GENERAL ARTICLES

Science Fights the Death Dust

Canadian scientists hope they have found a new weapon against silicosis—the invisible killer

THELMA CRAIG November 1 1939
GENERAL ARTICLES

Science Fights the Death Dust

Canadian scientists hope they have found a new weapon against silicosis—the invisible killer

THELMA CRAIG November 1 1939

Science Fights the Death Dust

Canadian scientists hope they have found a new weapon against silicosis—the invisible killer

THELMA CRAIG

WHEN Mike Chirkoski came up from underground at the end of the shift at the McIntyre, he went to the huge miners’ dry to wash up and change out of work clothes. Mike was breathing heavily. Puffing, in fact. A big man—Mike—a slab-shouldered sixfooter who looked tough and hard and healthy as Adam’s off ox. One of the finest-looking miners in the Porcupine gold camp. But he was puffing.

Some of Mike’s mates glanced at each other. They had noticed that the big fellow was getting short-winded. And they thought they knew why. When Mike picked up his lunch pail a powderman sang out, “Hi, Mike. Wait for me. I’ll drive you home.”

Mike shook his head. “I got a date,” he said. “St. Mary’s. The doc wants to give me a goin’ over.”

The big fellow tapped his chest significantly. He managed to grin. Then he went out, on his way to the hospital on the McIntyre property.

A new man, a carpenter’s helper, said. “What’s the matter with Mike?”

The powderman said, “You’re a tenderfoot, so we’ll excuse you. Notice how the big fellow is short-winded? Well, that’s bad. He’s been told to check in at the mine hospital for a silicosis test.”

“Silicosis?” said the helper, blankly.

“Sure. Creepin’ death. Know what happens when a ton of rock falls on you? It kills you. Well, it doesn’t take anywhere near a ton of rock to kill you the silicosis way.

You just breathe it in. That silicosis dust burns s¡x>ts on your lungs. Up here in the hardrock mines there ain’t anything we dread more, unless it’s a cave-in.”

The helper looked scared. “Can anybody get it?” “Anybody working underground or in the mill, if lie’s in a spot where he can breathe silica dust. This is hardrock country, buddy. You’ve got to break the ore up before you get the gold. That means quartz dust. Plenty of dust. The ventilation system in this mine is one of the slickest jobs ventilation engineers can manage. But this silica dust is hard to beat. You can’t see it and you can’t taste it. But boy, it’s there!”

“What’s the cure for this silicosis?”

The powderman shrugged.

“That’s the tough thing about silicosis. If you get it bad. you’re a gone goose. It burns out the lining of your lungs. It makes you a push-over for T.B. We’re all scared of it. buddy, but what can you do? Life’s a gamble anyway.” “You mean the doctors can’t do anything? You mean big Mike—”

“The doctors have been hunting a silicosis cure for years. But I’ll tell you something. If Mike has silicosis he has a better chance of getting cured now than he would have had a year ago. And a better chance right here at the McIntyre hospital than anywhere else. They’ve got a clinic. Banting Institute, Mining Association—the big fellows are all working on it.”

“A cure?”

“Those doctors and scientists won’t claim a cure for anything until it's airtight and nailed down. But they think they’ve got something. I had it straight from one of the boys at the laboratory yesterday. Mind you, they don’t say it’s a cure. A remedy maybe. A prevention. They’re just testing, trying it out. Maybe they’ll try it out on Mike. But they do think they’ve got this thing licked.” The powderman wagged his head solemnly. "And if it’s true, buddy, it will be the biggest thing that’s happened to mining since gold went to thirty-live bucks.”

Dust Battles Dust

WHAT is silicosis this subtle death that lurks in the dusty depths of the hardrock mines? What is the story of the great fight, that has been waged against it with the combined resources of science and industry? Do those tests that are now being carried on at St. Mary’s Hospital on the McIntyre property at South Porcupine really suggest that the end of the fight is actually in view?

