title: Spatio-temporal trends and monitoring design of perfluoroalkyl acids in the eggs of gull (Larid) species from across Canada and parts of the United States.
abstract: A large spatial dataset of perfluoroalkyl acid (PFAA) concentrations in eggs of herring gulls (Larus argentatus or congeneric species) collected from late April to early June between 2009 and 2014 from 28 colonies across Canada and parts of the Unites States was used to evaluate location-specific patterns in chemical concentrations and to generate hypotheses on the major sources affecting PFAA distributions. The highly bioaccumulative perfluorooctane sulfonic acid (PFOS) as well as other perfluoroalkyl sulfonic acids (PFSAs) showed the greatest concentrations in eggs from the lower Great Lakes of southern Ontario as well as from the St. Lawrence River. Despite the 2000 to 2002 phase-out of PFOS and related C8 chemistry by the major manufacturer at the time, ongoing losses from consumer products during use and disposal in urban/industrial locations continue to be major sources to the environment and are influencing the spatial trends of PFOS in Canada. In comparison to PFOS, perfluoroalkyl carboxylic acids (PFCAs) were not as concentrated in eggs in close proximity to urbanized/industrialized centers, but had surprisingly elevated levels in relatively remote regions such as Great Slave Lake, NT and East Bay in Hudson Bay, NU. The present results support the hypothesis that atmospheric transport and degradation of precursor chemicals, such as the fluorotelomer alcohols 8:2 FTOH and 10:2 FTOH, are influencing the spatial trends of PFCAs in Canada. A power analysis conducted on a representative urbanized/industrialized colony in the Toronto Harbour, ON, and a relatively remote colony in Lake Superior, emphasized the importance of consistent and long-term data collection in order to detect the anticipated changes in PFAA concentrations in Canadian gull eggs.
authors.affiliation: 310 Normandy Avenue, Waterloo, ON N2K 1X7, Canada.
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Gewurtz
authors.affiliation: Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment and Climate Change Canada, Burlington, ON L7R 4A6, Canada.
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Martin
authors.affiliation: Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Letcher
authors.affiliation: Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment and Climate Change Canada, Mount Pearl, NL A1N 4T3, Canada.
authors.forename: Neil M
authors.initials: NM
authors.lastname: Burgess
authors.affiliation: Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment and Climate Change Canada, Québec City, QC G1J 0C3, Canada.
authors.forename: Louise
authors.initials: L
authors.lastname: Champoux
authors.affiliation: Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment and Climate Change Canada, Pacific Wildlife Research Centre, Delta, BC V4K 3Y3, Canada.
authors.forename: John E
authors.initials: JE
authors.lastname: Elliott
authors.affiliation: Canadian Wildlife Service, Environment and Climate Change Canada, Downsview, ON M3H 5T4, Canada.
authors.forename: D V Chip
authors.initials: DVC
authors.lastname: Weseloh
mesh_terms: D017738:Alkanesulfonic Acids / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D002170:Canada; D002264:Carboxylic Acids / Q000032:analysis* / Q000378:metabolism; D046091:Charadriiformes / Q000378:metabolism*; D004531:Eggs / Q000032:analysis*; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000378:metabolism; D005466:Fluorocarbons / Q000032:analysis* / Q000378:metabolism; D010063:Ovum / Q000737:chemistry*; D062211:Spatio-Temporal Analysis; D013451:Sulfonic Acids / Q000032:analysis* / Q000378:metabolism; D014481:United States
chemical_list: D017738:Alkanesulfonic Acids; D002264:Carboxylic Acids; D004785:Environmental Pollutants; D005466:Fluorocarbons; D013451:Sulfonic Acids; C076994:perfluorooctane sulfonic acid
keywords: Canada; Gulls; Perfluoroalkyl acids; Power analysis; Sources; Spatial trends