Why do we call 48217 Michigan’s ‘most polluted zip code’?

Experts say more air quality monitoring and better assessment methods are needed to understand how cumulative exposures to pollution affects communities.

Planet Detroit was recently asked about the claim—frequently repeated by journalists—that Detroit’s 48217 zip code, home to the Boynton and Oakwood Heights neighborhoods, is Michigan’s “most polluted.” 

The commenter referred to this as a “hoax claim”, saying it had been invalidated by Michigan Department of Environment, Great Lakes, and Energy (EGLE) air quality testing in the area and that the label was “Detroit-bashing”.

We decided to take a closer look to see what had been learned about pollution in the area and if it was time to rethink the “most polluted” moniker.

“I think it’s fair to say that under almost any measure, the 48217 zip code and the surrounding zip codes bear a heavy burden of pollution,” Jeff Korniski with EGLE’s Air Quality Division told Planet Detroit. He adds, however, that calling it the most polluted zip code is “kind of subjective.” For example, it’s probably impossible to compare the PFAS contamination in Kent County with the air quality problems in Detroit and say one place is the “most polluted”.

Although some clearly object to the label, it hasn’t been all bad. Theresa Landrum, a neighborhood activist and member of Gov. Gretchen Whitmer’s Michigan Advisory Council for Environmental Justice (MAC EJ), feels that it’s helped bring attention to the area’s problems. “If that tagline had not come out … I don’t think the environmental justice movement would be what it is today,” she says.

As for our commenter’s contention that EGLE’s air quality monitoring has shown this claim to be false, exactly what these and other studies have revealed is unclear. Data like that collected by the EGLE monitor on the southwest side of 48217 shows pollutants like SO2—or sulfur dioxide—below thresholds set by the National Air Quality Standards (NAAQS), and even lower than readings from a similar monitor in Port Huron. (The NAAQS have been set by the EPA to protect “the health of ‘sensitive’ populations such as asthmatics, children, and the elderly.”) 

But other datasets and monitors on the downwind side of the Marathon refinery and other industries show significantly more problems, suggesting that EGLE’s monitor isn’t capturing much of the pollution in the neighborhood.

University of Michigan researcher Paul Mohai—whose research with Byoung-Suk Kweon lead to Tina Lam’s stories in the Detroit Free Press that first referred to 48217 as the “most polluted zip code”—suggests that more air quality monitoring and better assessment methods are needed to understand how cumulative impacts to pollution affect communities.

“I think there’s a lot of frustration in the environmental justice communities that current regulations only consider one pollutant at a time,” Mohai says. 

Map by Eve Washington

Some notable examples of efforts to consider cumulative impacts include University of Michigan studies to evaluate cumulative exposure factors in a health impact assessment for DTE Energy’s Integrated Resource Plan and to identify geographies exposed to multiple environmental and social burdens. Some states, including California and Minnesota, have begun implementing screening tools and are considering cumulative exposures in regulatory decisions. 

A reframing of the air quality discussion around the notion of cumulative impacts may prove to be an important legacy for the work of community activists like Landrum and Dr. Dolores Leonard, who have emerged as leaders in the fight for environmental justice in Detroit. 

Their efforts are pushing the state to move from a “risk paradigm” for assessing pollution to one that looks more holistically at impacts and how to address them.

What the studies tell us

In 2010, Sierra Club’s Rhonda Anderson invited Mohai and Kweon to come to her neighborhood and share their research about pollution around schools. Their study showed 48217 as having the highest air pollution burden of any zip code in the state. 

This research was based on the Environmental Protection Agency’s (EPA) Geographic Microdata from 2006, which is compiled from Toxic Release Inventory (TRI) data collected by facilities like Marathon and then reported to the EPA. Unlike EGLE monitors, this survey didn’t measure contaminants at specific locations. Instead, it reported on a much broader collection of pollutants from the pollution sources themselves.

“My colleague and I were careful to say that [our research] is based on that specific database,” Mohai says. “It doesn’t take into account other sources of air pollution. It doesn’t take into account mobile sources, for example.” 

Today, the data used in Mohai and Kweon’s study is 14 years old. Mohai believes an updated analysis is necessary. Yet the old data may still provide a better picture of what is likely happening in 48217 than the current EGLE air monitor at the New Mt. Hermon Baptist Church, which is upwind from Marathon, AK Steel, and several other significant polluters. It’s also away from much of the residential area that sits directly across I-75 from Marathon.

In 2017 and 2018, a monitor at the Salina School in Dearborn showed particulate matter (PM 2.5) within a couple of points of the NAAQS threshold. And a monitor on West Fort Street near Fort Wayne had SO2 higher than any other site included in a statewide study. Both of these monitors are downwind from 48217, although the Dearborn site is much closer. Korniski describes the Salina site as “representative of not only 48217, but 48209.” This second zip code has also been home to a lot of industry including the steel facilities on Zug Island.

