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Titel |
Factors affecting the atmospheric occurrence and deposition of polychlorinated biphenyls in the Southern Ocean |
VerfasserIn |
C. J. Galbán-Malagón, S. Del Vento, A. Cabrerizo, J. Dachs |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 23 ; Nr. 13, no. 23 (2013-12-12), S.12029-12041 |
Datensatznummer |
250085873
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Publikation (Nr.) |
copernicus.org/acp-13-12029-2013.pdf |
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Zusammenfassung |
Persistent organic pollutants, such as polychlorinated biphenyls, reach the
Southern Ocean atmosphere through long-range atmospheric transport. In this
study we report the largest dataset available for the atmospheric
occurrence of PCBs in the Southern Ocean surrounding the Antarctic Peninsula
from samples obtained during three cruises in 2005, 2008 and 2009. The gas
phase concentrations of total PCBs (Σ25PCBs) ranged from 1 to
70 pg m−3, while the aerosol phase concentrations were significantly
lower (0.04 to 0.4 pg m−3). The aerosol phase is enriched in the more
hydrophobic congeners consistent with the model predictions of gas-particle
partitioning. There is a net air-to-water diffusive flux of PCBs to the
Southern Ocean, up to 100 times higher than the dry deposition flux of
aerosol-bound PCBs. The air-water disequilibrium is higher for the more
hydrophobic congeners consistent with the role of the biological pump
removing PCBs from the water column by settling of PCBs bound to organic
matter. The atmospheric half-lives of PCB 52 and 180 are of 3.8 and 1 days,
respectively, as calculated from the measured atmospheric concentration and
depositional fluxes. The volatilization of PCBs from Antarctic soils during
the austral summer drives higher gas phase concentrations in the atmosphere
over Antarctica during the warmer periods. This temperature dependence is
not observed for PCBs over the adjacent Southern Ocean, probably due to the
importance of long-range atmospheric transport and atmospheric deposition
modulating the atmospheric occurrence of PCBs. |
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