Food Safety Assessment: Trace Metal Concentrations in Onion (Allium cepa L.) from Kewot District, North Shoa, Ethiopia

Food Safety Assessment: Trace Metal Concentrations in Onion (Allium cepa L.) from Kewot District, North Shoa, Ethiopia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Food Safety Assessment: Trace Metal Concentrations in Onion (Allium cepa L.) from Kewot District, North Shoa, Ethiopia Kebede Shewatatek Demessie, Eskinder Teklu Bekele, Temesgen Girma Kebede, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7940511/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The present investigation focused on assessing the concentrations of heavy metals in onion bulb samples collected from two kebeles (townships) within North Shewa, Ethiopia, a region known for extensive cultivation of onions (Allium cepa L). Onion bulbs (Allium cepa, L.) were randomly collected from the farms in Yelen Kebele and Kewot District Terre. Following appropriate pre-treatment, ICP-MS was used to determine the concentration levels of selected metals. The optimum parameters of 240oC digestion temperature, (3mL of 69% HNO3, 2mL of 37% HClO4, and 0.5ml of 30% H2O2) volume of reagents and 3 hours’ digestion time were employed. The results obtained showed that the average concentrations of Zn, Cu, Pb and Cd in onion bulb samples were in the range of 2.15-3.05 mg/kg, 0.10-0.125 mg/kg, 0.03-0.04 mg/kg, 0.0001 mg/kg respectively. The percentage relative standard deviations were 17.0 to 19.9%, 3.4 – 3.5%, 7.0 t0 9.5% and 10.0% for Zn, Cu, Pb and Cd, respectively. The accuracy of the method, expressed as percentage recovery, was in the range of 95.3 -113.5%, with corresponding %RSD (n = 3) values ranging from 1.7–6.5% being obtained. Results of comparison of the level of metals with WHO/FAO standard limits revealed that the level of all analyzed heavy metals were below the corresponding metals permitted values for vegetables. Health risk assessment of onions from Terre and Yelen revealed very low estimated daily intakes and target hazard quotients for Zn, Cu, Pb, and Cd, with cumulative hazard indices well below the safety threshold of 1. This indicates negligible non-carcinogenic health risks from consuming these onions. Therefore, onions from both kebele are considered safe regarding heavy metal contamination. Onion bulb Allium cepa L. ICP- MS Trace Metal Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7940511","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":594950699,"identity":"2cb7ab70-efab-44f6-9448-b3dfbe3bc078","order_by":0,"name":"Kebede Shewatatek Demessie","email":"","orcid":"","institution":"Debre Berhan University","correspondingAuthor":false,"prefix":"","firstName":"Kebede","middleName":"Shewatatek","lastName":"Demessie","suffix":""},{"id":594950700,"identity":"c2295a64-725a-4de5-87bc-6d4992ac6830","order_by":1,"name":"Eskinder Teklu Bekele","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/UlEQVRIiWNgGAWjYFACNgYGHgMgzcPcwPCB7QBIyIAoLRIMPIwNjDMQWvBpA2lhgGhh5iFGCz//sbQHbwru1fHzHGyTtim7k9jA3rxNgqHiD04tkjPSjhvOMSiWkOxtbJPOOfcssYHnWJkEwxncthjcYG+T5jFIkDA4z9gmndt2OLFBIsdMgrENtxb788chWuxBWixBWuTfALX8w2MLQ9oxiC28QIcxgm3hAWppwK1F4kZamuQcgwTJGWcONlv2nHtm3MaTVmyRcMwYpxb+/mNmEm/+JPDz9yQfvPGj7I5sP/vhjTc+1Mjh1IIJ2EBEAgkaRsEoGAWjYBRgAgAemk90tWBEkwAAAABJRU5ErkJggg==","orcid":"","institution":"Debre Berhan University","correspondingAuthor":true,"prefix":"","firstName":"Eskinder","middleName":"Teklu","lastName":"Bekele","suffix":""},{"id":594950701,"identity":"b6d3ca16-98ce-4e52-9bdf-719436f6bcb3","order_by":2,"name":"Temesgen Girma Kebede","email":"","orcid":"","institution":"University of South Africa","correspondingAuthor":false,"prefix":"","firstName":"Temesgen","middleName":"Girma","lastName":"Kebede","suffix":""},{"id":594950702,"identity":"aee7468c-c9ca-4515-a64e-42033af4cb01","order_by":3,"name":"Ramakwala Christinah Chokwe","email":"","orcid":"","institution":"University of South