Occupation and 11-year lung function decline in the HUNT Study

Background The association between occupational titles and lung function has mostly been examined through cross-sectional studies. Preventive measures are expected to mitigate adverse effects; hence, updated estimates are necessary.Aims To study change in lung function measured by spirometry across occupations.Methods This population-based prospective cohort study comprised 5618 working adult participants of the Tr & oslash;ndelag Health Study (HUNT3, 2005-07), Norway. Among these, 3800 individuals (43% men, mean age 42 years, range 20-55) also attended HUNT4 (2017-19). We analysed longitudinal decline in forced expiratory volume in 1 second (FEV1) z-score during the 11-year follow-up by occupation (white-collar workers as reference category), in mixed models, adjusting for age, sex and smoking. We assessed the prevalence of self-reported respiratory symptoms and disease in the working population in HUNT4 (n = 32 124) and HUNT3 (n = 32 070).Results Compared with white-collar workers, agricultural workers and 'drivers and mobile plant operators', had larger declines in FEV1 z-score during follow-up. In sex-stratified analyses, men defined as agricultural workers and 'drivers and mobile plant operators' had larger declines than white-collar workers. Among women, who were underrepresented in many blue-collar jobs, workers classified as 'machine operators and assemblers' experienced greater declines. In the working population in HUNT4, the prevalence of respiratory symptoms in connection with work was 8%, and lower among white-collar workers (6%) than blue-collar workers (14%).Conclusions Although certain workers in Norway remain at risk for occupational lung function decline, there were modest differences between occupations. The findings encourage continuous efforts to implement preventive measures in high-risk jobs. Occupational exposure can cause or exacerbate respiratory symptoms and lung disease. The association between occupation and lung function has mostly been examined through cross-sectional studies. Our large longitudinal population study indicates that agricultural workers and 'drivers and mobile plant operators' have larger lung function declines than white-collar workers. Overall, there were however modest differences between occupations. The prevalence of respiratory symptoms in connection with work in the employed population was stable during the last decade.