Traffic-related air pollution exposure over a 5-year period is associated with increased risk of asthma and poor lung function in middle age

Abstract

Current evidence concerning the impact of exposure to traffic-related air pollution (TRAP) on adult respiratory morbidity mainly comes from cross-sectional studies. We sought to establish more robust measures of this association and potential gene–environment interactions using longitudinal data from an established cohort study.Associations between measures of TRAP (nitrogen dioxide (NO2) and distance to major roads) and wheeze, asthma prevalence and lung function were investigated in participants of the Tasmanian Longitudinal Health Study at 45- and 50-year follow-ups. Generalised estimating equations were used to quantify associations and the potential modifying effect of glutathioneS-transferase gene variants.Living <200 m from a major road was associated with increased prevalence of current asthma and wheeze, and lower lung function. The association between living <200 m from a major road and current asthma and wheeze was more marked for carriers of theGSTT1null andGSTP1 val/valorile/valgenotypes. Over the 5-year period, higher NO2exposures were associated with increased current asthma prevalence. Higher NO2exposure was associated with lower forced vital capacity for carriers of theGSTT1null genotype.TRAP exposures were associated with increased risk of asthma, wheeze and lower lung function in middle-aged adults. The interaction with theGSTT1genotype suggests that deficient antioxidant mechanisms may play a role in these adverse health effects.