title: Egg concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans in double-crested (Phalacrocorax auritus) and pelagic (P. pelagicus) cormorants from the Strait of Georgia, Canada, 1973-1998.
abstract: Eggs of double-crested and pelagic cormorants were collected between 1973 and 1998 from colonies in the Strait of Georgia, BC, Canada, and assayed for concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and non-ortho- and mono-ortho-biphenyls (PCBs). Double-crested cormorant eggs contained (on average) up to 433 ng kg(-1) wet weight 1,2,3,6,7,8-HxCDD, 151 ng kg(-1) 1,2,3,7,8-PnCDD, and 74 ng kg(-1) 2,3,7,8-TCDD, whereas pelagic cormorant eggs contained up to 300, 99, and 28 ng kg(-1) wet weight of these respective congeners. The dominant non-ortho-PCB was CB-126, which ranged as high as 2263 ng kg(-1) in double-crested cormorant eggs. Concentrations of PCDDs and PCDFs fell dramatically in the early 1990s, following both severe restrictions on the use of chlorophenolic wood preservatives and antisapstains and a switch from molecular chlorine bleaching to alternative bleaching technologies at pulp mills in the region. Concentrations of PCBs did not show similar marked declines over time. On the basis of total TEQs > or = 148 ng kg(-1) and previously published documentation of effects in siblings of the cormorant eggs analyzed here, double-crested cormorant young may have exhibited significantly elevated EROD activity and/or brain asymmetries at all colonies from 1973 to 1989 and even at some colonies during the 1990s. Pelagic cormorant eggs collected from a few colonies in 1988-1989 also contained total TEQs greater than the threshold value estimated for double-crested cormorants.
authors.affiliation: Lorax Environmental, 111-1634 Carmi Avenue, Penticton, British Columbia, Canada V2A 8K5.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Harris
authors.forename: Laurie K
authors.initials: LK
authors.lastname: Wilson
authors.forename: Ross i
authors.initials: Ri
authors.lastname: Norstrom
authors.forename: John E
authors.initials: JE
authors.lastname: Elliott
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000493:pharmacokinetics*; D001717:Birds; D001955:British Columbia; D019363:Cytochrome P-450 CYP1A1 / Q000494:pharmacology; D000072338:Dibenzofurans, Polychlorinated; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000493:pharmacokinetics*; D004787:Environmental Pollution / Q000517:prevention & control; D007220:Industrial Waste; D010063:Ovum / Q000737:chemistry*; D010209:Paper; D011078:Polychlorinated Biphenyls / Q000493:pharmacokinetics*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D012989:Soil Pollutants / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants; D007220:Industrial Waste; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls; D019363:Cytochrome P-450 CYP1A1