As the powderman said: “Those doctors and scientists won’t claim a cure for anything until it’s airtight and nailed down. But they think they’ve got something

I f so. it will mark another milestone in the march of man’s light against disease. A Canadian milestone to rank with the discovery of insulin.

They think they’ve found a way to check the insidious

death by dust.

How?

By fighting dust with dust.

It may be as simple as that. But in the meantime the hardrock miners wait and hope.

Free silica, which constitutes the greater part of sand and rock, contributes to beauty in modern life. It is used in making fine china and crystal. But in powdered form, as a fine, insidious dust, it is a menace and a scourge.

I f breathed into the lungs habitually, the silica dust forms silicic acid, which kills the cells that normally protect lungs and air passages. This protective mechanism is usually efficient enough to throw off 99.5. per cent of the dust the average person breathes into his system. Little ciliated cells line the air passage. Down in the lungs tiny cells excrete dust. A sort of escalator carpeted in fluid runs from the lungs to the mouth, and these tiny cells act like wheelbarrows that load up any dust that gets into the lungs, carry it to the escalator and dump it. Little eyelashlike cells along the air passage beat up and down, propelling the escalator that carries the dust up out of the b<xiy.

That, in brief, is how nature protects the breathing apparatus against dust. But the particles of silica that do the damage are so small—less than one five thousandth of an inch in diameter—that even nature’s marvellous and delicate traps cannot cope with them. Once in the lungs, the silica dust creates poison—silicic acid. The acid kills the excretory cells. The little wheelbarrows cease to Continued on page 33

Continued from page 13

function. Silicosis has taken hold. With the slow paralysis of the protective mechanism, the inroads of dust become greater. The silicosis spreads.

Men who work in the hardrock mines day after day and year after year breathe in so much of the deadly and invisible silica dust that gradually their lungs become scarred, spotty, as if burned with acid. But the scar tissue doesn’t contract, as it does when a bum heals. On the contrary, it spreads. The scar tissue chokes more and more air cells until there is not enough tissue left to carry on natural respiration. The victim’s breath becomes shorter as his lung expansion lessens. His susceptibility to tuberculosis increases.

Tuberculosis may occur at any stage, but it does not usually appear until the silicosis is well advanced. If and when it does, the creeping death creeps no longer. It strikes viciously, swoops down abruptly.

Silicosis, then, is no trifling malady. Its spectre hovers over every mining camp in Canada. It looms especially grim over the hardrock areas—the goldfields. The more quartz, the greater the peril from silica dust.

The inroads of silicosis among miners have been so great that both governments and the mining industry itself have sought in every way they could find to protect the workers against the ravages of the disease.

In the first place they have made an attempt to take care of the victims through compensation. State legislation requires the industry to set aside funds for silicosis sufferers and their families in four Canadian provinces—Ontario, Quebec, Manitoba and British Columbia. The same is true in many parts of the United States, in South Africa and in Germany.

In Ontario, for example, each case such as Mike’s costs the mining industry an average of $11,000, but the figure may go as high as $20,000, or even $25,000.

Conscious of the toll taken in lives and disability, the Ontario Government in 1926 passed legislation making it compulsory for employers of miners to set aside reserves for compensation. The extent of the disease among miners can best be determined by the amount of compensation paid. By the end of 1938 approximately $4,400,000 had been collected by the Ontario Workmen’s Compensation Board from mining companies to establish reserves. Of this amount, $1,492,077 had actually been turned over to miners for compensation. Add to this the cost of medical aid and of handling claims in the cases involved, and silicosis cost the mining industry the substantial figure of $2,268,179. That in twelve years in the Province of Ontario alone!

The amount set aside for compensation depends on the hazard. Employers of miners in hard rock in Ontario must hand over to the Compensation Board 12'4 cents for each miner for each dust shift. That is usually for eight hours work underground. This regulation applies to all mines in the Porcupine, Kirkland Lake and other hardrock areas. Where the danger is less, the levy is lower. In the Sudbury nickel mines, it is only 2}/¿ cents and in the Cobalt silver camp, it is iy¿ cents.

