Asbestos was once considered so safe it was used as an ingredient in toothpaste. Today asbestos is recognized as a potent carcinogen by health experts and scientists worldwide. Despite this, in Canada it seems economic concerns take precedence over health when it comes to the international trade of asbestos.
History of asbestos
The history of asbestos and its uses goes back to ancient times. The ancient Greeks and Romans are known to have woven asbestos into cloth for funeral dress and shrouds, wicks, and napkins that could be easily cleaned by simply throwing them on fire.
Asbestos refers to six naturally occurring fibrous minerals found all over the world. Asbestos fibres have several unique, desirable qualities—such as low conductivity and resistance to high temperature and chemical attack—making them ideal for use in hundreds of products and applications.
What is it used for?
From the 1930s to 1990 there was widespread use of asbestos in house-building materials in Canada. Today asbestos can be found in insulation board, shingles, ceiling and floor tiles, and certain types of cement.
When does it pose a health threat?
Asbestos is believed to pose little risk when encapsulated in housing materials that are in good condition, and is only considered a health hazard when its fibres are present in the air.
According to Health Canada, health risks caused by asbestos depend on the
- concentration of fibres in the air
- length of exposure time
- frequency of exposure
- size of fibres inhaled
- amount of time since first exposure
When inhaled in large quantities or over a long period of time, the fibres present in the air accumulate in the lungs, causing irritation and inflammation that can reduce lung function and cause serious forms of cancer.
Politics and bad science
Despite asbestos being strictly regulated in Canada under the Hazardous Products Act (1985), Canada is the fifth largest exporter of chrysotile asbestos. Canada is the only G8 country still exporting asbestos. In 2011 Canada moved to block the listing of chrysotile asbestos as a hazardous product on the Rotterdam Convention, a United Nations treaty that encourages shared responsibility in the international movement of hazardous chemicals. In June 2011 the government released a statement that “all scientific reviews clearly confirm that chrysotile [white asbestos] fibres can be used safely under controlled conditions.”
This stance is at odds with many studies indicating that, although the nature of chrysotile fibres makes it less potent than other types of asbestos, chrysotile is still a powerful carcinogen known to cause cancers of the lung, mesothelium, and ovaries.
A potent carcinogen
In 2008 Health Canada created a panel of international experts to discuss the potency and carcinogenic effect of chrysotile asbestos relative to other forms of asbestos. The views expressed at the panel were divergent, but there was consensus that chrysotile asbestos is a potent carcinogen that causes lung cancer.
The results of the panel’s report were delayed for more than a year, causing members of the panel to speculate about the Canadian government’s misrepresentation of science to determine policy and economic agendas.
Canada is the only G8 country still exporting asbestos. In 2011 Canada moved to block the listing of chrysotile asbestos as a hazardous product on the Rotterdam Convention, a United Nations treaty that encourages shared responsibility in the international movement of hazardous chemicals.
This is not the first time Canada has lobbied to keep chrysotile off the Rotterdam Convention: in 2006 the government rejected Health Canada’s advice that chrysotile be added to the list.
The treaty was devised to protect health and the environment by creating a “right to know” process called Prior Informed Consent (PIC). Under PIC, countries exporting potentially hazardous materials are obligated to inform importers of any health or environmental risks of materials, allowing the importing countries to make informed decisions and exercise safe handling practices.
It is ironic that millions of dollars have been spent in Canada to remove asbestos from public buildings, including Parliament Hill and 24 Sussex Drive (the prime minister’s residence), due to its carcinogenic nature and potential health risk. Yet we continue to export asbestos to India and South Asia, while 100,000 people worldwide die each year of asbestos-related diseases.
Asbestos and health
As mentioned previously, asbestos is only considered hazardous to health when fibres are inhaled, and one-time exposure to asbestos is unlikely to cause illness. If you know or suspect you’ve had long-term or high-level exposure to asbestos in your home or workplace, it is important to meet with your health care practitioner regularly to catch any developing conditions early on. There are several conditions that have been linked to asbestos, and most develop many years after long-term or high-level exposure. The time from asbestos exposure to onset of an illness is called the latency period.
