• occupational lung disease
• respiratory measurement
• COPD epidemiology

In their published article, Alif et al report the findings from a carefully conducted longitudinal study showing the effects of occupational exposures on lung function decline between the ages of 45 and 50 years.1 Data from 767 participants in the Tasmanian Longitudinal Health Study (TLHS) were examined: ‘ever’ exposure to aromatic solvents was associated with an excess decline in FEV₁ over that expected by ageing (15.5 mL/year (95% CI −24.8 to 6.3)) and in FVC (14.1 mL/year (95% CI −28.8 t0 –0.7)); as was ‘ever’ exposure to metals (FEV₁ (11.3 mL/year (95% CI −21.9 to –0.7)) and FVC (17.5 mL/year (95% CI −34.3 to –0.8))). This accelerated decline was also apparent for cumulative exposure to aromatic solvents, and interestingly, despite having lower overall exposures, the decline was greater in women than in men. The authors also found an excess decline in FEV₁ in those with ever exposure to gases and fumes and to chlorinated solvents and in FVC in those exposed to ‘other’ solvents.

Accelerated decline in spirometric measures is important. It may, of course, herald future development of respiratory disease but has been shown to be a predictor of all-cause mortality, independent of smoking.2 As respiratory clinicians, we are often drawn towards trends in FEV₁, but there is also evidence suggesting the importance of FVC as an overall marker of lung health.3 The TLHS cohort was recruited at the age of 7 years, and therefore, importantly (and unusually), the authors were able to adjust for childhood socioeconomic status, a potentially important predictor of lung function decline.

While associations between occupational exposures and lower lung function have been observed in a number of cross-sectional studies, there are only a limited number of published longitudinal studies which can provide stronger evidence to support a causal relationship.

Alif et …