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1、AssessingpotentialdietarytoxicityofheavymetalsinselectedvegetablesandfoodcropsAbstract:Heavymetals,suchascadmium,copper,lead,chromiumandmercury,areimportantenvironmentalpollutants,particularlyinareaswithhighanthropogenicpressure.Theirpresenceintheatmosphere,soilandwater,evenintracescancaus
2、eseriousproblemstoallorganisms,andheavymetalbioaccumulationinthefoodchainespeciallycanbehighlydangeroustohumanhealth.Heavymetalsenterthehumanbodymainlythroughtworoutesnamely:inhalationandingestion,ingestionbeingthemainrouteofexposuretotheseelementsinhumanpopulation.Heavymetalsintakebyhuman
3、populationsthroughfoodchainhasbeenreportedinmanycountries.Soilthresholdforheavymetaltoxicityisanimportantfactoraffectingsoilenvironmentalcapacityofheavymetalanddeterminesheavymetalcumulativeloadinglimits.Forsoil-plantsystem,heavymetaltoxicitythresholdisthehighestpermissiblecontentinthesoil
4、(totalorbioavailableconcentration)thatdoesnotposeanyphytotoxiceffectsorheavymetalsintheediblepartsofthecropsdoesnotexceedfoodhygienestandards.Factorsaffectingthethresholdsofdietarytoxicityofheavymetalinsoil-cropsysteminclude:soiltypewhichincludessoilpH,organicmattercontent,claymineralandot
5、hersoilchemicalandbiochemicalproperties;andcropspeciesorcultivarsregulatedbygeneticbasisforheavymetaltransportandaccumulationinplants.Inaddition,theinteractionsofsoil-plantroot-microbesplayimportantrolesinregulatingheavymetalmovementfromsoiltotheediblepartsofcrops.Agronomicpracticessuchasf
6、ertilizerandwatermanagementsaswellascroprotationsystemcanaffectbioavailabilityandcropaccumulationofheavymetals,thusinfluencingthethresholdsforassessingdietarytoxicityofheavymetalsinthefoodchain.Thispaperreviewsthephytotoxiceffectsandbioaccumulationofheavymetalsinvegetablesandfoodcropsandas
7、sessessoilheavymetalthresholdsforpotentialdietarytoxicity.Keywords:Heavymetals,Dietarytoxicity,Vegetables,Foodcrops1.IntroductionRegulation,handlingandbioremediationofhazardousmaterialsrequireanassessmentoftherisktosomelivingspeciesotherthanhumanbeing,orassess
