Asbestos has been used for centuries and is not, as some think, a recent product. At one time items made from asbestos were regarded as having an equal value to gold. In fact, it is reputed that Charles the Great, (King of the Franks in the year 768) had a tablecloth made from asbestos. It does have a resistance to fire and heat and has been used over centuries for this practical purpose - from historical uses such as lamp wicks and Egyptian burial shrouds through to modern brake pad linings. It has been used for high temperature wiring insulation as well as in the construction of buildings to insulate and protect against fire.

There are many forms of asbestos but there are three main types, white, brown and blue.

White asbestos: otherwise known as chrysotile is the type preferred in industry. It has a flexible property and has been used in many theatres for fire safety curtains, as well as for firefighter's protective clothing. Some evidence exists that it is harmful but not as harmful as some other types.

Brown asbestos: also known as amosite, this type usually originates from Africa and is highly bio-hazardous.

Blue asbestos: also known as crocidolite comes from Australia and Africa. This type is believed to be the most dangerous type of asbestos, therefore it is extremely bio-hazardous.

There are other types that someone may come across, some of which include actinolite asbestos, anthophyllite asbestos and tremolite asbestos. These are not as commonly used industrially, but may still be found in some products.

The main danger to health from asbestos is from the fibres, which can be inhaled. The four main diseases associated with asbestos fibre inhalation are asbestosis, mesothelioma, asbestos-related lung cancer and diffuse pleural thickening.

Asbestosis: Caused by inhaling asbestos fibres, generally from heavy exposure. It is defined as lung fibrosis.

Mesothelioma: This is a form of cancer where cancerous or malignant cells are found in the mesothelium. This is the protective sac that most of the body's organs are covered with. It mainly affects the lining of the lungs, which is known as the pleura and the peritoneum, which surrounds the lower digestive tract. Around 80 percent of cases of mesothelioma show the patient to have had a history of exposure to asbestos.

Asbestos-related lung cancer: For many years now asbestos exposure has been recognised as a high risk factor for the development of lung cancer. It is not possible, however, to put a direct number to the amount of cases of lung cancer, which have been caused by asbestos. This is because there are other risk agents that cause the disease, tobacco smoke for instance. Unfortunately it is not possible to distinguish which risk agent was the cause of a case of lung cancer.

Diffuse pleural thickening: As mentioned previously the pleura is a membrane covering which lines the inside of the rib cage and also surrounds the lungs. If asbestos fibres are inhaled, some may work their way into the pleura and this can lead to scarring and or fibrosis. This may cause the pleura to thicken. The condition will show up on an x-Ray. If this thickening spreads over a large area it may cause a restriction of expansion of the lungs.

It has now become clear that exposure to asbestos can be harmful. Because of this, the use of it has virtually disappeared. If there are products in the home that may contain asbestos, it is advisable to have a professional contractor inspect them. It is a complex process to remove asbestos and should always be done by a qualified person. It can be a highly dangerous and even lethal substance. If in doubt then call someone out.