A sprawling public health crisis is unfolding in the neighbourhoods of Detroit, where the city's massive home demolition programme may have left behind a toxic legacy. Hundreds of sites where derelict houses were torn down are now suspected of being backfilled with soil contaminated with dangerous chemicals, including lead and asbestos.
A Programme of Unprecedented Scale Leaves a Toxic Trail
Detroit, the United States' lowest-income major city, has been grappling with the scars of deindustrialisation and population decline for decades. Its population plummeted from nearly 2 million in the 1950s to under 700,000 today, leaving tens of thousands of empty structures. In response, Mayor Mike Duggan's administration embarked on what is widely considered the nation's largest-ever demolition programme, spending hundreds of millions of dollars to tear down tens of thousands of homes over twelve years.
However, this blight elimination effort now faces serious allegations of mismanagement and environmental negligence. An investigation by the Detroit Office of Inspector General revealed earlier this year that a city-hired contractor used dirt contaminated with construction debris from the demolished Northland Shopping Mall to backfill residential demolition sites. Subsequent testing in early November found that 42 out of 47 sites examined exceeded pollution thresholds, with much of the material deemed "unsafe for direct human contact."
Protocols Ignored and a Growing List of Suspect Sites
This is not the first time contaminated backfill has plagued the programme. Similar issues emerged three times previously, drawing federal scrutiny in 2018. In response, protocols were developed with state and federal regulators to prevent a recurrence, including increased scrutiny of dirt sources and mandatory testing for material from commercial land.
Yet, according to experts and a former regulator, these safeguards were insufficient or ignored. Steve Hoin, a former geologist with Michigan's Department of Environment, Great Lakes and Energy (EGLE), questioned whether the administration followed the 2018 advisory protocols. "Regardless, it’s mismanagement because clearly they had knowledge in 2017, and before that, that contaminated fill was coming in, and they haven’t fixed the problem," Hoin stated.
RJ Koscielniak, a geology professor and scholar of urban decline, argued the city never implemented "legitimate controls," partly due to contractor opposition and a desire to maintain demolition speed. The protocols' loophole allowed contractors to falsely claim dirt came from residential areas to avoid testing.
By late December, Mayor Duggan announced that 424 sites had been identified as potentially contaminated. He stated that 32% of 50 sites tested exceeded "regional background levels," a threshold that triggers mandatory environmental cleanup. Duggan downplayed the immediate health risk, suggesting danger only existed if someone dug through the topsoil. However, he estimated remediation could cost around $18,000 per property.
A "Gargantuan" Public Health Threat for Residents
Environmental health experts strongly contest the mayor's assessment of the risk. The contaminants likely present—such as lead, mercury, cadmium, PAHs, and asbestos—are linked to severe health issues including cancer and reduced cognitive ability in children.
Allen Burton, an ecosystems management researcher at the University of Michigan, called the situation a "gargantuan problem," effectively creating small toxic waste dumps scattered across neighbourhoods. He dismissed Duggan's claims, noting that proper hazardous waste sites are capped with specialised liners or thick clay barriers, which are not present here. "Anything that is near the surface is going to be a hazard to the neighbourhood," Burton said.
Steve Hoin warned that residents face risks from dust blowing off the properties, while children playing on the sites face more immediate health impacts. He and Burton also noted that Detroit's background threshold for lead is higher than in other cities and does not guarantee safety.
As Mayor Duggan leaves office to campaign for governor, his successor, Detroit City Council Mayor Pro Tem Mary Sheffield, will inherit this escalating environmental and public health challenge. The Duggan administration, through spokesperson John Roach, defended its record, stating contaminated backfill is a national issue and that Detroit has been proactive in investigation and holding contractors accountable. EGLE stated it will work with the city on appropriate actions, including possible remediation.
The full test results, which the administration has not yet disclosed despite repeated requests, are awaited to reveal the full extent of the toxins buried in Detroit's communities.
