Scrap Metal Facility Releases Polluted Dust into Surrounding Neighborhoods

A community-academic research team from the University of Michigan and Detroit-area groups found dust pollution in several neighborhoods could be attributed to an industrial scrap metal processor.

The research was prompted by a ground-buckling upheaval event at a scrap metal facility that caused damage to infrastructure such as homes, roads, and water mains. The event resulted from excessive accumulation of mill scale, a type of scrap metal residue. Nearby residents were concerned about how this event at the facility might affect their health, which led researchers to work with them on a project to learn more about potential contamination.

The team describes its process for sampling and analyzing soil and dust surrounding the facility to address community concerns in a December 2023 paper, published in the journal Environments. The work demonstrates the local impacts of scrap metal facilities and may support future efforts to better control pollution at these facilities.

Engaging the Community to Gather Soil and Dust Samples

Scrap metal processing facilities can contribute to air pollution by releasing fugitive dust (FD), a form of particulate matter that is not released through a smoke stack. It is often transported by wind and traffic and comes from sources such as construction, agricultural tilling, and industrial metal production and processing. Often, FD is tracked by trucks handling and transporting materials or washed off as sediment in rainstorms. This type of dust, which typically accumulates close to its source, is an environmental health concern because it can contaminate soils and adversely affect respiratory and other health outcomes.

After the upheaval, the research partners hosted an event in a neighborhood near the facility to provide residents with information on plans and to answer questions.

The research team collected road dust and surface soil samples from 20 locations around the metal processing facility. Community members collected dust samples from 27 homes by using wipes on surfaces such as windows. The researchers analyzed the samples to determine which metals were present and at what concentrations.

The research team also analyzed soil at the facility. Through comparisons, the researchers found that metals in soils from the neighborhoods matched the unique metal profile found at the facility.

“We wanted to learn whether the dust from the facility was contaminated and whether that dust was directly released into areas surrounding the facility,” stated Stuart Batterman, Ph.D., lead researcher on the study. “We found elevated levels of metals in dusts and surface soils at the facility and that local neighborhoods had similar profiles. This profile was unique to the facility because of its high iron content, so it shows neighborhood metal pollution can be traced back to the facility.”

Results Support Community Advocacy Efforts

Metal processing facilities are not often included in inventories of industrial sites tracked for pollution. In fact, the researchers did not find the facility in the EPA National Emissions Inventory, which tracks pollution sources. When conducting an online search for other metal processing facilities, they found 271 unlisted facilities in Wayne County, where Detroit is located.

This study shows that understanding how scrap metal facilities contribute to neighborhood pollution could promote pollution reduction measures. The authors note ways to reduce pollution from metal processing facilities, such as by surrounding the facilities with solid fencing; enclosing operations and stockpiles; washing truck tires to reduce tracking metals outside the facility; paving work areas to reduce the spread of dust on tires and in air; planting vegetation to serve as buffers; and increasing oversight and other controls to reduce pollution, including regular inspections, assessments, and FD monitoring. In the case of the facility examined in this study, solid fencing surrounded the site, and streets were sometimes cleaned.

“Since we found FD from the metal processing facility was out in the community despite some control efforts, it appears that either enhancing existing pollution control measures or implementing additional measures could be useful in this case,” added Batterman. “Our data support community advocacy aimed at obtaining measures that protect public health.”