Study on relation between air pollution and children's respiratory illness prevalence using two-step regression method

Using two-step regression method, the relation between air pollution and children's respiratory illness prevalence was studied. The results show that particulate matters have markedly positive relation with most of the prevalence, SO2 has markedly positive relation with children's wheeze as catching cold, NOx has markedly positive relation with children's wheeze without catching cold. The results of the two regression methods are basically identical, in which the mix model method not only found the positive relations inter-cities but also intra-cities. Odds Ratio(OR) of children's respiratory illness prevalence under various air pollutants was given as well.