Lengthy latency period – 50 years – means diagnoses will continue
Early in October, a University of Manitoba professor made headlines when she said exposure to asbestos on campus may have been the cause of her rare form of cancer.
Patricia Martens, diagnosed with mesothelioma in February 2013, said during her early career years as a chemistry teacher she used asbestos heating pads with Bunsen burners. She also felt she was exposed to asbestos during the 30 years she studied and worked at the University of Manitoba.
Two other professors at the school were diagnosed with the same cancer and have since died.
Martens’ story is becoming all too common among long-time university and college employees, according to Laura Lozanski, occupational health and safety officer at the Canadian Association of University Teachers (CAUT).
"Asbestos-related diseases have a long latency period and many CAUT members may have been exposed in their early years of learning or working at Canadian post-secondary institutions."
Diagnosis of asbestos-related disease is on the rise as many buildings were built decades ago without full awareness of the dangers of asbestos-containing construction materials (ACM). With a latency period of 50 years, mesothelioma is now a leading cause of work-related fatalities in Canada, according to the Occupational Cancer Research Centre in Toronto.
"Asbestos was used in so many different applications and so many different types of configurations and properties that it isn’t uncommon for places like universities or large institutions to have asbestos materials," said Al Johnson, vice-president of prevention services at WorkSafeBC in Vancouver. "Again, it’s been a requirement for a number of years that those materials be managed safely and/or removed safely — but that’s not to say someone who’s been in that location for longer term might have been exposed."
Tracking, reporting to protect workers
While the dangers of asbestos are now well-known, provincial governments are working to better record the location and potential exposure to ACM. In addition to its asbestos information website www.hiddenkiller.ca, WorkSafeBC has a registry that tracks exposure.
"It’s a database that allows anyone in the province that believes they’ve been exposed to any type of hazardous substance or chemical, that they can then enter that information onto the registry and then it provides a permanent record of that type of exposure," said Johnson.
While the entries are subjective, they do allow for the exposure information to be logged with key information, he said. Previously, a worker might call to say he’d been exposed to asbestos, not sure what to do, and often he would go to his family doctor to have the information entered into his medical file — only to be forgotten 20 or 30 years later.
"This exposure registry now allows for that type of placement of information for future use," said Johnson.
The registry looks at any type of exposure, so it could be anything from silica or a chemical substance to a mercury spill, he said.
"We monitor what’s on there and if we’re seeing something of interest that we weren’t aware of, we can also use that information to proactively go out and do some inspections in a certain sector or an area or whatever the case may be. We can always follow up on that information if we think there’s something that can be done in the shorter term."
Most of the "gross exposures" to asbestos have been eliminated as asbestos was used in the shipbuilding industry, pulp mills and oil refineries — a lot of industrial applications in years gone by, said Johnson.
"Most of those heavy industrial uses, they’ve removed the asbestos or the asbestos that does remain is being managed very well, so they know it’s
there and they’re making sure people are not exposed to it. When they do disturb it or do have to do something with it, they’re taking the proper precautions."
Exposures today are coming predominantly from commercial buildings and homes that are being renovated or demolished, said Johnson. And British Columbia requires every building owner to do a hazardous material survey of the property.
"If they do have asbestos-containing materials, then prior to any renovation or demolition, those materials have to be safely removed," he said. "And if they’re not doing work but they have asbestos in their building, that has to be properly managed... for the most part, they have asbestos management programs in place."
While injury rates, serious injury rates and work-related deaths are all decreasing in the province, the occupational disease death rate is going in the opposite direction, said Johnson.
"Deaths related to occupational disease, predominantly disease from exposure to asbestos, is increasing," he said. "They are typically more senior in their age and they were a pipefitter, a carpenter, a painter, an insulator, who all were exposed to asbestos 30, 40 years ago, so we’re still fighting that increase in disease we expect to continue just because of the latency period of disease."
Raising awareness
Saskatchewan now requires mandatory asbestos reporting for Crown corporations, school districts, health regions and facilities and provincial government buildings. The registry is meant to ensure employers are meeting the regulatory requirements of occupational health and safety regulations in terms of identifying ACM within their workplaces, recording the condition and location of the materials and ensuring it is safe and no one operating there is under a risk of exposure, said Mike Carr, deputy minister of labour relations and workplace safety in Saskatchewan’s Ministry of Labour Relations and Workplace Safety in Regina.
The registry has been beneficial in encouraging employers to remember they have a responsibility in ensure a safe and healthy workplace, he said, and tracking the information now will help with claims down the road.
"One of the questions that always arises whenever there’s a claim that deals with a workplace exposure is really gathering the information and the evidence around that exposure, so one of the benefits of the regulations that have been in place in Saskatchewan since 1971 and the subsequent amendments we made here in 2014 has been that we do have a very clear opportunity to identify asbestos-containing materials, employers fully understand and appreciate it is their responsibility to do so. That then creates a record that workers may rely on if they are subject to anything related to asbestos exposure."
Most of the asbestos exposure occurred in industrial occupations or construction, said Carr, and since about 1985, buildings constructed and activities undertaken in new building construction have seen the elimination of ACM. However, there can still be concerns today," he said.
For example, firefighters have to be careful when exposed to old buildings with the materials, he said.
"Anything we can do to bring greater awareness to workplace hazards is a positive, and we certainly feel that the registry is going to be a benefit."
There is no requirement to remove the ACM — that’s a decision individual building owners and workplace owners make, said Carr, and, generally, the response has been positive.
"We’ve found some workplaces that are having a challenge because where previously they just had the knowledge of the asbestos-containing materials, they now have a specific set of things they must do to identify the location, to report on the condition of that asbestos-containing material and provide regular updates if they are doing work in the area
that would cause any interference with their disruption of that asbestos-containing material," he said, adding the challenge is finding professional services to deal with the issues as there are a limited number of resources available in the community.
While it’s still early days to know how much of an impact the registry is having, the government continues to improve the registry.
"We are moving… to standardized reporting, so we’ve made a template available on the website for all employers and we’ve asked that they reconsider what they may have previously submitted in order to ensure they’re meeting the new standard that we
expect them to comply with," said Carr.
He added the registry is also becoming more user-friendly in terms of searchability.
The facts on asbestos
Asbestos is a mineral-based fibre that has been widely used in building materials due to its resistance to heat and corrosive chemicals. Although there are six different varieties of asbestos minerals, there are three main types: chrysotile, amosite and crocidolite. Typically, asbestos appears as a whitish, fibrous material. The fibres can range in texture from coarse to silky.
When air contaminated with asbestos dust is breathed in, the small, sharp, barbed-like asbestos fibres find their way deep into the lung tissues and other internal organs where they remain for life. Over time, they can cause fatal diseases. Breathing even small, invisible quantities of asbestos is known to cause cancer 20 to 30 years after exposure.
Breathing in asbestos fibres can cause asbestosis and cancer. Asbestosis is an irreversible disease of the lung, which leads to scarring of the lung tissue. As the tissue scarring becomes more extensive, the lung loses its flexibility and breathing becomes more difficult. The loss of lung function often progresses to disability and to death.
Asbestos is also known to cause mesothelioma, which is a type of cancer almost exclusively associated with asbestos exposure. Mesothelioma develops in the thin membranes lining the lungs and abdomen. This type of cancer is inoperable and always fatal.
Exposure to asbestos can cause other cancers as well. Asbestos workers have increased rates of lung cancer and cancers of the esophagus, stomach, large intestine and rectum.
