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(15-25) Environmental concentrations and surface-air fluxes of PCB and PAH in a contaminated bay in the southern Baltic. Palm, Anna*,1, Wängberg, Ingvar1, Brorström-Lundén, Eva1, 1 IVL Swedish Environmental Research Institute Ltd, Stockholm, Sweden ABSTRACT- An extensive environmental investigation concerning PCB and PAH at the contaminated site ' Key words: PCB, PAH, concentration, fluxes |
rserumsviken' in the southern Baltic has been performed. One of the aims with the investigation was to evaluate the potential of the bay to act as a secondary source of chemicals to surrounding areas. Total amounts of PCB and PAH residing in the area have been estimated. In total about 360 samples have been analysed, representing four different environmental media, covering all four seasons of the year 2000. Fluxes of PCB and PAH from water and soil to air have been calculated using two different methods, and annual amounts released from the area have been estimated. A stainless steel chamber was used to collect evaporating chemicals from soil and water and fluxes were calculated by comparing concentrations of individual substances in in- and outgoing air of the chamber. Fluxes were also calculated using the 'two-film theory', adopting a fugacity approach. Results from the two calculation approaches were compared. Absolute values differed by a factor of 2-4, but the flux directions were consistent. The results indicated that PCB volatilises from water and soil to air in the area at a rate of about 200 g/year. The volatilisation flux of PCB is significantly elevated in the summer, due to an increase in temperature. The net flux of PAH is in the opposite direction to PCB, from air to surface throughout the year. The results from this study will be presented and compared to background concentrations and surface-air flux measurements that have been published in the literature.