PARENT SESSION
PM24 - Perfluorinated & Perchlorinated Chemicals
Monday, 18 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P428) Latitudinal trends of Perfluorinated Acids and Brominated Diphenyl Ethers in Eastern North America Inferred from Lake waters and Dated Sediment Cores.
Muir, Derek*,1, Scott, Brian1, Spencer, Christine1, Alaee, Mehran1, Cannon, Christina1, Teixeira, Camilla1, Chigak, Maxim1, Yang, Fan1, Martin, Jon2, Mabury, Scott2, 1 Environment Canada, National Water Research Institute, Burlington, ON, Canada2 Dept of Chemistry, University of Toronto, Toronto, ON
ABSTRACT- Sediment cores and lake surface waters were collected over a 40 degree latitude (4400 km) north-south transect from southeastern Ontario and northeastern USA to the northern limit of North America (northern Ellesmere Island), as well as along a longitudinal transect in Canada from northwestern Ontario to Labrador in order to study the historical deposition and current levels of perfluorinated acids (carboxylates and sulfonates) and brominated diphenyl ethers. Remote lakes, where the major or sole pathway for inputs of the contaminants was from atmospheric deposition, were compared with the Great Lakes (Ontario, Erie and Superior). Analysis of lake water showed low ng/L concentrations of C2-C8-perfluorocarboxylates (e.g. perfluorooctanoic acid;PFOA) in all arctic and temperate lakes indicating widespread dispersal of these persistent compounds or their precursors. Trifluoroacetic acid and perfluoropropionic acid were generally the predominant compounds, however, PFOA was also present in the range of 0.1-10 ng/L with highest levels in Lake Ontario. Fluxes (ng/m2 yr) of decabromodiphenyl ether (BDE209) in dated sediment cores (concentration, ng/g x sedimentation rate, g/m2 yr corrected for particle focussing) declined significantly with latitude. Recent BDE209 fluxes ranged from 56,000 ng/m2yr in Lake Ontario (west basin) to 1,100 ng/m2yr in Lake Opeongo (45oN) and 5 ng/m2yr in Lake AXAJ on Axel Heiberg Island (76 oN) indicating environmental dispersal, of this very non-volatile compound, from urban source areas.
Key words: Perfluoro acids, Brominated diphenyl ethers, sediments, lake waters