Assessment Study Of Air Pollution Exposure And Health Impacts Using Air Quality Model Predictions In Nanjing,China

Due to the continuous development of industry and the rapid increase of urban agglomerations in recent years,China has experienced severe regional air pollution.A number of epidemiological studies have found that PM_2.5 and O₃ pollution are closely related to a variety of diseases,which seriously threaten human health and have attracted strong attention from society.Air quality models have been widely used for research on health exposure and health effects because they can simulate the spatial and temporal changes of atmospheric pollutants.The purpose of this study is to analyze the characteristics of air pollutants,population exposure concentrations,and health effects through simulation of air quality models,and to provide a theoretical basis for reducing the health risks of air pollution.In this study,WRF/CMAQ models were used to simulate the changes in the concentration of major air pollutants in Nanjing,China in January,April,July,and October2016 at resolutions of 1km,4km,12km,and 36km,respectively.Combined calculation of population-weighted concentrations,as well as the premature deaths caused by exposure to PM_2.5 and O₃ to analyze the characteristics of air pollutants,and to assess the health exposure and health impact of air pollution.Research shows:?1?The model can better simulate the concentration of PM_2.5 and its components in Nanjing at high resolution especially at 1km resolution.The maximum ozone at 8 hours is best simulated at 12km resolution,and the model has underestimated the simulation of SO₂and CO.?2?The spatial distribution of pollutants is a key factor affecting the accuracy of health exposure assessment.Simulations with a resolution of 1 km in this study can better reflect the changes in the spatial scale of atmospheric pollutants.The average value of observations of PM_2.5 is close to the population-weighted concentration.The current observations can better represent the population exposure of PM_2.5 in Nanjing.The difference between the 8-hour maximum ozone observation and the population-weighted concentration is large,and the existing network of monitoring stations in Nanjing has significantly underestimated the ozone's population exposure concentration.Existing observation sites may overestimate population exposure concentrations of NO₂,SO₂,and CO?3?The number of premature deaths caused by exposure to PM_2.5 in Nanjing in 2016exceeded 7,000,with a per capita mortality rate of 11.8 per 10,000.The premature mortality settled from the observed values is close to the calculated results,and the health impact assessment using the PM_2.5 observations in Nanjing is more reliable.The number of premature deaths caused by exposure to O₃ is about 300,and the per capita mortality rate is0.46 per 10,000.The choice of model resolution will have an impact of about 20%on the estimation results.There is a large gap between the premature mortality calculated from the observed values and the calculated results,and the health impact assessment using the O₃observations at the existing observation stations in Nanjing will be underestimated.