Mapping pollution in Minneapolis

New state effort seeks to understand air quality at neighborhood level

MPCA monitor
An MPCA monitor tracks air pollutants at the corner of 28th & Xerxes in Cedar-Isles-Dean. Photo by Andrew Hazzard

The state of Minnesota has historically measured urban air pollution using monitors on top of buildings — an informative strategy, but one that misses the reality at the ground level.  

“That doesn’t give you a clear picture of what people are breathing in,” said Patrick Hanlon, director of environmental programs for the Minneapolis health department. 

But now, for the first time, the Minnesota Pollution Control Agency (MPCA) is collecting hyperlocal data in the state’s two biggest cities. In the spring of 2019, the MPCA finished installing 44 air monitors in every zip code in Minneapolis and St. Paul.  

“Air quality really varies from neighborhood to neighborhood,” said Dr. Monika Vadali, who is coordinating the project for the MPCA.

As the MPCA begins compiling the data from the monitors, Minneapolis is about to learn how great those neighborhood variances really are and what strategies could be helpful in cleaning the dirtiest pockets of city air. In Southwest Minneapolis, monitors are in Bryn Mawr, Cedar-Isles-Dean, Fulton, Kenny, Kingfield and Lyndale. 

Air quality in the metro is well-regarded by national standards and our pollution levels are below limits set by the Environmental Protection Agency, Vadali said. But to do even better, the state and its largest cities need to know where and in what form pollution is taking place. 

Building an understanding

Right now, the MPCA is in the information-gathering phase of the project, Vadali said, and hopes to release a preliminary data breakdown by the end of the year. 

When the project began, the MPCA had to adjust to how sensitive the sensors are. For example, if a landscaping company brought in a few large trucks for a project near a sensor, that level of small activity could be picked up by the monitor and appear alarming. To avoid false positives, researchers would like residents to “adopt” nearby monitors and inform the MPCA of increased activity. “That was a small learning curve for us,” Vadali said.

The monitors collect real-time data of several pollutants, including fine particulate matter (PM2.5) — which comes from vehicles, power plants and fires — as well as carbon monoxide, nitric oxide, nitrogen dioxide, ozone, sulfur dioxide and coarse particles (PM10). Through the project website page (, residents can examine the air quality around them and compare it with other communities. 

The city is hoping the results from the monitors will help them understand where to target improvement efforts. 

When the city did ground-level pollution research in 2015, it identified high levels of perchloroethylene, or perc, particularly near dry cleaning businesses. 

Using the Green Business Cost Sharing program and other grants to assist companies in switching to cleaner technology, Minneapolis has effectively eliminated perc pollution, Hanlon said.

“The steps the MPCA are taking right now are the most crucial. Before we take the steps to clean the air, we need to understand the areas that are at the highest risk,” said Jesse Berman, a University of Minnesota professor of public health who studies environmental epidemiology. 

Pollution effects

The effects of air pollution are wide-ranging, Berman said, from asthma exacerbation to hospitalization. It’s also linked to less known hazards, like stillbirths and mental health risks.

Air particles contain different compounds that vary area to area depending on nearby industry and vehicle traffic. Some of those compounds are toxic and people who are very young, very old or suffering from chronic illness 

can be susceptible to pollution to the point where even a small variation in air quality can have a large public health impact, Berman said. 

“It’s important to understand these small variations in pollution across an urban area,” he said.

Berman’s recent research even shows a link between air pollution and violence. His old lab partner, now a professor at Colorado State, was studying wildfire smoke and reviewing connections between crime and air pollution. Berman applied FBI crime statistics, which break down crimes as violent or nonviolent, to more typical air pollution and found lower air quality is correlated with more violent crime. 

High air pollution increases the chances that minor conflicts people experience in their daily lives revert to basic aggression and violent confrontations, Berman said. Those trends held steady in urban and rural areas and across socioeconomic and racial lines: More pollution means more violence.

“We kind of think it will exacerbate the fight and flight reaction in people,” he said.

The effects of climate change are making pollution worse, according to data from the past decade, Vadali said, with the warming global climate contributing to higher levels of pollution.

“That entire baseline we would expect to see is a little higher,” she said.

Environmental justice 

Although Twin Cities air quality is relatively good, differences in pollution do exist between neighborhoods, though Vadali said they haven’t found any “alarming” disparities yet. 

In Southwest, the Lyndale monitor regularly records higher levels of PM2.5 pollution than the Fulton monitor and more frequently records levels higher than the 12 micrograms per cubic meter standard set by the EPA, though both average well below the standard. 

In general, being closer to a major roadway or industrial site means pollution is worse, Vadali said. 

“A lot of where those major roadways go through are in low-income areas,” Hanlon said. 

Kyle Samejima, executive director of Linden Hills-based Minneapolis Climate Action (MCA), believes most people already have an idea of what the neighborhood by neighborhood pollution data will show. 

 “All of these things are affected by your zip code and your zip code is affected by systemic racism and poverty,” Samejima said.

MCA tries to improve the environment and disparities through community solar programs, which allow people to get their energy from a solar farm instead of installing expensive panels on their own homes, and by offering energy efficiency help for low-income residents. Right now, the organization is trying to promote using tap water to low-income residents and recent immigrants to help them save money and reduce pollution by working with community groups and speaking to ESL classes. 

MCA is trying to highlight the link between air quality and racist practices like redlining. 

“Can you imagine the Northern Metals recycling facility in Linden Hills or Fulton or Kenwood?” Samejina asked, referencing a scrap metal processing building in North Minneapolis that was closed in September after admitting to fabricating its pollution records.