Long-term air pollution exposure and living close to busy roads are associated with COPD in women

Background: Lung function and exacerbations of chronic obstructive
pulmonary disease (COPD) have been associated with short-term
exposure to air pollution. However, the effect of long-term
exposure to particulate matter from industry and traffic on COPD as
defined by lung function has not been evaluated so far. Our study
was designed to investigate the influence of long-term exposure to
air pollution on respiratory symptoms and pulmonary function in
55-year-old women. We especially focused on COPD as defined by GOLD
criteria and additionally compared the effects of air pollution on
respiratory symptoms by questionnaire data and by lung function
measurements. Methods: In consecutive cross sectional studies
conducted between 1985-1994, we investigated 4757 women living in
the Rhine-Ruhr Basin of Germany. NO2 and PM10 exposure was assessed
by measurements done in an 8 km grid, and traffic exposure by
distance from the residential address to the nearest major road
using Geographic Information System data. Lung function was
determined and COPD was defined by using the GOLD criteria. Chronic
respiratory symptoms and possible confounders were defined by
questionnaire data. Linear and logistic regressions, including
random effects were used to account for confounding and clustering
on city level. Results: The prevalence of COPD (GOLD stages 1-4)
was 4.5%. COPD and pulmonary function were strongest affected by
PM10 and traffic related exposure. A 7 mu g/m(3) increase in five
year means of PM10 (interquartile range) was associated with a 5.1%
(95% CI 2.5%-7.7%) decrease in FEV1, a 3.7% (95% CI 1.8%-5.5%)
decrease in FVC and an odds ratio (OR) of 1.33 (95% CI 1.03-1.72)
for COPD. Women living less than 100 m from a busy road also had a
significantly decreased lung function and COPD was 1.79 times more
likely (95% CI 1.06-3.02) than for those living farther away.
Chronic symptoms as based on questionnaire information showed
effects in the same direction, but less pronounced. Conclusion:
Chronic exposure to PM10, NO2 and living near a major road might
increase the risk of developing COPD and can have a detrimental
effect on lung function.