Air pollutants consist of a complex combination of gases and particulate matter (PM). In particular, fine PM significantly impacts human health, visibility, the ecosystem, the weather, and the climate. Although there have existed several comprehensive reviews on the topic of formation and growth of atmospheric aerosols, few have been focused specifically on the subject of urban fine PM.  Recently,  one review paper emphasizing the fundamental chemical aspects relevant to urban fine PM formation has been published in Chemical Reviews (Vol.115:3803-3855, 2015). First, the authors briefly introduced a historical perspective of urban PM pollution, and the mechanisms contributing to the secondary growth of urban fine PM with a focus on the formation of organic matter, sulfate, nitrate and basic species. Afterwards, the paper summarized atmospheric measurements of urban PM properties, and the current numerical approaches to quantitatively simulate urban fine PM in atmospheric models. Finally, the authors presented the concluding remarks and described future research needs.

(Zhang, R., G. Wang, S. Guo, M. L. Zamora, Q. Ying, Y. Lin, W. Wang, M. Hu, Y. Wang, 2015. Formation of urban fine particulate matter. Chemical Reviews, 115, 3803-3855, doi:3810.1021/acs.chemrev.3805b00067)

Link:  http://pubs.acs.org/doi/abs/10.1021/acs.chemrev.5b00067