Asbestos is a known carcinogen and exposure to asbestos fibres can increase your risk of developing an asbestos-related disease, including cancer.
What is asbestos?
Asbestos is the name given to a group of naturally occurring fibrous minerals (chrysotile, crocidolite, amosite, anthophyllite, tremolite and actinolite), which have excellent durability, fire resistance and insulating properties. Because of these properties, asbestos was used in a very wide variety of products. It is thought to have over 3000 uses worldwide.
Asbestos in Australia
In Australia, asbestos was mined and imported for use in the manufacture of a range of building products and other materials. During this time, Australia was one of the highest users, per capita, of asbestos. The two main mining operations were at Woodsreef NSW, where chrysotile (white asbestos) was mined until 1983, and Wittenoom WA, where crocidolite (blue asbestos) was mined until 1966. Smaller asbestos mines also operated in Tasmania and South Australia.
Asbestos-containing materials were manufactured and imported into Australia in vast quantities. The majority of these (~90%) were building materials, mainly asbestos cement products such as ‘fibro' sheets/board or cement pipe. Asbestos was also used in other products such as insulation (lagging, loose fill or spray insulation), automotive parts (brake pads, clutch linings), floor tiles (and their adhesives), roofing, textiles (blankets, rope, wraps), expansion joints, joining putty, textured paints and many other products. Final production of products containing asbestos occurred in late 2003, when production of automotive friction parts which contained asbestos was ceased.
Many workers were required to install or work with asbestos-containing materials through the course of their employment. Many of these asbestos-containing materials still remain in place in workplaces and homes throughout Australia. It is reported that approximately one third of all Australian homes built or renovated before 1990 contain asbestos products.
Due to the known health risks associated with asbestos, a national ban on asbestos, and all products containing asbestos, their use, importation, storage, sale, supply, or installation (except for disposal purposes) came into effect on 31 December 2003 throughout Australia. Asbestos is still mined in a number of countries and used to manufacture asbestos-containing products; however, these cannot be imported into Australia.
What makes asbestos dangerous?
All forms of asbestos occur as fibrous bundles that can be continuously separated down to individual fibres of microscopic dimensions including less than 1 micrometre in length. In comparison, they can be 50 to 200 times thinner than a human hair. At such small sizes they are invisible to the naked eye, are able to remain airborne for long periods once released and can travel in air currents.
Because of their microscopic size, asbestos fibres can be easily inhaled and can become trapped in the lungs. Once there, it is hard for your body to remove the fibres through natural processes and they can cause damage over a long period of time. Asbestos fibres can also be ingested by swallowing fibres, but this is less common.
Asbestos fibres can be found in the air from the breakdown of natural asbestos deposits and manufactured asbestos-containing materials. Fibres are mainly released when people work with or remove asbestos-containing material without taking proper precautions.
Asbestos-containing materials are broadly categorised into two groups:
• Bonded (non-friable) asbestos materials are made up of a bonding agent (such as cement) with asbestos added to give strength and fire resistance; and
• Friable (loosely bound) asbestos materials are those which can be crumbled, pulverized or reduced to powder by hand pressure and also includes broken, damaged or weathered bonded asbestos products.
Friable asbestos-containing materials are dangerous because the asbestos fibres can easily get into the air and may be inhaled by people living or working nearby. Friable materials can contain high levels of asbestos (up to 100% in some instances). Bonded materials usually contain a smaller proportion of asbestos (usually less than 15%). If bonded materials are in good condition, they normally do not release any fibres unless disturbed (i.e. if you use power tools to drill into them); however, bonded asbestos materials that are damaged or badly weathered, may become friable.
Health risks associated with asbestos
When asbestos fibres are breathed in, they may remain deep within the lungs. They can lodge in lung tissue and cause inflammation, scarring and some more serious asbestos-related diseases, which usually take many years, if not decades, to develop. There are reports which have stated that some types of asbestos are safer than others (i.e. chrysotile vs. amphibole classes); however, all types of asbestos are dangerous.
