Asian Dust Storm and pulmonary function of school children in Seoul.

Health effects of the Asian Dust Storm (ADS) have not been evaluated adequately, even though it may affect health of people in East Asia. This study was conducted to evaluate whether the ADS affects particulate air pollution and pulmonary function of children. We studied 110 school children in Seoul, Korea with daily measurement of peak expiratory flow rate (PEFR) from May 13 to June 15, 2007. PM(2.5), PM(10) and metals bound to the particles were also determined daily during the study period in Ala Shan and Beijing (China) as well as in Seoul (Korea). Three-day back trajectories showed that air parcels arrived at Seoul mostly from the desert areas in China and Mongolia through eastern China during ADS event affecting levels of particulate pollutants in the areas. Analysis of metals bound to the particulates showed that natural metal levels were much higher than the anthropogenic metal levels. We found that ambient concentrations of PM(2.5) and PM(10) were not significantly associated with PEFR in school children except asthmatics during the study period (P>0.05). However, most of the metal concentrations bound to the particulates were significantly associated with decrease of the children's PEFR (P<0.05). The effect of anthropogenic metals was not different from natural components of metals for reduction of PEFR. This result indicates that exposure to the metals bound to particles during the ADS period reduces children's pulmonary function, but there was no difference of potency for reduction of the pulmonary function between natural and anthropogenic metal components.