Hygiene and Environmental Health Advances (Jun 2023)
Personal and community-level exposure to air pollution and daily changes in respiratory symptoms and oxygen saturation among adults with COPD
Abstract
Background: Air pollution exposure is associated with hospital admissions for Chronic Obstructive Pulmonary Disease (COPD). Few studies have investigated whether daily personal exposure to air pollutants affects respiratory symptoms and oxygenation among COPD patients. Methodology: We followed 30 former smokers with COPD for up to 4 non-consecutive 30-day periods in different seasons. Participants recorded worsening of respiratory symptoms (sub-categorized as breathing or bronchitis symptoms) by daily questionnaire, and oxygen saturation by pulse oximeter. Personal and community-level exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) were measured by portable air quality monitors and stationary monitors in the Boston area. We used generalized and multi-level linear mixed-effects models to estimate associations of the 24-hour average of each pollutant in the previous day with changes in respiratory symptoms and oxygen saturation. Results: Higher community-level exposure to air pollutants was associated with worsening respiratory symptoms. An interquartile range (IQR) higher community-level O3 was associated with a 1.35 (95%CI: 1.07–1.70) higher odds of worsening respiratory symptoms. The corresponding ORs for community-level PM2.5 and NO2 were 1.18 (95%CI: 1.02–1.37) and 1.06 (95%CI: 0.90–1.25), respectively. Community-level NO2 was associated with worsening bronchitis symptoms (OR=1.25, 95%CI: 1.00–1.56), but not breathing symptoms. Personal PM2.5 exposure was associated with lower odds of worsening respiratory symptoms (OR=0.91; 95%CI: 0.81–1.01). Personal exposure to NO2 was associated with 0.11% lower oxygen saturation (95%CI: -0.22, 0.00) per IQR. Conclusions: In this COPD population, there was a pattern of worsening respiratory symptoms associated with community-level exposure to O3 and PM2.5, and worsening oxygenation associated with personal exposure to NO2.
