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Asbestos

Asbestos is a term used for the fibrous forms of several naturally-occurring minerals. All asbestos deposits originate from crystallisation of molten rock which, on cooling, produces the various types of fibrous forms. It is usually found as thin veins, up to a few inches thick, between layers of the parent rock, which may be in non-fibrous or crystalline form. Asbestos is a known carcinogenic i.e. a cancer causing agent.

Asbestos was  widely used in the building and construction industry up until 1999. The majority of buildings built between 1940 and 1985, during which time asbestos production peaked, contain asbestos in some form. Asbestos has been widely used in construction materials and for a number of purposes including:

  • fireproofing
  • thermal insulation
  • electrical insulation
  • sound insulation
  • decorative plasters
  • roofing products
  • flooring products
  • heat resistant materials
  • gaskets
  • chemical resistance

 

There are 3 types of asbestos:

  1. White Asbestos (Chrysotile)
  2. Blue Asbestos (Crocidolite)
  3. Brown Asbestos (Amosite)

 

Amosite – Brown Asbestos

This mineral has a fibrous form (fibre like texture) and is also known as Brown Asbestos. Due to the natural coloration of the fibres. Asbestos, being the name given to the collection of minerals grown in a fibrous manner.

The reason Amosite had such a wide range of applications is due to the properties the mineral offers:

  • High tensile strength
  • Very flexible
  • Heat durability
  • Thermal, electrical, and sound adsorption
  • Chemical, biological, and thermal degradation resistency

Amosite is the most commonly found Amphibole type of asbestos. More course and stronger than Chrysotile fibres – Amosite was widely used in rigid boards such as asbestos insulation boards (AIB). But is often used as part of mixture with Chrysotile. Brown Asbestos is also found in cement sheets, pipe insulation, break pads, and other roofing materials.

Like all types of asbestos. Any level of exposure to this substance can cause serious health conditions. Such as Asbestosis, Pleural disease, mesothelioma, and lung cancer.

Particularly Asbestos in the amphibole mineral family. Typically known to be the most dangerous, with very sharp barbed fibres. If inhaled the fibres are resistant to the bodies chemical dissolving mechanisms. Once embedded in the lungs the fibres removal is not an option.

 

Chrysotile – White Asbestos

This mineral has a fibrous form (fibre like texture) and is also known as White Asbestos. Due to the natural coloration of the fibres. Asbestos, being the name given to the collection of minerals grown in a fibrous manner.

Chrysotile white asbestos is the most common type used throughout the world. Having a hardness similar to a human fingernail. However, it is known to crumble very easily into fibrous strands composed of smaller bundles of fibrils.

Other properties of Chrysotile include:

  • High tensile strength
  • Very flexible
  • Heat durability
  • Thermal, electrical, and sound adsorption
  • Resistant to Chemical, biological, and thermal degradation

Being very durable it was spun into thread and woven into cloth. As well as, roofing products, insulation materials, cement, and break pads.

Likewise with other types of asbestos, any level of exposure to this substance can cause serious health conditions. Such as Asbestosis, Pleural disease, mesothelioma, and lung cancer. Although, compared to amphiboles (amosite and crocidolite) a lot less cases have been reported linking Mesothelioma to white asbestos.

 

Crocidolite – Blue Asbestos

This mineral has a fibrous form (fibre like texture) and is also known as Blue Asbestos. Due to the natural coloration of the fibres.  Asbestos, being the name given to the collection of minerals grown in a fibrous manner.

Crocidolite has many useful properties. Which is why it had such a wide range of industrial applications. These include:

  • High tensile strength
  • Very flexible
  • Heat durability
  • Thermal, electrical, and sound adsorption
  • Chemical, biological, and thermal degradation resistency

Because of these properties blue asbestos was commonly used as an insulator. Such as pipe insulation, spray-on coatings, plastics, as well as cement products. Also found in insulating boards, ceilings, tiles, and was even used to insulate steam engines.

Like all types of asbestos. Any level of exposure to this substance can cause serious health conditions. Such as Asbestosis, Pleural disease, mesothelioma, and lung cancer.

Particularly Asbestos in the amphibole mineral family. Known to be the most dangerous as the fibres are very sharp and also barbed. If inhaled they are resistant to the bodies chemical dissolving mechanisms. Once embedded in the lungs the fibres removal is not an option.

 

Asbestos Related Illnesses

Asbestosis: fibres penetrating deep into the lung can cause scarring of the tissue, which restricts breathing, leading to decreased lung volume and increased resistance in the airways.
Asbestos-related lung cancer (bronchial carcinoma): a malignant tumour of the lungs’ air passages. The tumour grows through surrounding tissue, invading and often obstructing air passages. Smoking greatly increases the risk of developing asbestos-related lung cancer.
Mesothelioma: a cancer of the cells that make up the lining around the outside of the lungs and inside of the ribs (pleura) or around the abdominal organs (peritoneum). By the time it is diagnosed it is almost always fatal.
The diseases can take many years (15–60) to develop. There are no immediate changes in someone’s health after breathing in asbestos. Other asbestos-related, non-fatal conditions exist, such as pleural plaques and pleural thickening, asbestos warts and corns. There is now adequate evidence that asbestos causes ovarian and laryngeal cancer. However, the asbestos-related risk is much higher for lung cancer and mesothelioma than for other cancers.
The likelihood of developing an asbestos-related disease depends on:
  • Asbestos type (blue, brown or white),
  • Age at first exposure (likelihood increases if exposures start young),
  • Dose or number of fibres inhaled,
  • Number of exposures and duration of each exposure, and
  • Smoking – a smoker who inhales asbestos is fifty times more likely to develop lung cancer than a non-smoker who has not been exposed to asbestos.
A one-off short-term exposure is unlikely to be of concern, but each time a person is exposed, the risk of developing an asbestos-related disease slightly increases.

Risk Assessment

  • Employers must do risk assessment.
  • Ask “Has an asbestos survey been carried out?” Plan work to avoid disturbing asbestos.
  • Should only be worked on if absolutely necessary.