生物技术转基因食品安全的英文论文.docx

生物技术转基因食品安全的英文论文.docx

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生物技术转基因食品安全的英文论文

Geneticallymodifiedfoodsafetyissues

Abstract

Asweallknow,modernbiotechnologyhasbroughthumannumerousbenefits:

Throughtheapplicationofbiotechnology,abroadandsignificantincreaseoffoodproductioncanbehappilyseenatglobalagriculturalproduction.ButwhenweenjoytheenormousbenefitsoftheGMfood,anewbutalarmingproblemalsocamethatifthesefoodissafeenoughforpeople?

ifsomethingseriouslyhappened,whatcanwedo?

Maybeyoucanfindsomeanswerinthisthesis.

Chapter1Introduction

Whatisbiotechnology?

Maybenottoomangpeopleknowitsdefinitionaccurately.Biotechnologyisatechnologywhichcanreformandmaketheuseofthenaturallivesontheingredientofthembytakingadvantageoftheresearchfindsinlifescienceswhichcangreatlyfollowthewillofpeople.Initspurestform,theterm"biotechnology"referstotheuseoflivingorganismsortheirproductstomodifyhumanhealthandthehumanenvironment.

Biotechnologyinoneformoranotherhasflourishedsinceprehistorictimes.Whenthefirsthumanbeingsrealizedthattheycouldplanttheirowncropsandbreedtheirownanimals,theylearnedtousebiotechnology.Thediscoverythatfruitjuicesfermentedintowine,orthatmilkcouldbeconvertedintocheeseoryogurt,orthatbeercouldbemadebyfermentingsolutionsofmaltandhopsbeganthestudyofbiotechnology.Whenthefirstbakersfoundthattheycouldmakeasoft,spongybreadratherthanafirm,thincracker,theywereactingasfledglingbiotechnologists.Thefirstanimalbreeders,realizingthatdifferentphysicaltraitscouldbeeithermagnifiedorlostbymatingappropriatepairsofanimals,engagedinthemanipulationsofbiotechnology.

Chapter2Statusofgeneticallymodifiedfoods

Asweallknow,modernbiotechnologyhasbroughthumannumerousbenifits:

Throughtheapplicationofbiotechnology,abroadandsignificantincreaseoffoodproductioncanbehappilyseenatglobalagriculturalproduction.Since1983whenthefirsttimehumangottransgenictobacco,potatobyusingrecombinantDNAtechnology,theplantgeneticengineeringtechnologyintheworldhasachievedrapiddevelopmentoftransgenicplantsforresearchanddevelopment,whichhasmadeaseriesofremarkableprogressandhasSuccessfullynurturedanumberofcropswithdisease-resistance,insecticideresistanceandevenanincrediblehigh-yield.withthehelpofthem,wecanfeedanothermorethanmillionsofpeople,Accordingtostatistics,uptonow,nolessthan1.6billionpeoplehavebenefitsfrombiotechnology.inthearea,ourmothercountryChinahasmadetremendouscontributionstotheworld'sbiotechnology.whatmustbementionedisBTcottonandhybridriceofYuanLongping.

Commercializegeneticallymodifiedcropsdatesfromtheyearof1996,includingSoybeans,cotton,cerealsandoilseedrape.GMcropsnowoccupy10%ofglobalarableland.In2010,81%ofworldwidesoybean,64%cotton,29%and23%ofthegrainisgeneticallymodifiedoilseedrape.Totally,29countriesgrowGMproductsallovertheworld.thetopthreecountrywiththelargestareaofcultivationisUnitedStates,BrazilandArgentina.TheproblemAboutthesafetyofGMproductshasbeencontroversial.Geneticallymodifiedfoodwillbringhumanandanimalallergensandtoxinsofunknown.

Chapter3GMfoodsafetyissues

Internationalconsensushasbeenreachedontheprinciplesregardingevaluationofthefoodsafetyofgeneticallymodifiedplants.Theconceptofsubstantialequivalencehasbeendevelopedaspartofasafetyevaluationframework,basedontheideathatexistingfoodscanserveasabasisforcomparingthepropertiesofgeneticallymodifiedfoodswiththeappropriatecounterpart.Applicationoftheconceptisnotasafetyassessmenpterse,buthelpstoidentifysimilaritiesanddifferencesbetweentheexistingfoodandthenewproduct,whicharethensubjecttofurthertoxicologicalinvestigation.Substantialequivalenceisastartingpointinthesafetyevaluation,ratherthananendpointoftheassessment.Consensusonpracticalapplicationoftheprincipleshouldbefurtherelaborated.Experienceswiththesafetytestingofnewlyinsertedproteinsandofwholegeneticallymodifiedfoodsarereviewed,andlimitationsofcurrenttestmethodologiesarediscussed.ThedevelopmentandvalidationofnewprofilingmethodssuchasDNAmicroarraytechnology,proteomics,andmetabolomicsfortheidentificationandcharacterizationofunintendedeffects,whichmayoccurasaresultofthegeneticmodification,isrecommended.Theassessmentoftheallergenicityofnewlyinsertedproteinsandofmarkergenesisdiscussed.Anissuethatwillgainimportanceinthenearfutureisthatofpost-marketingsurveillanceofthefoodsderivedfromgeneticallymodifiedcrops.Itisconcluded,amongothersthat,thatapplicationoftheprincipleofsubstantialequivalencehasprovenadequate,andthatnoalternativeadequatesafetyassessmentstrategiesareavailable.

