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| Titel |
Atmospheric occurrence, transport and deposition of polychlorinated biphenyls and hexachlorobenzene in the Mediterranean and Black seas |
| VerfasserIn |
N. Berrojalbiz, J. Castro-Jiménez, G. Mariani, J. Wollgast, G. Hanke, 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 ; 14, no. 17 ; Nr. 14, no. 17 (2014-09-01), S.8947-8959 |
| Datensatznummer |
250118993
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| Publikation (Nr.) |
 copernicus.org/acp-14-8947-2014.pdf |
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| Zusammenfassung |
| The Mediterranean and Black seas are unique marine environments subject to
important anthropogenic pressures due to direct and indirect loads of
atmospheric inputs of organochlorine compounds (OCls) from primary and
secondary sources. Here we report the results obtained during two east–west
sampling cruises in June 2006 and May 2007 from Barcelona to Istanbul and
Alexandria, respectively, where gas-phase and aerosol-phase samples were
collected. Both matrices were analyzed for 41 polychlorinated biphenyls
(PCBs), including dioxin-like congeners, and hexachlorobenzene (HCB). The
values reported in this study for gas-phase HCB and ∑41PCB
limit of detection (LOD)
to 418.3 pg m−3 and from 81.99 to 931.6 pg m−3 respectively)
are in the same range of those reported in former studies, possibly
suggesting a limited decline in their atmospheric concentrations during the
last decade for the Mediterranean region due to land-based OCl sources. There
is a clear influence of the direction of the air mass on the atmospheric
concentrations of PCBs, with higher concentrations when the air mass was
from southern Europe, and the lowest concentrations for air masses coming
from the SW Mediterranean and Atlantic Ocean. PCBs and HCB are close to
air–water equilibrium for most sampling periods, thus resulting in low
atmospheric deposition fluxes at open sea. This is consistent with the
oligotrophic character of the Mediterranean Sea with a small influence of
the biological pump capturing atmospheric PCBs. Therefore, degradation of
gas-phase PCBs by OH radicals is estimated to be the main loss process of
atmospheric PCBs during their transport over the Mediterranean Sea.
Conversely, atmospheric residence times of HCB are predicted to be very long
due to a lack of atmospheric degradation and low depositional fluxes due to
concentrations at air–water equilibrium. |
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