Population Exposure to PM(2.5) in the Urban Area of Beijing

The air quality in Beijing, especially its PM(2.5) level, has become of increasing public concern because of its importance and sensitivity related to health risks. A set of monitored PM(2.5) data from 31 stations, released for the first time by the Beijing Environmental Protection Bureau, covering 37 days during autumn 2012, was processed using spatial interpolation and overlay analysis. Following analyses of these data, a distribution map of cumulative exceedance days of PM(2.5) and a temporal variation map of PM(2.5) for Beijing have been drawn. Computational and analytical results show periodic and directional trends of PM(2.5) spreading and congregating in space, which reveals the regulation of PM(2.5) overexposure on a discontinuous medium-term scale. With regard to the cumulative effect of PM(2.5) on the human body, the harm from lower intensity overexposure in the medium term, and higher overexposure in the short term, are both obvious. Therefore, data of population distribution were integrated into the aforementioned PM(2.5) spatial spectrum map. A spatial statistical analysis revealed the patterns of PM(2.5) gross exposure and exposure probability of residents in the Beijing urban area. The methods and conclusions of this research reveal relationships between long-term overexposure to PM(2.5) and people living in high-exposure areas of Beijing, during the autumn of 2012.