“…Ten studies evaluated the association between respiratory outcomes and number of years worked (Table S13): one study reported a positive correlation between the score obtained from a screening questionnaire for COPD and number of years worked (numerical value for correlation not given); 100 one study found a higher prevalence of small opacities on chest X-ray (≥0/1) and either number of years worked or estimated cumulative exposure to respirable quartz; 106 four studies did not find any relationship between respiratory symptoms or lung function and number of years worked; 70,79,89,107 four studies found either a higher prevalence of respiratory symptoms or lower lung function with more years of work exposure. 5,80,88,114 Ten studies evaluated the association between respiratory outcomes and BKW occupation: three found more respiratory symptoms (including conditions like chronic bronchitis and asthma) in bakers when compared to other BKW types; 5,77,88 four did not find an association between lung function or respiratory symptoms and BKW type, 89,94,107,108 one found that among workers in the modulation, loading, burning and unloading sites, obstructive and restrictive impairments were highest in workers at the loading and burning sites, respectively, 108 one found that respiratory symptoms were lower in molders compared to carriers, stackers or firemen, 70 and one found more respiratory symptoms in bigaaris (translates to carriers) when compared to other brick kiln types. 80…”