A group of researchers based in Hamilton have uncovered insights into the issue of soot accumulation in neighborhoods near the city’s industrial zone. Residents have long voiced concerns over a black, sooty residue coating their properties. The problem resurfaced in early July with what some described as the most severe 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 group, are part of a study titled “What’s the Grime?” aimed at addressing this issue. Collaborating with volunteers to gather samples across the city in 2024 and 2025, the team discovered that the soot contains hazardous chemicals consistent with coal combustion. They also observed elevated levels of dust and polycyclic aromatic hydrocarbons (PAHs) in the vicinity of the industrial sector in northeast Hamilton.
Styler partnered with Environment Hamilton for this 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 experience with the soot issue. The researchers highlighted the longstanding nature of this problem, with historical references to soot dating back to at least the 1950s.
Utilizing sampling kits placed in the homes of 50 volunteers across the city, the team collected and analyzed soot samples at four-month intervals. Styler noted a higher concentration of dust closer to the industrial sector, with a corresponding increase in toxic compounds in that area.
The researchers examined 13 different PAHs but acknowledged that other harmful substances may also be present in the soot. Despite resource constraints limiting the scope of the study, Yao emphasized the significant role of coal combustion in producing the PAHs under investigation.
While the team refrained from pinpointing specific industrial sources of the PAHs, Styler suggested that with enhanced monitoring and analytical capabilities, such identification could be feasible. The findings, although unsurprising to residents directly impacted by the fallout, underscore the industrial origins of the soot.
Concerns have been raised regarding the lack of official information from regulatory bodies. The Ministry of the Environment, Conservation and Parks is conducting testing to identify potential sources of the soot, with results expected to be shared publicly. Styler’s team’s research contradicts the notion that road dust is the primary component of the soot.
The researchers plan to present their findings at a community meeting on August 20 and are in the process of submitting their work for peer review. They aim to expand the study to include 200 volunteers, explore additional compounds in the soot, and investigate effective cleaning methods for the affected areas.