THE STUDY OF THE BIOLOGICAL AGGRESSIVENESS OF DUST OF ASBESTOSFORMED AND ASBESTOS-FREE COMPOSITIONS, BOTH IN THEIR PRODUCTION AND OPERATION

Abstract

This manuscript provides basic information on the use of asbestos. Some physicochemical properties of the main component of serpentine asbestos (SA, 95% of all used asbestos) and the biological aggressiveness of the following are considered: dust types in the technology of creating asbestos-containing products and during their operation. Attention is also paid to the use of existing asbestos substitutes in similar products. The authors present data verifying that the incidence of asbestos-related diseases, including asbestosis of a professional and unprofessional nature, is increased, especially in the elderly, in the places of production of an SA variety – chrysotile asbestos {CA, aqueous magnesium silicate - Mg6[Si4O10](OH)8}. The authors pay particular attention to the use of CA in the production of asbestos-formed parts/products (AFP), for example, brake linings containing CA and its substitutes. It is known that such products undergo significant zonal stresses during operation. CA fibers lose hygroscopic and constitutional water (H2O = 13.04 – 14.80%) in the process of car braking due to high pressure and increased local temperature. As a result, they almost entirely turn into a non-aggressive (in the biological sense) material called forsterite. Studies of brake dust emitted during the braking of lightweight VAZ vehicles did not reveal similar transformations of СA degradation. They may occur when braking heavy vehicles with a mass of more than 2.5 tons and when braking high-speed trains with a mass of more than 60 tons.