A group of scientists in Hamilton has provided insights into the issue of soot accumulation in neighborhoods near the city’s industrial zone. Residents have long expressed concerns about a dirty, black substance covering their properties, with a recent spike in complaints in early July.
Sarah Styler, an environmental chemistry associate professor at McMaster University, and Grace Yao, a PhD candidate in Styler’s lab, are involved in a research project titled “What’s the Grime?” Their study, conducted in 2024 and 2025, involved collecting samples across the city and revealed that the soot contains harmful chemicals linked to coal combustion. Higher levels of dust and polycyclic aromatic hydrocarbons (PAHs) were found near the industrial area in northeast Hamilton.
Styler collaborated with Environment Hamilton on the study, funded by a $15,000 grant from the university. They collected soot samples from 50 volunteers’ homes at regular intervals and analyzed them to identify the presence of toxic compounds. The researchers observed that more dust and toxic compounds fell closer to the industrial sector.
The study highlighted that PAH levels were higher during winter compared to summer. Styler emphasized that while they studied 13 different PAHs, there could be additional toxic substances in the soot. The team couldn’t identify the specific industrial sources of PAHs due to resource constraints but pointed out coal combustion as a significant contributor.
Styler mentioned that the findings confirm what residents in affected neighborhoods have long suspected – that industrial emissions are likely the source of the soot. Despite the community’s frustration with the lack of official information, the Ministry of the Environment, Conservation and Parks is conducting tests to pinpoint the origin of the soot.
The researchers plan to present their findings at a community meeting on August 20. They are expanding their study to include 200 volunteers and explore more compounds in the soot, including research on effective cleaning methods.
