Quantitative screening level assessment of human risk from PCBs released in glacial meltwater: Silvretta Glacier, Swiss Alps

Persistent organic pollutants (POPs) are entrained within glaciers globally, reemerging in many alpine ecosystems. Despite available data on POP flux from glaciers, a study of human health risk caused by POPs released in glacial meltwater has never been attempted. Glaciers in the European Alps house the largest known quantity of POPs in the Northern Hemisphere, presenting an opportunity for identification of potential risk in an end member scenario case study. With methodology developed by the US Environmental Protection Agency (EPA), we provide a regional screening level human risk analysis of one class of POPs, polychlorinated-biphenyls (PCB) that have been measured in melt waters from the Silvretta Glacier in the Swiss Alps. Our model suggests the potential for both cancer and non-cancer impacts in residents with lifetime exposure to current levels of PCB in glacial meltwater and average consumption of local fish. For residents with an abbreviated 30-year exposure timeframe, the risk for cancer and non-cancer impacts is low. Populations that consume higher quantities of local fish are predicted to be at a greater risk, with risk to lifetime consumers higher by an order of magnitude. Based on the results of our screening study, we suggest that local government move to the next step within the risk assessment framework: local monitoring and management. Within the Alps, other glacial watersheds of a similar size and latitude may see comparable risk and our model framework can be adapted for further implementation therein.