[Effect of air pollutant burden on healthy children and children with lung diseases in southern Ticino].

To investigate the effects of air pollution on the respiratory health of children, a study was undertaken in the southern part of Switzerland covering 312 school children who lived in two zones with significantly different concentrations of NO2. In the more urban area the mean NO2 measured over a period of 10 months was 36.2 +/- 9.5 micrograms/m3 (25 14-day values greater than 40) compared to the mean of the second, rural area of 26.2 +/- 10.4 micrograms/m3 (6 14-day values greater than 40). Respiratory health was evaluated by determination of bronchial reactivity to Carbachol in 5 diagnostic groups (healthy: 109; healthy with positive family history of atopy: 60; allergic but not asthma: 59; asthma: 55; and "unclear cough": 29) by the technique of group specific sampling. The study shows differences in the incidence of bronchial hyperreactivity in children (PD65 less than 900 micrograms Carbachol). Within the 5 diagnostic groups, however, this distinction was significant only in the group of healthy subjects (p less than 0.005). In the other diagnostic groups the influence of the various trigger factors such as respiratory tract infections, allergen exposure, parental smoking and (last but not least) drug treatment seems to be as important as that of air pollution.