Effects of Industrial Air Pollution on Pulmonary Response to Methacholine in Schoolchildren

Abstract

The present study was performed to compare bronchial reactivity, measured by methacholine inhalation test, in a group of school children living in an industrialized area (Priolo, Siracusa, Italy) with another group of children living in a nonpolluted, nonindustrialized area (Scicli, Ragusa, Italy). All the children came from the fifth primary class of their school and represented all the children of that age group in each school. Eighty-nine children in Priolo and 93 in Scicli were enrolled in the study. The information on asthma, bronchitis, and passive smoking exposure was collected by a standardized and validated questionnaire. No statistical differences were recorded between the study and the control group for age, gender, cigarette smoking by parents or the children themselves, and parents' educational level. A statistically different significance was recorded for paternal job, which were workers in Priolo industries and farmers in Scicli (p < 0.01). No differences between the two groups were reported for asthma diagnosis and atopic status, but in the study group there was a statistical significant increase of bronchitis (tracheobronchial inflammation with mucus hyperproduction), 13 at Priolo and 3 at Scicli (p < 0.01). The methacholine was administered with the nebulizer connected to a dosimeter using a compressed air source (Mefar dosimeter). Bronchial reactivity of children living in the Priolo area was statistically higher (p < 0.001) than that of the control group living in Scicli. In the study group, 23 children (26%) demonstrated a 20% fall in forced expiratory volume at the first second (FEV₁), while only 4 (4.3%) from the control group presented a similar reduction. The mean PD20 of the Priolo group was significantly lower (ie, 832 ± 591 mg), than the mean of the Scicli group (ie, 1215 ± 675 mg). The results of the present study suggest that industrial pollution can be responsible for an increase in bronchial reactivity, and could, therefore, potentially contribute to an increase in the incidence and severity of respiratory disease in children.