An OHCOW Cluster Project
McIntyre Powder Project
OHCOW Researchers Make Valuable Contributions to Study of Occupational Illness caused by McIntyre Powder
McIntyre Powder (MP) was administered to miners for decades in Ontario mines in the belief that it prevented silicosis. OHCOW researchers have helped determine the harmful and life-long damage to miners’ health caused by preventable exposure to the substance.
The latest paper, “McIntyre Powder and its potential contributions to cardiovascular disease risk: A literature review through the McIntyre Powder historical lens,” appears in the American Journal of Industrial Medicine. Published in June of 2022, the study was published by Andrew M. Zarnke, BSc., an Occupational Hygienist at OHCOW, Sudbury; and Christine Oliver, MD, a medical consultant to OHCOW and an Adjunct Professor at the University of Toronto in the Division of Occupational and Environmental Health. More about...
The McIntyre Powder Project is a voluntary registry established by a miner’s daughter, Janice Martell, to document health issues (particularly neurological) in miners or other workers who were exposed to McIntyre Powder aluminum dust in their workplaces.
The aim of the project is to gather information on the types of health issues found in workers who were exposed to McIntyre Powder aluminum dust, for the purposes of establishing the need for further research into the long-term health impacts of aluminum dust exposure, and to seek compensation for those workers who suffered health issues related to their occupational exposure.
It has now been more than 40 years since McIntyre Powder was last used in Ontario mines.
Despite advances in laboratory testing, further research in this area is difficult because the miners with the highest levels of Aluminum dust exposure have already passed away.
Other exposures at work (like other metals or chemicals that are neurotoxic, or acids that may make Aluminum more toxic) are relevant.
Family genetics or exposure to Aluminum outside work might also help explain how work exposures did or did not help to cause a disease.
And because Aluminum can be stored in bones and then released years later, lifetime exposures must be explored.
OHCOW was invited by the McIntyre Powder Project and the United Steelworkers to participate in intake clinics for exposed workers.
Two-day clinics were established in Timmins in May 2016 and Sudbury in October 2016.
It was OHCOW’s role to conduct examinations and collect information on the working history and medical backgrounds of miners both living and deceased (with the assistance of their next-of-kin). Ongoing registration of affected miners since 2016 continues through outreach information sessions and telephone intake.
Over 500 miners have registered.
Through these examinations we are aiming to determine the health effects that McIntyre Powder has caused,
not only for miners but also their families.
Information from the intake clinics is being reviewed by OHCOW staff and physicians with support from other experts to see what current science can tell us and to decide whether individual medical testing or group research projects could tell us more. Individual reports will be provided whenever possible and general information will be made public.
But this will all take time…
It is impossible to predict the results of OHCOW’s work, but miners and their families are entitled to whatever answers can be found.
Ultimately, the Project will seek legislative changes to improve workplace safety and access to compensation for all workers who suffer health issues related to occupational disease or injury.
Significant administrative work continues in gathering miners’ medical records, WSIB claim files, employment and exposure history.
This information enables our multidisciplinary team to review individual files and investigate the potential work-relatedness of groups of specific health issues found within the McIntyre Powder cluster. Unfortunately, due to record retention schedules, some records no longer exist, making it challenging to proceed further for some workers who died many years ago.
If you have information that may assist us with our study, and you did not attend one of our earlier intake sessions, please contact us.
Key Areas of Progress
McIntyre Powder exposure is now being considered by the Ontario WSIB as a contributing factor to Chronic Obstructive Pulmonary Disease (COPD) development.
The Occupational Cancer Research Centre (OCRC) found a statistically significant elevated Parkinson’s risk for miners exposed to McIntyre Powder, leading to accepted workers’ compensation claims for McIntyre Powder-exposed miners who later developed Parkinson’s Disease.
The physical and chemical composition of McIntyre Powder was analyzed by OHCOW staff Andrew Zarnke and research partners at Health Canada, Laurentian University, and the University D’Evry. Their findings regarding the extremely small particle size of McIntyre Powder have implications for further research into potential links to cardiovascular disease.
In 2019, researchers at McMaster University conducted a pilot study measuring levels of bone aluminum in a group of 15 McIntyre Powder-exposed miners from Timmins, Ontario.
Our work with the McIntyre Powder miners continues, and future areas of focus include investigations into:
a number of sarcoidosis cases • idiopathic pulmonary fibrosis • interstitial lung disease • cardiovascular issues
as well as further work on neurological disorders.
OHCOW has established an interdisciplinary team as part of its ongoing occupational disease cluster work with McIntyre Powder-exposed mine workers.
Exposed miners report multiple diagnoses and/or symptoms related to exposure to McIntyre Powder (aluminum oxide dust) and the mining environment more generally, including cancers, respiratory, neurological, cardiovascular, and other health conditions.
OHCOW Medical consultants and Occupational Hygienists completed literature reviews on issues common to groups of miners.
The following videos/articles are relevant to this study:
The Fifth Estate
The Miner’s Daughter 
Miner’s Daughter Followup 
The Toronto Star
In human experiment, Ontario miners say they paid devastating price [2017, front page article]
For 20 years, miners sickened by toxic aluminum dust couldn’t file compensation claims. Why? [2018, followup article]