Processes affecting surface and chemical properties of chrysotile: Implications for reclamation of asbestos in the natural environment

Abstract

Holmes, E. P., Wilson, J., Schreier, H. and Lavkulich, L. M. 2012. Processes affecting surface and chemical properties of chrysotile: Implications for reclamation of asbestos in the natural environment. Can. J. Soil Sci. 92: 229–242. A landslide at the headwaters of the Sumas River in southwestern British Columbia, is a seasonal and episodic source of chrysotile asbestos to the floodplain soil. Fresh alluvial deposits of fibres have potential for aeolian movement, posing a health risk to the Sumas watershed population. To understand the effects aquatic and pedogenic processes have on the fibres, asbestos materials from the river and floodplain were subjected to organic acid treatments in the laboratory. Changes were monitored by X-ray diffraction, scanning electron microscopy and elemental analysis. Fibre surfaces modified by organic acid treatments were similar to those affected by natural processes in that they showed a high loss of elements from the brucite layer compared with the silica tetrahedral layer, and the surfaces became smoother due to the loss of a rough amorphous coating. To initiate sustainable reclamation practices, changes in fibre surfaces by natural processes need to be considered and enhanced by incorporation of organic amendments that produce complexing soil acids. Reclamation activities should focus on recently deposited sediment along the floodplain. Non-polluting organic material, such as peat, compost and sawdust could be applied to increase reaction potential and kinetics of the reaction of chrysotile with naturally occurring acids.