| At present,studies that the short-term effects of air pollution and extreme temperature on daily mortality in China are mostly concentrated in large and medium-sized cities.There were few studies in county-level administrative and rural areas due to poor data sources and quality.In order to explore the short-term effects of air pollution and extreme temperature on residents in county-level administrative and rural areas of China,this paper selected Shunyi and Chaoyang District of Beijing to carry out a suburban and urban comparative study.This study period is from January 2012 to December 2016.Air pollution data was obtained from national air quality monitoring stations in corresponding districts,including SO2,NO2,PM2.5,PM10,CO,O3,1h-max,O3.8h-max and O3.24h.Meteorological data was shared by the National Meteorological Information Center(http://data.cma.cn/).Mortality data was provided by Shunyi and Chaoyang District Center for Disease Control and Prevention,including age,sex,date of death,cause of mortality ICD-10 code etc.To evaluate the short-term effect of air pollution on daily mortality quantitatively,time-series generalized additive model(GAM)was applied to establish single-pollutant and two-pollutant model which control daily average temperature,relative humidity,long-term trend and day of week.To evaluate the short-term effect of extreme temperature(2.5th percentile and 97.5th percentile of mean temperature)on daily mortality quantitatively,time-series distributed lag nonlinear model(DLNM)was applied to establish single-variable model which controls relative humidity,long-term trends and day of week.Controlling PM10,O3.8h-max and ?AQI respectively in single-variable model to analyze the independence of effect of extreme temperature.And I applied such evaluations above to subgroups.The main findings were as follows.(1)Overall air pollution level in Shunyi District is lower than that in Chaoyang District with 0.65?0.97 times,While only O3.8h-max in Shunyi District was slightly higher than Chaoyang District with 1.08 times.There was a difference in the constituent ratio of cause-specified mortality in total mortality between the two districts.The constituent ratio of non-accidental mortality was slightly lower in Shunyi District than Chaoyang District,which was 95.4%and 96.8%in Shunyi and Chaoyang District,respectively.While that was remarkably higher in Shunyi District than Chaoyang District for circulatory system mortality,which was 57.3%and 43.1%in Shunyi and Chaoyang District,respectively.The socio-economic situation showed that Shunyi District had a remarkably higher the proportion of townships than Chaoyang District,while a remarkably lower per capita disposable income,education level and medical care than Chaoyang District.And the industrial structure of Shunyi District was mainly secondary industry and tertiary industry,while the Chaoyang District was basically the tertiary industry.(2)The effects of ambient SO2,NO2,PM2.5,PM10 and CO on mortality in Shunyi District were higher than Chaoyang District.As at the strongest lag effect period,10 ?g/m3 increase in PM10 concentration was associated with 0.48%(95%CI:0.22,0.73%)and 0.24%(95%CI:0.10,0.38%)increase in daily non-accidental mortality in Shunyi and Chaoyang District,respectively.10 ?g/m3 increase in O3.8h-max concentration was associated with 0.64%(95%CI:0.22,1.06%)and 0.68%(95%CI:0.34,1.01%)increase in daily non-accidental mortality in Shunyi and Chaoyang District,respectively.However,only the effect of NO2 on ischemic heart disease mortality had a statistically significant difference between the two districts.The effects of SO2 and O3 on ischemic heart disease mortality were higher than cerebrovascular disease mortality in Shunyi District.And the effects of NO2,PM2.5,PM10 and CO on cerebrovascular disease mortality were higher than ischemic heart disease mortality in Chaoyang District.It was suggested that more attention should be paid to ischemic heart mortality in Shunyi District and cerebrovascular mortality in Chaoyang District.The results of two-pollutant model showed that the effect of O3 on mortality was independent.There were no unanimous conclusions about the difference between the short-term effect of air pollution on subgroups.(3)The exposure-response curve of the association between daily temperature and mortality was "J" type.However,there the two districts were slightly different.The curve was flat "J" type in Shunyi District,and that was reverse "J" type in Chaoyang Distric.The minimum mortality temperatures varied by cause-specified mortality.Compared with the minimum mortality temperature,exposure to extreme temperature at lag 0?21 days may increase the counts of daily mortality of Shunyi District,but the effect was not statistically significant.Exposure to extreme temperature may increase the counts of daily mortality of Chaoyang District.While only the effect of extreme temperature on non-accidental mortality was statistically significant and extreme low temperature on circulatory system disease mortality.The effect of extreme high temperature on ischemic heart disease mortality was higher in Shunyi District than Chaoyang District.However,extreme low temperature on cerebrovascular disease mortality was higher in Chaoyang District than Shunyi District.But the difference between two districts was not statistically significant.The effect of extreme high temperature on ischemic heart disease mortality was higher than cerebrovascular disease mortality in Shunyi District.And extreme low temperature had a higher effect on cerebrovascular disease mortality than ischemic heart disease mortality in Chaoyang District.It was suggested that more attention should be paid to ischemic heart mortality of Shunyi District during high temperature,and more attention should be paid to cerebrovascular mortality of Chaoyang District during low temperature.The results of single-variable model showed that the effect of extreme temperature on mortality was independent.There were no unanimous conclusions about the difference between the short-term effect of extreme temperature on subgroups.Conclusion:The overall short-term effect of air pollution on daily mortality was higher in suburb than urban district.There was a slight difference between the short-term effect of extreme temperature.Which were a higher effect on ischemic heart disease mortality in suburb than urban district of extreme high temperature,and a higher effect on cerebrovascular disease mortality in urban district than suburb of extreme low temperature.However,the difference was basically not statistically significant.The difference of effect between suburb and urban district may be related to the socioeconomic status and spectrum of mortality cause in each district. |
PDF Full Text Request