The Effects Of Air Pollution On Mortality Of Population In Hefei, China

Objective This study aims at quantifying air pollution effects on mortality and at evaluating the effects of increase of pollutant concentration on mortality in Hefei,China.Methods Collect annual nonaccidental mortalities,respiratory mortalities, cardiovascular and cerebrovascular mortalities, annual air pollution concentration for SO₂, NO_x, TSP and annual meteorologic variables(tempreture,humidity).The observed subjects were grouped into seven groups,total population group, female group, male group, total aged 0-14 years group, total aged 15-39 years group, total aged 40-64 years group, total aged 65 and over years group.Caculate the loading coefficient and air quality index to show the pollution condition in Hefei city.Use Spearman rank correlation analysis to explore the trend of air pollutant and mortalities,and draw a line chart to directly see the trend of air pollutant and mortalities.Use single factor correlation analysis,linear regression and multiple linear regression methodology to quantify the effect of long-term exposure to ambient air pollution levels on mortalities.In the study ,we use exponential smoothing methodology predicting air pollution concentration from 2000 to 2005, and then predict different group mortalities from 2000 to 2005. Results 1. Air pollution conditionFrom 1990 to 1999,SO₂,TSP concentration almost all are below the air quality criterion,whereas NOx concentration is above the air quality criterion from 1994. In Hefei city, the air pollution is slight pollution and the main pollutant is NO_x in recentyears. In Spearman rank correlation analysis, NOx increases with time, SO2,TSP is no obvious changes with time. The result is as same as the result of line chart.2. Mortality condition in Hefei cityMale yearly average nonaccditonal mortality,respiratory mortalities are higher than female,and aged 65 and over years group mortality is the highest in all groups during 1990-1999 in Hefei city.But female yearly average cardiovascular and cerebrovascular mortality is higher than male.In Spearman correlation analysis,aged 0-14 years group, aged 15-39 years group nonaccditonal mortalities are drop and aged 65 and over years group nonaccditonal mortalities have a raise with the time. At the same time, total population group, male group, female group, total aged 0-14 years group, total aged 40-64 years group respiratory mortalities are drop with the time,the rank correlation coefficient is -0.733 ^ -0.709^ -0.830> -0.927^ -0.806 respectively,whereas total population group, female group, male group, aged 65 and over years group cardiovascular and cerebrovascular mortalities are raise with the time,and the rank correlation coefficient is 0.688,0.806,0.648,0.855 respectively. The result is as same as the result of line chart.3. Correlation coefficients among air pollution concentrations and mortality3.1 Correlation among air pollution concentrations and mortalityIn single factor correlation analysis,there is a significant association between SO2,TSP and different group nonaccidental mortalities , respiratory mortalities,especially the low aged group and high aged group,whereas NOx is no obvious association with nonaccidental mortalities and respiratory mortalities and NOx is association with cardiovascular and cerebrovascular mortality.Meanwhile,pollutants in different season affect on mortalities differently.3.2 Result of regression analysisIn linear regression analysis, the results showed that the increase of SO2, TSP contribute to a raise in nonaccidental and respiratory mortality,and the increase of...