title: Current use pesticide and legacy organochlorine pesticide dynamics at the ocean-sea ice-atmosphere interface in resolute passage, Canadian Arctic, during winter-summer transition.
abstract: Here, we present the first detailed analysis of processes by which various current use pesticides (CUPs) and legacy organochlorine pesticides (OCPs) are concentrated in melt ponds that form on Arctic sea ice in the summer, when surface snow is melting and ice eventually breaks up. Four current use pesticides (dacthal, chlorpyrifos, trifluralin, and pentachloronitrobenzene) and one legacy organochlorine pesticide (α-hexachlorocyclohexane) were detected in ponds in Resolute Passage, Canadian Arctic, in 2012. Melt-pond concentrations changed over time as a function of gas exchange, precipitation, and dilution with melting sea ice. Observed increases in melt-pond concentrations for all detected pesticides were associated with precipitation events. Dacthal reached the highest concentration of all current use pesticides in ponds (95±71pgL-1), a value exceeding measured concentrations in the under-ice (0m) and 5m seawater by >10 and >16 times, respectively. Drainage of dacthal-enriched pond water to the ocean during ice break-up provides an important ice-mediated annual delivery route, adding ~30% of inventory in the summer Mixed Layer (ML; 10m) in the Resolute Passage, and a concentrating mechanism with potential implications for exposures to organisms such as ice algae, and phytoplankton.
authors.affiliation: Centre for Earth Observation Science, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada. Electronic address: Monika.Pucko@umanitoba.ca.
authors.forename: Monika
authors.initials: M
authors.lastname: Pućko
authors.affiliation: Centre for Earth Observation Science, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Stern
authors.affiliation: Centre for Earth Observation Science, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada.
authors.forename: Alexis E
authors.initials: AE
authors.lastname: Burt
authors.affiliation: Air Quality Processes Research Section, Environment Canada, 6248 Eighth Line, Egbert, Ontario L0L 1N0, Canada.
authors.forename: Liisa M
authors.initials: LM
authors.lastname: Jantunen
authors.affiliation: Department of Chemistry, Umeå University, Umeå SE-901 87, Sweden.
authors.forename: Terry F
authors.initials: TF
authors.lastname: Bidleman
authors.affiliation: Centre for Earth Observation Science, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada; Institute of Ocean Sciences, Department of Fisheries and Oceans, 9860 West Saanich Road, Sidney, British Columbia V8L 4B2, Canada.
authors.forename: Robie W
authors.initials: RW
authors.lastname: Macdonald
authors.affiliation: Centre for Earth Observation Science, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada.
authors.forename: David G
authors.initials: DG
authors.lastname: Barber
authors.affiliation: Centre for Earth Observation Science, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada; Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark.
authors.forename: Nicolas-X
authors.initials: NX
authors.lastname: Geilfus
authors.affiliation: Centre for Earth Observation Science, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada; Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark; Department of Geological Sciences, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, R3T 2N2, Canada; Greenland Climate Research Centre, Greenland Institute of Natural Resource, 3900 Nuuk, Greenland.
authors.forename: Søren
authors.initials: S
authors.lastname: Rysgaard
keywords: Arctic sea; Melt ponds; Pesticides; Sea ice