2023年春节期间烟花爆竹燃放对汕头市PM_(2.5)污染影响分析

The Impact of Fireworks on PM_(2.5)Pollution in Shantou During the Spring Festival of 2023

基于常规污染物浓度与气象观测资料、第五代欧洲中期天气预报中心(ERA5)大气再分析资料与单颗粒气溶胶质谱在线监测数据,分析了2023年春节期间广东省汕头市细颗粒物(PM_(2.5))污染的气象成因、来源及化学成分变化,讨论了烟花爆竹燃放对空气质量的影响,并使用随机森林算法量化了春节期间烟花爆竹燃放对汕头市及各区县PM_(2.5)浓度的贡献。结果表明,烟花爆竹燃放与不利气象条件的叠加导致汕头市2023年春节期间PM_(2.5)浓度整体上升,造成了连续3 h的PM_(2.5)重度污染。PM_(2.5)来源解析结果显示,春节期间烟花爆竹对PM_(2.5)浓度的贡献率最大(35%),其次为扬尘源(14%)、移动源(12%)与二次无机源(12%)。集中燃放时段的特征离子数浓度大幅增加,是非集中燃放时段的3.5~39.3倍,特征离子(钡离子)在集中燃放时段的增幅最为明显。随机森林模型的量化评估显示,2023年春节期间烟花爆竹燃放对PM_(2.5)浓度的贡献率达36.9%。相比汕头市东部和北部地区,2023年春节期间烟花爆竹燃放对汕头西部和南部地区的贡献率更大。提出,汕头市应继续加强春节期间烟花爆竹监管,开展针对违法违规经营和燃放烟花爆竹的检查整治,并针对各区县空气质量受烟花爆竹的影响程度,科学划分烟花爆竹禁燃区域与集中燃放区域,以进一步改善城市环境和空气质量。

Based on the observation data of air quality and meteorology,ERA5 reanalysis data,and online monitoring data of single particle aerosol mass spectrometer,this study analyzes the meteorological causes,sources,and chemical composition changes of PM_(2.5)pollution in Shantou,Guangdong during the 2023 Spring Festival,discusses the impact of fireworks on air quality,and quantifies the contribution of fireworks during the Spring Festival period to PM_(2.5)concentration in Shantou and various districts and counties using the random forest algorithm.The results show that the combination of fireworks and adverse meteorological conditions caused an overall increase in PM_(2.5)concentration in Shantou during the 2023 Spring Festival,resulting in severe PM_(2.5)pollution for three consecutive hours.PM_(2.5)source apportionment analysis shows that fireworks have the largest contribution to PM_(2.5)during the Spring Festival period(35%),followed by dust sources(14%),mobile sources(12%),and secondary inorganic sources(12%).The concentration of characteristic ions during the concentrated burning period increased significantly,with an increase ranging from^(3).5 to 39.3 times compared with non-concentrated periods.The increase in the characteristic ion Ba+was most significant during the concentrated burning period.The quantitative evaluation of the random forest model shows that the irregular human impact of PM_(2.5)concentration,represented by fireworks during the 2023 Spring Festival,has increased significantly,with a contribution rate of 36.9%to PM_(2.5)concentration.Compared with the eastern and northern regions of Shantou,the contribution of fireworks during the 2023 Spring Festival to the western and southern regions of Shantou is greater.In conclusion,it is recommended that Shantou continue to strengthen the regulation of fireworks during the Spring Festival,carry out inspections and rectification against illegal and irregular operations and use of fireworks,and scientifically divide the prohibited fireworks area and the concentrated burning area based on the degree of impact of fireworks on air quality in each district and county,in order to further improve the urban environment and air quality.