Fluoride contamination in groundwater: A global review of the status, processes, challenges, and remedial measures

Abstract

Groundwater pollution by fluoride is one of the prime concerns of the world population due to its toxicity, which results in adverse health impacts. In this paper, we review the current scenario of the fluoride contamination of groundwater in various countries across the globe and its impact on human health. During the last decade, several newly affected regions have been reported all over the world, with more than 100 countries affected by fluoride contamination in groundwater (concentration exceeding the acceptable limit of 1.5 mg/L defined by the World Health Organization). Fluoride poisoning is mainly due to the unsupervised ingestion of products for dental and oral hygiene and over-fluoridated drinking water. It is estimated that more than 200 million people from different countries are affected by fluoride-related groundwater issues and health problems. The highest among these are from the countries in Africa (38), Asia (28), and Europe (24), followed by countries like South America (5), North America (3), and Australia (2). The source of fluoride in drinking water is primarily geogenic, together with forage, grasses and grains, tea, and anthropogenic sources. These countries affected were correlated with climatic zones and geological factors to gain insights into geospatial relations. Our analyses show that most of the fluoride pollution-prone zones are located in high-grade metamorphic terranes with granitoid or alkaline intrusions, geothermal hot springs, and volcanic regions with arid or semi-arid climatic conditions. This study also finds that children across the globe are more vulnerable than adults to fluoride contamination. The review finds that, although there are efficient fluoride removal techniques, including filters with next-generation nanomaterials, to date, there has not been a single technique developed that can claim to be a practically robust solution for fluoride removal from drinking water. Therefore, we suggest developing next-generation filters that can retain essential minerals in water and remove only harmful ones and selecting purification technologies according to need, climate, geology, and geographic location. The findings from our review would help policymakers take effective and sustainable measures for safe water supply in the affected areas. Within the framework of the Sustainable Development Goals (SDGs), particularly SDG 3 (Good Health and Well-being) and SDG 6 (Clean Water and Sanitation), this study emphasizes the critical role of fluoride as a key indicator. It underscores the imperative of addressing elevated fluoride levels in drinking water, particularly in African and Asian countries, to achieve the overarching objective of universal and equitable access to safe, affordable, and uncontaminated drinking water for global society by the targeted year of 2030.

Keywords

Fluoride / Groundwater / Water contamination / WHO standards / Climate zones / Remediation / Sustainable Development Goals

References

M.Y.Z. Abouleish. Evaluation of fluoride levels in bottled water and their contribution to health and teeth problems in the United Arab Emirates. The Saudi Dental Journal, 28 (4) (2016), pp. 194-202

J.L. Adam. Fluoride glass research in France: fundamentals and applications. J. Fluor. Chem., 107 (2) (2001), pp. 265-270

M.J. Addison, M.O. Rivett, H. Robinson, A. Fraser, A.M. Miller, P. Phiri, R.M. Kalin. Fluoride occurrence in the lower East African rift system, southern Malawi. Sci. Total Environ., 712 (2020), Article 136260

M.J. Addison, M.O. Rivett, O.L. Phiri, N. Milne, V. Milne, A.D. Mahon, R.M. Kalin. ‘Hidden hot springs’ as a source of groundwater fluoride and severe dental fluorosis in Malawi. Water, 13 (8) (2021), p. 1106

O.A. Adeyeye, C. Xiao, Z. Zhang, A.S. Yawe, X. Liang. Groundwater fluoride chemistry and health risk assessment of multi-aquifers in Jilin Qianan. Northeastern China. Ecotoxicology and Environmental Safety, 211 (2021), Article 111926

N. Adimalla, P. Li, H. Qian. Evaluation of groundwater contamination for fluoride and nitrate in semi-arid region of Nirmal Province, South India: a special emphasis on human health risk assessment (HHRA). Human and Ecological Risk Aeeseement, 25 (2018), pp. 81-103

N.I. Agalakova, O.V. Nadei. Inorganic fluoride and functions of brain. Crit. Rev. Toxicol., 50 (1) (2020), pp. 28-46

V. Agrawal, A.K. Vaish, P. Vaish. Groundwater quality: focus on fluoride and fluorosis in Rajasthan. Curr. Sci., 73 (9) (1997), pp. 743-746

A. Aiuppa, S. Bellomo, L. Brusca, W. d'Alessandro, C. Federico. Natural and anthropogenic factors affecting groundwater quality of an active volcano (Mt. Etna, Italy). Appl. Geochem., 18 (6) (2003), pp. 863-882

O.Y. Akimov, V.O. Kostenko. Role of NF-κB transcriptional factor activation during chronic fluoride intoxication in development of oxidative-nitrosative stress in rat’s gastric mucosa. J. Trace Elem. Med Biol., 61 (2020), Article 126535

A.I. Alabdulaaly, A.I. Al-Zarah, M.A. Khan. Occurrence of fluoride in ground waters of Saudi Arabia. Appl Water Sci, 3 (2013), pp. 589-595

