{ "abstract": "Fluoride (F¯) is a global geogenic contaminant in groundwater, occurring at elevated concentrations across almost every continent. While optimal fluoride intake benefits dental health, levels exceeding the WHO safe limit (1.5 mg L −1 ) can cause dental fluorosis and even severe skeletal fluorosis, with drinking water being the primary exposure pathway. Understanding the global occurrence and geochemistry of fluoride in groundwater is essential for minimizing associated health risks. Therefore, this study reviews the incidence, distribution, mobilization mechanisms of fluoride in groundwater, and identifies the key knowledge gaps related to fluoride contamination worldwide. The study presents a large-scale synthesis of contaminated aquifers, cost-effective defluoridation methods, socio-economic challenges, and strategies for safe drinking water supply. This was done by adopting the PRISMA 2020 systematic review framework with review period between 1953 and 2025. Findings confirm that fluoride contamination is prevalent in Asia, Africa, the Middle East, Europe, and the Americas, driven mainly by fluorine-bearing minerals in aquifers. Key factors intensifying the contamination includes hydrogeochemical conditions such as high pH, Na–HCO 3 water types, and low calcium (Ca 2+ ) concentrations. Identified hotspot are the East African Rift Valley, Indo-Gangetic plains, northern China, and volcanic or geothermal regions in Mexico and Türkiye, with localized anomalies observed in Estonia, Poland, and Australia. Anthropogenic inputs contribute in some localized areas, although their impact is minimal. The fluoride levels are particularly high in arid and semi-arid regions, where evaporation and prolonged water–rock interaction accelerate fluoride mobilization. Despite decades of research, monitoring gaps persist, and mitigation remains challenging, especially for rural communities who are entirely dependent on untreated groundwater. This study recommends prioritizing efforts on scalable, cost-effective solutions to provide fluoride-safe water, particularly in areas where populations are largely vulnerable.", "abstract_shown": true, "affiliations": [ "Department of Civil Engineering Science, Faculty of Engineering & the Built Environment, University of Johannesburg, Auckland Park, Kingsway Campus, Johannesburg, South Africa. shakiriitb@gmail.com", "School of Geosciences, The University of Edinburgh, Edinburgh, EH8 9XP, Scotland", "Department of Water Resources and Ecosystems, IHE Delft Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands", "School of Earth, Environment, and Sustainability, Missouri State University, Springfield, USA", "Department of Biosystems Engineering, Auburn University, Auburn, AL, 36849, USA", "Centre of Excellence in Environmental Science and Sustainability, Sir Padampat Singhania University, Udaipur, 313601, Rajasthan, India", "Department of Chemical Sciences, Faculty of Science, University of Johannesburg, Auckland Park, P.O. Box 524, Johannesburg, 2006, South Africa", "Mining Engineering, Faculty of Integrated and Advanced Technology, Sir Padampat Singhania University, Udaipur, 313601, Rajasthan, India", "Department of Civil Engineering, University of South Africa, [Florida Science Campus], Cnr Christian de Wet Road and Pioneer Avenue, Johannesburg, South Africa", "Department of Geology, Institute of Ecology and Earth Sciences, University of Tartu, Ravila 14a, 50411, Tartu, Estonia", "Department of Geology, Chukwuemeka Odumegwu Ojukwu University, Uli, Nigeria", "Research Management Office (RMO), Chukwuemeka Odumegwu Ojukwu University, Anambra, Nigeria", "Department of Chemical Engineering, University of Science and Technology of Mazandaran, Behshahr, Iran", "School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK", "Department of Geology, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka", "School of Water and Environment, Chang'an University, No. 126 Yanta Road, Xi'an, 710054, Shaanxi, China", "Disaster Science and management, Begum Rokeya University, Rangpur, 5400, Bangladesh", "Department of Earth and Environmental Sciences, Korea University, Seoul, 02841, South Korea", "Geography Department, Geosciences Institute, Universidade Federal Fluminense, Rio de Janeiro, Brazil", "Instituto de Geología de Costas y del Cuaternario (U.N. Mar del Plata-CIC BA), Instituto de Investigaciones Marinas y Costeras (CONICET-U.N. Mar del Plata), Mar del Plata, Argentina", "Department of the International Water Resources, Izmir Institute of Technology, Izmir, Türkiye", "Department of Environmental Sciences, Balochistan University of Information Technology Engineering and Management Sciences (BUITEMS), Quetta, Pakistan", "Department of Geology, Yazd University, Yazd, Iran", "Department of Earth & Environmental Sciences, Sana'a University, Sana'a, Yemen", "DAFWAT Research Group, Department of Water Resources Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar Es Salaam, Tanzania", "Geospatial Data Sciences