Effects of fireworks on air quality in the main urban area of Nanchong City during the spring festival of 2014-2019

The sources and variation trend of ambient air pollutants, the duration of pollution process and the conditions for decontamination were analyzed in this essay based on the ambient air pollutants data, PM2.5 source analysis data and meteorological factors in Nanchong City during 2014 to 2019. The results indicated that the concentrated discharge of fireworks on New Year’s Eve was the main reason for the sharp deterioration of the ambient air quality. PM2.5 and PM10 concentrations increased significantly after fireworks were set off, and the peak value appeared at about 02:00 on the Lunar New Year’s Day, but the value of PM2.5/PM10 did not change significantly. The concentration of SO2 in gaseous pollutants was slightly affected by fireworks, while NO2, CO and O3 were not affected basically. Having been affected by fireworks, the concentrations and percentages of K+, Cl- and Mg2+ of the water-solubility ions in PM2.5 significantly increased at the 0.01 level. Meanwhile, the concentrations and percentages of the metal elements, including Cu, Pb, Mg, Al, K and Ba, significantly increased at the 0.05 level. Restricted to the topography and meteorological factors, the duration of the pollution was prolonged.