Abstract:Based on atmospheric aerosol mass concentration and relative meteorological data in Tianjin urban areas during the Spring Festivals of 2009-2014, the distribution characteristics of aerosol concentration spectrum were gained and the impact factors of these distribution characteristics including fireworks and meteorological conditions were analyzed. The results showed that PM2.5 mass concentration reached its peak value in the New Year Eve due to firing fireworks. With the continuous fog and haze during the Spring Festival, firing fireworks made the PM2.5 concentration reach 1240 μg·m-3 in 2013 and this is the highest value in recent years. During the Spring Festival of 2014, the decreasing amount of fireworks and good condition of pollutant dispersion were the causes for lower PM2.5 mass concentration than in 2013. Distribution characteristics of aerosol number concentration spectrum had significantly differences in different weather conditions. Aerosol number concentrations during firing fireworks were comparable with that of fog and haze events.