But the monitoring EGLE did in 2017 and 2018 for these so called “criteria air pollutants” — a list of six common items including ozone, lead, and carbon monoxide–represented a significant reduction in testing from the original project in 2016 and 2017

Leading up to that study, the 48217 Community Environmental Health Board that included Landrum and Leonard had looked through a list of 150 pollutants, trying to figure out what was the most harmful, what could be tested for, and what they could afford with the limited $90,000 grant funding offered by the state in response to an outpouring of community concern. They ended up testing for a number of metals, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs)—compounds that are commonly released when fossil fuels are burned­—as well as SO2 and PM 2.5, among other pollutants.

The levels of pollution found in the study that ran from September 2016 to 2017 were perhaps lower than some had anticipated. Although 48217 is listed as a “nonattainment area” for SO2—meaning that the area isn’t meeting health standards based on three years of data—the EGLE air monitor at New Mt. Hermon Baptist Church showed levels well below NAAQS limits for both years of the study. However, elevated levels of benzene and manganese showed up at both the 48217 and Dearborn monitors during the study. Benzene in particular has been a frequent problem in the area and can cause leukemia.

Susan Klimer from EGLE’s Air Quality Division says the EGLE air monitoring showed “a lot of commonality in the types of results” across communities in southwest Detroit and the cities on the Detroit border. Of course, this doesn’t mean that the pollution situation in 48217 was “good” in any way, but it’s perhaps not worse than neighboring zip codes. 

Stuart Batterman, a professor of environmental health sciences at the University of Michigan says that recent EPA data backs this up. “I have looked at emissions at the county level … It’s no longer the top one,” he says of the 48217 area.

A new model is needed

One matter for which there’s broad agreement among experts interviewed for this article is that more monitoring is needed, if not an entirely different way to evaluate the threat that pollution poses to communities. For example, a single year of monitoring may not mean much, since air quality is often measured over years, and there’s been limited testing since 2017. 

This monitoring also might not capture the effect of events like the oil vapor leak at Marathon in February 2019. In a recent settlement the company was ordered to pay for air quality improvements at the nearby Mark Twain School, among other things. 

“I think it’s fair to say that our monitoring not only at that location, but statewide, doesn’t do a very good job of capturing singular events,” Korniski says. Such events tend to be leveled out in monthly data or missed entirely by periodic sampling, leaving residents in the dark about potential health impacts.

The need to put air monitors at fixed locations with power and security has also helped obscure the geographical reach of pollutants. In the case of 48217, EGLE sited their monitor at Mt. Hermon Baptist Church because it was one of the few places that would host the monitor while also meeting basic requirements for power and security. Batterman has plans for a mobile air testing lab that could allow researchers to take samples from areas like the northeast part of Boynton, closer to the Marathon refinery.

More data points could give a clearer sense of how bad the pollution is in 48217 and adjacent zip codes, but collection is just the first step. New models like California’s CalEnviroScreen combine pollution data with demographic information to establish a framework for addressing environmental injustice in order to drive policy. According to these metrics, once communities land above the 75th percentile they’re targeted for pollution reduction.

Landrum has worked to get similar reforms established in Michigan, first with former Gov. Rick Snyder’s Environmental Justice Working Group, where she pushed for cumulative assessments of pollution in their recommendations, and now as part of the MAC EJ, where she’s advocating for an environmental justice screening tool for Michigan. Her thinking on this matter was informed by the situation in 48217, where she saw issues like benzene pollution continue years despite never fully being accounted for by monitoring. 

“You’re looking at generations of exposure for people, and you’re looking at generations of illnesses,” she says. Among other things, a program like California’s would determine how badly impacted a community has already been before adding new pollution sources.

Regina Strong, EGLE’s Environmental Justice Public Advocate, told Planet Detroit that a workgroup of the Interagency Environmental Justice Response Team with input from the MAC EJ group is working on the development of an EJ screening tool for Michigan using both the examples from other states, as well as the University of Michigan model that was published in May of 2019. 

She hopes a screening tool can help inform decisions, but getting to a California-style model where such data would become part of the regulatory decision making process would likely require legislative action. Creating the tool would be a first step.

“Before you can say ‘change the law and include this’ you need to show them what should be included,” Strong said.

Researchers have referred to this change in thinking as moving from a “risk paradigm” to an “impact paradigm”. In other words, rather than focusing on how bad pollution is from one particular source, researchers and policymakers instead concentrate on how it affects people over time and what can be done about it.

Moving forward, whether or not 48217 is considered Michigan’s “most polluted zip code,” it continues to face added risk, most immediately from the Gordie Howe Bridge slated to open in 2024. This development is expected to contribute to the already high level of vehicle emissions in the area on account of two expressways and an increased volume of truck traffic. 

Landrum remains steadfast, noting how the work of residents to address generations of pollution also shows how “The environmental justice movement has taken off in Detroit and Michigan proper from the little group of African-American women … voicing their opinion.”


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