Atanearlystageintheintroductionofrecombinant-DNAtechnologyinmodernplantbreedingandbiotechnologicalfoodproductionsystems,effortsbegantodefineinternationallyharmonizedevaluationstrategiesforthesafetyoffoodsderivedfromgeneticallymodifiedorganisms（GMOs）.Twoyearsafterthefirstsuccessfultransformationexperimentinplants（tobacco）in1988,theInternationalFoodBiotechnologyCouncil（IFBC）publishedthefirstreportontheissueofsafetyassessmentofthesenewvarieties（IFBC,1990）.Thecomparativeapproachdescribedinthisreporthaslaidthebasisforlatersafetyevaluationstrategies.Other

organizations,suchastheOrganisationforEconomicCooperationandDevelopment（OECD）,theFoodandAgricultureOrganizationoftheUnitedNations（FAO）andtheWorldHealthOrganization（WHO）andtheInternationalLifeSciencesInstitute（ILSI）havedevelopedfurtherguidelinesforsafetyassessmentwhichhaveobtainedbroadinternationalconsensusamongexpertsonfoodsafetyevaluation.

At1993.theOECDformulatedtheconceptofsubstantialequivalenceasaguidingtoolfortheassessmentofgeneticallymodifiedfoods,whichhasbeenfurtherelaboratedinthefollowingyears（OECD,1993;OECD,1996;OECD,1998;Figure1）.Theconceptofsubstantialequivalenceispartofasafetyevaluationframeworkbasedontheideathatexistingfoodscanserveasabasisforcomparingthepropertiesofageneticallymodifiedfoodwiththeappropriatecounterpart.Theexistingfoodsupplyisconsideredtobesafe,asexperiencedbyalonghistoryofuse,althoughitisrecognizedthatfoodsmaycontainmanyanti-nutrientsandtoxicantswhich,atcertainlevelsofconsumption,mayinducedeleteriouseffectsinhumansandanimals.Applicationoftheconceptisnotasafetyassessmentperse,buthelpstoidentifysimilaritiesandpotentialdifferencesbetweentheexistingfoodandthenewproduct,whichisthensubjecttofurthertoxicologicalinvestigation.Threescenariosareenvisionedinwhichthegeneticallymodifiedplantorfoodwouldbe（i）substantiallyequivalent;（ii）substantiallyequivalentexceptfortheinsertedtrait;or（iii）notequivalentatall.Acompositionalanalysisofkeycomponents,includingkeynutrientsandnaturaltoxicants,isthebasisofassessmentofsubstantialequivalence,inadditiontophenotypicandagronomiccharacteristicsofthegeneticallymodifiedplant.

Inthefirstscenario,nofurtherspecifictestingisrequiredastheproducthasbeencharacterizedassubstantiallyequivalenttoatraditionalcounterpartwhoseconsumptionisconsideredtobesafe,forexample,starchfrompotato.Inthesecondscenario,substantialequivalencewouldapplyexceptfortheinsertedtrait,andsothefocusofthesafetytestingisonthistrait,forexample,aninsecticidalproteinofgeneticallymodifiedtomato.Safetytestsincludespecifictoxicitytestingaccordingtothenatureandfunctionofthenewlyexpressedprotein;potentialoccurenceofunintendedeffects;potentialforgenetransferfromgeneticallymodifiedfoodstohuman/animalgutflora;thepotentialallergenicityofthenewlyinsertedtraits;andthe

roleofthenewfoodinthediet.Inthethirdscenario,thenovelcroporfoodwouldbenotsubstantiallyequivalentwithatraditionalcounterpart,andacase-by-caseassessmentofthenewfoodmustbecarriedoutaccordingtothecharacteristicsofthenewproduct.

FAO（shortforFoodandAgricultureOrganization）andWHO（WorldHealth

Organization）havebeenorganizingworkshopsandconsultationsonthesafetyofGMOssince1990.AttheJointFAO/WHOConsultationin1996（FAO/WHO,1996）itwasrecommendedthatthesafetyevaluationshouldbebasedontheconceptofsubstantialequivalence,whichis‘adynamic,analyticalexerciseintheassessmentof

thesafetyofanewfoodrelativetoanexistingfood’T.hefollowingparametersshouldbeconsideredtodeterminethesubstantialequivalenceofageneticallymodifiedplant:

molecularcharacterization;phenotypiccharacteristics;keynutrients;toxicants;andallergens.

Thedistinctionbetweenthreelevelsofsubstantialequivalence（complete,partial,non-）ofthenovelfoodtoitscounterpart,andthesubsequentdecisionsforfurthertestingbaseduponsubstantialequivalence,aresimilartothosedefinedbyOECD（1996）.

TheCodexAlimentariusCommissionofFAO/WHOiscommittedtotheinternationalharmonizationoffoodstandards.FoodstandardsdevelopedbyCodexAlimentariusshouldbeadoptedbytheparticipatingnationalgovernments.TheCodexadhocIntergovernmentalTaskForceonFoodsDerivedfromBiotechnologyhasthetasktodevelopstandards,guidelinesandotherrecommendationsforgeneticallymodifiedfoods.DuringitsfirstsessioninChiba（Japan）inMarch2000definitionswere