Indoor Air Pollution and COPD Morbidity in Rural Appalachian Cohorts.

RATIONALE: Rural regions of the United States now face a growing burden of Chronic Obstructive Pulmonary Disease (COPD). Early studies have suggested that this may in part be driven by unique environmental factors. The indoor environment remains an important and modifiable contributor to COPD morbidity, however few studies have analyzed the impacts of the indoor environment on underserved rural communities.

OBJECTIVE

Determine if household air pollution is a significant contributor to COPD morbidity in two vulnerable areas of rural Appalachia.

METHODS

Longitudinal environmental cohorts were launched at two rural Appalachian sites (East Tennessee and Western Maryland) among former smokers with COPD. Study follow-up was over 6-months, with up to three paired clinical and environmental assessments to analyze associations between indoor pollutant concentrations (fine particulate matter [PM2.5] and Nitrogen Dioxide [NO2]) and COPD health measures.

RESULTS

Seventy-four participants contributed 184 health and environmental assessments. Mean indoor PM2.5 concentrations were 9.7 mg/m3 (SD 11.8), with only 14 (28%) homes having detectable NO2. Despite relatively low baseline concentrations, in adjusted analyses that accounted for demographics and lung function, every two-fold increase in PM2.5 was associated with increased COPD morbidity as measured by the St. George's Respiratory Questionnaire (1.79, 95% CI 0.74 to 2.79; P = .001) and increased odds of significant dyspnea based on the modified Medical Research Council dyspnea scale (Odds Ratio [OR] 1.34, 95% CI 1.02 to 1.77; P = .038). PM2.5 was additionally associated with an increase in measures of cough and sputum. No significant associations were observed between pollutants of interest and exacerbation risk in the study cohort.

CONCLUSIONS

Indoor pollutant exposure, particularly PM2.5, is a significant contributor to respiratory morbidity for individuals with COPD living in rural communities and has potential as a modifiable target to address COPD morbidity. Future studies and public health initiatives are warranted to evaluate interventions to reduce indoor air pollution in rural regions and improve COPD morbidity.