Causes of PM 2.5 Pollution in the Atmospheric Environment, Health Risks and Economic Losses in Different Geographical Administrative Regions

PM 2.5 has become a major pollutant in the atmospheric environment, posing a serious threat to people's health and seriously hindering the sustainable development of urban environments. However, there is still limited assessment of the health risks and economic losses associated with PM 2.5 pollution in megacities. Therefore, this study systematically analysed the spatiotemporal distribution characteristics, health risks and economic losses associated with PM 2.5 concentrations in seven typical Chinese cities. The results show a typical ‘bimodal’ structure with fluctuations up to 10–12 μg/m 3 throughout the day in the northern cities. Fluctuations are only 2–3 μg/m 3 throughout the day in southern cities. Seasonal differences in PM 2.5 concentrations are regular, showing an overall trend of winter > spring > autumn > summer. The distribution of PM 2.5 concentrations in different cities shows that PM 2.5 tends to accumulate in areas with high population density, high traffic density, high energy consumption and high heating emissions. PM 2.5 pollution causes an average of more than 50 premature deaths per million people per year in different cities. In addition, economic losses due to PM 2.5 pollution average more than 1.28 × 10 6 per year. PM 2.5 is inversely proportional to temperature and humidity concentrations, and has a significant positive correlation relationship with PM 10 , SO 2 , CO and NO 2 .