Study On Hazard Risk Of Atmospheric Particlate Matter To The Population Health In Beijing

T he research of health effect from atmospheric particulate matter pollution began in the 1970 s, but due to the limitation of data in China, most of the studies lack of systematic understandings on hazard risk of particles. The pollution of the capital Beijing and Beijing-Tianjin-Hebei urban agglomeration are very serious, and the composition of the pollutant are also complicated. With the rapid development of the integration of the Beijing-Tianjin-Hebei region, the health effect of particulate matter cannot be ignored. At the same time, pollution-related diseases harm populations are generally highly concerned. Study on the characteristics of health effect of atmospheric particle pollution will provide the scientific basis directly for evaluating, early warning, air pollution preventing and policy controlling of atmospheric environment of the capital area. The study will also provide important reference basis for the healthy development of the integration of Beijing and the Beijing-Tianjin-Hebei region.By using the data of airborne particulate matter(PM_2.5, PM₁₀) mass concentration, the chemical composition of particles and the deaths（diseases） of respiratory system, circulatory system, and non-accidental deaths from 2005 to 2009 in Beijing, we build the exposure-response model to analyze the short-term risk from the perspective of different size, different time, different composition of particulate air pollution in this study. We also used the dummy variable to build four composite models tentatively and found that the existing population health impact sensitivity key pollution concentration period of rapidly rising. We confirmed the interaction of meteorological elements and particles to health affect of people, and found that short-term risk of harm being tended to be increasing in recent years in Beijing, and the concrete results are as following:（1） Long-term observation found that, the average mass concentration of PM₁₀ and PM_2.5 in Beijing during the 2004 to 2010 was 131μg/m3 and 75μg/m3, respectively. The number of exceeding days of the annual average was 111 and 149 days, respectively. Compared with 2004, both the number of exceeding days and the rates showed a trend of falling volatility in 2010. The mass concentration of PM₁₀ and PM_2.5 fell by 1.5% and 6.3%, respectively, and the air quality improved slightly in recent years. Due to the dusty weathers, the average concentration of PM₁₀ reached up to 155±116μg/m3 in april, and the average concentration of PM_2.5 reached up to 88±63μg/m3 caused by coal burning in december. The mass concentration of PM₁₀ and PM_2.5 were 900、435μg/m3 at the worst of times。（2） The relative risk of PM_2.5 in Beijing is greater than others, and the relative risk of PM₁₀ is small, but PM_2.5-10 almost has no effect on human health. In the average condition of atmospheric pollution, when the concentration of PM_2.5 and PM₁₀ increase per 10 μg/m3, the total non-accidental deaths increase 0.65% and 0.15%, respectively, the respiratory system disease deaths increase by 0.67% and 0.08%, respectively, circulatory system disease deaths increase by 1.37% and 0.44%, respectively. While the API increase per 10 points, the total non-accidental deaths, respiratory system disease deaths, circulatory system disease death increase 0.50%, 0.43% and 0.50%, respectively. Obviously, circulatory system diseases are the most sensitive.（3） An increase of IQR in K⁺, Ca²⁺, NO₃^-, SO₄^2- of PM_2.5 in Beijing are corresponding to 1.03%, 0.42%, 0.32%, and 0.56% increasing of the total non-accidental deaths, respectively. Four kinds of ions are more significantly to disease population in the winterrimer, and the influence of the hazard risk are about 4⁵ times of the summertime.（4） Aiming at the shortcomings of the previous studies, concentration segmented exposure response model is built in this study. The model results show that the concentration range of the highest sensitivity are 20μg/m3≤PM_2.5≤60μg/m3, 80μg/m3≤PM₁₀≤140μg/m3, and 100 points≤API≤220 points for PM_2.5, PM₁₀, and API, respectively. We found a key range of pollution concentration in which the sensitivity is rising rapidly in the light pollution situation. At this critical stag, a 10μg/m3 of increaseing of PM_2.5 and PM₁₀ was corresponding to 5.99% of death risk and 6.24% of disease risk in Beijing, which was significantly higher than the average state（0.43%¹.37%）.（5） The concentration dummy variable model is build tentatively in the study, and found that under level 20 μg/m3 of PM_2.5 in Beijing, which were at the same concentration in Europe and the United States, the hazard risk of airborne particles to the disease population in Beijing was 4.60⁶.24%, which was more higer than in some European and American area where has gaseous pollutants leading atmospheric pollution condition（1.03%².20%）.（6） The synergy of meteorological factors and atmospheric particulate matter on human health have more significant harm effect on disease population. When the air temperature in Beijing is 24℃, and the relative humidity is 60%, the risk of the particulate matter to the disease is minimal. Under extreme low temperature and humidity conditions（temperature less than 4.21℃, and the relative humidity less than 27%）, the health hazards of particulate matter of is the most significant, which reach as high as 1.54%、2.84% for death and disease. The health hazards of particulate matter in winter especially in winter-spring time alternately, is much higher than the summer months. The maximum value of health hazards can reach as 2.8%, which is 5.6 times higer on circulatory system disease deaths than in summer. The annual trend on the hazard risk of particles in Beijing is fluctuating upward throughout the study period of 2005²009.