Snow Deposition and Melting as Drivers of Polychlorinated Biphenyls and Organochlorine Pesticides in Arctic Rivers, Lakes, and Ocean
2019
Cabrerizo, Ana | Muir, Derek C. G. | Teixeira, Camilla | Lamoureux, Scott F. | Lafreniere, Melissa J.
Concurrent sampling of freshwater (lakes and rivers), seawater, snow, air, and zooplankton for a range of legacy polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) was undertaken in the Canadian High Arctic during ice-covered, melting, and ice-free conditions. Overall, there was a general trend of higher fluvial PCB/OCP concentrations associated with the spring snow melt (early-mid June), while much lower concentrations were detected during the snow-free season (end of July). In contrast, PCB concentrations in two Arctic lakes (West and East Lakes, Melville Island) and in ocean waters, sharply increased in the ice-free period, likely because of inputs from the ice/snow layer melting and river runoff. The resulting air–water fugacity ratios and fluxes followed a remarkable shift during the sampling campaign. PCBs and OCPs shifted from equilibrium during ice/snow-covered conditions toward a clear net volatilization of PCBs and most of the OCPs during snow/ice-free conditions. Differences in the bioaccumulation factor for PCB/OCPs in zooplankton between West and East Lakes were observed, likely because of zooplankton being exposed to more contaminated food in West Lake due to higher turbidity related to in-lake disturbances.
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