There are three more common types of asbestos in the UK :
White asbestos (technically Known as chrysotile)
Brown asbestos (amosite / gunerite)
Blue asbestos (crocidolite / riebeckite)
~ and three more unusual types in the UK :
All of them are recognised as carcinogens by the World Health Organisation.
When made into building materials, most are mixed in a cement based slurry ~ and this cement coats every fibre, so that when it dries / sets, it all looks grey. Because it just looks grey (dirty white ?), many people just assume that it will all be white asbestos, but this isn’t true.
The only way to know what asbestos is present, is to have it properly surveyed, sampled and analysed in a UKAS accredited laboratory.
Despite asbestos often being referred to as white, brown or blue, this is misleading, as other trace elements sometimes present, can colour them differently.
There’s also a compressed form of blue asbestos, known as Tigerite, that’s brown ~ and is often sold in gift shops (in the UK), as a pretty stone.
White asbestos is also known as ‘serpentine’, as its’ fibres are bendy. All the rest are called ‘amphibole’, as their crystals are constructed in columns (and so more rigid and liable to snap into tiny fragments).
The relative exposures (needed to cause illness), between white, brown and blue asbestos, are virtually impossible to calculate or to measure, because of different individual circumstances :
How old were you when you were with the asbestos ?
Do you smoke ? How severe was the asbestos ?
Individual susceptibility differences.
The long times (up to 40 years), between contamination and the onset of illness. etc.
At an asbestos seminar at University College London in 2004, it was estimated (by statistical analysis), that in comparison to the ‘toxicity’ of white asbestos, that brown was about 2½ times worse and that blue was about 2½ times that of the brown.
~ but if it was one of your family that fell ill from asbestos, then all these statistics would become irrelevant !
As per current Regulations, the Control Limit for airborne asbestos fibres is 0.1 fibres per ml of air. This tends to sound not very much, but there are one million millilitres in a cubic metre ~ and so the Control Limit is effectively 100,000 fibres per cubic metre.
After asbestos has been removed, and an air test done, this should show less than 0.01 fibres per ml ~ the equivalent of 10,000 fibres per cubic metre.
There are two principal recognised asbestos illnesses :
Asbestosis results from lung tissue becoming scarred as a result of inhaling asbestos fibres. The lungs’ own immune system tries to remove them, though the process reacts with the fibres and tissue damage and scarring occur.
Mesothelioma is (generally), a form cancer that develops from cells of the mesothelium (an area in the outer lining of the lung). The cancer progressively constricts the available lung space.