ABSTRACT
Objective To investigate the short-term effect of particulate matter in air on the mortality of stroke. Methods Using time-stratified case-crossover study design,an association was examined between stroke mortality and particulate matter with aerodynamic diameter of ＜10μm(PM10) of 2002- 2004 in Hangzhou city.Meanwhile,the acute health effect of other gaseous pollutants (sulfur dioxide,SO2 and nitrogen dioxide,NO2) was also analyzed.Results A total of 9906 deaths of stroke were included.The crude stroke mortality was 83.54 per 100 000.After being adjusted for meteorological factors,when an increase of 10 μg/m3 in PM10,SO2 and NO2 in three days was noticed,it appeared that the increases of mortality of stroke were 0.56%(95%CI:0.14%-0.99%),1.62%(95%CI:0.26%-3.01%) and 2.07%( 95%CI:0.54%-3.62%) respectively.There was no distinct association in multipollutant models.In sensitivity analysis,the associations were found in all single-pollutant models but not statistically significant in multi-pollutant models after replacing the missing values.Conclusion It is suggested that the short-term elevation in PM10 as well as SO2 and NO2 daily concentrations were related to the increase of stroke mortality in Hangzhou city.