GENOTOXICITY OF DIMETHYLNITROSAMINE IN THE PRESENCE OF CHRYSOTILE ASBESTOS UICC-B AND XONOTLITE

Interactions of particulates with chemical genotoxic agents may play an important role in the induction of carcinogenesis. With respect to bronchogenic cancer, the synergism associated with combined exposure to asbestos and tobacco smoke is a well-documented phenomenon. The present work focused on chrysotile asbestos and xonotlite. The latter is a fibrous calcium silicate which is increasingly being used to replace asbestos in various industrial applications. The study was aimed at testing the possible interaction of these materials with dimethylnitrosamine (DMN), a genotoxic component of tobacco smoke. The capacity of fibers to interfere with the genotoxic response elicited by DMN in the UDS/hepatocytes assay sytem specifically designed for sensitive detection of short-patch DNA repair, was looked for. The properties of the selected fibers with respect to binding affinity towards DMN were also examined.