Workers Health & Safety Centre

Cancer rates higher in Ontario industrial cities, study finds

Residents of Sarnia, Hamilton, Thunder Bay, Sault Ste. Marie and St. Catharines are developing and dying from leukemia at rates “strikingly higher” than the national average.
A new study recently published in the journal Cancer, analyzed the geographical distribution of the 18,085 cases of acute myeloid leukemia (AML) across Canada from 1992 to 2010. Sarnia topped the list of AML “hot spots” with the northern part of the city and nearby Point Edward Village at three times the Canadian average.

Industrial pollution key risk factor

While smoking and other personal risk factors are discussed, authors of this study suggest toxins used in industrial facilities may be a key cause of AML in these communities. Specifically, they mention benzene — a solvent the International Agency for Research on Cancer (IARC) classifies as “carcinogenic to humans” based on evidence that it causes AML. In fact, this current study found cities with the highest benzene air concentrations were also the cities with the highest rates of AML.
IARC, an agency of the World Health Organization, also says benzene is linked to other forms of cancer and there is no safe level of exposure. This same concern is raised by CAREX Canada stating “benzene is considered a ‘non-threshold toxicant’, where adverse health effects may occur at any exposure level.”

Harmful emissions allowed in Ontario

Despite these concerns and conclusions, Ontario’s Ministry of Environment and Climate Change sets daily and annual “desirable” ambient air quality criteria (AAQC) for benzene. The Ministry claims their criteria protect against adverse effects on health or the environment. Even still, of the eight Ontario monitoring locations, the annual AAQC for benzene was exceeded at five sites – Sarnia, Windsor West, Kitchener, Hamilton Downtown and Brampton. Further still, at the Aamjiwnaang First Nation just south of Sarnia, the annual AAQC has been exceeded every year since 2011. 
There are also regulatory efforts targeting the polluters. Ontario Regulation 419/05 made under the Ontario Environmental Protection Act sets legally-binding air quality standards limiting concentration of specific pollutants, including benzene from industrial facilities. Though, a regulatory loophole allows benzene emissions from Ontario petrochemical facilities and refineries to be exempt and instead regulated under an industry technical-based standard. In short, these facilities are not breaking the law when polluting the surrounding communities as long as they agree to make “progressive” technical modifications.
For Sarnia-area residents in particular, these exposures and loopholes are a serious problem considering the vicinity is home to more than 60 refineries and chemical plants — both major sources of benzene in outdoor air. In fact, these nearby facilities were responsible for 30 per cent of the total benzene emitted in 2016 by industry in Ontario.

Harmful occupational exposures too

Governments here in Ontario and across the country also continue to establish allowable benzene exposure levels at work. 
In fact, it is estimated more than 140,000 Ontario workers are exposed to benzene on the job, including many employed in industrial facilities in Sarnia and the other cities identified as AML hotspots. Others exposed commonly work in automotive repair, public transit and the printing sector.

Pursuing prevention

In a recent report exposing the continued concern of air quality in Sarnia and the surrounding communities, Ecojustice Canada questions Ontario’s air quality standards. They argue, “Clear, strong, legally-binding air quality standards and stronger regulation of industrial air pollution emissions are necessary to protect Ontarians’ right to a healthy environment.” 
As early as 1973, a convention seeking to limit ‘poisonous’ benzene exposures at work was adopted by the International Labour Organization. Significantly, it too excluded the use of benzene for chemical synthesis and in motor fuel. Even still, although 38 countries signed on, including many European trading partners, Canada has never ratified this convention.
As of January 1, 2020 Ontario Regulation 833, governing control of occupational exposures to biological and chemical agents will include specific mention of the need for employers to consider substitution of regulated substances such as benzene. Enforcing this addition to the hierarchy of controls though is another thing.
At the workplace level, many health and safety advocates suggest there must be zero tolerance for exposure to carcinogens — that government must compel industry to use less-toxic substances in place of benzene and other carcinogens. At a minimum, processes should be enclosed and have effective filtration systems to reduce workplace exposures. Of course, successful workplace efforts to eliminate or reduce exposure to benzene and other toxins would translate into less emissions into surrounding communities.
Lead author of this AML incidence and geographic distribution study, Dr. Ivan Litvinov, assistant professor, McGill University, Department of Medicine, Division of Experimental Medicine, offers a broader view to limit exposures. “I would encourage citizens and workers to work with government officials along with local employers to introduce workplace, community and culturally-appropriate ways to decrease exposure to benzene and other harmful toxins.”

WHSC supports healthy workplaces and communities

WHSC has always believed workplace health and safety and a healthy environment are two sides of the same coin. We offer a range of resources and training designed to help workplace parties better understand how toxins can damage the health of exposed workers and the wider community when emitted from the workplace.

We also offer training programs to help employers meet the training and competency requirements for supervisorsjoint committee members and worker health and safety representatives, who all play essential roles in the pursuit of healthier, safer workplaces and the environment surrounding facilities.

For additional information about toxic chemicals at work and harmful emissions, contact the WHSC and ask to speak with a training services representative. 

Call:    1-888-869-7950