Effect of Asian dust storms on daily mortality in seven metropolitan cities of Korea

The adverse effects of dust storms on health have been a major issue in several countries. A substantial number of studies have found significant associations between dust storms and morbidity such as emergency visits and hospitalizations. However, the results of the studies on the association between dust storms and mortality are inconsistent. In Korea, no study has found statistically significant effect of Asian dust storms on daily mortality. Thus, this study aims to explore the effect of Asian dust storms on daily mortality in Korea during 2001–2009. All analyses were confined to non-accidental mortality. We used generalized additive model with Quasi-Poisson regressions. We considered the lag effect of dust storms up to 7 days and performed subgroup analyses by disease, sex and age. Current dayʹs temperature, relative humidity, barometric pressure, day of the week, season and time trends were controlled for in a basic model. SO2, NO2 and PM10 levels were also added in the further analyses. Meta-analysis was applied for seven metropolitan cities in Korea to estimate the pooled effects of Asian dust storms. We reported results as excessive mortality by percentage due to Asian dust storms. We found significant positive associations between Asian dust storms and mortality at lag 0 (cardiovascular: 2.91%; 95% CI: 0.13, 5.77, male: 2.74%; 95% CI: 0.74, 4.77 and <65 years: 2.52%; 95% CI: 0.06, 5.04), at lag 2 (male 2.4%; 95% CI: 0.43, 4.4 and <65 years: 2.49%; 95% CI: 0.07, 4.97), at lag 3 (total non-accidental: 1.57%; 95% CI: 0.11, 3.06, male: 2.24%; 95% CI: 0.28, 4.25 and <65 years: 2.43%; 95% CI: 0.01, 4.91) and at lag 5 (cardiovascular: 3.7%; 95% CI: 0.93, 6.54 and male: 2.04%, 95 CI: 0.08, 4.04) in the model which adjusted for NO2 additionally. Other models showed similar significant results except the PM10-adjusted model. This is the first study to show the significant relationship between Asian dust storms and mortality in Korea and to present a pooled effect estimate by meta-analysis of multiple cities in a country. Asian dust storms could significantly affect daily mortality in Korea.