[Evaluation of Changes in PM_2.5 Exposure Concentration and Health Risk for Urban Resident in Zhengzhou Based on High...

In recent years, complex air pollution with the characteristic pollutant of PM_2.5 has remained serious in China. Long term exposure to PM_2.5 might harm residential health and can increase premature death from specific diseases. The annual average concentration of PM_2.5 in Zhengzhou was much higher than the national secondary standard, which has an extremely negative impact on the health of residents. Based on the high spatial resolution grids of population density established through web-crawling and outdoor monitoring concentrations and urban residential emissions used to evaluate PM_2.5 exposure concentration, the exposure concentration of PM_2.5 for urban residents of Zhengzhou was assessed, considering both indoor and outdoor exposures. Relevant health risks were quantified with the integrated exposure-response model. Finally, the contributions of various reducing measures and different standards of air quality to the decreases in PM_2.5 exposure concentration were analyzed. The results showed that in 2017 and 2019, the time weighted exposure concentrations of PM_2.5 for Zhengzhou's urban residents were 74.06 μg·m^-3 and 60.64 μg·m^-3, respectively, which was decreased by 18.12%. In addition, the mass fractions of the indoor exposure concentrations in the time weighted exposure concentrations were 83.58% and 83.01%, and its contribution to the drop of the time weighted exposure concentrations was 84.06%. In 2017 and 2019, the numbers of premature deaths attributed to PM_2.5 exposures for urban residents of Zhengzhou over the age of 25 were 13285 and 10323, respectively, showing a 22.30% decrease. By using these comprehensive measures, PM_2.5 exposure concentration for Zhengzhou's urban residents could be reduced by 86.23% at most, and 8902 premature deaths could be avoided.