Polychlorinated biphenyls in glaciers: 2. Model results of deposition and incorporation processes
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In: Environmental Science & Technology, Vol. 48, No. 14, 15.07.2014, p. 7849-7857.
Research output: Journal contributions › Journal articles › Research › peer-review
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TY - JOUR
T1 - Polychlorinated biphenyls in glaciers
T2 - 2. Model results of deposition and incorporation processes
AU - Steinlin, Christine
AU - Bogdal, Christian
AU - Scheringer, Martin
AU - Pavlova, Pavlina A
AU - Schwikowski, Margit
AU - Schmid, Peter
AU - Hungerbühler, Konrad
PY - 2014/7/15
Y1 - 2014/7/15
N2 - In previous work, Alpine glaciers have been identified as a secondary source of persistent organic pollutants (POPs). However, detailed understanding of the processes organic chemicals undergo in a glacial system was missing. Here, we present results from a chemical fate model describing deposition and incorporation of polychlorinated biphenyls (PCBs) into an Alpine glacier (Fiescherhorn, Switzerland) and an Arctic glacier (Lomonosovfonna, Norway). To understand PCB fate and dynamics, we investigate the interaction of deposition, sorption to ice and particles in the atmosphere and within the glacier, revolatilization, diffusion and degradation, and discuss the effects of these processes on the fate of individual PCB congeners. The model is able to reproduce measured absolute concentrations in the two glaciers for most PCB congeners. While the model generally predicts concentration profiles peaking in the 1970s, in the measurements, this behavior can only be seen for higher-chlorinated PCB congeners on Fiescherhorn glacier. We suspect seasonal melt processes are disturbing the concentration profiles of the lower-chlorinated PCB congeners. While a lower-chlorinated PCB congener is mainly deposited by dry deposition and almost completely revolatilized after deposition, a higher-chlorinated PCB congener is predominantly transferred to the glacier surface by wet deposition and then is incorporated into the glacier ice. The incorporated amounts of PCBs are higher on the Alpine glacier than on the Arctic glacier due to the higher precipitation rate and aerosol particle concentration on the former. Future studies should include the effects of seasonal melt processes, calculate the quantities of PCBs incorporated into the entire glacier surface, and estimate the quantity of chemicals released from glaciers to determine the importance of glaciers as a secondary source of organic chemicals to remote aquatic ecosystems.
AB - In previous work, Alpine glaciers have been identified as a secondary source of persistent organic pollutants (POPs). However, detailed understanding of the processes organic chemicals undergo in a glacial system was missing. Here, we present results from a chemical fate model describing deposition and incorporation of polychlorinated biphenyls (PCBs) into an Alpine glacier (Fiescherhorn, Switzerland) and an Arctic glacier (Lomonosovfonna, Norway). To understand PCB fate and dynamics, we investigate the interaction of deposition, sorption to ice and particles in the atmosphere and within the glacier, revolatilization, diffusion and degradation, and discuss the effects of these processes on the fate of individual PCB congeners. The model is able to reproduce measured absolute concentrations in the two glaciers for most PCB congeners. While the model generally predicts concentration profiles peaking in the 1970s, in the measurements, this behavior can only be seen for higher-chlorinated PCB congeners on Fiescherhorn glacier. We suspect seasonal melt processes are disturbing the concentration profiles of the lower-chlorinated PCB congeners. While a lower-chlorinated PCB congener is mainly deposited by dry deposition and almost completely revolatilized after deposition, a higher-chlorinated PCB congener is predominantly transferred to the glacier surface by wet deposition and then is incorporated into the glacier ice. The incorporated amounts of PCBs are higher on the Alpine glacier than on the Arctic glacier due to the higher precipitation rate and aerosol particle concentration on the former. Future studies should include the effects of seasonal melt processes, calculate the quantities of PCBs incorporated into the entire glacier surface, and estimate the quantity of chemicals released from glaciers to determine the importance of glaciers as a secondary source of organic chemicals to remote aquatic ecosystems.
KW - Chemistry
KW - Air
KW - Air Pollutants
KW - Ice Cover
KW - Models, Theoretical
KW - Polychlorinated Biphenyls
KW - Switzerland
U2 - 10.1021/es501793h
DO - 10.1021/es501793h
M3 - Journal articles
C2 - 24999726
VL - 48
SP - 7849
EP - 7857
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 14
ER -