Occupational disease – the silent epidemic

Twenty five years ago for the first time, Ontario workers won the statutory right to know about the substances they worked with; the right to help promote and ensure safe and healthy workplaces through their participation in joint health and safety committees; and the right to refuse work they believe to be unsafe.

Bill 70- An Act Respecting the Occupational Health and Safety of Ontario Workers- was written and passed into law, on October 1, 1979. Despite the passage of the law, a quarter of a century later, occupational diseases have become a “silent epidemic”. The reasons why are explored in an article written by Occupational Health Clinics for Ontario Workers (OHCOW) Managing Director Mary Cook and published in the Toronto Star on Labour Day September 5th.

Complete Article:

Sep. 5, 2005. 01:00 AM

Occupational disease: Today's silent epidemic

Twenty-five years after the passage of Ontario's Occupational Health and Safety Act, it would be nice to be able to say on this Labour Day that, at the very least, we know how many thousands of workers are stricken each year by diseases related to work.

The bitter truth is, we don't even know that. Part of the reason is our obsession with scientific proof.

While science has contributed hugely to the quality of our lives, it has also led to a situation where we now depend on it to provide answers to every question. The problem, of course, is there are some issues where science is incapable of providing answers with the certitude we demand.

Climate change is one example. Scientists can tell us they believe human activity has an effect on climate but they can't prove it conclusively. In spite of that scientific caution, Canada and most other countries have decided to act because the consequences of not acting are so great.

In the case of greenhouse gas emissions, society has decided to apply the precautionary principle, which says we're better safe than sorry.

But there's a similar example where science and public policy collide. It's a case that, for many people, has a much more immediate effect on their lives but we have yet to take the same cautionary step.

It's the silent epidemic of occupational disease.

The World Health Organization estimates that 1,000 new chemicals are introduced into workplaces every year. Given the array of workplace chemicals in use, it's no surprise that cancer is an occupational disease.

Again, precise numbers are hard to come by. Cancer Care Ontario suggests about 4 per cent of cancers may be related to occupational factors.

Even at that conservative estimate, there would be about 2,000 new occupational cancer cases in Ontario each year. But in 2003, only 51 lost-time cancer claims were allowed, according to the Annual Report of the Workplace Safety and Insurance Board.

There are several reasons for the lack of precise numbers about the extent of the problem. There is no database of occupational disease in Ontario — no one keeps records. In addition, Ontario doctors are not required to report incidences of occupational disease. Sexually transmitted diseases, yes; gunshot wounds, yes; mesothelioma from asbestos exposure, no.

As well, medical schools do a poor job of educating doctors about occupational disease.

Staff at Ontario's five occupational health clinics have seen cases where family or company physicians have declared patients to be in good health even though they have diseases like asbestosis.

Legislation can deal with some of those issues. But the bigger problem is our insistence on amassing unequivocal scientific proof before we even acknowledge that there is a problem.

The particular science involved in ferreting out medical mysteries is epidemiology, the study of disease patterns among populations.

But epidemiology may simply be too crude a tool to investigate the clusters of occupational diseases that occur, for the simple reason that the number of cases is usually too small.

Scientists are trained to look for high levels of statistical significance and avoid false positives — finding associations where none exist.

This deep-seated avoidance however leads to another problem: making false negatives — the failure to identify an association where one really does exist.

When studying occupational disease, it is often not possible to collect data of adequate quality and quantity to achieve statistical significance. That puts workers' health in jeopardy.

Science and numbers go together and scientists have strict protocols on what kind of evidence they consider.

That leaves workers unable to depend on more qualitative forms of evidence that can show links between disease and work.

Qualitative data include employment and exposure history, the occurrence of symptoms or diseases within a workforce, or even testimony by co-workers.

In the context of workers' compensation, the burden of proof should not be on exposed workers to prove work has made them sick.

"Better safe than sorry" was a principle good enough for our grandmothers. When dealing with the silent epidemic of occupational disease, it should be good enough for us.

Governments, industry and the WSIB, should follow the same precautionary principle.

Mary Cook Managing Director of the Occupational Health Clinics for Ontario Workers (OHCOW)