Adult lung function and long-term air pollution exposure. ESCAPE: a multicentre cohort study and meta-analysis

Objectives To investigate the association of long-term exposure to ambient air pollution with lung function level and change in adult participants from five cohorts in the European Study of Cohorts for Air Pollution Effects (ESCAPE). Design Multicentre cohort study and meta-analysis of the results. Setting Centres from five cohorts in Belgium, France, Germany, Italy, Spain, Sweden, Switzerland and the United Kingdom Participants 7613 participants undergoing spirometry twice within a decade were enrolled. Main outcome measures Residential exposure to nitrogen oxides (NO2, NOx) and particulate matter (PM) was modeled and traffic indicators were assessed in a standardized manner. The spirometric parameters FEV1 and FVC were considered as outcomes. Cohort-specific analyses were performed by mixed linear regression adjusting for sex, age, height, BMI, education and smoking status. Cohort-specific results were combined using meta-analysis. Results We did not observe an association of air pollution with the longitudinal change in lung function, but we observed that a 10 µg/m3 increase in NO2 exposure was associated with lower levels of FEV1 (-14.0 mL (95%CI:-25.8,-2.1)) and FVC (-14.9 mL (-28.7,-1.1)). An increase of 10 µg/m3 in PM10, but not other PM metrics (PM2.5, PM coarse, PM absorbance), was associated with a lower level of FEV1 (-44.6mL (-85.4,-3.8)) and FVC (-59.0mL (-112.3,-5.6). Higher traffic load at home address was also significantly associated with lower levels of FEV1. The associations were particularly strong in obese persons. Conclusions This study adds to the evidence for an adverse association of ambient air pollution with lung function in adults at very low levels in Europe.