PARENT SESSION
HA4 Pollution control and management in the Mediterranean Sea
9:00 AM to 1:30 PM, Thursday, 10 May 2001
Session Chair:
Room 4

(447) Atmospheric concentration and deposition fluxes of chlorinated POPs at background marine and urban sites of Eastern Mediterranean.

Mandalakis, M.¹, Tsoga, A.¹, Stephanou, E.¹, ¹

ABSTRACT- Atmospheric measurements of chlorinated persistent organic pollutants (POPs) such as PCBs, dioxins and furans (PCDD/Fs) are rare for the area of Mediterranean Basin while inexistent for the Eastern Mediterranean part. The atmospheric concentration of PCBs and PCDD/Fs and the corresponding atmospheric flux of PCBs in East Mediterranean have been measured since 1999 at two urban areas (Athens and Heraclion) and a background marine station (Finokalia) on the Island of Crete. The concentration of PCBs (sum of 63 congeners) at the background marine site varied from 33 up to 144 pg/m³ while the average value was 39 pg/m³. The corresponding average concentration at the urban sites was 250 pg/m³. At all studied sites, the fraction of PCBs that was associated with the particulate phase never exceeded 3% of the total amount. Conversely, almost 97% of PCBs where found in the gas phase of atmosphere. Also, in all studied sites the predominance of Di-CBs to Tetra-CBs was obvious since their mass fraction corresponded to the 77-75% of the total amount of PCBs. The dry deposition flux of PCBs at the background marine site varied from 71 to 329 ng.m^-2.y^-1, while the average value was 155 ng.m^-2.y^-1. The corresponding range of dry deposition flux at the urban site (Heraclion) varied between 119 and 1200 ng.m^-2.y^-1, with an average value of 419 ng.m^-2.y^-1. The higher atmospheric concentration (6 times) and dry deposition flux (3 times) at urban sites relatively to the background marine one shows even after 20-25 years of PCBs ban, urban areas continue to constitute a significant source of PCBs emission to the environment. The dioxin congeners measured in our study (tetra-octa CDDs) varied from 89 up to 795 fg/m³ at the urban sites and from 43 to 60 fg/m³ at the background marine site. The corresponding concentrations for furans (tetra-octa CDFs) were 101-800 fg/m³ for the urban sites and 61-80 fg/m³ for the background marine site. These concentrations are lower than those reported in North and West Europe. Measurement performed near uncontrolled landfills (very common in Greece) demonstrated higher dioxin (up to 3.5 pg/m³) and furan (up to 4 pg/m³) concentrations.

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