The body normally does a very good job dealing with airborne foreign particles. If the nostril hairs don’t keep dust out, it might get caught up in mucus and coughed up, spat out or swallowed. Dust that does get through may still be absorbed at the cellular level.

That’s not the case with asbestos.

A great heat insulator, asbestos was long used to protect houses, office buildings, ships and other structures from fire, temperature extremes and other damage. Unfortunately, it is equally tough inside the human body and can bypass all of those protective mechanisms, lodge itself in a person’s lung and never leave.

Workers were exposed to asbestos long before it was declared a hazardous substance. Many didn’t know it was a respiratory hazard — or that it was silently present in their bodies — until it was too late.

Most of Canada’s asbestos mines ceased operation in the 80s, and the number of workplaces that manufacture or assemble products containing asbestos is low. Yet because of the long latency period of asbestos-related diseases, individuals who were exposed in the 60s or 70s are being diagnosed now. In Canada, the annual incidence rate and number of new cases of asbestos-related illnesses increased steadily and are expected to peak between now and 2020.

Meanwhile, the hazard continues to surface whenever someone works on an old structure containing asbestos. “We’re still seeing a lot of asbestos exposure, notably in the construction industry, where people disturb, maintain or remove things like pipe insulation, fire-proofing materials and boiler insulation,” says Thomas Lee, provincial hygienist and program lead for hygiene services with the Ontario Ministry of Labour. Asbestos exposure can also originate from heating and electrical ducts, roof shingles, caulking, vinyl wall coverings or floor tiles, asphalt floor tiles, cement siding, fire doors, blankets or curtains.

Workers in shipyards are also at risk. Asbestos was traditionally used as an insulator and to protect vessels from damage, so today’s shipyard workers are exposed to it when they repair or renovate those vessels.

“It’s not an old hazard,” says Keith McMillan, national representative for the Communications, Energy and Paperworkers Union of Canada (CEP), who specializes in health and safety. “They don’t install asbestos anymore, but it’s out there. It’s in our homes, in our malls, even in the west block of parliament.”

In his industry, workers are exposed to steel beams in buildings that were sprayed with fire retardant containing asbestos. Many of those fire retardants were installed when asbestos contents were still allowed in that mix. “Some might have contained one per cent asbestos, but some were 40 to 50 per cent asbestos,” he says.

Today’s awareness of the hazard offers certain advantages. Hazardous substance legislation outlines precautions such as testing air quality; testing samples of insulation, fireproofing, floor tiles, caulking and other building materials suspected to contain asbestos; or even talking to an attorney about any asbestos-related laws. Occupational health and safety regulations outline several requirements, notably informing workers about the presence of asbestos on the job site; training workers on the safe handling of asbestos and the potential health risks of exposure; and making appropriate personal protective equipment available to workers.

McMillan says that unless employers are adhering to those control measures, workers still risk being exposed to asbestos. He is glad the requirements are strict but wishes the hazard didn’t exist at all. “What I’d like to see happen is a proactive plan in place for buildings to get rid of this stuff, even if it takes time,” he says. “What I have always advocated is, if you’re going to repair a pipe that’s rapped with asbestos, why not actually apply the work to removing the asbestos, eliminating the hazard at the source?”