Persistent organic pollutants in shallow percolated water of the Alps Karst system (Zugspitze summit, Germany).

In the German Calcareous Alps at the Zugspitze, percolated water close to a permafrost bedrock in a tunnel system was monitored long-term for polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), and 28 organochlorine pesticides (OCP). Semi-permeablemembrane devices (SPMD) were deployed in a temporary surface water systemat the Zugspitze plateau and analysed for PCB, PAH, and OCP. The high-volumewater samplingwas successfully implemented and all compounds were identified in the water percolated through the Karst system. However, the percentage distribution of contaminants in the percolated water differed significantly from that found in surface waters. The highest chlorinated PCDD homologues were the predominant compounds of the PCDD/F family, whereas percentages of PCB #52 increased in percolated water. Toxic equivalent values (TEQ) of samples ranged from 2.0 to 4.2 pg TEQ/m(3) and from 0.017 to 0.069 pg TEQ/m(3) for PCDD/F and PCB, respectively. Low and intermediate molecular weight PAH were the prevailing compounds in the samples. Endosulfan sulfate, endrin, and cis-heptachlor epoxide were enhanced afterwater percolation through the Karst systemin comparison with the surface waters (wet deposition). The relative enrichment on these pesticides was related to the environmental bedrock conditions and glacier melting sources. In summary, the Karst systemhighly influenced the fate of organic persistent pollutants generating different chemical patterns in their percolated waters than those found at the surface systems. (C) 2016 Elsevier B.V. All rights reserved.