Time Series Study On The Effect Of Air Pollution On The Health Of Residents In Chongqing

Objective: Air pollution is a global hazard, the effect of environment on human's health is hotspot of research. Epidemiologic studies have found out that it is associated with human's health and can lead to increased mortality and morbidity. This study aims to explore the effect of the current air pollution on the health of residents in Chongqing and to evaluate and forecast the short-term adverse efects of air pollution.Methods: We have collected daily air pollution index data, meteorologic data (including temperature, air pressure and relative humidity), hospitalization data of residents in Yuzhong District from January 1, 2003, to December 31, 2004. After controlling long time trend, seasonal patterns,meteorological factors and other confounding variables using smoothing function, a Poisson regression of time series in generalized additive model (GAMs) was used to analyze the relationship between air polluton index (API) and counts of residents'daily hospitalization. An exposure-response relationship was established.Result: Four models were built to evaluate the effect of air pollution on the overall hospitalization group, elderly hospitalization group, hospitalization for respiratory disease group and hospitalization for cardiovascular disease group resrespectively. The analysis of GAM indicated that : (1) For each increase 39 units in API, all the daily hospitalization counts of overall hospitalization group, elderly hospitalization group and hospitalization for cardiovascular disease group were found to increase 0.96%(95%CI: 0.49%～1.44%), 1.82%(95%CI: 0.93%～2.73%)and 2.40%(95%CI: 1.15%～3.67%) respectively; (2) Air pollution had lagged effect on the overall group and elderly group.Conclusion: GAM can flexibly control confounding factors, so it is appropriate to be applied to the study of the association between air pollution and the health of population. Our findings indicate that the current air pollution has an acute effect on daily hospitalization in Yuzhong District of Chongqing.