Short term changes in PCB and OC pesticide concentrations in surface snow.

The short-term fate of polychlorinated biphenyl (PCB) and organochlorine (OC) pesticides in the surface snowpack was investigated by taking consecutive air and snow samples over a 12 day period at Troms in the Norwegian Arctic. A wide range in PCB and OC pesticide concentrations was observed in snow and was attributed to the systematic decrease in concentrations that occurred over the study period. For example, PCB concentrations ranged from 2500 to 300 pg L-1 (meltwater) with a rapid decrease observed during the first 96 h. Rates of decline (ks) conformed to first-order kinetics, with similar rates observed for all compounds measured in this study (ks = 0.01 ± 0.001 h-1). Because the particle bound fraction accounted for