Air pollution, lung function and COPD: results from the population-based UK Biobank study.

Dany Doiron,Yutong Cai,Anna L Hansell,Nicole Probst-Hensch,Isabel Fortier,Kees De Hoogh,Sara De Matteis

doi:10.1183/13993003.02140-2018

Abstract

Ambient air pollution increases the risk of respiratory mortality, but evidence for impacts on lung function and chronic obstructive pulmonary disease (COPD) is less well established. The aim was to evaluate whether ambient air pollution is associated with lung function and COPD, and explore potential vulnerability factors.We used UK Biobank data on 303 887 individuals aged 40-69 years, with complete covariate data and valid lung function measures. Cross-sectional analyses examined associations of land use regression-based estimates of particulate matter (particles with a 50% cut-off aerodynamic diameter of 2.5 and 10 µm: PM2.5 and PM10, respectively; and coarse particles with diameter between 2.5 μm and 10 μm: PMcoarse) and nitrogen dioxide (NO2) concentrations with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), the FEV1/FVC ratio and COPD (FEV1/FVC <lower limit of normal). Effect modification was investigated for sex, age, obesity, smoking status, household income, asthma status and occupations previously linked to COPD.Higher exposures to each pollutant were significantly associated with lower lung function. A 5 µg·m-3 increase in PM2.5 concentration was associated with lower FEV1 (-83.13 mL, 95% CI -92.50--73.75 mL) and FVC (-62.62 mL, 95% CI -73.91--51.32 mL). COPD prevalence was associated with higher concentrations of PM2.5 (OR 1.52, 95% CI 1.42-1.62, per 5 µg·m-3), PM10 (OR 1.08, 95% CI 1.00-1.16, per 5 µg·m-3) and NO2 (OR 1.12, 95% CI 1.10-1.14, per 10 µg·m-3), but not with PMcoarse Stronger lung function associations were seen for males, individuals from lower income households, and "at-risk" occupations, and higher COPD associations were seen for obese, lower income, and non-asthmatic participants.Ambient air pollution was associated with lower lung function and increased COPD prevalence in this large study.

Highlights

Ambient air pollution increases the risk of respiratory mortality, but evidence for impacts on lung function and obstructive lung disease is less well established
Two blows were recorded for each participant and a third blow was administered if the differences between both forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) of the first two blows were >5%
Individuals from lower-income households had approximately twice as low FEV1 and FVC levels compared to higher-income participants and individuals with at-risk for chronic obstructive pulmonary disease (COPD) occupations showed three-fold lower FEV1 and FVC levels compared to individuals not in these occupations, per unit increase in PM2.5 or NO2

Summary

Introduction

Ambient air pollution increases the risk of respiratory mortality, but evidence for impacts on lung function and obstructive lung disease is less well established. Recent studies and reviews have reported suggestive evidence linking outdoor air pollution and lung function and chronic obstructive pulmonary disease (COPD) [1,2,3,4]. The European Study of Cohorts for Air Pollution Effects (ESCAPE) project showed that higher ambient nitrogen dioxide (NO2) and exposure to particulate matter with a 50% cut-off aerodynamic diameter of 10 μm (PM10), as well as higher traffic load on roads near residences were associated with impaired lung function in adults, using a meta-analysis across five European cohorts [5]. A separate meta-analysis of four of these same cohorts found positive but nonsignificant associations between chronic exposure to ambient air pollution and COPD [6]. Sample size limitations have curtailed exploration of associations among population subgroups

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