Asbestos is a naturally occurring mineral silicate that was quarried, processed and manufactured into various building materials used in the building industry. In Australia asbestos was used widely in the 1980s and its usage declined in the following years however asbestos-containing products were still imported in the 1990s. Australia banned manufacturing, usage or import of any form of asbestos in 2003.
Due to its excellent fire and water-resistant characteristics, asbestos was used widely in building products in various applications. Click here to know the various places where asbestos could be present in residential properties
Types of asbestos?
The types of asbestos broadly fall under two mineral families – Serpentine and Amphibole.
Chrysotile (White Asbestos):
Chrysotile asbestos commonly known as white asbestos is a form that was used widely in many manufactured building products. Due to the flexibility of the fibres in Chrysotile asbestos, it was used for a range of applications such as asbestos sheets, adhesives, insulation, brake pads, vinyl tiles, fireproofing, roof sheeting, drywall. Chrysotile asbestos is prevalent in 95% of asbestos products worldwide and Australia.
There are many types of amphibole asbestos. They are amosite, crocidolite, anthophyllite, tremolite and actinolite. The fibres of the amphibole family of asbestos are needle-shaped and exposure to this family of asbestos has a higher potential to cause cancer compared to serpentine asbestos. Amosite and crocidolite are the most commonly used commercial form of asbestos.
Amosite (brown asbestos):
Amosite asbestos (also called as brown asbestos) was referred in the past as magic mineral. Due to its highly resistant property to heat and acid and tensile strength, it was used as an effective insulator material in electricity boards and various other applications including brake pads, insulation for heating systems, wall sheets, roof sheets etc. Historically, amosite has been mixed with cement and other forms of asbestos (chrysotile and crocidolite) to make various building products.
Crocidolite (blue asbestos):
Crocidolite asbestos (commonly referred to as blue asbestos). The needle-shape and small diameter of the fibres may lead to deeper penetration of the fibres into the lungs and cause cancer. Crocidolite is observed to be mixed with Chrysotile and Amosite and used in various applications such as asbestos sheetings, brake pads, insulation etc.
Asbestos fibres when disturbed can become airborne and can be respirable. When inhaled the fibres settle in the lung tissues and causes scarring of the tissues. Over the years, the scarring can get worsen and lead to serious asbestos-related diseases. It may take years or decades to develop symptoms.
The four major asbestos-related diseases are summarised below.
- Pleural plaques – Areas of white, raised scar tissue on the outer lining of the lung which is an early sign of exposure to asbestos. This condition causes little impaired lung function.
- Asbestosis – A chronic condition caused by inflammation or scarring in the lung tissues. Usually caused by prolonged exposure to asbestos. This condition causes shortness of breath from permanent lung damage.
- Lung Cancer – Tumours along the lining of the lungs and the air passages that lead to the lungs and inside the lungs.
- Mesothelioma – Cancer of the tissues that line the cavities particularly in the chest and abdominal region. Australian mesothelioma cases have recorded previous exposure to asbestos.
Information adapted from The Australian Government Department of Health and Ageing – Asbestos – A guide for householders and the general public (February 2013)