On decreasing carcinogenic activity of calcified chrysotile fibers
When chrysotile fibers treated with Portland cement, Mg was partially substituted by Ca, therefore monolayer of Ca(OH)<sub>2</sub> was formed as a cover, and that changed acidity force, number of active centers and biological activity (absent mutageneity, generation of active oxygen forms by macrophages was characterized by lower maximum and longer time to background level vs. native chrysotile).