Environmental effects of prohibiting urban fireworks and firecrackers in Jinan, China

Eight national air quality monitoring stations were selected to examine the environmental effects of prohibiting fireworks and firecrackers since January 1, 2018, in Jinan, China, by using an air quality index (AQI) on three time scales. In 2014-2018, the average annual AQI decreased year on year, but a downward trend in 2018 was only found by applying a Daniel trend test. The change in monthly data for 2016-2018 followed a "W" pattern. The overall AQI value was lower on New Year's Eve than during Spring Festival, and the 2-day AQI in 2018 was lower than that in 2017. The GIS analysis method was used for spatial visualization. The AQI in the built-up part of Jinan was high in the west and low in the east on New Year's Eve and Spring Festival of 2017, being lowest in the Development Zone. The AQI spatial distribution was high in the city core but low in its periphery; in 2018, the high-AQI center appeared near the Provincial Seed Warehouse on New Year's Eve and Spring Festival. Multiple linear regression was used to analyze the relationship between AQI and pollutants. Six pollutants were found to be positively correlated with the AQI. PM2.5 and PM10 had the strongest correlations on New Year's Eve and Spring Festival, for which the correlations of SO2, CO, and NO2 were significantly weaker in 2018 than in 2017.