Authors: Phillips JI, Norman G and Renton K

Source: Occupational Health Southern Africa. March/April 2009, 15 (2); 24-27

The presence of asbestos in the roofs of the original houses of Soweto has been confirmed. An earlier study monitored the air in and around Soweto houses and concluded that the number of asbestos fibres present was low and below the limit of detection for the methods used.
This study shows that asbestos fibres may be leached from roofs onto the soil below. All of the 61 soil samples taken from directly below asbestos cement roofs contained asbestos. In some cases over 2,000,000 asbestos fibres per gram of soil were identified. The extent of the contamination beyond the water run off line is unknown.
Wetting the soil to suppress asbestos fibres liberation is recommended when excavation work is in progress.