关键词: PM_2.5, 人口暴露, 人口加权, 风险评估

Abstract:

Through GIS spatial analysis, this study firstly conducts spatial distribution of PM_2.5 concentrations using PM_2.5 data from 35 automatic air quality monitoring stations in Beijing during the period of 2014–2016. Then population spatial processing is carried out based on DMSP/OLS nighttime light data. On this basis, the authors assess the exposure risk to PM_2.5 pollution in Beijing from four aspects: PM_2.5 concentration, the characteristic of population exposure, the population exposure intensity, and the population weighted concentration. The results show that 1) high PM_2.5 concentrations were mainly distributed in the south, while low concentrations were distributed in the north. There was a good spatial coincidence between the distribution of population exposure to PM_2.5 and population distribution, i.e. the densely populated area had high risk of population exposure to PM_2.5. 2) During 2014–2016, 100% of population exposed to high PM_2.5 yearly mean concentrations (>35 μg/m³) which exceeded the secondary level of Ambient Air Quality Standards (GB 3095–2012), and the ratio of population exposed to 24 hourly mean concentrations (>75 μg/m³) declined over a 3-year period. The share of population exposure to exceeding standard PM_2.5 concentration was much higher than those in global average level. 3) The population weighted PM_2.5 yearly average concentrations and PM_2.5 yearly average concentrations had difference, which is related with exposed population and the distribution of PM_2.5 pollution. 4) The distributions of PM_2.5 concentration and population are different, so the real impact level on health of human of PM_2.5 pollution is different from PM_2.5 concentration. Thus, taking the factor of population into account, the risk assessment of exposure to PM_2.5 pollution is more accurate.

Key words: PM_2.5, population exposure, population weighted, risk assessment