Introduction
Chronic obstructive pulmonary disease (COPD) is a disease in which lung
function decreases faster than other organ functions due to abnormal
inflammatory reactions in the lungs. It is a heterogeneous disease,
characterized by airflow limitation caused by a mixed form of
parenchymal destruction (emphysema) and small airway disease
(obstructive bronchiolitis). COPD is currently the fourth leading cause
of death and is expected to be the third leading cause by 2020 (GOLD
CRITERIA).
Symptoms of COPD include cough, sputum, and exertional dyspnea. The
cause may be smoking or air pollution. For example, it has been reported
that air pollution such as fine dust less than 2.5 µm/10 µm (PM2.5/10)
and NO2 affects COPD prevalence.1There have also been reports of significant adverse effects on lung
maturation and development in children exposed to high levels of
NO2 and particulate matter less than 2.5 µm
(PM2.5).2 However, there have been no studies on the
delayed effect of short-term and high peak exposure of air pollution on
COPD.
COPD exacerbation (CE) is a disease that requires additional treatment
due to the rapid deterioration of respiratory symptoms caused by COPD,
and is a serious disease which may lead to death.3Some of the factors that are known to be closely related to CE include a
history of two or more frequent CEs and an increase in blood eosinophil
levels.4 However, there have been no studies showing
the relationship between air pollution and CE.
Therefore, in this paper, we investigated the effects of air pollution,
including fine dust, and environmental factors on CE using 6 years of
cohort data.