MARINE ARCTIC FOG - AN ACCUMULATOR OF CURRENTLY USED PESTICIDE

Coincident samples of arctic marine fog and air were found to contain the following pesticides, chlorpyrifos, chlorothalonil, metolachlor, t erbufos and trifluralin. The levels of the different pesticides in the fog ranged from 0.08 to 12 ng/L and for the air from < 0.1 to 5.0 pg/ m(3). Field derived air-water partition coefficients (Henry's law cont stants-HLCs) were calculated from the paired air and water concentrati ons for chlorpyrifos and trifluralin. Comparisons of the field measure d HLC values with laboratory determined HLCs (based on distilled water and on the fogwater itself) indicated that the pesticides were enrich ed in the field collected fogwater. The enrichments appear to be predo minantly caused by surface interaction processes. Concentrations of th e pesticides in the fog were much higher than adjoining compartments o f snow, ice, air, water or microlayer. Exchanges at these interfaces m ay be a common occurrence in the Arctic especially since fogs are comm on over much of the area. Published by Elsevier Science Ltd.