A group of researchers based in Hamilton have uncovered insights into the issue of soot accumulation in neighborhoods adjacent to the city’s industrial zone. Residents have long raised concerns about a dark, dirty substance coating their properties, with a recent surge in complaints during early July marking one of the most severe instances of fallout in recent memory.
Sarah Styler, an associate professor specializing in environmental chemistry at McMaster University, along with Grace Yao, a PhD candidate in Styler’s research team, are part of a study titled “What’s the Grime?” aimed at addressing this prevalent question. Through collaboration with volunteers who collected samples across Hamilton in 2024 and 2025, the researchers identified toxic elements in the soot consistent with coal combustion, particularly noting elevated levels of dust and polycyclic aromatic hydrocarbons (PAHs) near the industrial hub in northeast Hamilton.
Styler collaborated with Environment Hamilton on this study, supported by a $15,000 university grant awarded in 2024. Drawing from personal encounters with soot in east Hamilton and Corktown, Styler and Yao emphasized the longstanding nature of this issue, with historical references dating back to the 1950s uncovered during their investigation.
The team’s sampling approach involved gathering soot from the residences of 50 volunteers across the city, with periodic analysis revealing higher dust deposition closer to the industrial sector, accompanied by a greater presence of toxic compounds. Additionally, an update shared on the Environment Hamilton website highlighted seasonal fluctuations in PAH levels, with higher concentrations observed in winter compared to summer.
While the study focused on 13 different PAHs, Styler cautioned that the grime could contain various other harmful substances besides those identified, underscoring the significance of coal combustion in generating the PAHs detected. Despite limitations in examining all potential sources of the fallout, the researchers stressed the need for continued monitoring and enhanced analytical capabilities to pinpoint industrial-specific origins of the pollutants.
Styler acknowledged that the study’s findings may not be surprising to residents directly impacted by the fallout, suggesting an industrial emission source for the soot plaguing neighborhoods near coke plants. However, she noted community frustration over the perceived lack of information from official channels, citing ongoing testing by the Ministry of the Environment, Conservation and Parks to identify potential sources in Hamilton’s north end.
As Styler’s team prepares to share their results at a community meeting on August 20 and pursues expanded research involving more volunteers and a broader scope of compounds within the grime, their goal remains to provide insights into effective cleaning methods for addressing this persistent environmental concern.
