Occupations associated with COPD risk in the large population-based UK Biobank cohort study

Objectives Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Exposure to occupational hazards is an important preventable risk factor but the contribution of specific occupations to COPD risk in a general population is uncertain. Our aim was to investigate the association of COPD with occupation in the UK population. Methods In 2006-2010, the UK Biobank cohort recruited 502 649 adults aged 40-69 years. COPD cases were identified by prebronchodilator forced expiratory volume in 1 s/forced vital capacity<lower limit of normal according to American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines. Current occupations were coded using the Standard Occupational Classification (SOC) 2000. Prevalence ratios (PRs) and 95% CIs of COPD for each SOC-coded job were estimated using a robust Poisson model adjusted for sex, age, recruitment centre and lifetime tobacco smoking. Analyses restricted to never-smokers and non-asthmatics were also performed. Results Of the 353 occupations reported by 228 614 current working participants, several showed significantly increased COPD risk. Those at highest COPD risk were seafarers (PR=2.64; 95% CI 1.59 to 4.38), coal mine operatives (PR=2.30; 95% CI 1.00 to 5.31), cleaners (industrial: PR=1.96; 95% CI 1.16 to 3.31 and domestic: PR=1.43; 95% CI 1.28 to 1.59), roofers/tilers (PR=1.86; 95% CI 1.29 to 2.67), packers/bottlers/canners/fillers (PR=1.60; 95% CI 1.15 to 2.22), horticultural trades (PR=1.55; 95% CI 0.97 to 2.50), food/drink/tobacco process operatives (PR=1.46; 95% CI 1.11 to 1.93), floorers/wall tilers (PR=1.41; 95% CI 1.00 to 2.00), chemical/related process operatives (PR=1.39; 95% CI 0.98 to 1.97), postal workers/couriers (PR=1.35; 95% CI 1.15 to 1.59), labourers in building/woodworking trades (PR=1.32; 95% CI 1.04 to 1.68), school mid-day assistants (PR=1.32; 95% CI 1.01 to 1.74) and kitchen/catering assistants (PR=1.30; 95% CI 1.10 to 1.53). Associations were similar in analyses restricted to never-smokers and non-asthmatics. Conclusions Selected occupations are associated with increased COPD risk in a large cross-sectional population-based UK study. Further analyses should confirm the extent to which these associations reflect exposures still of concern and where strengthened preventive action may be needed.