An Industrial Hazard

.ACCURATE statistics regarding the incidence of the disease and the number of persons who are disabled or die as a result of it, are hard to obtain because the condition takes so many years to develop. Anyone who works in silica dust may get silicosis. A sandblaster may require only two or three years exposure to the dust to develop it. A porcelain worker, on the other hand, has been known to develop it only after sixteen years exposure. Mine workers in hard rock require an average of twelve or thirteen years to give clinical and X-ray evidence of the disease.

In the United States, figures compiled by the National Silicosis Conference, and filed with the Department of Labor, estimate that one million workers in that country are exposed to some form of silica hazard, that half of that number are exposed to a serious hazard and that some 110,000 of those have silicosis to some degree. Another study in that country, just published this year by Dr. C. O. Sappington, a consulting industrial hygienist, expresses the belief that twenty-five per cent of all those exposed to the dust, will have silicosis eventually. It is known that silicosis in the States costs industry many millions of dollars each year.

Some reports of the frequency of the disease are to be found in England also. In 1935 the Silicosis Medical Board pointed out the incidence continued to be “serious and widespread.” During the years 1932 to 1934 the board certified “fifty-two cases of disablement and seventeen deaths from ganister mines and silica brick works; 252 cases of disablement and seventy-nine deaths from the getting and manipulation of sandstone at quarries or premises in conjunction therewith; 289 cases of disablement and ninety-two deaths from the pottery industry; 532 cases of disablement and 105 deaths from coal mines, and 319 cases of disablement and 142 deaths from other industries.” Industry hasn’t been sitting by and letting men who work in silica dust just die like flies. The mining industry, for example, has attempted to control the disease by:

Ventilation: to drive the dust away from the workers.

Examination: to prevent men who

show a spread of tuberculosis or a case history of lung disease going into the mines.

In Ontario all prospective miners must have physical examinations before being accepted for mine work. Moreover, all miners working underground are given X-ray chest examinations once a year at one of four centres in the northern part of the province. Now, too, children of miners in many areas are being inspected regularly for pulmonary infection.

Science Offers Hope

T) UT NOW comes a new hope of combating the miner’s dread.

Science, working in its characteristically patient and persistent fashion, has made an amazing discovery.

Science has found that silicosis can be prevented in animals. By pumping pure, finely powdered aluminum dust into the lungs of animals that have breathed silica dust, the inroads of silicosis have been checked.

There is the discovery in all its simplicity. One more step—the greatest step of all—remains. That is to test and prove the efficacy of the discovery on human beings. It will take time. The tests are proceeding now. But—“they think they’ve got something.”

The existence of the disease has been known for centuries, hut the first serious campaign against silicosis in the mining industry was not undertaken until after the first World War, when the Rand gold mines in South Africa were reopened and it was discovered that only a small proportion of gold miners were available for work. Their mates had died of “miners’ phthisis.” That situation drew attention to siliceous dust as a major problem of industrial hygiene. The fight was on.

The most important primary discovery concerning silicosis was made in England by W. E. Gye, chairman of the Imperial Cancer Research Fund, when he found that the damage caused by silica dust in the lungs was the result of a chemical process. Up to that time it had been

thought that the sharp, rough particles of silica dust simply rubbed the sensitive tissue of the lungs and caused inflammation.

It was while investigating the spread of tetanus infection among soldiers in France that Gye followed up a theory concerning the soil and its possible effect on the development of tetanus spores. His investigations on this line, however, appeared to lead up a blind alley when he found that the only possible agent was apparently ordinary sand. He put some of the sand from French soil into water as a routine experiment. Silicic acid resulted.

Even then the discovery did not seem very important to Gye, but like a good scientist he followed it up further. He injected some mice with the acid. It is said that he forgot about the mice for a year. They existed, more or less comfortably, in the laboratory until Gye got around to examining them one day. Then he found that at the points of injection the mice had developed small rounded lumps similar to those found in silicotic lungs.

