To assess the association between ambient particulate matter and cardiovascular death in seven cities in the Republic of Korea during the period of 2002-2008.

A time-stratified case-crossover design was used to examine association between particulate matter and deaths from cardiovascular or cerebrovascular disease; hypertensive disease 12,821, ischemic heart disease 39,577, cardiac arrhythmia 1,627, cerebrovascular disease 88,047. Mortality data was obtained from National Statistical Office, and hourly mean concentrations of particulate matter ≤ 10 µm in aerodynamic diameter and meteorological data were obtained from the Ministry of Environment. The percent increase in the risk of death associated with an interquartile range increase in particulate matter was determined by conditional logistic regression analysis after adjusting for national holidays and meteorological factors.

The largest association was a 0.8% increase (95% confidence interval [CI], 0.1-1.6) in death risk related to an interquartile range increase in particulate matter ≤ 10 µm (average of 0 to 2 days prior to the day of death). Classified as the cause of death, the association was a 1.2% increase (95% CI, 0.2-2.2) in death from cerebrovascular disease related to an interquartile range increase in particulate matter ≤ 10 µm. But others were statistically not significant. After stratification of death cases by year of death, statistically significant associations were a 2.3% increase (95% CI, 0.1-4.4) in death risk from ischemic heart disease in 2002-2004 and 2.0% increase in death from cerebrovascular disease (95% CI, 0.3-3.8) in 2006-2008.

Our results suggest that ambient air pollution increases the risk of deaths from cardiovascular and cerebrovascular disease in the Republic of Korea.