Heavy Metals in Coal Fire Sponges in the Wuda Coalfield, Inner Mongolia

Heavy Metals in Coal Fire Sponges in the Wuda Coalfield, Inner Mongolia | 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 Research Article Heavy Metals in Coal Fire Sponges in the Wuda Coalfield, Inner Mongolia Guiyu Wu, Xiuping Hong, Lichao Zhang, Fei Liu, Xin Wang, Yingying Zhang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7533939/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 20 Nov, 2025 Read the published version in Environmental Geochemistry and Health → Version 1 posted 11 You are reading this latest preprint version Abstract Coal fire sponge (CFS) is a sponge-like pollutant commonly found in areas affected by coal fires. This study investigated heavy metals in CFSs and soil samples in the vicinity of the Wuda Coalfield, Inner Mongolia. Studies of the sources and functions of heavy metals in CFSs and their impacts on the surroundings were conducted. The concentrations of Hg, Cd, As, Cr, and Zn were determined using inductively coupled plasma mass spectrometryand atomic fluorescence spectrometry. The results revealed that the concentrations of Hg (16,831.39 ng/g), As (30.32 μg/g), Cd (11.7 μg/g), Cr (185.99 μg/g), and Zn (795.06 μg/g) in CFSs were significantly higher than those in background samples, which indicates that CFSs have become a significant point source of heavy metal pollution in the region. The positive matrix factorization model identified four sources of heavy metals in CFSs: the accumulation of coal gangue, underground coal fires, industrial and traffic composite sources, and natural sources. Underground coal fires were the primary contributors, accounting for 43.6% of the total heavy metals. The ecological risk assessment demonstrated that Cd and Hg were the dominant potential risk factors, with CFSs exhibitinglevels ranging from heavily to extremely contaminated. CFSs not only effectively capture heavy metals from coal-fire emissions, but also serve as natural collectors of coal-fire pollutants, providing a convenient resource to study the chemical composition of coal-fire smoke. Coal fire area Coal fire sponge Heavy metals Risk assessment Full Text Additional Declarations No competing interests reported. Supplementary Files SupplementaryMaterial.docx Cite Share Download PDF Status: Published Journal Publication published 20 Nov, 2025 Read the published version in Environmental Geochemistry and Health → Version 1 posted Editorial decision: Revision requested 13 Oct, 2025 Reviews received at journal 25 Sep, 2025 Reviews received at journal 13 Sep, 2025 Reviewers agreed at journal 12 Sep, 2025 Reviewers agreed at journal 11 Sep, 2025 Reviewers agreed at journal 10 Sep, 2025 Reviewers agreed at journal 10 Sep, 2025 Reviewers invited by journal 09 Sep, 2025 Editor assigned by journal 05 Sep, 2025 Submission checks completed at journal 04 Sep, 2025 First submitted to journal 04 Sep, 2025 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-7533939","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":514554926,"identity":"f55c41fc-6bc4-46a5-94ee-c34ceae2031c","order_by":0,"name":"Guiyu Wu","email":"","orcid":"","institution":"Huaibei Normal University","correspondingAuthor":false,"prefix":"","firstName":"Guiyu","middleName":"","lastName":"Wu","suffix":""},{"id":514554927,"identity":"b9075110-830e-4da8-b8e3-a8eab584c1ef","order_by":1,"name":"Xiuping Hong","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIie2RsW7CMBCGHSHddKXroaDkFYwiVQyIvIojECwdOlWZWJDSJd2DxEuwMDuKxBTBA3jJI4QtY+2yMNSBsYO/yTr50+//zJjD8S9BJltOCGElpehmDJ5QvLJIp8GQIGmu+eopZVBhnUYBYTQpoHoscPUty11GSebnbz7iJR7624Z16dGqjPZnIa9GGZ8+fZwqc+BeXiur8krv/JbCFkedogSQ4AMvsyuglerlVxH6YXCOgdZtr2JSdH2KgJamvvQyPelVRvua6yVTAHgyS14kWvko+7pwlUdtyzcYfm3NV87jsFgfmi61K4z+Gkr7fZvicDgcjnt+AF0XWaZ+w+PjAAAAAElFTkSuQmCC","orcid":"","institution":"Huaibei Normal University","correspondingAuthor":true,"prefix":"","firstName":"Xiuping","middleName":"","lastName":"Hong","suffix":""},{"id":514554928,"identity":"baecf7c9-5a59-4cfb-90ee-accd5f3b0ab7","order_by":2,"name":"Lichao Zhang","email":"","orcid":"","institution":"Huaibei Normal University","correspondingAuthor":false,"prefix":"","firstName":"Lichao","middleName":"","lastName":"Zhang","suffix":""},{"id":514554929,"identity":"7fc97669-25ef-4cbb-b5c2-dadad73b07fd","order_by":3,"name":"Fei Liu","email":"","orcid":"","institution":"Huaibei Normal University","correspondingAuthor":false,"prefix":"","firstName":"Fei","middleName":"","lastName":"Liu","suffix":""},{"id":514554930,"identity":"19fd7654-b964-4ae8-b46d-7267462f6ad8","order_by":4,"name":"Xin Wang","email":"","orcid":"","institution":"Huaibei Normal University","correspondingAuthor":false,"prefix":"","firstName":"Xin","middleName":"","lastName":"Wang","suffix":""},{"id":514554932,"identity":"a085433c-a4db-420c-909c-ce2be29b13b2","order_by":5,"name":"Yingying Zhang","email":"","orcid":"","institution":"Huaibei Normal University","correspondingAuthor":false,"prefix":"","firstName":"Yingying","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2025-09-04 08:38:25","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7533939/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7533939/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10653-025-02893-z","type":"published","date":"2025-11-20T15:58:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":96650167,"identity":"e6c95ac2-a567-4e57-acc5-f53743847611","added_by":"auto","created_at":"2025-11-24 16:09:08","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":781894,"visible":true,"origin":"","legend":"","description":"","filename":"manuscipt.