The article deals with peculiarities in diagnosis of diseases caused by environmental hazards. The diagnosis covers population level and includes evaluation of environmental quality. Analysis of health for whole population and for risk groups enables to reveal "indicator" diseases. Social and hygienic monitoring, complex sanitary and ecologic examination recommend disclosure of facts and causes for any "nonspecific" diseases, definition of disorders caused by specific environmental hazards. The authors consider unity of hygienic and epidemiologic analysis for causative relationships in "human-environment" system in evaluation of noninfectious risk factors.