Organochlorine Pesticides and PAHs in the Surface Water and Atmosphere of the North Atlantic and Arctic Ocean

Surface seawater and boundary layer atmospheric samples were collected on the FS Polarstern during cruise ARKXX in the North Atlantic and Arctic Ocean in 2004. Samples were analyzed for persistent organic pollutants (POPS), with a focus on organochlorine pesticides, including hexachlorocyclohexanes (HCHs), chlordanes, DOTS, hexachlorobenzene (HCB), and polycyclic aromatic hydrocarbons. In addition, the enantiomer fractions (EFs) of pesticides, notably alpha-HCH and cis-chlordane (CC), were determined. Concentrations of dissolved HCB increased from near Europe (similar to 1-2 pg/L) toward the high Arctic (4-10 pg/L). For dissolved HCB, strongest correlations were obtained with the average air or water temperature during sampling, not latitude. In the western Arctic Ocean, surface waters with elevated concentrations of HCB (5-10 pg/L) were flowing out of the Arctic Ocean as part of the East Greenland current In contrast to dissolved compounds, atmospheric POPS did not display trends with temperature. Air-water exchange gradients suggested net deposition for all compounds, though HCB was closest to air-water equilibrium. EFs for alpha-HCH in seawater ranged from 0.43 to 0.50, except for two samples from 75 degrees N in the East Greenland Sea, with EFs of 0.31 and 0.37. Lowest EF (0.47) for CC were also at 75 degrees N, other samples had EFs from 0.49 to 0.52. It is suggested that samples from around 75 degrees N in the Greenland Gyre represented a combination of surface and older/deeper Arctic water.