Exposure time and place: do COPD patients differ from the general population?

Time-activity patterns in a panel of 70 patients with COPD (35 males) are compared to an age-matched subgroup from the randomly sampled Canadian Human Activity Pattern Survey. Total time indoors and outdoors were similar in both groups but significantly more indoor time in COPD subjects was spent at home than the indoor time of controls, who were more often indoors elsewhere. As part of improving their indoor air at home, COPD subjects were significantly more likely to have air conditioning at home. These results suggest that while outdoor air exposure strategies need not differ in COPD subjects from normals, indoor mitigation strategies should emphasize source pollutant control in the patient's home.