A group of researchers based in Hamilton has uncovered insights into the issue of soot accumulation in neighborhoods adjacent to the city’s industrial zone. Concerns over a dark, sooty residue coating properties have persisted for years and resurfaced in early July with residents reporting significant fallout.
Sarah Styler, an environmental chemistry associate professor at McMaster University, along with Grace Yao, a PhD candidate under Styler’s supervision, are involved in a study titled “What’s the Grime?” aimed at addressing the issue. Through the collaboration with volunteers who gathered samples across the city in 2024 and 2025, the team discovered that the soot contained harmful chemicals associated with coal burning. Moreover, elevated levels of dust and polycyclic aromatic hydrocarbons (PAHs) were detected in the vicinity of the industrial sector in northeast Hamilton.
Styler partnered with Environment Hamilton for the study, funded by a $15,000 grant from the university in 2024. Both Styler and Yao, residing in East Hamilton and Corktown respectively, have firsthand encounters with the soot issue. Styler emphasized the long-standing nature of the problem, tracing references to soot back to the 1950s in news archives.
The research involved the collection of soot samples from 50 volunteers’ homes across the city using sampling kits. These samples were analyzed at four-month intervals to draw conclusions. Styler pointed out that more dust and toxic compounds were found closer to the industrial zone, emphasizing the presence of harmful substances near industrial activities.
An update shared by the team on the Environment Hamilton website highlighted that PAH levels peaked during winter compared to summer. While the study focused on 13 PAHs, Styler mentioned that other toxic elements might also be present in the soot, which she described as a viscous mess. Due to constraints, the study couldn’t investigate all components in the soot, potentially leaving room for other contributors to the fallout.
Styler stressed the need for enhanced monitoring and analytical capabilities to pinpoint the industrial sources generating the PAHs. The findings, according to Styler, may not come as a surprise to residents in heavily affected neighborhoods, who have long suspected industrial emissions as the root cause of the issue.
Despite the community’s frustration over the lack of official information, efforts are ongoing to determine the primary sources of the soot. The team plans to present their findings at a community meeting and expand their research to include more participants and explore additional compounds in the soot.