Polycyclic aromatic hydrocarbons (PAHs) in the Mediterranean Sea: atmospheric occurrence, deposition and decoupling with settling fluxes in the water column

Abstract: 

The first comprehensive assessment of gas and aerosol phase PAH concentrations and deposition fluxes across the Mediterranean Sea and in the South West Black Sea is presented. ?30PAH gas phase concentrations (13 - 86 and 22 - 40 ng m-3 in the Mediterranean and Black Seas, respectively) dominated the atmospheric levels due to the high contribution of phenanthrene, dibenzothiophene and their alkylated derivates. The high variability of PAH atmospheric concentrations observed in the different Mediterranean sub-basins is due to several factors such as air-mass trajectory, proximity to potential sources and losses by deposition. The ?30PAH atmospheric deposition (dominated by low molecular weight PAH net air-water diffusive fluxes) to the Mediterranean and Black Seas are estimated to be ~3100 and ~500 ton y-1 , respectively. In addition, net volatilization for certain PAHs was estimated. Atmospheric deposition fluxes are 1-2 orders of magnitude higher than reported PAH settling fluxes in the water column, confirming the existence of an important depletion/sink of water column PAH concentrations in the photic zone, especially for low MW PAHs. Degradation processes in the water column may be responsible for this decoupling. Conversely, high MW PAHs dry deposition fluxes are similar than their settling fluxes.

Authors
Authors: 
WOLLGAST Jan, DACHS Jordi, BERROJALBIZ Naiara, CASTRO-JIMENEZ Javier
Publication Year
Publication Year: 
2012
Type

Type:

Appears in Collections
Appears in Collections: 
Institute for Health and Consumer Protection
Science Areas
JRC Institutes
Publisher
Publisher: 
ELSEVIER SCI LTD
ISSN
ISSN: 
0269-7491
Citation
Citation: 
ENVIRONMENTAL POLLUTION p. 40-47 vol. 166
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