improving community conditions in Milwaukee neighborhoods.
“We want to be able to use our data to support community health,” Verdin said.
How air quality is tracked
MKE FreshAir Collective has received almost $30,000 worth of donated consumer-grade sensors from IQAir in recent years and installed them in areas with high asthma hospitalizations. The collective also received funding from the Wisconsin Department of Health Services.
The sensors record hourly data, which the Data You Can Use team analyzed to produce daily and monthly averages.
“It’s a lot easier to grasp what’s going on in the day-to-day or even a month-to-month basis, rather than just every single hour, because little things can happen,” said Rohan Katti, data systems program manager for Data You Can Use.
Though the sensors measure a few different pollutants, the report focuses on particulate matter called PM2.5, fine inhalable particles that are 2.5 micrometers in diameter or smaller and can be found in dust, soot, chemicals and other substances.
The concentrations of PM2.5 are measured using the U.S. Air Quality Index, or AQI. The AQI scale ranges from 0 to 500, with higher numbers indicating more pollution and greater risk for human health.
What neighborhoods had the best and worst air quality in 2024?
Verdin said 2024 was a pretty good year for air quality in Milwaukee neighborhoods, with less wildfire smoke than 2023.
Still, there were 10 days where at least one sensor had a daily average AQI classified as “unhealthy for sensitive groups” or worse.
The Menomonee Valley (South), Near West Side and Franklin Heights sensors reported higher monthly averages, while Harambee, Silver Spring and King Park had consistently lower averages.
Verdin said the Menomonee Valley air quality is expected given the industrial area and is not super concerning because not many people live there.
“Folks do work down there, though, so we partner with a couple of organizations down there to make sure folks have that information,” Verdin said.
How can you learn more about your own neighborhood’s air quality?
The report breaks down each neighborhood with graphs of daily AQI, charts tracking the number of days per month in each AQI category and a map of a half-mile radius around the sensor.
The neighborhood snapshots have demographic data because some groups have more risk associated with being exposed to air pollution, such as children, pregnant people, elderly populations and people with preexisting health conditions like cardiac and pulmonary diseases.
The highest daily average AQI level was recorded in Havenwoods at 154.46 on Dec. 26, 2024, while the lowest daily average was reported as 0.71 in Harambee on Jan. 16, 2024.
“I think our next approach is going to be a little different because when you look at it over a month, it makes those bad days just kind of go away,” Verdin said.
Katti and Amanda Beavin, a community data and research program manager for Data You Can Use, had hoped to correlate areas with high asthma hospitalizations with neighborhood spikes in air quality, but they faced challenges because of limited data and delays in residents seeking asthma treatment.
“Maybe they’re not insured, or maybe they need to go to work, so they wait a couple days until it’s no longer manageable and they have to go see care,” Beavin said. “We’re trying to find a way to connect those events even though there is that kind of lag.”
Next steps
MKE FreshAir Collective has already expanded its network of sensors to 26 and is planning to add more sensors along the Beerline Trail. A sensor installed in Melvina Park this fall will automatically alert elected officials when the AQI is higher than 100, which is considered unhealthy for sensitive groups.
Katti and Beavin are working with Carmelo Knight, a Data You Can Use intern, and Ayanna Bell, a community engagement and data communication coordinator for the organization and Trinity Fellow from Marquette University, to run more statistical testing for the 2025 report.
“It actually makes me really excited to keep working on this because there’s so many more things to unpack,” Katti said.
To learn more
Take this survey if you have feedback on the project, or reach out to langston@mkefreshair.com or amanda@datayoucanuse.org with questions on the report.
Data You Can Use created an air quality dashboard, which maps monthly sensor AQI averages from 2023 and 2024.
To access neighborhood air quality data in real time, download the AirVisual app by IQAir or view the map here. The app allows a user to follow neighborhood sensors directly and be notified when air quality gets worse.
Meredith Melland is the neighborhoods reporter for the Milwaukee Neighborhood News Service and a corps member of Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues and communities. Report for America plays no role in editorial decisions in the NNS newsroom.
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