Continuing dangers of asbestos

Teaching unions have recently called for a full audit of the dangers of asbestos in schools, following a survey in which none of the schools involved fully met its health and safety requirements in relation to asbestos management.

Asbestos occurs naturally in two forms: serpentine and amphibole. The serpentine structure is that of a continuous sheet, bending to form tubes, giving a fibrous structure. The amphiboles are double chain silicates containing side groups, the positioning and orientation of which determine the overall structure and properties of the asbestos.

The mineral’s ability to withstand fierce heat and chemical attack, while being flexible enough to be spun and woven, has led to its widespread use in the construction and components industry.

Asbestos is found in two-thirds of the rocks in the earth’s crust, in both metamorphic and igneous formations, and is created under conditions of intense heat and pressure. Fibres are released naturally by erosion and carried by winds, forming part of the natural environment. This low-level of exposure appears to pose no threat to health.

Current thinking involves managing rather than removing asbestos. It is harmless until disturbed or damaged, when fibres are released into the air. It affects people who come into contact at every level of exposure, from miners who extract the raw mineral, throughout the transport chain, and not only workers involved in the manufacture and application of asbestos, but also their families, as the fibres are carried into the home on workers’ clothing.

Exposure to asbestos has been linked with several fatal diseases. Asbestosis is a progressive condition in which the lung tissue is scarred as a result of the abrasive action of asbestos fibres in the alveoli.

Lung cancer associated with asbestos exposure is virtually untreatable, due to the damage already caused to the lungs. Mesothelioma is a type of cancer affecting the lung or abdominal cavity. It can be contracted from relatively low exposure to asbestos.

All these conditions have a long latency period, taking up to 50 years from initial exposure to death. This means there are still about 2,000 deaths annually in the UK attributable to asbestos exposure, a figure that is not expected to peak until around 2015.