RESUMEN
The authors assessed the prevalence of symptoms of bronchial asthma by means of a standardized questionnaire used in the international survey PEACE (Pollution Effect on Asthmatic Children in Europe). The questions about complaints were addressed to children aged 6-13 years (the questionnaires were completed with the parents assistance). In urban areas 5669 children participated from Prague 5, i.e. 35% of all elementary school children, in Teplice 2489 (21% children), in rural areas: in the Benesov district 5619, i.e. 61% children, in the Prachatice district 1983, i.e. 37% children. The response rate of questionnaires in the urban areas was 86-88%, in rural areas 93%. In urban areas the annual prevalence of wheezing in the chest or dyspnoea or possibly both symptoms was within the range of 3.8-13.8% and differed significantly from the prevalence in rural areas where it was 2.4-3.6%. The most frequent symptom was nocturnal dry cough without a cold (in urban areas 14.1-36.7%, in rural areas 6.0-10.6%). Rural areas differed from urban ones by a lower contamination of the atmosphere, a lower density of the population as well as some parameters caused by a different lifestyle.