Aims To assess the relationship between levels of ambient air pollutants and hospitalization
rates for asthma in Hong Kong (HK). Methods This is a retrospective ecological study. Data
of daily emergency hospital admissions to 15 major hospitals in HK for asthma and indices
of air pollutants [sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), particulates with
an aerodynamic diameter of< 10 μm particulate matter (PM10) and 2.5 μm (PM2. 5)] and
meteorological variables from January 2000 to December 2005 were obtained from several …

Many studies have shown associations between air pollution and asthma admissions in
Korea, but have not reported whether these effects differ by age classification. The purpose
of this study was to determine whether air pollution effects on asthmatic hospital admissions
are different by three age groups (years): children (less than 15), adults (15–64; reference
group), and the elderly (over 65). Daily time-series data from seven metropolitan cities in
South Korea were analyzed in two stages. In the first stage, relative asthma morbidity rates …