二噁英是一类具有致癌、致畸和致突变特性的持久性有机污染物。随着城市经济的高速发展，能源和原材料消耗不断增加，大量的二噁英在城市排放和积累，严重威胁到城市的生态安全和人群健康。本项目以长三角城市群为典型研究区，基于动态二噁英排放因子数据库，建立长三角城市群二噁英的高时间、高空间和高源分辨率排放清单，解析二噁英排放的时间、空间、排放源谱和排放成分谱变化特征。耦合空气质量模式CMAQ和城市多介质模型（MUM），实现对二噁英在大气、土壤、水体、沉积物和植被介质/界面过程的动态模拟，探究二噁英在城市群多介质/界面中的迁移转化规律和典型归趋行为，阐明各地区和各排放源排放对城市群各介质中二噁英污染、人群通过呼吸、皮肤接触和摄食等途径暴露的二噁英量和由此所产生的健康风险的贡献和影响，为城市群可持续发展和环境安全决策提供科学依据。

PCDD/Fs are a kind of persistent organic pollutants with carcinogenic, teratogenic and mutagenic properties. With the rapid development of urban economy, the consumption of energy and raw materials is increasing, and a large amount of PCDD/Fs are emitted and accumulated in the urban area, which seriously threatens the urban ecological safety and human health. The Yangtze River Delta urban agglomeration will be selected as the study area. Based on a dynamic PCDD/Fs emission factor database, the high temporal, high spatial and high source resolution emission inventory of PCDD/Fs will be developed for the Yangtze River Delta urban agglomeration, and the characteristics of PCDD/Fs emission in temporal trend, spatial distribution, source profile and composition profile will be analyzed. The air quality model CMAQ and urban multimedia model (MUM) will be coupled to dynamic simulate the atmosphere, soil, water, sediment and vegetation media/interface processes. The migration and transformation in the multi-media/interface of urban agglomeration and typical fate behaviors of PCDD/Fs will be investigated. The contribution of PCDD/Fs emissions from different regions and sources to the PCDD/Fs pollution in multimedia of urban agglomeration, the human exposure to PCDD/Fs through breathing, skin contact and food intake and the resulted health risks will be clarified, providing a scientific basis for decision-making for the sustainable development and environmental safety of the urban agglomeration.