Carbon monoxide pollution is associated with decreased lung function in asthmatic adults

Abstract

The aim of the present study was to test the effects of exposure to air pollutants on lung function. A panel of 19 adult asthmatics living in Padua (Italy) was followed for five 30-day periods during 2 yrs consecutively (1,492 morning and 1,434 evening measures analysed). Peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV1) were measured using a pocket electronic meter. Daily levels of air pollutants and meteorological variables were collected at outdoor city monitoring sites. Significant inverse associations were observed between morning and evening PEF and carbon monoxide level (p50.01-0.03), without clear differences between lags (0-3 days). An increment of 1 mg·m-3 CO was associated with a PEF variation ranging -2.6- -2.8%. All effect estimates on PEF for CO remained significant and even increased after controlling for particles with a 50% cut-off aerodynamic diameter of 10 μm (PM10), nitrogen dioxide and sulphur dioxide in single and multipollutant models. A similar trend was observed for FEV1, but the associations were nonsignificant. A nonsignificant inverse relationship between evening PEF and SO2 was also detected. PEF and FEV1 were not related to PM10 and NO2 concentrations. The present results indicate that, in this panel of adult asthmatics, the worsening of lung function is associated with exposure to gaseous pollutants and occurs at levels of CO and SO 2 lower than current European standards. Copyright©ERS Journals Ltd 2010.