A number of papers have already been published by the APHH-Beijing programme including those in this special issue (J. Wang et al.,2019; Pan et al., 2019; Xia et al., 2018; Zhou et al., 2018; H. Wang et al., 2018; Lyu et al., 2019; Hollaway et al., 2019; Du et al., 2018; Liu et al., 2019, 2018; Smith et al., 2019; Vu et al., 2019; El zein et al., 2019).

More papers are being prepared for publication in this special issue and elsewhere, which will cover (but are not limited to) emission fluxes of air pollutants, chemical composition and source apportionment of fine particles, satellite observations of trace gases and aerosols, sources and processes leading to haze events and photochemical smogs, physical and optical properties of aerosol particles, formation processes of secondary aerosols, urban meteorology, feedbacks between haze, photochemistry and meteorology, integrated regional and urban scale modelling, personal exposure to air pollutants and human health effects of air pollution