Polybrominated diphenyl ethers and selected organochlorine chemicals in grey seals (Halichoerus grypus)intheNorthSea O.I. Kalantzi a , A.J. Hall b , G.O. Thomas a, * , K.C. Jones a a Department of Environmental Science, IENS, Lancaster University, Lancaster LA1 4YQ, UK b Sea Mammal Research Unit, Gatty Marine Laboratory, University of St Andrews, Fife, Scotland KY16 8NS, UK Received 19 June 2003; received in revised form 14 June 2004; accepted 13 July 2004 Abstract Blubbersamplesfromgreyseal(Halichoerusgrypus)pupswerecollectedin1998throughto2000.Twentyfournewly weaned pups were sampled in November 1998, 13 of which were re-sampled during their first year of life, between March and December 1999, and an additional 48 and 25 samples (new cohorts) were obtained in 1999 (November– December) and 2000 (May–September) respectively. P PBDE concentrations (sum of Di-HxBDEs) ranged from 45 to1500ng/glipid,withageometricmeanof290ng/glipid.BDE47dominatedthecongenerprofile,followedbyBDEs 100,99,153and154. P PCBconcentrations(sumof41congeners)rangedfrom100to93000ng/glipid,withageomet- ricmeanof4600ng/glipid,withCBcongeners153,138and180makingup84%ofthetotalPCBconcentrations.The predominant OC pesticides were p,p 0 -DDE (geometric mean=860ng/g lipid, range=160–3800ng/g lipid) and p,p 0 - DDT(geometricmean=120ng/glipid,range=30–670ng/glipid).Nosignificantdifferenceswerefoundbetweenmales andfemales,probablyduetotheyoungageoftheanimals.Significantdecreases(P <0.01forPBDEsand P <0.05for PCBs/OCs)wereobservedbetweennewlyweanedsealsin1998and1999,butnotforthemajorityofjuvenilesin1999 and 2000. Significant differences (P < 0.01) were also found between the different seasons in 1999 newly weaned and juvenile seals, reflecting changes in blubber mass. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: PBDEs; PCBs; Organochlorine pesticides; United Kingdom; Pinnipeds 1. Introduction Since the 1960s there has been growing concern about the adverse effects of human activity on the mar- ineenvironment.Inthemid-1960sorganochlorinepesti- cides (such as DDT and dieldrin) were first detected in harbour seals (Phoca vitulina) from the Wadden Sea, the Netherlands (Koeman and van Genderen, 1966). Shortly after, Jensen et al. (1969) reported PCBs for the first time in grey seals (Halichoerus grypus) from Sweden. These two classes of chemicals peaked in con- centrations in biota in the 1970s and since then they havebeenbannedand/orrestrictedandtheirconcentra- tions have been decreasing. In the late 1970s, however, 0045-6535/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2004.07.039 * Correspondingauthor.Tel.:+441524510214/593974;fax: +44 1524 593985. E-mail addresses: o.i.kalantzi@lancaster.ac.uk (O.I. Kalantzi), g.o.thomas@lancaster.ac.uk (G.O. Thomas). Chemosphere 58 (2005) 345–354 www.elsevier.com/locate/chemosphere