中文摘要：

由于经济规模迅速扩大和城市化进程加快,大气气溶胶污染日趋严重,由气溶胶造成的能见度恶化事件越来越多,这些人类活动排放的污染物,包括直接排放的气溶胶和气态污染物通过化学转化与光化学转化形成的细粒子二次气溶胶,可形成灰霾（特指人类活动源排放的大气污染物诱发的低能见度事件）,致使能见度下降。我国东部地区灰霾天气迅速增加,灰霾天气的本质是细粒子气溶胶污染,与光化学烟雾相关联,形成灰霾天气的气溶胶组成非常复杂。近年来由于灰霾天气日趋严重引发的环境效应问题和气溶胶辐射强迫引发的气候效应问题,广泛地引起科学界、政府部门和社会公众的关注,而成为热门话题。文章讨论了目前对灰霾天气的认识,灰霾的定义与判别标准,灰霾天气与光化学烟雾、气象条件的关系,也涉及灰霾天气对人体健康的影响。展望了灰霾研究的前景与主要研究方向和内容。

英文摘要：

Aerosol pollution in the atmosphere has become a critical environmental problem due to the rapid expansion and urbanization,which has led to frequent incidents of the haze weather over the east part of China in particular.The essence of haze weather is atmospheric pollution of fine particulates associated with photochemical smog,and the composition of aerosol is very complicated.Present knowledge about haze was discussed,the debate about haze in terms of definition and criteria was reviewed.The relationship of haze with photochemical smog and meteorological condition,as well as health impact of haze on human body was presented.