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EffectsofdecontaminatedfishoilorafishandvegetableoilblendonpersistentorganicpollutantandfattyacidcompositionsindietandfleshofAtlanticsalmon(Salmosalar)MatthewSprague1,EldarA˚.Bendiksen2,JamesR.Dick1,FionaStrachan1,JarunanPratoomyot1,MarcH.G.Berntssen3,DouglasR.Tocher1andJohnGordonBell1*1InstituteofAquaculture,UniversityofStirling,StirlingFK94LA,UK2BioMarAS,NordreGate11,N-7484Trondheim,Norway3NationalInstituteofNutritionandSeafoodResearch,N-5817Bergen,Norway(Received16June2009–Revised2December2009–Accepted4December2009–Firstpublishedonline1March2010)Thehealthbenefitsofseafoodarewelldocumentedandbasedontheuniquesupplyofn-3highlyunsaturatedfattyacids(HUFA).Aquaculturenowcontributesabout50%offood-gradeseafoodgloballyandAtlanticsalmon(Salmosalar)isarichsourceofn-3HUFA.However,salmonandotheroilyfishcanaccumulatelipophilicpersistentorganicpollutants(POP),includingdioxins(PCDD/F),polychlorinatedbiphenyls(PCB)andpolybrominateddiphenylethers(PBDE),derivedlargelyfromfeed.Inthepresentstudy,triplicategroupsofsalmon,ofinitialweight0·78kg,werefedoneofthreeexperimentaldietsfor11weeks.Thedietswerecoatedwitheitheranorthernfishoil(FO)withahighPOPcontent(cNFO),thesameoilthathadbeendecontaminated(deNFO)orablendofsouthernfishoil,rapeseedandsoyabeanoils(SFO/RO/SO).DietaryPCDD/Fþdioxin-likePCB(DL-PCB)concentrationswere17·36,0·45and0·53ngtoxicequivalents(TEQ)/kg,respectively.After11weeks,thefleshcon-centrationsinfishfedthecNFO,deNFOandSFO/RO/SOdietswere6·42,0·34and0·41ngTEQ/kg,respectively.TherewerenodifferencesinfleshEPAandDHAbetweenfishfedthecNFOordeNFOdietsalthoughEPAandDHAwerereducedby50and30%,respectively,infishfedtheSFO/RO/SOdiet.Thus,decontaminatedFOcanbeusedtoproducesalmonhighinn-3HUFAandlowinPOP.SalmonproducedusingdeNFOwouldbeofhighnutritionalvalueandverylowinPOPandwouldutilisevaluablefishoilsthatwouldotherwisebedestroyedduetotheirhighpollutantconcentrations.Fattyacidcomposition:Atlanticsalmon:Dioxins:Polychlorinatedbiphenyls:DecontaminatedfishoilInthe1970s,studiesonGreenlandInuitpopulationsestablishedthat,despiteconsuminghigh-lipiddiets,cardiacdiseasewasvirtuallyabsentinthesepopulationsandthatthiswasduetotheirhighfishintake(1).Subsequently,theben-eficialeffectsofn-3highlyunsaturatedfattyacids(HUFA),especiallyEPA(20:5n-3)andDHA(22:6n-3),havebeenshowntohavecardioprotectiveactivity(2,3).Morerecently,thebenefitsofincreasedEPAandDHAintakehavebeenshownforawiderangeoflifestyledisorderswithanassoci-atedinflammatorypathology(4,5)aswellasimprovingthesymptomsofcertainneurologicaldisorders(6).Duetotheprovenbenefitsofn-3HUFA,numerousgovernmentalandnon-governmentalorganisationsacrosstheworldcurrentlyadviseincreasedfishintakeasameansofimprovingthehealthoftheircitizens(7,8).Atlanticsalmon(Salmosalar)canstorelargequantitiesofoilintheirfleshandthismakesthemarichsourceofn-3HUFA(9,10).However,theoil-richfleshcanalsoaccumulatelipophilicundesirablecompounds,includingpolychlorinateddibenzo-p-dioxins(PCDD)andpolychlorinateddibenzofurans(PCDF)(collectivelyknownasdioxinsorPCDD/F),dioxin-likenon-orthoandmono-orthopolychlorinatedbiphenyls(PCB),knowncollectivelyasdioxin-like(DL)PCBandpoly-brominateddiphenylethers(PBDE),amongothers(11–15).Forthesereasonsthereiscurrentlyconsiderableinteresttoinves-tigatethetransferofpersistentorganicpollutants(POP)fromfeedtofarmedfishaswellasassessingthepotentialfortrans-fertohumansandanyconsequencesforhumanhealth(16,17).Thereare210dioxin(seventy-fivePCDDand135PCDFcongeners)and209PCBcongeners,ofwhichseventeenPCDD/PCDFcongenersandtwelveDL-PCBhavebeenassignedtoxicequivalencyfactors(TEF)bytheWHO,accordingtotheirrelativetoxicityto2,3,7,8tetrachlorinateddibenzodioxin(TCDD).TheconcentrationofPCDD/Fand*Correspondingauthor:ProfessorJohnGordonBell,faxþ441786472133,[e-mail]:ASEe,acceleratedsolventextractor;cNFO,controlnorthernfishoil;deNFO,decontaminatednorthernfishoil;DL,dioxin-like;EU,EuropeanUnion;FO,fishoil;FSA,FoodStandardsAgency;HUFA,highlyunsaturatedfattyacid;PBDE,polybrominateddiphenylether;PCB,polychlorinatedbiphenyl;PCDD,polychlorinateddibenzo-p-dioxin;PCDD/F,dioxins;PCDF,polychlorinateddibenzofuran;POP,persistentorganicpollutant;QC,quality-control;SFO/RO/SO,southernfishoil;rapeseedoil,soyabeanoil;TEF,toxicequivalencyfactor;TEQ,toxicequivalent;VO,vegetableoil.BritishJournalofNutrition(2010),103,1442–1451doi:10.1017/S0007114510000139qTheAuthors2010BritishJournalofNutritionDL-PCBisexpressedastoxicequivalents(TEQ),whereaTEFisappliedtotheconcentrationoftheindividualconge-nersandsummedtogeneratethetotalTEQinamixtureofthetwenty-ninePCDD/FandDL-PCBcongeners.TheTEFestablishedin1997bytheWHOhavebeenmostwidelyusedforhumanriskassessmentbygovernmentbodies(18);theseTEFwerere-evaluatedin2005(19).ApplicationofthesefactorstoindividualPCDD/FandDL-PCBcongenerconcentrationsinafeedorfishcanbeusedtodeterminethelevelofTEQpresent.PCDD/FandPCBhaveoriginatedeitherbynaturalmeans,suchasforestfiresandincompletecombustion(dioxins),orbyindustrialactivity(PCDD/FandPCB)andbothhavehalf-livesofseveraldecadesandarehighlypersistentinthemarinebiota(20).Inad