Asbestos is a commercial term applied to a number of naturally occurring minerals. Like any other mineral, for example iron or copper, it is mined from the earth.
There are two classes of asbestos, Amphibole and Serpentine. These two groups contain six different types of asbestos, three of which have been used commercially.
The three commercially used asbestos types are commonly known by their colour, brown asbestos (amosite), blue asbestos (crocidolite) and white asbestos (chrysotile).
Brown and blue are Amphibole and needle shaped. White asbestos is of the Serpentine variety, and as the name suggests, has a curly shape.
Asbestos is popular in industry because it is made up of bundles of fibres which easily separate. It is flexible, light but very strong. It is resistant to heat, fire, chemicals and friction. Due to its flexibility, it can be woven to make fabrics for use in heat resistant and insulating materials.
It has been used in industry for almost 150 years but has been known about and used for much longer than that. The Egyptians used asbestos in the cloth wrapping of mummies. The Romans used it for napkins and it is said that they simply threw the napkins into a fire to cleanse and purify them.
Contrary to popular belief, asbestos has not been banned and is still being mined and made into products every year. Asbestos has mainly been mined in South Africa, Western Australia, Canada, Russia and the US. Russia is currently the main producer of white asbestos. As demand for asbestos is declining in the western world it is increasing in Africa, Asia and Latin America, where there is still a heavy demand for an inexpensive but durable construction material.
Asbestos Related Illnesses
Asbestos is the greatest single cause of work place deaths in the UK. There is usually a long delay between exposure to asbestos and the onset of disease. Symptoms can appear up to 40 years or more after exposure to asbestos.
It is estimated that there are up to 10000 deaths per year from asbestos related diseases. Despite this, asbestos is often called the silent killer because there is little recognition of those suffering from asbestos diseases.
Asbestos can cause several different conditions and these vary in severity.
- Pleural Plaques - A condition where areas of the pleura thicken as a result of scarring of the tissue. The lungs are wrapped in a thin membrane called the Pleura. Asbestos fibres embed themselves in the lungs and may lead to lung and pleural damage and disease. Often without symptoms pleural plaques can nevertheless cause impairment of the lung and affect breathing. Pleural plaques are visible on xray and do not necessarily lead to other asbestos related conditions.
- Pleural Effusion - A condition where fluid collects between the lung and the chest wall. This may cause breathlessness and may indicate the potential for pleural thickening to develop.
- Pleural Thickening - A thickening of the lung lining often causing breathlessness.
- Asbestosis – Lung fibrosis or scarring of the lungs caused by heavy asbestos exposure. This condition causes breathlessness and in severe cases can prove fatal.
- Lung Cancer - This condition may be preceded by asbestosis and is a malignant tumour on the lung. Asbestos workers who have smoked multiply their risk of contracting this form of cancer.
- Mesothelioma - A cancer caused only by asbestos that appears on the lining of the lung or abdomen.
Jobs and Industries that used Asbestos
Asbestos has been in use as an insulation material and fire retardant since the late 1800’s. Asbestos was widely used in many industries. The harmful effects of asbestos were recognised legally for the first time in 1931 but the use of asbestos was not restricted in the UK until the 1980s.
Many employers’ health and safety measures did not protect their workers sufficiently from the effects of exposure. As a result there are an increasing number of people suffering from diseases caused by asbestos and currently up to 3000 deaths a year from exposure to asbestos and related illnesses. This figure is forecast by the Health and Safety Executive (HSE) to increase until between 2015 & 2020.
According to the HSE, the ten occupations found to have the highest risk of Mesothelioma, the most serious asbestos related cancer, based on deaths between 1980 and 2000 were:
- Metal Plate Workers
- Vehicle Body Builders
- Plumbers and Gas Fitters
- Carpenters
- Electricians
- Sheet Metal Workers
- Electrical Plant Operators
- Production Fitters
- Construction Workers
- Electrical Engineers
Because asbestos was cheap, plentiful, flexible and proved resistant to heat, fire, chemicals and friction, it was widely used in the following industries:
- Railway engine and carriage building
- Construction
- Shipbuilding
- Oil refineries
- Textiles
- Car brake pad manufacture
- Power generation
