Medical ecology is a branch of human ecology and a direction in modern preventive medicine that analyzes the links and dependence of public health and its disorders on the factors of the natural, social and anthropogenic environment. It is a branch of science, which is at the junction of medicine and ecology, studying the general patterns of interaction between the environment and people in the sphere of their health. The object of medical ecology is the environment, spatial and territorial anthropo(mediko)-ecological systems. The subject of medical ecology is the properties of medico-ecological systems, manifested in the influence on health, environmental prerequisites of health and disease of people. The aim of medical ecology is the development of measures ensuring preservation (restoration) of optimal ecological balance for health of people on particular territories. Since mid-20th century in connection with sharp deterioration of environment as a result of anthropogenic activity the interest to ecology has sharpened and simultaneously its broader interpretation as a science of interaction of human society with natural environment and ecological consequences of this interaction has appeared. This rethinking of ecology was also fixed terminologically - the concept of "social ecology" emerged, emphasizing that it is not a biological phenomenon, but a social one, which also has biological consequences. The process of "socialization" of ecology has not ignored both medicine and an integrated approach to the study of man. A number of scientific directions emerged that used the ideas of ecology on the regularities of interaction between the objects of study (human communities, pathogens, keepers and carriers of zooanthroponoses, etc.) and the environment in which they live. Ecologization of public consciousness and modern science has led to the emergence of a number of "ecologized" scientific directions - geochemical ecology, radiation ecology (radioecology), ecology of health, ecology of diseases, ecological and hygienic research. They constitute medical ecology, although each of them goes beyond the scope of medical problems only. For example, geochemical ecology studies the impact of the geochemical situation on both humans and any other living organisms, and endemic diseases resulting from it are recorded not only in humans, but also in animals. This applies equally to radioecology, since ionizing radiation of the environment affects not only humans. Ecology of diseases (nosoecology) is a scientific discipline, which studies causes of appearance, existence and distribution of certain diseases in their natural foci (nosoecological loci) or among certain population groups in relations and relations with the totality of specific conditions, one way or another affecting these processes. Disease ecology does not replace or substitute for traditional epidemiology. The object of study of ecology of diseases may be the most diverse groups of diseases - zooanthroponoses, anthroponoses, endemic diseases, oncological and cardiovascular pathology, etc. Health ecology (sanoecology) studies the regularities of health formation in specific communities (groups) of population in connection with environmental factors that affect or may affect the level of health. There is also such a direction as ecological medicine. It is an integrated scientific discipline that considers all aspects of the impact of the environment on the health of the population with a focus on environmental diseases. If traditional prevention was focused on the disease, on finding and eliminating the influence of pathogenic factors on the body, modern prevention considers health, its quality, the amount of reserves in the body sufficient to maintain health, the ability to manage them, identifying the pre-disease period, the role of environmental factors in the preservation and promotion of health as its main subject.