More than half of the public parks in the United States are located within two miles of an active industrial facility that handles toxic chemicals, according to a new study from researchers at the University of Michigan. The analysis offers one of the most detailed national examinations to date of how public green spaces intersect with the country’s industrial and hazardous-waste landscape, revealing that parks, playgrounds and hiking trails frequently exist alongside facilities regulated for toxic chemical releases or sites requiring federal cleanup.
The researchers found that approximately 80,000 of the nation’s public parks are situated within two miles of a facility listed in the federal Toxics Release Inventory, or TRI. The inventory, administered by the U.S. Environmental Protection Agency, tracks industrial facilities that manufacture, process or use significant quantities of certain chemicals and are required to report releases, transfers and waste-management activities. The study also identified nearly 27,000 parks located close to Superfund sites, which are heavily contaminated locations designated for emergency federal remediation under the Comprehensive Environmental Response, Compensation, and Liability Act. More than 2,400 parks actually contain land that overlaps a Superfund site.
To conduct the analysis, the University of Michigan team used data from ParkServe, a national database containing 151,366 public parks and other publicly accessible recreational spaces. The inventory includes large national and state parks as well as neighborhood parks, school playgrounds, local trails and smaller green spaces that may be used daily by nearby residents. Researchers cross-referenced the geographic boundaries and coordinates of those parks with the locations of TRI facilities and Superfund sites, calculating how many parks fell within specific distances, including half a mile and two miles. The approach made it possible to examine environmental proximity at a national scale rather than focusing only on individual contaminated properties or selected communities.
The results, published in Scientific Reports, show that the relationship between parks and potential pollution sources is not limited to a handful of unusual locations. Sixty-three parks had a TRI facility within their boundaries, while more than 14,000 had one within half a mile. At the two-mile threshold, the number rose to roughly 80,000 parks, meaning that a substantial share of the nation’s public recreational infrastructure is located near an industrial operation that handles reportable toxic chemicals. Proximity, however, does not necessarily mean that pollutants are entering a park or that people using it are being exposed. Instead, the findings identify places where environmental conditions may warrant closer investigation.
“While spaces like parks are easy to spot, polluting sites often hide in plain sight—even right next to where we live and work,” said Elliott Chemberlin, a co-author and scholar in the University of Michigan Institute for Social Research’s Junior Professional Researcher program. The study was designed to show how apparently separate elements of the built environment—public recreation, industry, housing and waste management—often occupy the same neighborhoods. In many communities, a park may be viewed as a symbol of health and investment while an industrial facility, waste site or former factory remains just beyond a tree line, road or fence.
That physical proximity creates a complicated public-health picture. A large body of research links parks and other green spaces with increased physical activity, improved mental well-being, greater social connection and reduced exposure to extreme urban heat. Trees and vegetation can capture some airborne particles, provide shade, cool surrounding surfaces and contribute to improved local air quality. Parks may also increase property values and serve as important gathering places, particularly in densely populated neighborhoods. At the same time, studies of industrial facilities and hazardous-waste sites have associated long-term environmental exposures with elevated risks of cardiovascular and respiratory disease, certain cancers, birth defects and neurological harm. The two realities can exist side by side, complicating the assumption that access to a park automatically represents an unqualified health benefit.
Philippa Clarke, a University of Michigan professor of epidemiology and researcher at the Institute for Social Research, said that green-space research must account for the environmental conditions surrounding parks. “While communities may experience health benefits from parks, our findings indicate that this does not necessarily occur in isolation from toxic exposures,” Clarke said. “Understanding that parks and polluting sites overlap adds important nuance to public health research on the health benefits of green space.” In other words, the presence of vegetation alone cannot fully describe the environmental experience of park users. The quality, history and neighboring land uses of a park may matter as much as its size or accessibility.
The study did not measure contamination inside individual parks, determine whether chemicals were moving from nearby facilities or estimate the exposure of park users. A facility’s presence in the TRI database does not indicate that it is violating environmental regulations, and a Superfund designation can refer to a site at different stages of investigation, containment or remediation. Actual exposure depends on numerous technical factors, including the identity and concentration of pollutants, the routes by which they travel, whether contamination is in soil, groundwater, surface water or air, the effectiveness of containment systems and the progress of cleanup efforts. Weather, wind direction, rainfall, flooding and seasonal conditions can also influence how pollutants disperse. As a result, distance is best understood as a screening measure rather than a direct estimate of health risk.
The researchers have created a web-based map and public dataset through the National Neighborhood Data Archive, allowing communities, planners, journalists and scientists to examine the locations of parks, TRI facilities and Superfund sites in relation to one another. The tool could help identify areas where soil, water or air testing may be useful, support community advocacy and guide decisions about future park construction or redevelopment. The researchers note that some parks were deliberately created on former industrial properties or landfills after remediation, while many older cities historically placed factories and parks alongside waterways. In the American West, some national parks were established near mining areas, creating additional layers of historical overlap. By making these patterns visible, the study may encourage planners to consider alternatives farther from active pollution sources while also prompting more detailed assessments of parks built on remediated land. The authors emphasize that the map is a starting point for research and public discussion—not a diagnosis of contamination or a declaration that every nearby park is unsafe.
Subject of Research: Proximity of public parks to industrial facilities handling toxic chemicals and federally designated hazardous-waste sites in the United States.
Article Title: Proximity of parks to polluting sites in the United States
Web References: University of Michigan; National Neighborhood Data Archive; Scientific Reports article: https://www.nature.com/articles/s41598-026-65808-7
References: DOI: 10.1038/s41598-026-65808-7
Keywords
Public parks, toxic chemicals, industrial pollution, Superfund sites, Toxics Release Inventory, environmental health, green space, public health, urban planning, hazardous waste, environmental exposure, University of Michigan