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7533939/v1_covered_c9ca83fd-c4f4-4488-b01f-6a31e6984c29.pdf"},{"id":91598413,"identity":"795ed7ab-4965-4834-9199-ec96fa36d345","added_by":"auto","created_at":"2025-09-18 08:09:06","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":37767,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-7533939/v1/97c970afc20ea7c78c4e4ba0.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Heavy Metals in Coal Fire Sponges in the Wuda Coalfield, Inner Mongolia","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"environmental-geochemistry-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"egah","sideBox":"Learn more about [Environmental Geochemistry and Health](https://www.springer.com/journal/10653)","snPcode":"10653","submissionUrl":"https://submission.nature.com/new-submission/10653/3","title":"Environmental Geochemistry and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Coal fire area, Coal fire sponge, Heavy metals, Risk assessment","lastPublishedDoi":"10.21203/rs.3.rs-7533939/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7533939/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCoal fire sponge (CFS) is a sponge-like pollutant commonly found in areas affected by coal fires. This study investigated heavy metals in CFSs and soil samples in the vicinity of the Wuda Coalfield, Inner Mongolia. Studies of the sources and functions of heavy metals in CFSs and their impacts on the surroundings were conducted. The concentrations of Hg, Cd, As, Cr, and Zn were determined using inductively coupled plasma mass spectrometryand atomic fluorescence spectrometry. The results revealed that the concentrations of Hg (16,831.39 ng/g), As (30.32 μg/g), Cd (11.7 μg/g), Cr (185.99 μg/g), and Zn (795.06 μg/g) in CFSs were significantly higher than those in background samples, which indicates that CFSs have become a significant point source of heavy metal pollution in the region. The positive matrix factorization model identified four sources of heavy metals in CFSs: the accumulation of coal gangue, underground coal fires, industrial and traffic composite sources, and natural sources. Underground coal fires were the primary contributors, accounting for 43.6% of the total heavy metals. The ecological risk assessment demonstrated that Cd and Hg were the dominant potential risk factors, with CFSs exhibitinglevels ranging from heavily to extremely contaminated. CFSs not only effectively capture heavy metals from coal-fire emissions, but also serve as natural collectors of coal-fire pollutants, providing a convenient resource to study the chemical composition of coal-fire smoke.\u003c/p\u003e","manuscriptTitle":"Heavy Metals in Coal Fire Sponges in the Wuda Coalfield, Inner Mongolia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-18 08:01:01","doi":"10.21203/rs.3.rs-7533939/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-13T06:05:55+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-25T10:08:35+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-13T11:04:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"92535123270627126389526558544884307360","date":"2025-09-12T08:02:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"279139644114388305345711403642378958322","date":"2025-09-11T06:29:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"9723924651365735225066969728166445368","date":"2025-09-10T09:51:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243078085312763243269029905130562153994","date":"2025-09-10T08:28:12+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-10T00:14:22+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-05T18:15:37+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-04T19:37:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Geochemistry and Health","date":"2025-09-04T08:26:24+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-geochemistry-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"egah","sideBox":"Learn more about [Environmental Geochemistry and Health](https://www.springer.com/journal/10653)","snPcode":"10653","submissionUrl":"https://submission.nature.com/new-submission/10653/3","title":"Environmental Geochemistry and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"e0177dca-2c5f-41bd-8b4b-d43f987e2226","owner":[],"postedDate":"September 18th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-24T16:02:23+00:00","versionOfRecord":{"articleIdentity":"rs-7533939","link":"https://doi.org/10.1007/s10653-025-02893-z","journal":{"identity":"environmental-geochemistry-and-health","isVorOnly":false,"title":"Environmental Geochemistry and Health"},"publishedOn":"2025-11-20 15:58:00","publishedOnDateReadable":"November 20th, 2025"},"versionCreatedAt":"2025-09-18 08:01:01","video":"","vorDoi":"10.1007/s10653-025-02893-z","vorDoiUrl":"https://doi.org/10.1007/s10653-025-02893-z","workflowStages":[]},"version":"v1","identity":"rs-7533939","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7533939","identity":"rs-7533939","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}