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| Titel |
Increasing and decreasing trends of the atmospheric deposition of organochlorine compounds in European remote areas during the last decade |
| VerfasserIn |
L. Arellano, P. Fernández, R. Fonts, N. L. Rose, U. Nickus, H. Thies, E. Stuchlík, L. Camarero, J. Catalán, J. O. Grimalt |
| 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 ; 15, no. 11 ; Nr. 15, no. 11 (2015-06-04), S.6069-6085 |
| Datensatznummer |
250119785
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| Publikation (Nr.) |
 copernicus.org/acp-15-6069-2015.pdf |
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| Zusammenfassung |
Bulk atmospheric deposition samples were collected between 2004 and 2007 at
four high-altitude European sites encompassing east (Skalnaté Pleso),
west (Lochnagar), central (Gossenköllesee) and south (Redòn)
regions, and analysed for legacy and current-use organochlorine compounds
(OCs). Polychlorobiphenyls (PCBs) generally showed the highest deposition
fluxes in the four sites, between 112 and 488 ng m−2 mo−1, and hexachlorobenzene (HCB)
the lowest, a few ng m−2 mo−1. Among pesticides, endosulfans were found at higher
deposition fluxes (11–177 ng m−2 mo−1) than hexachlorocyclohexanes
(HCHs) (17–66 ng m−2 mo−1) in all sites except Lochnagar that was
characterized by very low fluxes of this insecticide.
Comparison of the present measurements with previous determinations in
Redòn (1997–1998 and 2001–2002) and Gossenköllesee (1996–1998)
provided for the first time an assessment of the long-term temporal trends
in OC atmospheric deposition in the European background areas. PCBs showed
increasing deposition trends while HCB deposition fluxes remained nearly
constant. Re-emission of PCBs from soils or as a consequence of glacier melting
and subsequent precipitation and trapping of the volatilized compounds may
explain the observed PCB trends. This process does not occur for HCB due to
its high volatility which keeps most of this pollutant in the gas phase.
A significant decline of pesticide deposition was observed during this
studied decade (1996–2006) which is consistent with the restriction in the
use of these compounds in most of the European countries. In any case,
degassing of HCHs or endosulfans from ice melting to the atmosphere should
be limited because of the low Henry's law constants of these compounds that
will retain them dissolved in the melted water.
Investigation of the relationship between air mass trajectories arriving at
each site and OC deposition fluxes showed no correlation for PCBs, which is
consistent with diffuse pollution from unspecific sources as the predominant
origin of these compounds in these remote sites. In contrast, significant
correlations between current-use pesticides and air masses flowing from the
south were observed in Gossenköllesee, Lochnagar and Redòn. In the
case of Redòn, the higher proportion of air masses from the south
occurred in parallel to higher temperatures, which did not allow us to
discriminate between these two determinant factors of pesticide
deposition. However, in Gossenköllesee and Lochnagar, the relationship
between pesticide concentration and southern air masses was univocal,
reflecting the impact of regions with intensive agricultural activities. |
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