Symptoms of bronchial hyperreactivity and asthma in relation to environmental factors

Abstract

A questionnaire study regarding airway morbidity in children and environmental factors was performed in April 1985. The parents of 5301 children, aged 6 months to 16 years, from different rural areas in mid Sweden were sent a validated questionnaire and 4990 (94%) responded. The cumulative prevalence of bronchial hyperreactivity was 9·7% and of allergic asthma 5·2%. Children living near a paper pulp plant more often had symptoms suggesting bronchial hyperreactivity (124 (13·0%), relative risk 1·3) and allergic asthma (68 (7·1%), relative risk 1·3). In children living in a damp house problem bronchial hyperreactivity was found in 76 (19·0%) (relative risk 1·9) and allergic asthma in 35 (8·7%) of the children (relative risk 1·9). Children living in a damp house with parents who smoked had the highest figures: bronchial hyperreactivity was found in 44 (23·5%) (relative risk 2·8) and allergic asthma in 22 (11·6%) (relative risk 2·5). The results indicate that various moderate environmental pollutants may act synergistically to increase bronchial hyperreactivity and allergy especially in children with a family history of allergy.