The pervasive use of asbestos within the construction industry, historically, characterises previous ignorance in relation to the health hazards that are now synonymous with asbestos. It was not until the 1930's that production using asbestos involved any effort to bring harmful fibre levels down to an extent whereby contact with asbestos ceased to put individuals at risk of pulmonary fibrosis, bronchial carcinoma, and mesothelioma. Up until that point, people were regularly subjected to environments where levels of asbestos were as high as 100 parts per ml.    

This massive level of concentration is underpinned by the fact that now, asbestos can only be used in a capacity whereby no more than 1 part per ml (or less), is released into the atmosphere. Furthermore, where its use involves construction within the general environment, such as buildings, asbestos levels have to be below the 1 part per ml level. Ongoing tests by the Institute of Occupational Medicine, in Edinburgh, have discovered that it is not simply airborne particles that contribute to risk of illness, but also the length and durability of fibres that are released into the atmosphere. Tests on vermin reveal that long, thin fibres pose the most threat. The research also discovered that exposure duration also plays a part in defining the level of risk that an individual is placed under.