Air pollution exposure impairs lung function in infants

Aim: To assess associations between air pollution exposure and infant lung function. Methods: Healthy infants from Stockholm were recruited to two cohorts (n = 99 and n = 78). Infant spirometry included plethysmography and raised volume forced expiratory flows. In pooled analyses, lung function at similar to 6 months of age was related to time-weighted average air pollution levels at residential addresses from birth until the lung function test. The pollutants included particulate matter with an aerodynamic diameter < 10 mu m (PM10) or <2.5 mu m and nitrogen dioxide. Results: There were significant inverse relations between air pollution exposure during infancy and forced expiratory volume at 0.5 s (FEV0.5) as well as forced vital capacity (FVC) for all pollutants. For example, the decline was 10.1 ml (95% confidence interval 1.3-18.8) and 10.3 ml (0.5-20.1) in FEV0.5 and FVC, respectively, for an interquartile increment of 5.3 mu g/m(3) in PM10. Corresponding associations for minute ventilation and functional residual capacity were 43.3 ml/min (-9.75-96.3) and 0.84 ml (-4.14-5.82). Conclusions: Air pollution exposure was associated with impaired infant lung function measures related to airway calibre and lung volume, suggesting that comparatively low levels of air pollution negatively affect lung function in early life.