1096 Environmental Toxicology and Chemistry, Vol. 28, No. 5, pp. 1096–1103, 2009  2009 SETAC Printed in the USA 0730-7268/09 $12.00 + .00 LEVELS AND TEMPORAL TRENDS (1983–2003) OF POLYBROMINATED DIPHENYL ETHERS AND HEXABROMOCYCLODODECANES IN SEABIRD EGGS FROM NORTH NORWAY LISA B. HELGASON,† ANUSCHKA POLDER,*‡ SIRI FØREID,‡ KINE BÆK,‡ ELISABETH LIE,‡ GEIR W. GABRIELSEN,† ROBERT T. BARRETT,§ and JANNECHE U. SKAARE‡ †Norwegian Polar Institute, Polar Environmental Centre, NO-9296 Tromsø, Norway ‡Department for Food Safety and Environment, Norwegian School of Veterinary Science, P.O. Box 8146, NO-0033 Oslo, Norway §Tromsø University Museum, University of Tromsø, NO-9037 Tromsø, Norway National Veterinary Institute, P.O. Box 750, Centrum, NO-0106 Oslo, Norway ( Received 1 September 2008; Accepted 1 December 2008) Abstract—The present study assessed temporal trends (1983–2003) of polybrominated diphenyl ethers (PBDEs) and hexabro- mocyclododecanes (HBCDs) in eggs of herring gulls (Larus argentatus), Atlantic puffins (Fratercula arctica), and black-legged kittiwakes (Rissa tridactyla) in North Norway. Generally, PBDE concentrations increased between 1983 and 1993 and then leveled out, although species-specific trends were reported. Levels of -HBCD increased in all species throughout the 20-year period. Levels of nona-BDEs and BDE 209 ranged from nondetectable to parts per billion. Nevertheless, highly variable procedural blanks were reported for the nona-BDEs and BDE 209, which clearly illustrates the importance of including blanks repeatedly during determination of these compounds. Keywords—Polybrominated diphenyl ethers Hexabromocyclododecanes Norwegian Arctic Seabird eggs Temporal trends INTRODUCTION Polybrominated diphenyl ethers (PBDEs) commonly are used to fireproof electrical and electronic equipment and tex- tiles. These chemicals leak from products, and increasing con- centrations have been reported in, for example, the Canadian Arctic in ivory gull (Pagophila eburnea) eggs during the pe- riod from 1976 to 2004 [1] and in ringed seals (Pusa hispida) during the period from 1981 to 2000 [2]. Although little is known about the effects of PBDEs on wildlife, results from laboratory experiments indicate estrogenic potencies in human cell lines [3], induction of developmental neurotoxic effects in adult mice [4], and activation of ethoxyresorufin-O-deethy- lase activity in human, rat, chick, and rainbow trout cells [5]. In the last few decades, penta-BDE, octa-BDE, and deca-BDE have been among the most extensively used technical BDE-mix- tures (http://www.epa.gov/oppt/pbde/pubs/proj-plan32906a.pdf). Nevertheless, manufacture and use of penta-BDE and octa-BDE were banned within the European Union (EU) in 2004 [6]. Fur- thermore, production of penta-BDE and octa-BDE was discon- tinued voluntarily in the United States at the end of 2004 (http://www.epa.gov/oppt/pbde/pubs/proj-plan32906a.pdf), and in Japan, no use of commercial penta-BDE and octa-BDE has been permitted since 1991 and 2000, respectively [7]. The pro- duction of deca-BDE continued as a substitute for the banned penta-BDE and octa-BDE, with total production in 2006 ex- ceeding 60,000 metric tons worldwide (http://www.epa.state.il. us/reports/decabde-study/available-research-review.pdf). How- ever, the production and use of deca-BDE was banned and re- * To whom correspondence may be addressed (anuschka.polder@veths.no). Published on the Web 12/22/2008. stricted in some parts of the United States in 2007 and 2008 and, most recently, in the EU on July 1, 2008. Commercially man- ufactured deca-BDE is composed almost entirely of BDE 209, but it also contains low levels of nona-BDEs (BDEs 206, 207, and 208) [8]. In addition, hepta-, octa-, and nona-BDEs also may be formed during debromination/biotransformation of BDE 209 [9–12]. Few studies have assessed the levels of deca-BDE and isomer-specific levels of nona-BDEs in the environment and, in particular, in biota samples. Hexabromocyclododecanes (HBCDs) are used mainly in thermoplastic polymers and textiles [13]. Hexabromocyclo- dodecane is a technical product composed of different HBCD isomers (i.e., -HBCD, -HBCD, and -HBCD) [13]. Whereas -HBCD is the most dominant isomer in technical mixtures and sediments [14], -HBCD is the primary isomer detected in most biota samples [14–16]. Hexabromocyclododecanes disrupt the thyroid hormone system, inhibit cytochrome P450 (CYP) 1A enzyme activity, and are associated with neurobe- havioral alterations [13,17,18]. Nevertheless, little is known about the biological effects associated with HBCD exposure in free-ranging animals. Most studies so far have been con- ducted with laboratory animals using technical products of HBCD, in which the  isomer dominates. Additionally, little is known about levels, isomer patterns, and temporal trends of HBCDs in seabirds. In the present study, we addressed the information gap regarding temporal trends of PBDEs and HBCDs in wildlife by determining the levels of these compounds in eggs of her- ring gulls (Larus argentatus), Atlantic puffins (Fratercula arctica), and black-legged kittiwakes (Rissa tridactyla) col- lected in North Norway. Furthermore, the congener-specific