[Oxidative stress as a basic mechanism of the carcinogenic effect of man made mineral fibers on the human body].

Man made mineral fibres have been recently introduced into industry as asbestos exchangers due to their much less harmful effect on workers' health. However, in 1988 IARC classified such mineral fibres as glass wool, rock wool and slag wool as probably carcinogenic for a man. The mechanism how MMMF may induce the carcinogenic process remains still unclear. It is assumed that the involvement of these fibres in the production of free oxygenic radicals is one of the most important factors contributing to the initiation of this process by MMMF. In the condition where free oxygenic radicals are produced very fast, the cell is exposed to an oxidative stress. The DNA damage is an important consequence of the oxidative stress. New oxygenic radicals may modify DNA and lead to mutation and finally they may contribute to the occurrence of neoplastic cells. OH is an oxygenic radical which most often damages DNA. It was also indicated that MMMF contributes to the increase of the number and activity of neutrophilic granulocytes and macrophages. The appearance of MMMF fraction in granulocyte results in an increased production of free oxygenic radicals which may damage DNA of epithelial cells. Experimental studies indicate that the production of free oxygenic radicals by neutrophilic granulocytes and macrophages activated by MMMF increases under the influence of chemicals embodied in tobacco smoke. The fibres when combined with tobacco smoke enlarge the number of DNA damages. Notwithstanding the information on a possible induction of a carcinogenic process by MMMF, epidemiological studies indicate that MMMF shows much less carcinogenic hazard than asbestos fibres.