 asbestos is an important occupational and environmental toxicant that affects several cell types in the respiratory tract . in an effort to understand how asbestos causes cell injury and/or altered proliferation and differentiation of cells 
 , this laboratory has focused on reactive oxygen species as mediators of asbestos - induced biological effects . 
 a compendium of experimental results reported by this laboratory and others supports this hypothesis . 
 for example , scavengers of reactive oxygen metabolites and iron chelators ( i.e. , desferroxamine ) prevent cytotoxicity after addition of asbestos to a variety of cell lines and macrophages in vitro . 
 dna strand breakage associated with toxicity of crocidolite asbestos in c3h10 t 1/2 cells also is ameliorated with use of desferroxamine . 
 all types of asbestos cause lipid peroxidation in mammalian cells and artificial membranes , a phenomenon that can be prevented by removal of catalytic iron . 
 last , asbestos causes generation of active oxygen species after interaction with leukocytes or by reduction of oxygen on the surface of the fibers.imagesfigure 1 . 
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