study of $PM_{2.5}$ and $PM_{10}$ concentrations in the atmosphere of large cities in Gansu Province, China, in summer period

摘要

Due to rapid economic growth of the country in the last 25 years, particulate matter (PM) has become a topic of great interest in China. The rapid development of industry has led to an increase in the haze created by pollution, as well as by high levels of urbanization. In 2012, the Chinese National Ambient Air Quality Standard (NAAQS) imposed a€?more stricta€? regulation on the PM concentrations, i.e., 35 and70 ??g/m^3 for annual $PM_{2.5}$ and $PM_{10}$ in average, respectively (Grade-II, GB3095-2012). The Pearsona€?s correlation coefficient was used to determine the linear relationship of pollution between pollution levels and weather conditions as well as the temporal and spatial variability among neighbouring cities. Thegoal of this paper was to investigate hourly mass concentration of $PM_{2.5}$ and $PM_{10}$ from June 1 to August 31, 2015 collected in the 11 largest cities of Gansu Province. This study has shown that the overall average concentrations of $PM_{2.5}$ and $PM_{10}$ in the study area were 26 and $66 ??g/m^3$. In PM2.5 episodedays (when concentration was more than $75 ??g/m^3$ for 24 hrs), the average concentrations of $PM_{2.5}$ was 2a€“3 times higher as compared to non-episode days. There were no observed clear differences during theweekday/weekend PM and other air pollutants $(SO_2, NO_2, CO$ and $O_3)$ in all the investigated cities.