Effect of haze on pupils respiratory symptoms in Dongwan city

ObjectiveTo explore the effect of haze on pupils’ respiratory symptoms in Dongwan city and to provide reference for management of haze pollution and health protection of the students.MethodsTwo primary schools were selected in Dongwan city with cluster random sampling.All the students of grade 4-6 were followed-up for respiratory symptoms in the two weeks for forty weeks.The data of haze and atmospheric pollutants were collected simultaneously by environment monitoring.Generalized poisson linear regression model was used for statistical analysis.ResultsSingle factor model analysis showed the odds ratio(OR) value of haze to cough,sputum,wheezing and cough in the 2 weeks was 0.996 3,0.971 7,0.920 1,and 0.955 5,respectively,with statistical significance except for wheezing in the 2 weeks.The three air pollutants(particalate matter less than 10 microns in diameter,nitrogen dioxide,and sulfur dioxide) showed significantly positive effects on cough in the two weeks,with the OR of 1.265 7,1.296 7,and 1.292 0.Multivariate analyses indicated that haze could increase the risk of wheezing in the two weeks with an OR of 1.104 5.The OR for respiratory syptoms of PM₁₀ increased remarkably after adjusting the effect of SO₂.The OR values of NO₂ for cough and sputum were 1.390 4 and 0.653 1 in multivariate analyses.In addition,the lagged effects of haze and the three pollutants on respiratory symptoms were remarkably stronger than the immediate effects.ConclusionEffect of haze was adverse to respiratory system health of pupils in Dongwan city and the effect was related to mulitiple pollutants with a stronger delayed influence.