[The effect of air pollution on the allergic reactivity of the population].

An epidemiological study was carried out in several regions in Bulgaria polluted by industry and motor vehicle transport. The investigation included monitoring of ambient air pollution, a questionnaire study of 13040 persons, and allergological/immunological testing of representative groups of population. The testing was performed on persons selected by the questionnaire study, who were not exposed professionally to toxicants. The ambient air was contaminated by particulates and gaseous contaminants in the majority of the studies areas. The questionnaire study revealed an increased incidence of complaints indicative of allergic reactions, such as recurring skin eruptions, allergic rhinitis, conjunctivitis, asthmatic bronchitis. The positive skin tests were twice as common among the residents of polluted areas as compared to control. A decreased activity of the complement and increased levels of immunoglobulins (IgG, IgA, IgM) were found in the exposed population. The changes found in the study suggest a health risk for the population created by air pollution.