Occurrence of legacy and emerging organic contaminants in snow at Dome C in the Antarctic

Concentrations of 9 organophosphate esters (OPEs), 16 perfluoroalkylated substances (PFASs) and 17 polycyclic aromatic hydrocarbons (PAHs) were investigated in surface snow samples collected at Dome C on the Antarctic Plateau in summer 2016. Tris(1-chloro-2-propyl) phosphate (TCPP), tris-(2-chloroethyl) phosphate (TCEP) and tri-n-butylphosphate (TnBP) were the dominant compounds of OPEs, with mean concentrations of 8157 ± 4860, 1128 ± 928 and 1232 ± 1147 pg/L. Perfluorooctanoic acid (PFOA, mean: 358 ± 71 pg/L) was the dominant compound of PFASs, and following by perfluoro-n-hexanoic acid (PFHxA, mean: 222 ± 97 pg/L), perfluoro-n-heptanoic acid (PFHpA, 183 ± 60 pg/L) and perfluoro-n-pentanoic acid (PFPeA, 175 ± 105 pg/L). 2-(Heptafluoropropoxy)propanoic acid (HFPO-DA, mean: 9.2 ± 2.6 pg/L) was determined in the Antarctic for the first time. Significantly positive correlations were observed between HFPO-DA and the short-chain PFASs, implying they have similar emission sources and long-range transport potential. High levels of 2-methylnaphthalene and 1-methylnaphthalene, as well as the ratios of PAH congeners indicated PAHs were attributable mostly to combustion origin. Occurrence and profiles of the indicators of OPEs, PFASs and PAHs, as well as air mass back-trajectory analysis provided direct evidences of human activities on Concordia station and posed obvious impacts on local environments in the Antarctic. Nevertheless, the exchange processes among different environmental matrices may drive the long-range transport and redistribution of the legacy and emerging Organic contaminants from coast to inland in the Antarctic.