Association of long-term air pollution with spirometry and lung diffusing capacity: Results from the KORA FF4 study

Abstract

Exposure to ambient air pollution (AAP) has been shown to be associated with impaired spirometry but data regarding pulmonary gas exchange are scarce. We examined associations between AAP exposure and spirometry as well as lung diffusing capacity in a population-based sample of adults. The transfer factor of the lung for CO (TLCO) and spirometric indices were determined in 964 adults aged 48-68y (Augsburg region, Germany). Long-term AAP exposures at their home addresses were estimated via land use regression models considering PM10, PM2.5, PM2.5-10, particle number concentration, NOx and NO2. Cross-sectional associations were assessed by linear regression models adjusting for individual and environmental covariates. The AAP burden was in the expected range for middle-sized European cities. All PM size fractions were negatively associated with TLCO with estimates ranging between -0.07 and -0.13 mmol/min/kPa per interquartile range (IQR) increase in pollutant. PM10, PM2.5-10 and NO2 had a negative effect of on alveolar volume ranging between -61 and -67 mL per IQR increase in pollutant. For spirometry, a positive association of PM2.5 with FEV1/FVC (+0.008) and a negative effect of PM10 on FVC (-52 mL) were observed. Effects on TLCO were more pronounced in smokers compared to ex- and never-smokers. Our findings reveal a negative impact of long-term AAP on lung diffusing capacity. The results indicate that exposure to ambient particulate matter of different size fractions exerts adverse effects in the periphery of the lung, particularly in subjects with concomitant risk factors such as smoking. Supported by Helmholtz Zentrum Munchen (Environmental nanoparticles and health).