A case-crossover study on the relationship between air pollution and acute onset of cerebral hemorrhage in Hangzhou city / 中华流行病学杂志

ABSTRACT

Objective To explore the relationship bet-ween air pollution and acute onset of cerebral hemorrhage in Hangzhou.Methods Time-stratified case-crossover study was used to analyze the effect of aerosol optical depth(AOD),PM10,SO2 and NO2 on the acute onset of cerebral hemorrhage.Conditional logistic regression was used to estimate the odds ratios(Ors) and their 95% confidence intervals(Cis) in relation to an increase of one unit of AOD and 10 μg/m3 of air pollutants.Results After adjusted temperature and relative humidity,the Ors of acute onset of cerebral hemorrhage by a unit increase in AOD at a 2 day-lag were 1.727(95%CI1.103-2.703)in first half year and 2.412 (95%CI1.230-4.733) at a 2 day-lag in spring.For a 10 μg/m3 increase in SO2,the Ors were 1.119(95% CI1.019-1.229),1.230(95%CI1.092-1.386),1.254(95%CI1.076-1.460) in the whole year(2 day-lag),in first half year(2 day-lag) and in spring(2 day-lag),respectively.NO2 exposure in first half year(2 day-lag) was associated with cerebral hemorrhage,with OR as 0.841(95% CI0.734-0.964).However,there were no statistical significances for AOD,SO2,NO2 in the rest time-periods(P>0.05).Additionally,no association was found between PM10 and the acute onset of cerebral hemorrhage in any time-periods(P>0.05).Conclusion Our data showed that there was association between air pollution and the acute onset of cerebral hemorrhage,especially in spring and in the first half of the year.