A longitudinal study of ambient air pollutants and the lung peak expiratory flow rates among asthmatic children in Hungary.

BACKGROUND We conducted this study in Budapest, Hungary, to better characterize the effects of exposure to ambient air pollutants on the lung function of asthmatic children. METHODS The 60 study participants were 9-14 years old, had physician-diagnosed asthma, and were symptomatic during the previous year. Their ambient air pollutant exposures to total suspended particulates (TSP) and sulphur dioxide (SO2) were estimated from measurements made at the air monitor nearest their residence. We used analysis of variance and a fixed-effects model to assess the impact of the pollutants upon their morning and evening peak expiratory flow rates (PEFR) from 13 September to 5 December 1993. RESULTS Total suspended particulates and SO2 concentrations exceeded World Health Organization guideline limits on several days. Pollutant concentrations and PEFR increased during the study period. After adjusting for temperature, humidity, weekend/weekday, and the time trend, we found no consistent association between air pollutant concentrations and PEFR. CONCLUSIONS Fall to winter seasonal changes had a large influence on PEFR and may have overshadowed the effects of the air pollutants during the study period. Seasonal influences should be carefully considered when planning future studies.