and Technology (Geomatics) Section, Department of Transportation and Geotechnical Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar Es Salaam, Tanzania", "Water and Environmental Management Research Group, Faculty of Science, Engineering and Agriculture, University of Venda, Limpopo Province, Thohoyandou, 0950, South Africa", "Department of Water and Environmental Regulation, Perth, WA, Australia", "Polish Geological Institute-National Research Institute, Warsaw, Poland", "Centro de Investigaciones de Materiales Avanzados, Dgo.34147, Durango, México", "Institute of Geography and Geoecology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia", "Centre for Ecology Environment and Sustainable Development, Tata Institute of Social Sciences, Guwahati, Assam, India", "Environmental Hydro Geochemistry Lab, Department of Environmental Sciences, Quaid-I-Azam University, Islamabad, Pakistan", "Department of Chemical Engineering, Ege University, Izmir, Türkiye", "Department of Chemical Engineering, Izmir Institute of Technology, Izmir, Türkiye", "Área de Toxicología, Universidad de La Laguna, 38071, La Laguna, Tenerife, Islas Canarias, Spain", "KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, 114 28, Stockholm, Sweden" ], "article_type": "review", "arxiv": null, "author_total": 32, "authors": [ { "affs": [ 0 ], "name": "Shakir Ali", "orcid": "0000-0002-7743-9965" }, { "affs": [ 1 ], "name": "Pratibha Mishra", "orcid": "0009-0004-2737-2100" }, { "affs": [ 2 ], "name": "K. Brindha", "orcid": "0000-0002-4369-276X" }, { "affs": [ 3 ], "name": "Melida Gutiérrez" }, { "affs": [ 4 ], "name": "Rakesh Kumar", "orcid": "0000-0001-7264-5682" }, { "affs": [ 5, 6, 7 ], "name": "Emmanuel Daanoba Sunkari", "orcid": "0000-0002-0898-2286" }, { "affs": [ 8 ], "name": "Patrick Kirita Gevera", "orcid": "0000-0001-5760-425X" }, { "affs": [ 9 ], "name": "Enn Karro", "orcid": "0000-0002-0510-6926" }, { "affs": [ 10, 11 ], "name": "Johnbosco C. Egbueri", "orcid": "0000-0003-0281-1213" }, { "affs": [ 12, 13 ], "name": "Reza Dehbandi", "orcid": "0000-0001-5575-4713" }, { "affs": [ 14 ], "name": "Rohana Chandrajith", "orcid": "0000-0003-3072-5240" }, { "affs": [ 15 ], "name": "Peiyue Li", "orcid": "0000-0001-8771-3369" }, { "affs": [ 16 ], "name": "Abu Reza Md. Towfiqul Islam", "orcid": "0000-0001-5779-1382" }, { "affs": [ 17 ], "name": "Seong‐Taek Yun", "orcid": "0000-0001-9443-2872" }, { "affs": [ 18 ], "name": "Hullysses Sabino", "orcid": "0000-0002-3200-9507" }, { "affs": [ 19 ], "name": "MARTÍNEZ DANIEL EMILIO" }, { "affs": [ 20 ], "name": "Alper Baba", "orcid": "0000-0001-5307-3156" }, { "affs": [ 21 ], "name": "Taimoor Shah Durrani", "orcid": "0000-0003-2478-4842" }, { "affs": [ 22 ], "name": "Vahab Amiri", "orcid": "0000-0001-9734-9812" }, { "affs": [ 23 ], "name": "Adnan Aqeel" }, { "affs": [ 24, 25 ], "name": "Julian Ijumulana", "orcid": "0000-0002-7435-1677" }, { "affs": [ 26 ], "name": "Joshua Nosa Edokpayi", "orcid": "0000-0002-2550-3988" }, { "affs": [ 27 ], "name": "David Schäfer" }, { "affs": [ 28 ], "name": "Lidia Razowska-Jaworek", "orcid": "0000-0001-9834-8491" }, { "affs": [ 29 ], "name": "María Teresa Alarcón-Herrera" }, { "affs": [ 30 ], "name": "Odsuren Batdelger", "orcid": "0000-0003-3879-8401" }, { "affs": [ 31 ], "name": "Ritusmita Goswami", "orcid": "0000-0003-2834-2638" }, { "affs": [ 32 ], "name": "A Farooqi" }, { "affs": [ 19 ], "name": "Alcaraz Emiliano Fabio" }, { "affs": [ 33, 34 ], "name": "Yaşar Kemal Recepoğlu", "orcid": "0000-0001-6646-0358" }, { "affs": [ 35 ], "name": "Soraya Paz Montelongo" }, { "affs": [ 36 ], "name": "Prosun Bhattacharya", "orcid": "0000-0003-4350-9950" } ], "bibtex": "https://research.draconitic.com/paper/99bnmv5dk8zps.bib", "cited_by": 5, "doi": "10.1007/s10653-026-03187-8", "fulltext_url": null, "id": "99bnmv5dk8zps", "issns": [ "0269-4042", "1573-2983" ], "landing_url": "https://doi.org/10.1007/s10653-026-03187-8", "language": "en", "licence": "CC-BY", "licence_label": "CC BY", "licence_source": "journal", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "openalex", "2312|Fluoride Effects and Removal" ] ], "openalex": "W7165004988", "pdf_url": "https://link.springer.com/content/pdf/10.1007/s10653-026-03187-8.pdf", "pmcid": "PMC13275634", "pmid": "42307780", "published": "2026-06-01", "publisher": "Springer Science+Business Media", "ris": "https://research.draconitic.com/paper/99bnmv5dk8zps.ris", "sources": [ { "first_seen": "2026-11-06T13:20:43Z", "native_id": "W7165004988", "source": "openalex", "url": "https://doi.org/10.1007/s10653-026-03187-8" } ], "subjects": [ { "field": "earth", "origin": "openalex:2312|Fluoride Effects and Removal", "subfield": "hydrology-soils" } ], "title": "Global groundwater contamination by geogenic fluoride", "title_text": "Global groundwater contamination by geogenic fluoride", "type": "peer-reviewed", "updated_at": "2026-11-08T13:20:55Z", "url": "https://research.draconitic.com/paper/99bnmv5dk8zps", "venue": "Environmental Geochemistry and Health", "versions": [] }