Temporal and spatial variation of particulate matter and its correlation with other criteria of air pollutants in Lanzhou, China, in spring-summer periods

Özet

The present study on major atmospheric pollutants is based on data received from 5 ground-based air-quality monitoring stations and satellite sounding which provides for the use of Moderate Resolution Imaging Spectroradiometer (MODIS) to study aerosol optical depth on the territory of the city of Lanzhou, Gansu Province. Data were received in the spring-summer period of 2014–2017. The present paper is intended to analyze the mass concentrations and spatial-temporal variation of PM 2.5 , PM 10 , CO, SO 2 , NO 2 and O 3 in the above city. When comparing and averaging the daily, monthly, and annual pollutants concentrations, it was revealed that the average PM 2.5 and PM 10 concentrations exceeded the Chinese Ambient Air Quality Standards (CAAQS) and were 42.37 and 112.67 μg/m 3 , respectively. Of all studied days, 62.5% showed high PM 2.5 con- centration, and 78.2% - high PM 10 concentration. PM 2.5 and PM 10 demonstrated a strong correlation (R 2 = 0.81) with PM 2.5 being about 37% of PM 10 . This indicates that decrease of PM 10 emissions is very critical for reducing pollution with PM and thus for improving the air quality in China. The linear correlation analysis reveals un- stable correlation between PM and gaseous pollutants, average correlation between PM and SO 2 (PM 2.5 /SO 2 r = 0.439; PM 10 /SO 2 r = 0.328), negative correlation between PM, SO 2 , NO 2 , CO and O 3 (PM 2.5 /O 3 r = −0.335, PM 10 /O 3 r = −0.213, SO 2 /O 3 r = −0.527, NO 2 /O 3 r = −0.272, CO/O 3 r = −0.558), and strong correlation between other gaseous pollutants (NO 2 /CO r = 0.502, NO 2 /SO 2 r = 0.534, SO 2 /CO r = 0.706).