Experimental carcinogenicity and mutagenicity of non-asbestos natural fibres--preliminary report.

The aim of this investigation was to quantify the carcinogenic and mutagenic activity of antigorite occurring in the form of admixtures in different mineral raw materials (serpentinite, magnesite, dolomite and nickel ore). The carcinogenicity of dusts was evaluated after intraperitoneal injections of 5 mg (mice) or 20 mg (rats) of dust suspended in saline. A pathomorphological examination was performed in all the dead animals. For two raw materials--serpentinite and nickel ore--their mutagenic potency was investigated (SCE test was used in this study). Results obtained in the experiments on animals (rats and mice) showed that the biological aggressiveness of the mineral raw materials tested was associated with the content of antigorite fibres. Particularly the frequency of mesothelioma (5-85%) was related to the number of antigorite fibres longer than 5 microns. Both of the investigated raw materials (serpentinite and nickel ore) were mutagenic in the SCE test.