Introduction This study investigated the hypothesis that common occupational and environmental chemical exposures with known irritant or sensitising properties trigger exacerbations for patients with chronic obstructive pulmonary disease (COPD).

Methods We conducted a case crossover study in 168 COPD patients who were members of a disease management group (DMG) in central Massachusetts. Participants completed a baseline health survey and several short exposure surveys. Exposure surveys were administered by a nurse when a participant telephoned to report an exacerbation (case periods) and at a maximum of 3 randomly identified control periods when they were not experiencing an exacerbation. We compared exposures in the week preceding an exacerbation with exposures in normal (non-exacerbation) weeks. The questionnaire assessed short-term (one week) home, community and workplace activities and exposures that may be associated with COPD exacerbation.

Result Self-reported exercise was protective (OR=0.59 95% CI: 0.35–1.00). Among the chemical exposures, car and truck exhaust (OR=4.36, 95% CI: 1.76–10.80) and use of scented laundry products (OR=2.69, 95% CI: 1.31–5.52) showed strong positive effects. Self-reported respiratory infections were strongly associated with COPD exacerbation (OR=7.90, 95% CI: 4.29–14.50). Variations in outdoor temperature were associated with COPD exacerbation risk (moderate versus cold temperature OR=1.95, 95% CI: 0.26–0.70).

Discussion These results suggest that some environmental chemical exposures may play a role in triggering COPD exacerbations. If confirmed, they may provide useful guidance for COPD patients to better manage their diseases.