Summary and conclusions

Asbestfibre i jordmiljøet

Background and purpose

Asbestos has been used in a wide range of materials and products, and is found widespread in buildings and construction parts in Denmark. As a consequence activities like demolition, decommissioning and decontamination, or accidents like fires, might result in the spreading of asbestos or asbestos-containing material on the surface or in the soil.

The aim of this project is to describe the fate of asbestos fibres in the soil environment, and to quantify the risk of exposure to humans from asbestos fibres and asbestos-containing material in soil.

Investigations

This report is based on a survey of literature regarding human exposure to asbestos fibres located in the soil environment, including information with respect to factors and levels of concentration, which are expected to have a strong influence on the release or the binding of asbestos fibres in the soil.

Main conclusions

Based on the information found in the literature, it is concluded that the fate of asbestos fibres in the soil environment is closely related to their mineral origin and character. The fibres might be bound to water and particles of clay, probably due to the chemical composition of the surface of the asbestos fibre. The fibres are not degradable, but in the long term, just as all other soil minerals. the asbestos fibres will disintegrate due to chemical processes in the soil.

The effects on human health from asbestos fibres are well known and related to the respiratory system, and the exposures of humans are closely related to the inhalation of asbestos fibres which are deposited in the lung tissue. The main route of exposure from asbestos fibres and asbestos-containing material in the soil is re-suspension of fibres from the soil due to wind erosion or activity.

Project results

It is found that asbestos fibres and asbestos-containing material located in the soil environment make up a potential for re-suspension of fibres to the air, with a resulting risk of human exposure. Studies of the re-suspension of asbestos fibres from soil made in laboratories and under field conditions show that the concentration of asbestos fibres in air will be at the required safety level or lower, when the soil concentration level of asbestos fibres is 10 mg/kg DM or less.