RESUMEN
Buccal epithelium cytograms were analyzed in workers of chrysotile-asbestos production "Kostanaiskiye mineraly" JSC. Findings are that 10-20 years of service are associated with increased number of 4th differentiation grade cells and correspondingly decreased number of 5th differentiation grade cells. Later, with 20 years of service, numbers of 4th and 5th grade epitheliocytes reach initial values. With 10-20 years of service, integral parameters of differentiation index, cornification index and intracellular relations decrease. Findings are that 10-20 years of service are connected with domination of proliferation over differentiation processes. Length of service over 20 years is with adaptive processess in the workers. These data are important in evaluation of mucosal system in variable length of occupational service.