Polycyclic Aromatic Hydrocarbons (PAHs) at High Mountain Site in North China: Concentration, Source and Health Risk Assessment

Polycyclic aromatic hydrocarbons (PAHs) in fine particulate matter (PM2.5) samples were analyzed at the top of Mount Tai in northern China from June to August of 2015. The mean concentration of PM2.5 was 54.94 µ g m–3 (10–126 µg m–3), and the mean concentration of PM2.5-bound PAHs was 1.359 ng m–3 (0.296–5.349 ng m–3). Phe, Flu and IcdP were the three most abundant PAH species, with a mean concentration of 0.331, 0.128 and 0.100 ng m–3, respectively. Particle phase organics were scavenged at the early stage of cloud/fog event, which cause a clear decrease in PAHs concentration. However, the concentration of PAHs increased after cloud/fog events since the liquid phase organics in clouds could be absorbed by particle phase organics. The results of PAHs levels used potential source contribution function, diagnostic ratio and principal component analysis suggested that significant contributions regions of PAHs at Mount Tai are the north (Hebei Province) and southeast (Henan Province) directions. Furthermore, vehicular emission, coal combustion and biomass combustion were the possible emission sources of PAHs. The estimated inhalation incremental lifetime cancer risk (ILCR) of three groups (Infants, Children, Adults) were less than 1 × 10–6, with mean values of 2.49 × 10–9, 1.14 × 10–8 and 5.09 × 10–8, respectively, suggesting the baseline of inhalation exposure values are acceptable in this present study.