Thousands of US parks may sit dangerously close to toxic waste and chemical releases; researchers mapped more than 151,000 public parks to uncover the risk

Public parks are usually seen as places where people can escape built-up surroundings. Trees, open lawns and recreational spaces offer a break from traffic and dense development. Yet their location within the wider urban landscape can sometimes place them close to industrial facilities and hazardous-waste sites.

According to Scientific Reports, a nationwide analysis mapped 151,366 public parks using the 2024 ParkServe database and compared their locations with facilities listed in the US Environmental Protection Agency's 2023 Toxics Release Inventory and 2024 Superfund database. The researchers found that 52.6% of the mapped parks were within two miles of a facility reporting to the Toxics Release Inventory, while 9.3% had such a facility inside the park or within half a mile of its boundary. The analysis also found that 17.7% of parks had some area within two miles of a current or former Superfund site, while 1.6% directly overlapped one.

When green space meets industrial land


The study does not suggest that every park located near a pollution source is contaminated. Instead, it reveals a geographical relationship that has received relatively little attention: the same landscapes that contain public green spaces can also contain or border sites associated with industrial chemicals and hazardous waste.

One reason for this overlap may be the long history of urban development. Industrial activity has often developed around waterways, transport routes and established population centres, while parks have also been created in and around these urban landscapes. As cities changed, some former industrial areas were redeveloped and neighbouring land was converted into recreational or public uses. The researchers' choice of the Toxics Release Inventory is important because it does not represent a list of every polluted property in the country. The EPA's TRI programme requires certain industrial facilities to report information about the management and environmental release of listed toxic chemicals. The database is therefore a record of reported chemical activity rather than a direct map of contamination. That distinction means the map cannot be used as evidence that people using nearby parks are exposed to toxic substances.

What the map revealed

According to Scientific Reports, the geographical pattern becomes more striking when the two types of sites are considered separately. More than half of the mapped parks were within two miles of a TRI-reporting facility, while fewer than one in 10 had a facility inside the park or within half a mile. For Superfund locations, 17.7% of parks had some parkland within two miles of at least one current or former site.

Scientific Reports also notes that the overlap was not distributed evenly across the country. Both parks and Toxics Release Inventory (TRI) reporting facilities were more concentrated in urban areas, although the researchers cautioned that this pattern was partly influenced by the ParkServe dataset itself. The database covers named, publicly accessible parks in Census-designated places that intersect urban areas with populations of at least 5,000. Therefore, the 151,366 parks analysed should not be interpreted as representing every public park in the United States.

The Superfund comparison adds another layer because these sites represent places associated with releases or threatened releases of hazardous substances that have been prioritised for investigation and potential cleanup. The EPA's National Priorities List is designed to identify sites that warrant further investigation under the federal Superfund programme. The mapping also showed that direct overlap was relatively uncommon in some parts of the country. Five states, Arkansas, Maine, Mississippi, North Dakota and Wyoming, had no parkland directly overlapping a Superfund site in the dataset. Meanwhile, Missouri and Virginia had the highest number of TRI-reporting facilities located within parks, with six in each state.

A warning about what proximity means

The most important finding may be less about declaring parks unsafe and more about identifying places where closer examination could be useful. Distance alone cannot establish whether a chemical is reaching a park or affecting people who use it. Pollutants differ in how they move through air, water and soil, and actual exposure depends on factors such as the chemical involved, environmental conditions and the route through which contact occurs.

The researchers therefore describe their work as a nationwide geospatial overview rather than an exposure study. They did not measure pollutant concentrations in parks, track individual visitors or assess health outcomes. The analysis instead provides a starting point for identifying locations where environmental testing or more detailed investigation may be warranted. That distinction is particularly important because parks are valued precisely for the benefits associated with access to outdoor space. Finding that a park is near an industrial facility does not erase those benefits, but it does raise questions about how environmental risks are considered when public spaces are planned, redeveloped or maintained. The new map offers a different way to examine urban green spaces. A park may appear disconnected from nearby industry, but its location can reflect years of development that placed recreational land near pollution sources.