What is asbestos?
Asbestos is a term for a group of six naturally occurring mineral fibres belonging to two groups:
- Serpentine group – comprised of only chrysotile (white asbestos), and
- Amphibole group – comprised of anthophyllite, amosite (brown asbestos or grey asbestos), crocidolite (blue asbestos), tremolite and actinolite.
What was asbestos used for?
Asbestos was long considered one of the most versatile minerals because of its flexibility, tensile strength, insulation from heat and electricity, chemical inertness and affordability.
This made it attractive to many industries and it is known to have more than 3000 applications worldwide. Australia was one of the highest users of asbestos per capita in the world up until the mid 1980s, including a significant number of asbestos products in homes. The widespread use of asbestos has left a legacy of asbestos-containing materials (ACMs) in our built environment.
The risks of exposure to asbestos fibres
Asbestos is a known carcinogen. Inhalation of fibres is associated with increased incidences of a number of respiratory diseases including asbestosis, mesothelioma, pleural and lung cancers.
The World Health Organisationi and the International Agency for Research on Cancerii,iii have stated there is no identified safe threshold for exposure to asbestos. Even limited or short-term exposure to asbestos fibres can be dangerous; however exposure does not necessarily make development of mesothelioma inevitable. There is still much unknown about why some people are susceptible to mesothelioma, while others who have been regularly exposed to asbestos do not develop any asbestos-related disease. This is why a precautionary approach to exposure to asbestos fibres is adopted.
Australia has the highest reported per capita incidence of asbestos-related disease in the world, including the highest incidences of mesotheliomaiv. In 2012, 652 Australians died from mesotheliomav. It is estimated that for every death attributed to mesothelioma two more people die from lung cancer caused by asbestosvi. Based on existing evidence, it is predicted as many as 25,000 Australians will die from mesothelioma over the next 40 yearsvii. Due to the long latency period for mesothelioma, these figures may not reflect current management practices but still need to be addressed. Recent evidence indicates there is now a third wave of asbestos-related disease caused by non-occupational exposure associated with home renovationsviii. This highlights the need to refocus efforts to prevent asbestos-related diseases and strengthen the management of asbestos risks.
When does asbestos pose a risk?
ACMs can be categorised as friable and non-friable. Non-friable asbestos, where it is mixed with other bonding materials like cement and is maintained in good condition, is the type most commonly found in our built environment. Friable asbestos is material that contains asbestos and is in a powder form, or can be crumbled, pulverised, or reduced to a powder by hand pressure when dry. Individual fibres can become airborne and cause a risk to a person’s health through the inhalation of asbestos.
Both friable and non-friable asbestos may pose a significant health risk to the community if the materials are not properly maintained or safely removed. Potential health risks are posed by any contact with airborne asbestos fibres. This can be caused by:
- weathering of ACMs
- damage to ACMs
- building and/or maintenance work involving ACMs
- demolition and/or removal of ACMs z unsafe disposal of ACMs
- asbestos contaminated land.
The risk of exposure to asbestos fibres is broad if not effectively managed, and is therefore a significant issue for the entire Australian community.
When was asbestos banned?
In the 1980s, Australian governments began banning asbestos due to concerns about asbestos- related deaths and diseases. Most states and territories introduced a ban on the mining of raw asbestos and the manufacture, importation and installation of products containing crocidolite and amosite asbestos from 31 December 1984. By the late 1980s, the use of asbestos in building products was banned in most Australian states and territories. On 31 December 2003, a national ban on all uses of chrysotile asbestos came into effect. The ban also extended to the import and export of all products containing asbestos.
Despite the bans on mining and industrial use, many asbestos products that were used in the past are still present in our built environment today, including in many government, commercial and residential buildings. The presence of in-situ asbestos means it needs to be managed and the risks of exposure may continue for many years to come.
The international management of asbestos is an issue that impacts the Australian community. While Australia has implemented a ban on the importation of ACMs, not all other countries have done so, and its use in products produced in some parts of the world continues to be widespread. There are also inconsistencies with the definition and labelling of what is defined as ‘asbestos free’, which has led to the inadvertent importation of products that contain asbestos into Australia.
Jump to reference i World Health Organisation (2006), Elimination of Asbestos-Related Disease, Geneva, http://whqlibdoc.who.int/hq/2006/WHO_SDE_OEH_06.03_eng.pdf
Jump to reference ii International Agency for Research on Cancer (1977), ‘Asbestos’ Monographs on the Evaluation of Carcinogen Risks of Chemicals to Man, vol 14.
Jump to reference iii International Agency for Research on Cancer (1987), Asbestos. In Overall Evaluation of Carcinogenicity. IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Humans, suppl 7. Lyon, France: International Agency for Research on Cancer. pp 106-116.
Jump to reference iv Australian Institute of Health and Welfare Australian Cancer Incidence and Mortality: Mesothelioma for Australia (ICD10 C45). Retrieved from www.aihw.gov.au/acim-books/
Jump to reference v Australian Mesothelioma Registry. (2014). 3rd Annual Report – Mesothelioma in Australia 2013. Retrieved from http://www.mesothelioma-australia.com/publications-and-data/publications
Jump to reference vi Leigh, J, Davidson, P, Hendrie, L, Berry, D (2002), ‘Malignant mesothelioma in Australia, 1945-2000’. American Journal of Industrial Medicine Volume 41, Issue 3: pp. 188-201.
Jump to reference vii Peto, Julian. (2008). The Killer Within. The University of Melbourne Voice, vol. 3, no. 2.
Jump to reference viii Olsen, Nola J Franklin, P, Reid, A, de Klerk, N, Threlfal, T, Shilkin, K, Musk, B (2012), ‘Increasing incidence of malignant mesothelioma after exposure to asbestos during home maintenance and renovation’, The Medical Journal of Australia, vol. 195, no. 5.