Africa","correspondingAuthor":false,"prefix":"","firstName":"Ramakwala","middleName":"Christinah","lastName":"Chokwe","suffix":""},{"id":594950703,"identity":"bad1e39c-2c7a-480b-be96-7fa72300d52c","order_by":4,"name":"Simiso Dube","email":"","orcid":"","institution":"University of South Africa","correspondingAuthor":false,"prefix":"","firstName":"Simiso","middleName":"","lastName":"Dube","suffix":""},{"id":594950704,"identity":"873f4e9e-8ced-42ba-ab14-b01d6e9bfc2f","order_by":5,"name":"Mathew Muzi Nindi","email":"","orcid":"","institution":"University of South Africa","correspondingAuthor":false,"prefix":"","firstName":"Mathew","middleName":"Muzi","lastName":"Nindi","suffix":""}],"badges":[],"createdAt":"2025-10-25 01:51:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7940511/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7940511/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103505505,"identity":"5ab90277-c469-4b46-9f33-6696fe0b8a8c","added_by":"auto","created_at":"2026-02-26 13:31:32","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":511722,"visible":true,"origin":"","legend":"","description":"","filename":"FoodSafetyAssessmentManuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7940511/v1_covered_21b2bffb-394e-4a3e-bd2a-92bbf8c4b42e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eFood Safety Assessment: Trace Metal Concentrations in Onion (Allium cepa L.) from Kewot District, North Shoa, Ethiopia\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Onion bulb, Allium cepa, L., ICP- MS, Trace Metal","lastPublishedDoi":"10.21203/rs.3.rs-7940511/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7940511/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The present investigation focused on assessing the concentrations of heavy metals in onion bulb samples collected from two kebeles (townships) within North Shewa, Ethiopia, a region known for extensive cultivation of onions (Allium cepa L). Onion bulbs (Allium cepa, L.) were randomly collected from the farms in Yelen Kebele and Kewot District Terre. Following appropriate pre-treatment, ICP-MS was used to determine the concentration levels of selected metals. The optimum parameters of 240oC digestion temperature, (3mL of 69% HNO3, 2mL of 37% HClO4, and 0.5ml of 30% H2O2) volume of reagents and 3 hours’ digestion time were employed. The results obtained showed that the average concentrations of Zn, Cu, Pb and Cd in onion bulb samples were in the range of 2.15-3.05 mg/kg, 0.10-0.125 mg/kg, 0.03-0.04 mg/kg, 0.0001 mg/kg respectively. The percentage relative standard deviations were 17.0 to 19.9%, 3.4 – 3.5%, 7.0 t0 9.5% and 10.0% for Zn, Cu, Pb and Cd, respectively. The accuracy of the method, expressed as percentage recovery, was in the range of 95.3 -113.5%, with corresponding %RSD (n = 3) values ranging from 1.7–6.5% being obtained. Results of comparison of the level of metals with WHO/FAO standard limits revealed that the level of all analyzed heavy metals were below the corresponding metals permitted values for vegetables. Health risk assessment of onions from Terre and Yelen revealed very low estimated daily intakes and target hazard quotients for Zn, Cu, Pb, and Cd, with cumulative hazard indices well below the safety threshold of 1. This indicates negligible non-carcinogenic health risks from consuming these onions. Therefore, onions from both kebele are considered safe regarding heavy metal contamination.","manuscriptTitle":"Food Safety Assessment: Trace Metal Concentrations in Onion (Allium cepa L.) from Kewot District, North Shoa, Ethiopia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-24 03:45:43","doi":"10.21203/rs.3.rs-7940511/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"802d82f0-3397-4ad9-8d25-7907aa985377","owner":[],"postedDate":"February 24th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-02-24T03:45:43+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-24 03:45:43","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7940511","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7940511","identity":"rs-7940511","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}