This study assessed the relationships between levels of PM₁₀ and hospitalization rates for asthma among children from 2003 to 2005 at four major cities in Korea. In addition, we estimated the reduced number of asthma hospitalization associated with an ambient PM₁₀ improvement to the acceptable levels as recommended by the World Health Organization (WHO). The Generalized Additive Model (GAM) was used to estimate the relative risks (RR) of asthma hospitalization associated with changes in PM₁₀ The RRs of children's asthma hospitalization for every 10 μg/m³ increment in PM₁₀ were 1.009(95% CI = 1.004-1.014) in Seoul, 1.013(95% CI = 1.006-1.021) in Incheon, 1.009(95% CI = 1.002-1.016) in Busan, and 1.021(95% CI = 1.005-1.037) in Ulsan. We assessed PM₁₀ related health benefits from implementing the WHO's guidelines (24-hour average 50 μg/m³) using the U.S. Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program. The estimated benefits were 439(95% CI = 216-666) reduced asthma hospitalization in Seoul, 720(95% CI = 304-1,151) in Incheon, 260(95% CI = 66-459) in Busan, and 126(95% CI = 30-228) in Ulsan. It was concluded that improving PM₁₀ condition to the WHO guideline would make a significant contribution to the reduction in asthma hospitalization among children. Therefore, public health measures are still needed to improve air quality in Korea.

Keywordsasthma hospitalization, children, PM₁₀, Generalized Additive Model, health benefits, BenMAP