We studied increase in cancer incidence in the population and the dynamics of the carcinogenic benzo(a)pyrene content in the atmospheric air of cities in the Irkutsk Region. Sources of air pollution boilers and household furnaces, aluminum production, motor vehicles, forest fires were considered. Individual and population carcinogenic risks of benzo(a)pyrene for the health of the population in industrial, agricultural and South Baikal cities were assessed. We also could establish the tendency of increasing risks and the dependence of the incidence of malignant neoplasms in the population on the content of benzo(a)pyrene in the atmosphere. The conclusion was made about the need to assess pollution sources, about the development of a monitoring system for benzo(a)pyrene and its analogs - polycyclic aromatic hydrocarbons - in the environment.