Respiratory function and bronchial responsiveness among industrial workers exposed to different classes of occupational agents: a study from Algeria

Abstract

Occupational exposures play a role in the onset of several chronic airway diseases. We investigated, in a cross-sectional study, lung function parameters and bronchial hyper-responsiveness to histamine in workers exposed to different airborne compounds.The study group totalled 546 male subjects of whom 114 were exposed to welding fumes, 106 to solvents, 107 to mineral dust, 97 to organic dust and 123 without known exposure to airway irritants. A questionnaire was administered and spirometry and bronchial responsiveness to histamine were assessed by one observer, in the morning before work to prevent effects of acute exposure.The mean (SD) age of the participants was 39.3 (7.8) years, with a mean duration of employment of 13.8 (6.6) years. Both before and after adjustment for smoking status, forced expiratory volume in 1 second (FEV1, expressed as % predicted) was lower in welders -4.0% (95% confidence interval [CI], -6.3 to -1.8; p = 0.01) and workers exposed to solvents -5.6% (CI: -7.9 to -3.3; p = 0.0009) than in control subjects. Furthermore, solvent workers had an odds ratio of 3.43 (95% CI: 1.09-11.6; p = 0.037) for bronchial hyperresponsiveness compared with the reference group.The higher prevalence of bronchial hyperresponsiveness in solvent workers adds to the growing body of evidence of adverse respiratory effects of occupational solvent exposure. These results point to the necessity of preventive measures in solvent workers to avoid these adverse respiratory effects.

Figure 1

Histamine responsiveness. Mean FEV₁ as the percentage of the initial value (0) after increasing doses of inhaled histamine, administered by aerosol by a hand held nebuliser, according to exposure group. Error bars have been deleted for clarity. * denotes significant difference (p < 0.05) compared with controls. At the higher doses the numbers of subjects are slightly lower than indicated in the legend because the test was interrupted when FEV₁ decreased by 20% or more (i.e. detectable PD₂₀, see table 2 for the number of subjects with a detectable PD₂₀ in each group).