• COPD

It was 30 years ago that Margot Becklake's seminal work appeared arguing that occupational exposures were a salient factor in chronic airflow limitation.1 It took over a decade after her work was published for the first major systematic review and statement on the subject to be produced by a professional society, concluding that, ‘occupational exposures account for a substantial proportion (ie, from 10% to 20%) of either symptoms or functional impairment consistent with COPD’.2 At the time, this assessment met with considerable scepticism among pulmonologists and occupational practitioners alike. Over the ensuing years, however, a great deal of further data accumulated supporting a causal association between occupational exposures and chronic obstructive pulmonary disease (COPD). This body of evidence indicates that the population attributable fraction (PAF) of COPD linked to occupation is indeed in the order of 15%.3 ,4 The burden of smoking, of course, is larger, with a PAF of 70–80% depending on the underlying mix of risk factors. In general, it appears that cigarette smoking and occupation act as additive risks for COPD, which is plausible given that each of these exposures subsumes a heterogeneous mix of toxic materials.

Studies among non-smokers indicate that, within the group of non-smokers, the occupational contribution to COPD is substantially greater even than the 15% value seen overall.4 ,5 This observation is consistent with a …