Release of PCBs from Silvretta glacier (Switzerland) investigated in lake sediments and meltwater

• Published in: Environmental science and pollution research international Vol. 23; no. 11; pp. 10308 - 10316
• Main Authors: Pavlova, P. A., Zennegg, M., Anselmetti, F. S., Schmid, P., Bogdal, C., Steinlin, C., Jäggi, M., Schwikowski, M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2016; Springer Nature B.V
• Subjects: Aquatic Pollution; Archives & records; Atmospheric Protection/Air Quality Control/Air Pollution; Cesium radioisotopes; Chemicals; Climate change; Contaminated sediments; Earth and Environmental Science; Ecotoxicology; Ecotoxicology and Engineering; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental science; Fractionation; Geologic Sediments - analysis; Glacial streams; Glaciers; Glaciohydrology; Ice Cover - chemistry; Investigations; Lake sediments; Lakes; Lakes - analysis; Melting; Meltwater; PCB; Persistent organic pollutants; Pollutants; Pollution levels; Polychlorinated biphenyls; Polychlorinated Biphenyls - analysis; Radioactive tracers; Recent Sediments: Environmental Chemistry; Rivers; Sediments; Stream water; Studies; Switzerland; Temporal distribution; Trends; Waste Water Technology; Water - analysis; Water Management; Water Pollutants, Chemical - analysis; Water Pollution Control; Water sampling; Switzerland; Switzerland, Alps Mts; Glaciers; Sediments; Persistent organic pollutants; Polychlrinated biphenyls; Passive sampling; Meltwater
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-015-5854-z

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.