Exposure to asbestos can increase the risk of developing chronic (long-term) health problems, including asbestosis and benign pleural abnormalities, and an increased risk of a number of cancers including lung, mesothelioma, ovarian and larynx.[2-5]
Risk factors for developing asbestos related diseases
There are many factors that increase a person's risk of developing an asbestos-related disease, including the:[2,6,7]
• Length of time a person is exposed to airborne asbestos
• Concentration or levels of asbestos fibres in the air breathed
• Frequency of exposure to asbestos fibres
• Time since exposure occurred
• Age at which exposure occurred
• Type and size distribution of asbestos fibres
• Exposed individual's susceptibility
• Tobacco smoking history of the exposed person (i.e. current or previous smoker)
How do I avoid exposure to asbestos?
In the workplace
Asbestos-containing materials were used in a wide variety of commercial and industrial products. It was commonly used for insulation materials, automotive parts, expansion joints and construction materials. If there is a possibility that you might be exposed to asbestos at work, such as during renovating old buildings (pre-1990 construction), working on mobile equipment or plant (pre-2003 models) or working in a high risk occupation, you should always use the proper personal protective equipment, work practices and safe work procedures designed for work around asbestos. WorkSafe WA designates specific safe work practices that must be followed to control the risk of exposure to asbestos in the workplace. If you have concerns about exposure to asbestos in your workplace you should contact your work supervisor, health and safety representative, union representative or WorkSafe WA.
In the home
To minimise your risk of exposure to asbestos at home, it is important for homeowners to identify if and where any asbestos-containing products were used within their home (you should also consider any structural additions, sheds, outhouses or fences on your property as well). Some asbestos-containing products are easy to recognise, although others are not. Asbestos-containing materials may be covered up by other products, painted, look similar to non-asbestos products or may be in places you don't think to look.
As a general guide, if your home was built or renovated:
|Before the mid 1980's||It is very likely to contain asbestos-containing materials|
|Mid 1980's to 1990||It is likely to contain asbestos-containing materials|
|After 1990||It is unlikely to contain asbestos-containing materials|
Note: automotive friction parts containing asbestos did not cease production in Australia until 2003.
You shouldn't always rely on dates or visual inspections to verify the presence of asbestos. If you are unsure if a material in your home contains asbestos, you should always treat it as though it does contain asbestos. The only sure way to verify if a material in your home contains asbestos is to have a sample of it tested at an accredited laboratory. You can find an accredited laboratory by visiting the National Association of Testing Authorities (NATA) website or call 1800 621 666.
Homeowners may be exposed to asbestos fibres during accidental damage to asbestos-containing materials in the home, or as a result of the unsafe handling of asbestos-containing material (such as cutting materials with power tools or washing them with high pressure sprays), either by tradespeople or by the homeowners themselves (during DIY home renovations). Fibres may also be released from asbestos-containing materials which have been damaged by storms or fire, or weathered over long periods of time.
If you are planning to do a home renovation, you should always think asbestos.
It is important that you know about the potential health risks of asbestos and the safety precautions required before renovating a house that may contain asbestos. Removing asbestos safely can be a complicated process. For this reason it is best carried out by licensed professionals who have completed relevant training. If you are considering a renovation that may involve you working with asbestos-containing material in your home take the time to complete the free kNOW asbestos in your home online eLearning module. This module will provide invaluable information about how to identify asbestos, understand the risks, and develop safe work practices when working with or removing small amounts of asbestos-containing materials.
Asbestos at work
Many asbestos-containing materials still remain in place throughout Australia. Tradespeople such as painters, electricians and builders are still at risk of exposure to the asbestos fibres in these materials.
Information about asbestos in the workplace, employers legal obligations and what you can do to reduce your risk of developing an asbestos related cancer will be available here shortly.