| Either the concentration or the species of air pollutants had been changed greatly over the past 20 years, so a great lots groundwork of the affection of air pollution on people health need to be done. At the same time, the prevalent rates of, allergic respiratory diseases and symptoms in children have increased, stimulative respiratory diseases and symptoms in children have decreased in many countries. In order to plan effective interventions to reverse this trend, we need a better understanding of the risk factors for respiratory diseases and symptoms in early life. The present study was undertaken to investigate the prevalent rates of, and risk factors for, respiratory diseases and symptoms among preschool and school age children .Participants and Methods1. Study PopulationWe selected 7 cities ( Shenyang, Dalian, Anshan, Benxi, Dandong, Ii-aoyang and Panjin. ) of Liaoning province on the basis of previously states of air pollution, the levels of air pollution of each city were divided into three categories ; 1 slight pollution, 2 moderate pollution, 3 heavy pollution according to the results of air pollution measurement of each city. A day care center and a primary school were selected from slight, moderate, and heavy pollution areas, respectively. In seven cities, a total of 42 of day care centers and primary schools were selected according to their proximity to the air monitoring sites (less than 1500 meters) and depending on geographies of primary schools and day care centers districts. A total of 16330 of preschool and school age children were recrui-ted in this study. A standard respiratory health questionnaire [ from American Thoracic Society ( ATS) ] was distributed to each child for completion by patents and trained physician.2. Statistical AnalysisThe data were analyzed using the statistical package SAS( Version 6. 12 , SAS Institute Inc, Cary, NC. USA). Prevalent rates ( population proportions) were presented with their 95% confidence intervals(95% CI) . For all analyses p values of <0.05 were regarded as statistically significant.X2 tests were used to compare the proportions between groups and the Coch-ran - Mantel - Haenszel x test for trend was used to determine if a significant linear trend was present in ordered categorical variables. Hemogeneity of the odds ratios for each potential risk factor. Logistic regression analyses were conducted to identify independent risk factors for respiratory diseases. The attributable fraction was estimated using the adjusted odds ratio from the final logistic regression model and the proportion of the population exposed.ResultsOf 16330 were investigated, eligibilities for statistical analysis were 14556, of which 7386 were male, remains were female. Eligible rate was 89. 14%.The prevalence of persistent cough, persistent phlegm, asthma, current asthma, wheeze and wheeze symptom in children was 10. 17%, A. 11% , 1. 07% , 0. 65% , 6. 62% and 5. 54% , respectively. The prevalence of male children was slightly higher than that of female children, but this difference was not significant(p >0. 05). In different stages of age, the prevalence of respiratory disease in children was declining trend with increasing of age.On the basis of the tenet for Euclid ( x1 - y1)2 , all of 18 air pollution areas from 6 cities( no including 3 air pollution areas from Dalian city) were divided into three categories by results of clustering analysis, i. e. ( 1) slight pollution area, (2) moderate pollution area, and (3) heavy pollution area. After statistical analysis, the prevalence of respiratory disease in children was heighten with increasing degree of pollution. The prevalent rates of respiratory diseasesin children living along the streets were significantly heighten except for current asthma; the prevalence of respiratory disease in children was also heighten with shorting distance from their homes to main lines of communication.The difference of prevalent rates of respiratory diseases between passive smoking children and no passi...
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