This isolated discovery was, up to that time, the biggest single step in the study of silicosis. It defined the deadly dust’s attack as being chemical.

In Canada, responsible men in the goldmining industry were worried about the silicosis problem. It was costing lives and money. A pair of research workers at the McIntyre Mine, at South Porcupine, were working on the < problem in November, 1932. Sir Frederick Banting—discoverer of insulin—and his staff at Banting Institute were also engaged in silicosis research. The Ontario Mining Association was interested. Everything that science knew about silicosis was being studied and examined. The Gye discovery, of course, had opened up a new avenue of approach.

Research work at the McIntyre was under the direction of J. J. Denny and Dr. W. D. Robson. Denny, the mine metallurgist, had been connected with Queen’s University for some time and had gone north to Cobalt in the early days of mining in Northern Ontario, later went to the McIntyre organization. Robson, the mine surgeon, was a graduate of the University of Toronto and a native of New Westminster, B.C. He is a member of the famous family whose name was given to Mount Robson, highest peak in the Canadian Rockies.

Down in Toronto, at the Banting Institute, a third man was conscripted into action some time later. He was Dr. Dudley A. Irwin, native of London, Ont., graduate of the University of Toronto, and now associate professor in the department of medical research. Although much investigation was done separately at the mine and the Banting Institute, no real lead to the prevention of silicosis was found until the mine, the institute and the Ontario Mining Association, began to pool their resources and attack the problem.

As its contribution to the massed onslaught on the problem, ' the Mining Association turned over $50,000 to the Banting Institute. Individual mining men likewise donated substantial sums for research.

The “Dusting” Method

IN THEIR early studies at the mine.

Denny and Robson were led to believe that mine gases might be a predisposing factor in the production of the disease. So they “dusted” guinea pigs in a manner duplicating actual industrial conditions. But none of their experiments got the scientists anywhere.

Still with dogged determination Denny and Robson sought one line of approach after another. Each afternoon they continued to explore one another’s ideas, and each evening they met to devour research material from the world’s laboratories.

One day they came across a paper written by an Englishman named P. HefTernan. following up research work of a well-known scientist, Sir William Bragg, also an Englishman.

The Heffernan paper gave them a clue.

It reported that when quartz was freshly fractured—broken up as in a mine explosion—it presented numerous oxygen atoms on its surface. These atoms stuck out, it appeared, like quills on a porcupine.

Now, thought the scientists to themselves, it must be those oxygen atoms that caused the formation of silicic acid which Gye said was responsible for forming the scar tissue of silicosis. If they could neutralize those oxygen atoms, then perhaps they could prevent silicic acid from forming.

Their problem was to find something that would do the neutralizing. They knew that aluminum would act in either acid or alkaline solutions. So they selected it.

Into a beaker they poured some quartz dust. Then they added a bit of aluminum finely ground. Then they added water. They knew that whenever water was added to quartz dust alone, the quartz dissolved to form the silicic acid.

This time they got a surprise!

They gazed incredulously at the beaker. The quartz dust had hardly disappeared at all. Their theory had been correct. Aluminum had done the trick. Perhaps, after all, their dream of defeating silicosis would come true.

Perhaps, after all, if human lungs could be dusted somehow with aluminum, the quartz dust breathed by the miners would not form silicic acid.

Of course, their experiment had been only in a beaker. Would aluminum dust have the same effect in the living lung?

That was on March 4, 1936.

They turned to experimental animals to test their theory. The two investigators conscripted thirteen healthy young rabbits and on June 10 of the same year they began pumping dust into the animals’ lungs. They passed them through specially constructed chambers where the rabbits breathed the dust quite naturally. Six of the control animals were “dusted” with quartz alone. The other seven were “dusted” with quartz and a sprinkling of aluminum.

Newborn babies were never pampered more than those thirteen rabbits. For six months the experiment continued. The rabbits were bathed and groomed and fed regularly. And just as regularly they inhaled their allotted apportions of dust.

Then came the time for checking. The lungs and other organs of the rabbits were forwarded to Dr. Irwin for pathological examination.

