Respiratory effects of particulate air pollution episodes in former smokers with and without chronic obstructive pulmonary disease: a panel study

Abstract

Background: Air pollution is associated with adverse health effects in individuals with chronic obstructive pulmonary disease (COPD). It is uncertain if and how individuals with COPD differ from former smokers without airflow obstruction in their response to naturally occurring episodes of particulate air pollution. We hypothesized that episodic temperature inversions with high particulate matter (PM) air pollution during the winter would be associated with increased pulmonary inflammation and oxidative stress, increased respiratory symptoms, and decreased lung function in individuals with COPD compared to controls. Methods: We conducted a panel study of former smokers, 16 with moderate-to-severe COPD and 12 without airflow obstruction as controls. We measured biomarkers (nitrite/nitrate (NOx), 8-isoprostane) in exhaled breath condensate (EBC), spirometry, and respiratory symptoms during periods of low and high PM 2.5 (PM < 2.5 microns in diameter). We compared differences between pollution and clean air days within the COPD and control groups using linear mixed effect models. Results: High PM 2.5 levels were associated with increased EBC NOx in participants with COPD (mean ratio 3.16, p = 0.007), but not in controls (mean ratio 0.49, p = 0.23, difference between groups p = 0.01). Respiratory symptoms significantly increased on pollution days in COPD participants but not in controls. We did not detect a difference in pulmonary function or EBC 8-isoprostane. Conclusions: Former smokers with COPD have a distinctive response to particulate air pollution episodes compared to former smokers without airflow obstruction, with increased airway inflammation and respiratory symptoms.

Investigating the relationship between particulate matter and inflammatory biomarkers of exhaled breath condensate and blood in healthy young adults

“…One of the newest methods for estimating the effects of air pollution in humans is the examination of biological markers in exhaled breath condensate 46 , 47 . The main advantage of this method is its non-invasiveness and safety even for sensitive individuals, such as children and people with respiratory illness 48 – 50 .…”

Historic and Modern Air Pollution Studies Conducted in Utah

“…Among adult smokers with COPD, an increase of 100 µg/m 3 in PM 10 was significantly associated with a 2% decrease in forced expiratory volume [24]. For adult COPD patients, respiratory symptoms significantly increased after days with increased PM 2.5 [29] .…”

“…Subjects administered the extracts of PM from filters taken while the steel mill was in operation had significantly high levels of neutrophil infiltration and elevated concentrations of fibronectin and α-1-antitrypsin, indicating inflammatory lung injury [25]. In a separate study, human exhaled breath condensate was collected from former smokers with moderate to severe COPD on days with PM 2.5 that was considered "clean" and on days with higher PM 2.5 pollution during winter inversions [29]. High PM 2.5 levels were associated with increases in nitrite plus nitrate (NO x ), a biomarker of oxidative stress in COPD patients (mean of 3.16 difference between polluted and clean days), but not former smokers without COPD.…”