Impact of occupational exposure on severity of COPD

The relationship between occupational exposures and COPD has been analyzed in population-based and occupational cohort studies. However, the influence of these exposures on the clinical characteristics of COPD is not well known. The aim of this study was to analyze the impact of occupational exposures on respiratory symptoms, lung function, and employment status in a series of COPD patients.

We conducted a cross-sectional study of 185 male COPD patients. Patients underwent baseline spirometry and answered a questionnaire that included information on respiratory symptoms, hospitalizations for COPD, smoking habits, current employment status, and lifetime occupational history. Exposure to biological dust, mineral dust, and gases and fumes was assessed using an ad hoc job exposure matrix.

Having worked in a job with high exposure to mineral dust or to any dusts, gas, or fumes was associated with an FEV(1) of < 30% predicted (mineral dust: relative risk ratio, 11; 95% confidence interval [CI], 1.4 to 95; dusts, gas, or fumes: relative risk ratio, 6.9; 95% CI, 1.1 to 45). High exposure to biological dust was associated with chronic sputum production (odds ratio [OR], 4.3; 95% CI, 1.6 to 12), dyspnea (OR, 2.7; 95% CI, 1.1 to 6.7), and work inactivity (OR, 2.4; 95% CI, 1.4 to 4.2). High exposure to dusts, gas, or fumes was associated with sputum production (OR, 2.8; 95% CI, 1.2 to 6.7) and dyspnea (OR, 1.2; 95% CI, 1.1 to 1.4).

Occupational exposures are independently associated with the severity of airflow limitation, respiratory symptoms, and work inactivity in patients with COPD.