The most common condition to result from exposure to asbestos is pleural plaques. Pleural plaques are nonmalignant collagen fibre deposits that can become calcified. These can occur after low-level exposure to asbestos, and generally lack symptoms.
Even though pleural plaques are relatively benign, the presence of this condition indicates past exposure to asbestos has likely occurred. If you have been diagnosed with pleural plaques, have regular medical checkups to help monitor and mitigate onset of serious asbestos-related diseases such as asbestosis or mesothelioma.
Caused by long-term exposure to high levels of asbestos, asbestosis has a latency period of 25 to 40 years. Inhaled asbestos fibres become trapped in lung tissue, and as the body attempts to dissolve the fibres, scarring and hardening of the lungs occur. This condition reduces lung function such as the ability to deliver oxygen and remove carbon dioxide from the blood.
Asbestosis also decreases total lung capacity (the maximum volume lungs can be expanded). Symptoms include shortness of breath, dry cough, chest pain, and difficulty undertaking physical activity. Although itself nonmalignant, asbestosis increases the risk of developing cancers of the lung or mesothelioma.
Having past work-related exposure to asbestos significantly increases the risk of developing lung cancer, and combining this past exposure with smoking is a deadly combination. Asbestos exposure alone increases lung cancer risk five-fold, and heavy smoking alone increases risk ten-fold. In combination, the risk jumps by 50 to 90 times.
Recent studies have confirmed that asbestos exposure has been linked to development of cancer in the ovaries. The mechanism for how this occurs—or how asbestos fibres find their way into the ovaries—is still not understood.
This rare form of cancer occurs in the mesothelium, the protective lining of several organs and body cavities. Past exposure to asbestos is the main cause of mesothelioma.
There are three types of mesothelioma:
- pleural (attacking the lining of the lungs and chest)
- peritoneal (affecting the abdominal cavity)
- pericardial (affecting the membrane of the heart)
Pleural mesothelioma is the most common form and accounts for 66 percent of cases. Symptoms of pleural mesothelioma include persistent dry cough, bloody cough, painful breathing, and persistent pain in the chest and rib cage area. Symptoms for all forms of mesothelioma include fatigue, night sweats, fever, and unexplainable weight loss. The latency period is anywhere between 20 and 50 years.
If you know or suspect you’ve had long-term or high-level exposure to asbestos in your home or workplace, it is important to meet with your health care practitioner regularly to catch any developing conditions early on. If you smoke, it is important to quit right away.
Dangerous DIY home repairs
Another major source of asbestos exposure is building materials uncovered by home renovations. Most housing materials containing asbestos do not pose health risks, provided the materials are in good condition. If you discover asbestos-containing materials in your home, it is often best to leave them intact and undisturbed.
However, some materials disintegrate easily and can release asbestos fibres into the air; these materials are known as “friable.” Friable materials include, but are not limited to, attic insulation, spray-on popcorn ceilings, sprayed fireproofing, and sprayed thermal insulation.
Nonfriable materials, such as asbestos cement products and asbestos ceiling and vinyl floor tiles, contain asbestos fibres that are “bound.” They are not released into the air except through damage caused by repair, maintenance, renovation, and demolition activities, such as sanding, drilling, and cutting.
If you know or suspect you have asbestos-containing materials in your home that are friable, in bad condition, or have been damaged, it is important to seek out professional help to remove or encapsulate the material right away.
By taking proper precautions you can reduce your risk of being exposed to asbestos. As for citizens of developing nations who are receiving Canada’s dangerous asbestos exports, it is up to us to pressure our government to take a responsible stance.
Additional asbestos info
Are you thinking of renovating your home or want to learn more about how to avoid exposure to asbestos? Check out the following resources to help keep you and your family safe:
Health Canada –
United States Environmental Protection Agency – epa.gov/asbestos/pubs/ashome.html
The Mesothelioma Center – asbestos.com/abatement/