In the study of work related diseases, John Corbett McDonald was a pioneering investigator, whose research and techniques in many ways defined occupational epidemiology. His best known role from the mid-1960s onwards—analysing the effects on health of different forms of asbestos—yielded controversy in a highly contentious field. An inspiration to epidemiologists worldwide, McDonald produced res...

In modern conditions, the number of various employees in field education is increasing, whose work connected with overstrain voice apparatus, psycho-emotional load, unfavorable mode, which made it necessary to study functional state peculiarities process and risks harmful effects on health. Among occupational diseases, there are diseases vocal apparatus an nature, such as pharyngitis, laryngiti...