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

Abstract

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, DDTs, 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 (approximately 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.

Organochlorine Pesticides in the Atmosphere and Surface Water from the Equatorial Indian Ocean: Enantiomeric Signatures, Sources, and Fate

“…Equilibrium or deposition was also found in a few stations due to the quite low concentrations in the water phase, especially in Stations 4, 9, 10, and 11. This is different from those observed in the North Atlantic and Arctic Ocean area, where net deposition was found for p,p′-DDE in 2004, 8 although net evaporation for p,p′-DDE was also found after the bloom in 2008. 11 Similar to DDT compounds, volatilization from the water was observed at most stations for TC, CC, and heptachlor, and status of near to equilibrium or net deposition was found at some stations ( Figure S1).…”

“…4 To date, many studies have been carried out on the air−water exchange and biogeochemical processes of OCPs in oceans and seas. Those studies focused on the Arctic region and subarctic area, such as the eastern Arctic Ocean, 7,8 the North American Arctic Ocean, 9,10 and the North Atlantic Ocean. 8,11 Studies on the Chinese marginal seas have also been conducted.…”

Organochlorine pesticides in seawater and the surrounding atmosphere of the marginal seas of China: Spatial distribution, sources and air–water exchange

“…In addition, oceans act as remote monitoring sites of regional/global distribution and temporal trend of POPs, as the outflow of these pollutants from adjacent land sources, carried by monsoon/air masses, can travel long distances. This phenomenon has been confirmed by the observation of some oceanic regions (Ding et al, 2009;Lohmann et al, 2009;Wurl et al, 2006;Zhang et al, 2007).…”

Neutral poly- and perfluoroalkyl substances in air and seawater of the North Sea

“…5), and the exchange fluxes were calculated using the two-film model that have been applied in Lohmann et al (2009) and Xie et al (2011). Briefly, the fugacity ratio was calculated using Eq.…”

“…Due to uncertainties of the estimated Henry's law constant, a significant deviation from equilibrium cannot be assessed within a factor of 3 around a fugacity ratio of 1 (Bruhn et al 2003;Lohmann et al 2009). …”