Current use and legacy pesticide deposition to ice caps on Svalbard, Norway

Abstract

Transport and deposition of current use (CUP) and legacy pesticides (LP) and residual products to the Arctic have been documented in abiotic matrices. These observations show that some “low-persistence” pesticides with high OH· reaction rates are stable enough to accumulate in a polar environment. In 2005, we drilled an ice core on Holtedahlfonna, one of the major ice fields on Svalbard, Norway to measure the input of 47 CUPs and 17 LPs to a high-elevation abiotic environment with no local pesticide sources. Of these, 9 CUPs and 12 LPs were observed in at least one of 6 core segments dating to 1953: 15 of these were found in enough core segments to reveal time-related trends. CUPs often observed included chlorpyrifos, dacthal, α- and β- endosulfan, endosulfan sulfate, trifluralin, and γ-HCH. LPs most often observed included methoxychlor, α- and γ-chlordane, cis- and trans- nonachlor, endrin, dieldrin, and p,p′-DDE. In our comparison of core burdens at Holtedahlfonna and Austfonna (220 km ENE from Holtedahlfonna), we found twice as many CUPs at Austfonna along with greater amounts of dieldrin, methoxychlor, α-endosulfan and chlorpyrifos suggesting different accumulation processes or sources. Air mass back trajectories over a 10-year period of comparison between sites (1986–1995) show air mass flow from Eurasia 74% of the time to Austfonna and 45% to Holtedahfonna which may account for some of the differences.