Inhomogeneity in response to air pollution in European children (PEACE project)

Objectives-The PEACE study is a multicentre panel study of the acute effect s of particles with a 50% cut off aerodynamic diameter of 10 mu m (PM10), b lack smoke (BS), sulphur dioxide (SO2), and nitrogen dioxide (NO2) on respi ratory health of children with chronic respiratory symptoms. In the complet e panels no consistent association between air pollution and respiratory he alth was found. The study evaluated whether potentially more sensitive subg roups in the panels did show effects of air pollution. Methods-To evaluate heterogeneity in response to air pollution, effect esti mates of air pollution on peak expiratory flow (PEF) and respiratory sympto ms were calculated in subgroups based on presence of chronic respiratory sy mptoms, use of respiratory medication, atopy, sex, and baseline lung functi on. Results-The association between PEF and air pollution was positive in asthm atic children who used respiratory medication whereas the associations tend ed to be negative in children who did not use respiratory medication select ed only on cough. No consistent association was found among asthmatic child ren who did not use medication. The association between daily prevalence of symptoms and concentrations of air pollution was not different between the se subgroups. Conclusion-None of the predefined potentially more sensitive subgroups show ed a consistent association between air pollution, PEF, and respiratory sym ptoms.