[Epidemiologic methods and their application].

The first part of the paper pertains to the concept of the approach to investigations of health in relation to the living environment. It is based on the fact that man is exposed to the action of basic groups of factors: physical, chemical, biological and psychosocial. Attention is devoted not only to the specific action of individual factors or their groups to the health of man but also to certain general trends, i.e. the influence on the immunobiological status of the organism, the influence on the cardiovascular system and the influence on the genetic apparatus with all sequelae, in particular in the sphere of diseases of civilization. As these factors only rarely act isolated, a comprehensive approach to the problem is essential. In the main part of the paper the principles of the application of epidemiological methods in the sphere of investigations of the health status and living environment are analyzed. The following pattern is used: 1. Descriptive epidemiology (using mortality and morbidity statistics); 2. Analytical epidemiology (prospective and retrospective approach); 3. Experimental epidemiology. The key problem remains assessment of exposure and subsequent effect on health. In conjunction with it certain principles of assessment and monitoring are mentioned as well as advantages and limitation of the basic methods of approach.