Nicotine in Fine Particles in Shanghai: Temporal Variations and Influencing Factors

To investigate the temporal and spatial variations in smoking activities in Shanghai, atmospheric fine particles (aerodynamic diameter ≤ 2.5 μm) were collected at four sites in different functional zones, a central urban site (XJH), an urban site (PD), a suburban site (BS), and a rural site (QP), between 2012 and 2020 with the concentration of nicotine measured by GC-MS. The results showed that smoking activities in Shanghai decreased significantly from 2012 to 2020. The average concentration of nicotine in fine particles at XJH (2012–2013) was 13.86 ng m−3, while it was 3.39 ng m−3 at BS (2017–2018), and 1.13 ng m−3 and 0.58 ng m−3 at PD and QP during 2018–2020. Nicotine concentration in Shanghai showed strong spatial variability but generally followed a seasonal trend of high in winter and low in summer. At XJH and BS, where higher nicotine concentrations were detected, positive correlations between nicotine and organic carbon in fine particles were observed, but not at PD and QP. A negative correlation between nicotine and ozone was found at QP, suggesting the influence of transported nicotine at the rural site. In general, the concentration of nicotine in atmospheric fine particles is primarily governed by local smoking activities, but is also influenced by meteorological conditions.