A group of researchers based in Hamilton has unveiled findings regarding the soot accumulation in neighborhoods adjacent to the city’s industrial zone. Residents have long been troubled by a dark, sooty residue covering their properties, with concerns peaking in early July due to what some described as the most severe fallout in recent memory.
The study titled “What’s the Grime?” conducted by Sarah Styler, an environmental chemistry associate professor at McMaster University, and Grace Yao, a PhD candidate under Styler’s supervision, aimed to address the issue. By collaborating with volunteers to gather samples across the city in 2024 and 2025, the researchers identified toxic substances consistent with coal combustion in the soot. Additionally, elevated levels of dust and polycyclic aromatic hydrocarbons (PAHs) were detected near the industrial area in northeast Hamilton.
Styler collaborated with Environment Hamilton on the project, funded by a $15,000 grant from the university in 2024. Living in east Hamilton, both Styler and Yao have experienced the soot firsthand in their respective neighborhoods. Styler highlighted the longstanding nature of the problem, mentioning references to the soot in news archives dating back to the 1950s.
The research involved collecting soot samples from 50 volunteers’ homes throughout the city using sampling kits. Samples were analyzed at four-month intervals to track changes. Styler emphasized that more dust and toxic compounds were found closer to the industrial sector, suggesting a correlation.
The team’s recent update on the Environment Hamilton website stated that PAH levels were higher during winter compared to summer. While the study focused on 13 different PAHs, Styler noted that other toxic substances could also be present in the soot, describing it as a viscous mess. Despite resource constraints preventing a comprehensive analysis, Yao emphasized the significant contribution of coal combustion to the detected PAHs.
Styler clarified that while the study couldn’t pinpoint the specific industrial sources generating the PAHs, continuous monitoring and enhanced analytical capabilities could facilitate such determinations. The findings, according to Styler, likely confirm what residents in the affected neighborhoods already suspected – that industrial emissions are the primary source of the soot.
Residents have expressed frustration over the perceived lack of information from official channels. The Ministry of the Environment, Conservation and Parks announced ongoing testing to identify potential sources of the soot, with results set to be shared publicly. Styler’s team disagreed with the notion that the soot is predominantly road dust, supporting the community’s claims of industrial origins.
The researchers plan to present their results at a community meeting on August 20 and are preparing a manuscript for peer review. They aim to expand the study to include 200 volunteers, explore more compounds in the soot, and investigate effective cleaning methods.