AIRBORNE FIBRE MONITORING

What is Asbestos?

Asbestos is the fibrous form of mineral silicates belonging to the serpentine and amphibole groups of rock-forming minerals. There are many varieties of serpentine and amphibole minerals that are considered harmless, however a few exhibit specific properties that are collectively referred to as asbestos. The most common forms of asbestos used in Australia are crocidolite (blue amphibole asbestos), chrysotile (white serpentine asbestos) and amosite (brown amphibole asbestos).

The excellent fire resistance, insulating properties, durability, fibre strength and flexibility of asbestos minerals resulted in the manufacturing of over 3000 asbestos-containing products worldwide. These products ranged from household products including ovens and toasters to construction material and industrial products. In Australia, asbestos was extensively used in building and structures and other manufacturing between the 1950s to the 1970s. In Australia, the cement manufacturing industry was responsible for over 60% of all production and 90% of all consumption of asbestos fibre. Asbestos products were first phased out during the 1980s, with asbestos containing flat sheet first between 1981 and 1983, corrugated products such as fencing and roofing in 1985 and some friction and lining type products were in use until 2003. New materials containing asbestos are not to be manufactured, imported, or reused.

With the banning of asbestos in late 2003, the presence of asbestos containing products (ACM) is very common among various pre-1990 built forms including government buildings, residential properties, schools, hospitals, industrial and manufacturing products.

Despite this ban asbestos containing materials have been found to be incorrectly imported or reused and therefore, if any material is suspected of containing asbestos fibres, expert opinion should be sort and the material treated as asbestos until proven otherwise.

The vast majority of ACM products were used in construction. Generally, ACM will be found in two forms including friable and non-friable (bonded). Friable materials are more likely to release fibres which greatly increases the risk of exposure. Such products include textiles, papers, insulating products, spray on fire proofing, pipe lagging, ceiling tiles and woven gaskets. Non-friable (bonded) asbestos means the fibres are bonded within a matrix of other materials and due to this it has less chance of asbestos fibre release unless damaged or deteriorated. Such products include vinyl flooring products like tiles, sheets and adhesives, cement products like corrugated roof sheeting, fencing, flat wall cladding and bitumen products to name a few.

The Risk

The health risks associated with asbestos are now widely known. Asbestos leads to the most serious category of occupational diseases. These diseases are not obscure workplace hazards linked to a fading industrial past, but rather a current hazard which in some cases is getting worse, particularly due to complacency.

Inhaling or ingesting asbestos fibres through the nose and mouth can result in fibres embedding themselves in the lungs, resulting in various health risks including Pleural Plaques, Asbestosis, Lung Cancer and Mesothelioma. These symptoms may appear as late as 25-40 years after the exposure to asbestos fibres.

The exposure standard for all types of asbestos is 0.1 fibres per millimetre of air (fibres/ml).