Determination ofconcentration levels of selected heavy Metals in common vegetables from hidabu abote district, Northshoazone ,Oromia regionalstate,Ethiopia

Abstract

Vegetablesarevitaltohumandietprovidingessentialnutrientstomaintainnormal physiologicalfunctions.Contaminationofagriculturalcropsincludingvegetablesbyheavy metalsduetogeochemicalprocessesandvariousanthropogenicactivitiesarebecoming priorityconcernworldwide.Thisstudyaimstoinvestigateconcentrationofselectedheavy metalsincabbageandsupportingsoilsamplescollectedfrom potentiallyvegetableproducing threevillagesofHidabuAbotedistrictofNorthShowa,Oromiaregionalstate,Ethiopia.Wetacid digestiontechniquewasemployedtodigestthecabbageandsoilsamples.Thecabbage samplewasdigestedusingmixtureofHNO3,HClO4andH2O2involumeratioof4:3:1,whilefor soilsampledigestionmixtureofHF,HNO3,HClO4andHClwereusedinvolumeratioof5:5:3:5 followingstandardprotocols.FAASwasemployedforheavymetalsanalysis.Estimationof qualitycontrolparameterswerealsocarriedouttovalidatetheusedanalyticalmethod.The measuredvaluesofmethodvalidationparameterswererangedfrom 0.018–0.037mg/kg-dw, 0.9918–0.9996,81.4–116.1%and0.4977–12.49%,forLOQ,r2 ,%recovery,and%RSD, respectively.Ourresultshowedthatallthestudiedheavymetalswerefound/quantifiedinall cabbageandsoilsamples.Themean(minimum –maximum)valuesofthestudiedheavy metalsmeasuredwere0.74(0.11-2.22)mg/kg-dw,and0.846(0.176-2.22)mg/kg-dwin cabbageandsupportingsoilsamples,respectively.Theconcentrationsofthemetalsin cabbageareintheorderofCd<Pb<Zn<Cu<Ni<Co<Cr,butinsupportingsoilfollowedthe orderofCd<Pb<Co<Cu<Ni<Zn<Cr.Thecomparisonofourresultswithinternationally establishedstandardlimitsshowedthatCd,CrandPbconcentrationlevelsincabbage exceededtheguidelinevalue,indicatingtheirpossiblehealthrisktotheconsumers