The relative importance of socio-economic status, parental smoking and airpollution (SO2) on asthma symptoms, spirometry and bronchodilator responsein 11-year-old children

The aim of this study was to evaluate the relative contribution of several risk factors to the prevalence of allergic respiratory symptoms, and the po sitivity of the bronchodilator test with fenoterol, and to establish the re lative importance of these factors on the variability of FVC, FEV1, PEF, ME F25, MEF50 and MEF75. A total of 340 11-year-old children attending school in polluted and non-polluted areas of the city of Cartagena, Spain, were st udied. The polluted area had had an annual mean of 75 mu g/m(3) of SO2 over the last 10 years and the non-polluted area had < 20 mu g/m(3) during this period. A questionnaire about allergic respiratory symptoms was completed by the parents. Specific questions about parental smoking habits and socio- economic level were included. Each child's performance in spirometry before and after administration of 0.2 mg of inhaled fenoterol was evaluated. The only significant predictive variables in the logistic regression (for suff ering any symptom or a positive bronchodilator response) were male sex for nasal symptoms (RR 1.37; p = 0.04) and housing near heavy traffic for eye s ymptoms (RR 1.45; p = 0.01). Living in the polluted area reduced the risk o f a positive bronchodilator response (RR 0.61; p = 0.004). Maternal smoking , even though not statistically significant, tended to increased the risk o f suffering any symptom (RR 1.26; p = 0.07) or of having a positive broncho dilator response (RR 1.23; p = 0.1). None of the risk factors studied was o f significant importance in explaining the variability of spirometry result s. Although none of the risk factors were specifically determinant to the s ymptom questions, bronchodilator test or spirometric measurements, having a mother who smokes seems more important than living in a polluted area if s tatistically non-significant trends are considered.