All the animals that had breathed quartz dust alone had well-developed silicosis.

And not a single one of the seven bunnies that had been sucking in aluminum dust as well as the silica showed even the slightest trace of silicosis.

Check and Double-Check

BUT scientific men take no chances.

They check and double-check. They test and double-test their theories and their findings before they present them to the world as conclusive.

Spurred on by apparent success, the McIntyre Mine and the Ontario Mining Association shifted their attention to the Banting Institute. And more bunnies in the pink of condition were conscripted for experiment in the dust mill. A whole row of cages housing a dozen rabbits each was arranged to take care of different types of dusting. Like their predecessors, some rabbits breathed quartz dust alone and some were fed quartz and aluminum together. Various concentrations were used. Dusts were breathed for longer or shorter periods.

Would the results be the same, or had some unknown factor entered into those of the experiments at the mine? If those results were corroborated, how much aluminum was required to make the silica inert?

Months went by. A year passed. More months. The “dusting” went on.

The Canadian Medical Journal reported the findings last spring. I n precise, scientific terms, the Journal stated that metallic

aluminum dust used in small quantities would prevent the development of silicosis in experimental animals. It further pointed out that the amount of aluminum powder required was one per cent, or slightly more, of the quartz dust inhaled.

Not only that, but the experiments had shown that where well-developed silicosis was already present, further progress of the disease could be halted by inhalation of the aluminum dust.

So there is still hope for big Mike, the miner.

It seems that the aluminum dust wraps itself around the particles of quartz in the lungs and prevents them from forming silicic acid. Instead, the little wheelbarrows come along and put the overcoated bits of quartz on the escalator that travels to the mouth. And it’s good-by to the insidious silica dust.

Those findings stirred the whole world of science. They brought congratulations to the Canadians concerned from government agencies, medical associations, mining groups and individuals all over the map. In Canada itself, Dr. Robson and Dr. Irwin were given the McCharles award, which is a prize awarded by the University of Toronto for “marked contribution in scientific research of a practical nature.” And Mr. Denny received the big platinum medal which the Canadian Institute of Mining and Metallurgy reserves for very special scientific achievements.

Now all that remains to be done is to determine how successfully aluminum dust may be used on human beings. And the best way of applying it to industry.

To this end investigation in Ontario is going full steam ahead. It will concern, first of all, those miners who are already suffering from silicosis. Aluminum dust will be pumped into their lungs in small quantities by methods yet to be deter-

mined. If these men benefit, as it is hoped ! they will, consideration will be given to j inhalation of the dust by miners who as yet show no symptoms of the disease.

To carry out this further work, the gold mines in the Porcupine area have set aside j $25,000 and a clinical laboratory is being equipped in St. Mary's Hospital at the | McIntyre Mines at a cost of $10,000. The work has the blessing of the Ontario Medical Association, the Ontario Workmen’s Compensation Board and the Provincial Department of Health.

This investigation, which is about to get under way, will be directed by Dr. David Crombie, superintendent of the Queen Alexandra Sanatorium, London, Ont., who has an outstanding record in the treatment of pulmonary diseases. Associated with him as chief of laboratory activities will be Dr. J. L. Blaisdell, pathologist, of the same institution.

Even a very slight contact with miners makes one see what all this may mean to those whose lives have been shadowed by fear of disablement or death through silica dust. And not only miners, but all those others who suck in the dust during their work whether that work be quarrying, sandblasting, molding, grinding, porcelain ; or abrasive soap manufacture, or any of j the other numerous industrial processes in ! which silica dust is a menace.

Here was reason enough why the seienj tist who likes to work for the good of man; kind should seek the cause and the remedy. ! War may come and has come, but still j science goes on to challenge disease and destruction of the human race. Perhaps another year or two and the disease of silicosis—miner’s consumption, grinder’s rot, potter’s asthma or stone mason’s phthisis, call it what you will—may have been worsted. But science, cautious as always, merely says: “We’re hoping.”