Characterization of Air Quality Index for both Handan and Kaifeng Cities, China

Abstract

In this study, the atmospheric PM10, SO2, NO2, CO, and O3 concentration from 2015-2017, in Handan and Kaifeng were investigated. Besides, the seasonal variations of AQI values and their corresponding primary pollutants of six AQI grades were also discussed. In Handan, the daily AQI values ranged from 22 to 500 in 2015, from 19 to 500 in 2016, and from 27 to 500 in 2017, for which the corresponding average values were 143, 132 and 151, respectively. In Kaifeng, the daily AQI ranged from 25 to 496 in 2015, from 20 to 420 in 2016, and from 21 to 434 in 2017, for which the corresponding average values were 129, 124 and 131, respectively. During the three-year study, in Handan, the average proportion of grades I, II, III, IV, V and VI were 4.0%, 35.0%, 25.6%, 31.7%, 2.5% and 1.2% in spring; were 4.0%, 35.1%, 22.6%, 35.8%, 2.5% and 0% in summer; were 14.2%, 31.0%, 15.3%, 35.8%, 3.7% and 0% in fall, and were 3.3%, 26.1%, 20.0%, 37.8%, 8.1% and 4.7% in winter. In Kaifeng, the average proportion of grades I, II, III, IV, V and VI were 2.6%, 34.0%, 24.4%, 36.1%, 2.6% and 0.3% in spring; were 18.2%, 41.9%, 21.8%, 17.0%, 1.1% and and 0% in summer; were 8.6%, 34.3%, 17.4%, 34.8%, 4.9% and 0% in fall, and were 2.1%, 15.1%, 7.8%, 44.5%, 26.2% and 4.3% in winter. Overall, the air quality in the two cities were the worst in winter. The AQI values were between 101 and 150, where in Handan, PM2.5, PM10, and O3 were the primary air pollutants over the three years. In Kaifeng, the primary air pollutants were PM2.5, PM10, NO2, and O3 in 2015; were PM2.5, PM10, and O3 in 2016, and were PM2.5, PM10, and O3 in 2017. When AQIs ranged between 151 and 200, in Handan, the primary air pollutants were PM2.5, PM10, and O3 in both 2015 and 2016, and were PM2.5, PM10, NO2, and O3 in 2017. In Kaifeng, PM2.5, PM10, and O3 were the primary air pollutants from 2015-2017. When AQIs were between 201 and 300, in Handan, the primary air pollutants were PM2.5 and PM10 in 2015 and were PM2.5 and O3 in 2017. In Kaifeng, the primary air pollutants comprised PM10 in 2015, PM2.5 and PM10 in 2016, and PM2.5 and O3 at the same time. When the AQI values were between 301 and 500, which did not occur in Handan in 2015, the primary air pollutants comprised PM10 in 2016, PM2.5 and PM10 in 2017, and in Kaifeng from 2015-2017, PM2.5, and PM10 were the primary air pollutants. This study investigated the AQI values and corresponding primary pollutants in each season in more detail, the control strategies for these air pollutants will be more precisely.