In-Home Air Pollution is Associated With Respiratory Symptoms in Patients With Chronic Obstructive Pulmonary Disease

Background: Ambient particulate matter (PM) has shown adverse effects of health on respiratory diseases. To date, although studies have demonstrated that PM was associated with increased morbidity, readmission rates, resource utilization, and the mortality in chronic obstructive pulmonary disease (COPD), few studies investigated the influences of indoor PM on respiratory symptoms, lung function, and acute exacerbations in patients with COPD. Objective: In this longitudinal study, we investigated the relationships between indoor PM (PM_2.5 & PM₁₀), respiratory symptoms, lung function, and acute exacerbations in patients with moderate to very severe COPD. Methods: Indoor air quality (PM_2.5 and PM₁₀ levels) was monitored by using an aerosol spectrometer (Model TSI8532) in the patients’ bedroom, kitchen, living room, and front door at baseline and every two months until one year. At each home visit, the patients were asked to complete spirometry and questionnaire testing, including respiratory symptoms and clinical characteristics. Respiratory symptoms were evaluated using a modified version of the symptoms section of the St. George’s Respiratory Questionnaire (SGRQ). Clinical characteristics included Charlson comorbidity index (CCI), FEV₁ at first visit, and length of COPD diagnosis in years. Exacerbations were assessed by chart review. Generalized estimating equation (GEE) analysis was used to analyze data. Results: The results of the present study (n = 83) showed that the level of wheezing was significantly higher in patients whose living room and kitchen had abnormal (higher than the maximum accepted) PM_2.5 (B = 0.80; B = 1.03, respectively) and PM₁₀ levels (B = 0.36; B = 0.38, respectively). Conclusions and clinical application: Increased PM levels were associated with worse respiratory symptom and increased admission rate in patients with moderate to very severe COPD. Future investigations are needed to determine the effectiveness of environmental interventions or self-management programs to reduce PM concentrations and improve health outcomes in this susceptible population.