title: Temporal trends in "legacy" organochlorine contaminants in blubber of ringed seals (Phoca hispida) from Ulukhaktok, NT, Canada between 1972 and 2010.
abstract: In blubber of ringed seals (Phoca hispida) from Ulukhaktok, NT, residues of DDT, other organochlorine pesticides, and PCBs declined between 1972 and 2010. The rate of decline varied: concentrations of the DDT-group began to fall after 1981, whereas those of PCBs fell rapidly between 1972 and 1981, and then slowed. Concentrations of cis- and trans-chlordane and of HCB in both sexes, and of cis-nonachlor in males, declined slowly between 1978 and 2010; those of other organochlorine pesticides remained steady. Exponential half-lives of p,p'-DDT and p,p'-DDE in female seals are about 9 and 36 y (corresponding to initial declines of 7.8% and 1.9% per year, respectively) and those of PCB congeners from about 20 to 60 y (declines of 3.2% to <1.5% per year); the more refractory residues may be detectable for centuries to come. Exploratory PCA of PCB congener distribution identified temporal changes apparently not related to molecular structure.
authors: 1705 Eagle View Place Duncan BC Canada V9L 6R1. Electronic address: rfaddison@shaw.ca.
authors: R F
authors: RF
authors: Addison
authors: D C
authors: DC
authors: Muir
authors: M G
authors: MG
authors: Ikonomou
authors: L
authors: L
authors: Harwood
authors: T G
authors: TG
authors: Smith
authors: J
authors: J
authors: Alikamik
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D001110:Arctic Regions; D002849:Chromatography, Gas; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005260:Female; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism; D008297:Male; D015873:Northwest Territories; D046049:Phoca / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D006843:Hydrocarbons, Chlorinated; D007306:Insecticides; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls
keywords: Arctic; Organochlorines; Persistent; Ringed seals; Trend