The Right Chemistry: Canadian solution not a proud moment for science


HomeHome / News / The Right Chemistry: Canadian solution not a proud moment for science

Aug 06, 2023

The Right Chemistry: Canadian solution not a proud moment for science

Despite the lack of evidence, for 35 years miners around the world inhaled aluminum dust for their good health. It wasn't. The workers, all covered in white dust, looked like ghosts as they emerged

Despite the lack of evidence, for 35 years miners around the world inhaled aluminum dust for their good health. It wasn't.

The workers, all covered in white dust, looked like ghosts as they emerged from the Hawks Nest Tunnel near the town of Gauley Bridge, West Virginia in 1931. More than seven hundred of the tunnelers would soon die, earning Gauley Bridge the nickname, “the town of the living dead.” The ticket for the journey to the realm of ghosts was silicosis, a deadly disease of the lungs.

Subscribe now to read the latest news in your city and across Canada.

Subscribe now to read the latest news in your city and across Canada.

Create an account or sign in to continue with your reading experience.

Don't have an account? Create Account

Union Carbide had an iron smelting operation near Gauley Bridge that required electricity. The company decided to build a hydroelectric plant nearby using water diverted from the New River through a three-mile long tunnel to turn the turbines. With America mired in the Great Depression, recruiting workers to dig the tunnel was not difficult. But digging the tunnel was. Nearly 3000 workers, mostly African-American, unequipped with respirators, drilled and blasted through the sandstone kicking up clouds of silica dust that they could not help inhaling. Crystalline silicon dioxide is devastating to lung tissue, causing lesions and inflammation. Depending on extent of exposure, the effects can range from coughs and shortness of breath to weight loss, respiratory failure and death. To make matters worse, the International Agency for Research on Cancer (IARC) classifies silica dust as a known human carcinogen.

Most of the tunnel diggers got sick to some extent and there were reports of ailing labourers being forced to work at gunpoint. Deaths were frequent with some being buried in unmarked graves without relatives even being notified. They are remembered today with a monument that marks the burial site of the victims of the worst industrial disaster in American history. But the Hawks Nest Tunnel diggers are just one example, albeit a brutal one, of the scourge of silicosis. Miners, particularly of gold and uranium, also have to drill through quartz, a form of silicon dioxide, putting them at risk of silicosis.

Get the latest headlines, breaking news and columns.

A welcome email is on its way. If you don't see it, please check your junk folder.

The next issue of Headline News will soon be in your inbox.

We encountered an issue signing you up. Please try again

That brings us to a rather dark episode in Canadian history. Sandy McIntyre was a Scottish immigrant who in 1906 began to prospect near the northern Ontario town of Porcupine. He struck gold and began what came to be known as the “Porcupine gold rush.” In 1912, the McIntyre Mine was incorporated and soon became a huge operation, retaining the name even after McIntyre had sold his interest. Business was good but there was the constant problem of battling silicosis. Costs of compensating workers for an occupationally acquired disease could prove to be paralyzing, so the company searched for a solution. And they found it, in of all things, aluminum powder.

At the time it was believed that silica’s damaging effects were due to the sharp edges of its crystals scarring lung tissue. If the silica particles could be coated with some material that dulled their surface, perhaps the plague of silicosis could be avoided. In the 1930s, the mine’s officials sought help from the University of Toronto’s prestigious Banting Institute that led to dosing guinea pigs and rabbits with aluminum powder before exposing the animals to silica dust. These experiments were deemed to be successful enough to warrant testing on seven dying miners at St. Mary’s Hospital in Timmins. When they seemed to respond to the aluminum treatments McIntyre Mine’s metallurgist James Denny and physician Wilmot Robson patented finely ground aluminum as “McIntyre Powder (MP)” for the treatment and prevention of silicosis.

Between 1940 and 1943 the powder was put to a test with workers inhaling it before their shift. How these workers were chosen, and to what extent they were informed about the experiment isn’t clear. Neither was it clear on what basis these experiments were judged to be successful. What is clear, however, is that starting in 1943, all McIntyre miners were made to inhale aluminum powder before descending into the mines. They filed into a chamber, the doors were closed, and the aluminum powder was pumped into the air from canisters. The workers were instructed to breathe deeply for 10 minutes and were told that the powder would protect their lungs. They had no choice. If they objected, they were told that they could find another job.

The use of McIntyre Powder was taken up by mines around the world and unbelievably the practice continued until 1979. Why unbelievably? Because there was never any evidence that the aluminum offered protection against silicosis! Miners were kept from complaining about ailments by financial incentives to keep working. Bonuses were offered for no lost time for injuries but were contingent on not a single worker in a group missing work. A sick or injured miner would do everything not to miss a shift to ensure that colleagues would not be prevented from getting the bonus. Gifts were also offered for reaching a goal of a set number of days not lost to illness or injury. So sick or not, miners just carried on. By 1979, though, it had become obvious that inhaling aluminum did not prevent silicosis, and worse, it created problems of its own.

Much of this we know thanks to the work of Janice Martell, who founded the McIntyre Powder Project in 2015. Janice’s father, Jim Hobbs, had worked in the mines and was subsequently diagnosed with Parkinson’s disease. When he recounted the story of being made to inhale aluminum powder to his daughter, she decided that the can of worms needed to be opened. The McIntyre Powder Project solicited accounts of experiences in the mines and documented a number of cases of neurological problems, particularly Parkinson’s disease. Stories emerged from angry miners who felt that they had been treated like guinea pigs and had been prevented from receiving compensation for illness caused by inhaling the aluminum powder that had been promoted as a miracle antidote to lung disease.

Finally, in 2022, thanks to Janice’s long campaign, the Ontario government recognized Parkinson’s disease as an occupational disorder linked to the use of McIntyre Powder and agreed to accept compensation claims from former workers as well as from families of miners whose death may have been linked to the involuntary inhalation of aluminum powder.

These days, when there is so much concern about air pollution and inhaling microscopic particles, it is hard to believe that for some 35 years miners were made to inhale aluminum dust, supposedly for their health despite a lack of supporting evidence of safety and efficacy. Not a proud moment for science.

Joe Schwarcz is director of McGill University’s Office for Science & Society ( He hosts The Dr. Joe Show on CJAD Radio 800 AM every Sunday from 3 to 4 p.m.

[email protected]

Postmedia is committed to maintaining a lively but civil forum for discussion and encourage all readers to share their views on our articles. Comments may take up to an hour for moderation before appearing on the site. We ask you to keep your comments relevant and respectful. We have enabled email notifications—you will now receive an email if you receive a reply to your comment, there is an update to a comment thread you follow or if a user you follow comments. Visit our Community Guidelines for more information and details on how to adjust your email settings.

To contribute to the conversation, you need to be logged in. If you are not yet registered, create your account now - it's FREE.