Atmospheric deposition of persistent organic compounds to the sea surface

Measurements of persistent organic pollutants (POP) in air and deposition have been carried out at sea-based and coastal sites on the Swedish west coast. The aim was to obtain knowledge concerning the input of these contaminants to the Skagerrak via atmospheric transport and deposition. The measurements showed a continuous deposition of POP, here represented by PAH, PCB and HCH, to the sea surface of the Skagerrak and an important episodic input in connection with long-range air transport especially together with precipitation. However, the deposition fluxes may also be affected by local sources. A seasonal variation was observed in the concentrations of the different compounds in both air and deposition. The deposited amounts of the selected compounds were within the same order of magnitude at the coastal and sea-based stations but there were differences in the deposition on the individual sampling occasions. There were minor geographical variations with a somewhat greater deposition of HCH and PAH in the southern part of Skagerrak.