July 28, 2005
By Dr. Noel Kerin
Asbestos was recognized for centuries before scientists and industrialists saw it as the dream answer to acid and heat resistance. Asbestos did not conduct electricity and was resistant to the massive heating/cooling cycles that were the basis of the industrial revolution. No wonder the great industrial corporations of the late-19th and 20th centuries embraced asbestos with such fervor.
It was not until the early 1960s that the first warnings of a wolf in sheep’s clothing appeared in medical literature, with Wagner describing several cases of a rare lung cancer (mesothelioma) in asbestos miners in South Africa. Other researchers of that time also claimed evidence of asbestos’ capability to cause cancer and other illnesses – primarily of the respiratory tract.
Predictably, these early findings triggered fierce debate between two camps: the asbestos industry defending itself, and the scientific community drawing attention to the now-obvious damaging health effects of asbestos. Sadly, the debate lasted decades, and the issues were often muddied or misdirected by inadequate knowledge.
For example, as recently as 2000, in our own city of Toronto, a prominent occupational medical physician could write in full belief that “…the train carrying asbestos diseases has arrived at the train station and the burden of asbestos diseases has been unloaded, and now the train has left the station.” This seemingly authoritative statement has since been proven horribly wrong.
Most of the burden of correcting this type of opinion has fallen to the trade union movement in Canada – as it did in the United States, when the great Selikoff was employed to review worker asbestos damages in New York City. Here in Ontario, the CAW has led the fight, forcing the Workplace Safety and Insurance Board (WSIB) of Ontario to accept the huge health damage brought about by the now-defunct Holmes Foundry in Sarnia, where literally hundreds of ex-workers have developed asbestos-related diseases from mesothelioma to lung cancers, bowel cancers and lung fibrosis (asbestosis).
More recently, CAW has tackled the asbestos problem in another huge manufacturing company in Ontario, where hundreds of asbestos-related cancers and respiratory diseases have been discovered.
In both communities, the cause of the various cancers often went unrecognized or unreported. We know that mesothelioma is caused almost exclusively by asbestos exposure, yet in the majority of these cases we found that no compensation claim had been launched on the workers’ behalf.
To grasp the extent of the lack of reporting, and the lack of acceptance of occupationally induced lung cancers, we need only look at the total claims accepted by Workplace Safety and Insurance Board of Ontario in the years 2002/2003. Seven. Seven lung cancers for the Province of Ontario. Contrast that total with today’s reality, where one occupational medical physician alone has seven times that total number of asbestos-related lung cancers currently launched before WSIB.
Does this mean there are seven times the 2002/3 number of (either declared or accepted) lung cancers than had been previously accepted? Yes. At least that many. I’m convinced the estimated numbers will prove hopelessly conservative.
Four decades after the first warnings, we’re only now lifting the veil from a great tragedy. All the mounting knowledge indicates that asbestos exposure’s full impact on cancers and other occupational diseases will be massive. This unhappy prognosis is not helped by the reality that belated acceptance of the medical evidence has left no overall plan in place to deal with this huge, unfunded liability in our province.
Occupational diseases are the price society pays for industry’s past willingness to accept health risks as a justifiable cost of doing business. More correctly stated, it is the price that workers are paying. And now – like the old Ontario Hydro stranded debit – it falls to the public of Ontario in the 21st century to pick up the cost of the past’s excessive ways. How did it come to this?
The old adage “Out of sight, out of mind” is nowhere more relevant than in the field of occupational diseases. With a latency period of up to 50 years between exposure to workplace hazards and expression of a disease such as asbestosis (scarring of the lungs or lung cancer), industry could view the risks as a problem for a distant tomorrow.
But tomorrow always comes. As the earlier “train station” quote indicates, asbestos-related diseases were considered to be issues of the 20th century. However, in examining the asbestos exposure file of one regional town, we found ten times the national average rate of occurrence for mesothelioma – with most cases identified in the 21st century! There is now broad consensus in the field of epidemiology that the appearance of diseases resulting from old exposures to asbestos will not peak until 2015 to 2020 at the earliest.
What does this all mean? If we think of it as a crime story, it means we’ve caught and convicted the perpetrator – but we’re still actively gathering evidence to learn the true scope of its legacy. It means that new knowledge imposes on us the need for new vigilance and new thinking.
For example, lung cancer. We can no longer make the automatic assumptive link between lung cancers and cigarette smoking. Other known primary cancer exposures must now be taken into account – and particularly the huge lung-cancer impact of asbestos.
Evidence of the emerging shift in thinking can be found in the new “asbestos” guidelines developed by the American Thoracic Society ATS document (in PDF format), the leading international experts on respiratory disease. Published in 2004, the guidelines were developed over several years, under the chairmanship of Prof. Tee Goidotti. They set out new criteria for addressing diagnoses and assessing the damages brought about by asbestos exposures (functional impairment).
We have posted our KOHC synopsis of this very-detailed publication on our site. We have also posted a quick asbestos decision-making algorithm for the health-care practitioner who is faced with a potentially asbestos-exposed worker.
So far, we have not discussed any other systems damaged by asbestos, but it is now clear that many of the so-called cigarette smoking laryngeal (throat) cancers are, in fact, partially or totally caused by asbestos-fiber damage. Similarly, stomach and colon cancer are, in some cases, caused by old asbestos-fiber exposure.
However, when a surgeon looks at a pre-malignant or malignant polyp in a patient’s colon, there is no reliable indicator to determine if pre-cancer or cancerous changes were caused by asbestos. As we know, with most cancers the causes are multi-factorial. Diet has something to do with the appearance of bowel cancer, as have genetics and, unfortunately, asbestos. There is strong epidemiological evidence supporting the notion that these cancers appear more frequently in asbestos-exposed than non-exposed workers.
Finally, when we felt we knew all about asbestos, and the ten-year exposure to asbestos was the standard for accepting asbestos-related diseases, research by Erlich out of the United Kingdom crumpled our comfort zone – with a clear statement that one month of heavy asbestos fibre-dust exposure is sufficient to induce asbestos-caused pulmonary fibrosis (asbestosis) in 20% of cases.
I’ll end with this thought. For well over a century, asbestos exposure has been a deadly, silent killer. The toll across the generations can only have been horrific. The evidence is indisputable. To ignore it is unconscionable.
Copyright © Dr. Noel Kerin and KOHC. All rights reserved.
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Posted by KOHC at July 28, 2005 09:39 AM
Are brake pads a source of asbestos that we need to be worried about?
Posted by: Bill at February 28, 2006 01:38 PM
They used to be - but not now. Much older vehicles may still have them.
Posted by: KOHC at April 4, 2006 10:34 AM