title: Polychlorinated biphenyls in glaciers. 1. Deposition history from an Alpine ice core.
abstract: We present a highly time-resolved historical record of polychlorinated biphenyls (PCBs) from an Alpine ice core (Fiescherhorn glacier, Switzerland). Introduced in the 1940s, PCBs were widely used industrial chemicals. Because of their persistence they are still found in the environment, long after their production phase-out. The Fiescherhorn ice core record covers the entire time period of industrial use of PCBs, that is, 1940-2002. The total concentration of six PCBs varies from 0.5 to 5 ng L(-1) and reveals a temporal trend, with an 8-fold increase from the early 1940s to the peak value in the 1970s. The level in 2002 is comparable to the concentration in the 1940s, when PCBs were introduced into the market. The time trend of PCBs associated with the particulate fraction closely follows the trend found in the dissolved fraction, but the absolute values are a factor of 10 lower. In addition to changing emissions, fluctuations in the PCB record were explained by variabilty in convective transport and postdepositional processes such as surface melting. Concentrations of PCBs are in agreement with data from seasonal snow samples in the Alps, but are a factor of 100 higher than concentrations measured in the Arctic. Contrasting time trends and congener patterns between the Alpine and Arctic region indicate the importance of atmospheric transport and postdepositional effects.
authors: Empa, Swiss Federal Laboratories for Materials Testing and Research, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors: Pavlina Aneva
authors: PA
authors: Pavlova
authors: Peter
authors: P
authors: Schmid
authors: Christian
authors: C
authors: Bogdal
authors: Christine
authors: C
authors: Steinlin
authors: Theo M
authors: TM
authors: Jenk
authors: Margit
authors: M
authors: Schwikowski
mesh_terms: D017753:Ecosystem; D004785:Environmental Pollutants / Q000032:analysis; D005843:Geography; D046448:Ice Cover / Q000737:chemistry*; D052638:Particulate Matter / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D012995:Solubility; D013557:Switzerland
chemical_list: D004785:Environmental Pollutants; D052638:Particulate Matter; D011078:Polychlorinated Biphenyls