MA7 Global Atmospheric Transport
201 Oregon Ballroom
8:00 AM - 12:00 PM, Monday
() Atmospheric semi-volatile organochlorine compounds in European high mountain areas (Central Pyrenees and High Tatras).
Grimalt, J.1, van Drooge, B.1, 1 Department of Environmental Chemistry, Barcelona, Catalonia, Spain
ABSTRACT- Atmospheric samples from two European high mountain areas showed similar composition of semi-volatile organochlorine compounds (SOC). Nearly all compounds were predominantly found in the gas phase and only the less volatile such as some polychlorobiphenyls (PCB), e.g. congeners 149, 118, 153, 138 and 180, were found in higher abundance in the particulate phase. Hexachlorobenzene, 49-85 pg per cubic meter, is the dominant SOC. This compound is only found in the gas phase being well distributed through the troposphere and showing a uniform composition irrespective of season. SOC of present use, like hexachlorocyclohexanes and endosulfans, were found in higher concentrations in the warm periods, 32-46 pg per cubic meter and 4-10 pg per cubic meter in the gas+particulate phase, respectively, reflecting their seasonal pattern of use in many European countries. PCB and 4,4′-DDE, 39-42 pg per cubic meter and 4-6 pg per cubic meter in the gas + particulate phase, respectively, also showed a seasonal trend despite they are not manufactured and their use has been drastically restricted since the eighties. The seasonal differences mainly reflect a higher occurrence of air masses with strong continental inputs in the warm than in the cold periods. In this respect air masses travelling at the high troposphere (backwards air mass trajectories > 6000 m) have been observed to carry considerably smaller PCB and 4,4′-DDE loads (9.3±2.8 pg per cubic meter and 0.4±0.05 pg per cubic meter, respectively) than average.
Key words: high mountain areas, organochlorine compounds, long-range transport, transport seasonality