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ASBESTOS — A group of minerals that includes chrysotile, crocidolite, amosite, anthopyllite, tremolite and actinolite — is one of the most important occupational carcinogens.
World Health Organization (WHO), Chrysotile Asbestos, September, 4, 2014.
More than a century of intensive asbestos mining and extensive use confirmed that asbestos causes cancer, usually decades later. Now with shut-down of mining and banning of products, the lines between work and home are blurred. Asbestos remains in buildings and infrastructure, and long-delayed asbestos-related cancers still loom over Canada.
On Saturday, March 25 at 7 p.m., CTV W5 investigated aging asbestos pipes across Canada, and the potential health hazards if this known and potent carcinogen ends up in your tap water:
Why is this news? In 1977 the Science Council of Canada reviewed regulation of such hazardous substances.
Asbestos is a fibrous silicate mineral with unique physical properties which make it valuable in a wide range of industrial applications. … It is used in about 3000 industrial products including building materials, textiles, and electrical products. It is also a deadly hazard whose adverse and irreversible health effects, particularly on workers, have been known for decades.
The federal Department of National Health and Welfare … has also been involved in analysis under the Food and Drug Act of the levels and distribution of asbestos dust in drinking water. A 1974 report to the International Joint Commission had shown high asbestos levels in water samples of large industrial centres bordering on the Great Lakes.
Bruce Doern. Science Council of Canada Background study No. 41 Regulatory Processes and Jurisdictional Issues in the Regulation of Hazardous Products in Canada. October 1977.
Asbestos fibres are thin and sharp. They migrate throughout the body, into tissues and the blood stream, and fibres as well as minerals can be excreted in the urine, over months and years.
In 2012, the International Agency for Research on Cancer updated its asbestos monograph, following assessments in 1972, 1976 and 1987. The working group concluded:
There is sufficient evidence in humans for the carcinogenicity of all forms of asbestos (chrysotile, crocidolite, amosite, tremolite, actinolite, and anthophyllite). Asbestos causes mesothelioma and cancer of the lung, larynx, and ovary. Also positive associations have been observed between exposure to all forms of asbestos and cancer of the pharynx, stomach, and colorectum.
There is sufficient evidence in experimental animals for the carcinogenicity of all forms of asbestos. All forms of asbestos (chrysotile, crocidolite, amosite, tremolite, actinolite and anthophyllite) are carcinogenic to humans (Group 1). For cancer of the colorectum, the Working Group was evenly divided as to whether the evidence was strong enough to warrant classification as sufficient for inclusion in Group 1.
Health Canada, and the United States Environmental Protection Agency and Department of Health and Human Services all agree that asbestos causes cancer.
For decades, Canada was a major global asbestos supplier, principally of chrysotile asbestos. In 2018, many decades of illnesses and advocacy bore fruit when Canada banned production, trade, sales and use of new asbestos-containing products. All forms of asbestos, including chrysotile asbestos, were listed as “Toxic,” under the Canadian Environmental Protection Act, 1999, with Prohibition of Asbestos and Products Containing Asbestos Regulations (SOR/2018-196).
Kathleen Ruff detailed Canada’s winding, conflicted path to finally restricting and eventually phasing out most uses of asbestos, on the website Right on Canada.
The World Health Organization lists how a century or so of legacy asbestos lingers in buildings (e.g., insulation, roofing shingles, floor tiles and coatings); in industries (e.g.,fire blankets, insulation and machinery parts); vehicles (e.g.,clutches and brakes, gaskets and pads); in asphalt on roads; and exposed minerals and mine tailings. Canada still permits a few specialized uses for as long as cost-effective alternatives do not yet exist, such as for membranes used in electrolytic chlor-alkali cells, and in nuclear facilities. Canada’s asbestos restrictions aim largely to reduce risks of asbestosis and related cancers, from breathing asbestos fibres.
Underground, out of sight and out of mind, asbestos remains in infrastructure, including asbestos cement (AC) water pipes. These rapidly-deteriorating pipes were installed in Canada from the 1930s into the 1990s, and they shed asbestos into water. Unfortunately, Canada does not yet regulate asbestos in drinking water. Assessment by Health Canada dates to 1989.
The United States does regulate asbestos in drinking water, with a maximum allowable concentration of 7 million fibres per litre.
Even though asbestos does not dissolve in water, fibers can enter water by being eroded from natural deposits or piles of waste asbestos, from asbestos-containing cement pipes used to carry drinking water, or from filtering through asbestos-containing filters. Most drinking water supplies in the United States have concentrations of less than 1 million fibers per liter (MFL), even in areas with asbestos deposits or with asbestos-cement water supply pipes. However, in some locations, water samples may contain 10–300 million fibers per liter or even higher.
Asbestos Public Health Statement by the U.S. Agency for Toxic Substances and Diseases Registry.
The Canadian Centre for Occupational Health and Safety states:
Asbstos is associated with cancers:
– colon and rectum
– larynx
– lung
– mesothelioma
– ovary
– stomach
The Government of Canada states,
The Government of Canada recognizes that breathing in asbestos fibres can cause cancer and other diseases, and that the health risks related to asbestos containing materials are no longer tolerated by the Canadian public. The Prohibition of Asbestos and Products Containing Asbestos Regulation became enforceable on December 30, 2018.
Canada’s Update on materials containing asbestos (2019)
What the Update neglects to mention is that tens of thousands of kilometres of asbestos cement water pipes, which contain approximately 20% chrysotile asbestos, were exempt from the regulations.
Canada has been flying blind on asbestos in drinking water.
Historic Turnaround on Asbestos Puts Canada on a New, Difficult Path As sure as asbestos-caused cancer can be…