title: Release of PCBs from Silvretta glacier (Switzerland) investigated in lake sediments and meltwater.
abstract: This study is part of our investigations about the release of persistent organic pollutants from melting Alpine glaciers and the relevance of the glaciers as secondary sources of legacy pollutants. Here, we studied the melt-related release of polychlorinated biphenyls (PCBs) in proglacial lakes and glacier streams of the catchment of the Silvretta glacier, located in the Swiss Alps. To explore a spatial and temporal distribution of chemicals in glacier melt, we combined two approaches: (1) analysing a sediment record as an archive of past remobilization and (2) passive water sampling to capture the current release of PCBs during melt period. In addition, we determined PCBs in a non-glacier-fed stream as a reference for the background pollutant level in the area. The PCBs in the sediment core from the Silvretta lake generally complied with trends of PCB emissions into the environment. Elevated concentrations during the most recent ten years, comparable in level with times of the highest atmospheric input, were attributed to accelerated melting of the glacier. This interpretation is supported by the detected PCB fractionation pattern towards heavier, less volatile congeners, and by increased activity concentrations of the radioactive tracer (137)Cs in this part of the sediment core. In contrast, PCB concentrations were not elevated in the stream water, since no significant difference between pollutant concentrations in the glacier-fed and the non-glacier-fed streams was detected. In stream water, no current decrease of the PCBs with distance from the glacier was observed. Thus, according to our data, an influence of PCBs release due to accelerated glacier melt was only detected in the proglacial lake, but not in the other compartments of the Silvretta catchment.
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland.|PSI, Paul Scherrer Institute, CH-5232, Villigen, PSI, Switzerland.|Oeschger Centre for Climate Change Research, University of Berne, CH-3012, Bern, Switzerland.
authors.forename: P A
authors.initials: PA
authors.lastname: Pavlova
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Zennegg
authors.affiliation: Oeschger Centre for Climate Change Research, University of Berne, CH-3012, Bern, Switzerland.|Institute of Geological Sciences, University of Berne, CH-3012, Bern, Switzerland.
authors.forename: F S
authors.initials: FS
authors.lastname: Anselmetti
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Schmid
authors.affiliation: Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1, CH-8093, Zürich, Switzerland. christian.bogdal@chem.ethz.ch.|Agroscope, Institute for Sustainability Sciences ISS, CH-8046, Zürich, Switzerland. christian.bogdal@chem.ethz.ch.
authors.forename: C
authors.initials: C
authors.lastname: Bogdal
authors.affiliation: Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1, CH-8093, Zürich, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Steinlin
authors.affiliation: PSI, Paul Scherrer Institute, CH-5232, Villigen, PSI, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Jäggi
authors.affiliation: PSI, Paul Scherrer Institute, CH-5232, Villigen, PSI, Switzerland.|Oeschger Centre for Climate Change Research, University of Berne, CH-3012, Bern, Switzerland.|Department of Chemistry and Biochemistry, University of Berne, CH-3012, Bern, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Schwikowski
mesh_terms: D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis; D046448:Ice Cover / Q000737:chemistry*; D060106:Lakes / Q000032:analysis; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D045483:Rivers; D013557:Switzerland; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; D011078:Polychlorinated Biphenyls
keywords: Glaciers; Meltwater; Passive sampling; Persistent organic pollutants; Polychlrinated biphenyls; Sediments