A.A. Alcaine, C. Schulz, J. Bundschuh, G. Jacks, R. Thunvik, J.P. Gustafsson, C.M. Mörth, O. Sracek, A. Ahmad, P. Bhattacharya. Hydrogeochemical controls on the mobility of arsenic, fluoride and other geogenic co-contaminants in the shallow aquifers of northeastern La Pampa Province in Argentina. Sci. Total Environ., 715 (2020), pp. 136-671

S. Alemu, E. Mulugeta, F. Zewge, B.S. Chandravanshi. Water defluoridation by aluminium oxide–manganese oxide composite material. Environ Technol, 35 (15) (2014), pp. 1893-1903

S. Ali, Y. Fakhri, M. Golbini, S.K. Thakur, A. Alinejad, I. Parseh, P. Bhattacharya. Concentration of fluoride in groundwater of India: a systematic review, meta-analysis and risk assessment. Groundw. Sustain. Dev., 9 (2019), pp. 100-224

B. Alloway, J. Centeno, R. Finkelman, R. Fuge, U. Lindh, P. Smedley. Essentials of Medical Geology. (Revised Edition.), Springer Science & Business Media (2013)

H. Amano, T. Ichikawa, K. Fujimoto, K. Nakagawa. Hydrogeochemical factors controlling the fluoride concentration in spring/groundwater in Aso caldera in the volcanic region, Japan. Environ Earth Sci, 82 (2023), p. 321

N. Ameer, G. Mustafa, I. Khan, M. Zahid, M. Yasinzai, S. Shahab, S. Ahmad. Chemical sensors: promising tools for the online monitoring of fluorides. Flioride, 51 (3) (2018), pp. 252-266

E. Antonijevic, Z. Mandinic, M. Curcic, D. Djukic-Cosic, N. Milicevic, M. Ivanovic, M. Carevic, B. Antonijevic. “Borderline” fluorotic region in Serbia: correlations among fluoride in drinking water, biomarkers of exposure and dental fluorosis in schoolchildren. Environ. Geochem. Health, 38 (2016), pp. 885-896

T. Aoba. The effect of fluoride on apatite structure and growth. Crit. Rev. Oral Biol. Med., 8 (2) (1997), pp. 136-153

W.B. Apambire, D.R. Boyle, F.A. Michel. Geochemistry, genesis, and health implications of fluoriferous groundwaters in the upper regions of Ghana. Environ. Geol., 33 (1997), pp. 13-24

I. Arnala, E.M. Alhava, P. Kauranen. Effects of fluoride on bone in Finland: Histomorphometry of cadaver bone from low and high fluoride areas. Acta Orthop. Scand., 56 (2) (1985), pp. 161-166

E. Asav, E. Yorganci, E. Akyilmaz. An inhibition type amperometric biosensor based on tyrosinase enzyme for fluoride determination. Talanta, 78 (2) (2009), pp. 553-556

G. Asgari, B. Roshani, G. Ghanizadeh. The investigation of kinetic and isotherm of fluoride adsorption onto functionalize pumice stone. J. Hazard. Mater., 217 (2012), pp. 123-132

T. Ayenew. The distribution and hydrogeological controls of fluoride in the groundwater of central Ethiopian rift and adjacent highlands. Environ. Geol., 54 (2008), pp. 1313-1324

S. Ayoob, A.K. Gupta. Fluoride in drinking water: a review on the status and stress effects. Crit. Rev. Environ. Sci. Technol., 36 (6) (2006), pp. 433-487

F. Aziz, I. Din, S. Khan, M. Khan, G. Mustafa, F. Nawab, K. Ahmad. Fluorides in drinking water and its health risk assessment in district Malakand, Khyber Pakhtunkhwa, Pakistan. Arab. J. Geosci., 14 (2021), pp. 1-9

T. Balaji, T. Yokoyama, H. Matsunaga. Adsorption and removal of As (V) and As (III) using Zr-loaded lysine diacetic acid chelating resin. Chemosphere, 59 (8) (2005), pp. 1169-1174

A. Bårdsen, K. Bjorvatn, K.A. Selvig. Variability in fluoride content of subsurface water reservoirs. Acta Odontol. Scand., 54 (6) (1996), pp. 343-347

D.G. Barnes, M. Dourson, P. Preuss, J. Bellin, C. Derosa, R. Engler, L. Erdreich, T. Farber, P. Fenner-Crisp, E. Francis. Reference dose (RfD): description and use in health risk assessments. Regul. Toxicol. Pharm., 8 (4) (1988), pp. 471-486

H.T. Basavarajappa, M.C. Manjunatha. Groundwater quality analysis in Precambrian rocks of Chitradurga district, Karnataka, India using Geo-informatics technique. Aquat. Procedia, 4 (2015), pp. 1354-1365

M.M. Bayón, A.R. Garcia, J.I.G. Alonso, A. Sanz-Medel. Indirect determination of trace amounts of fluoride in natural waters by ion chromatography: a comparison of on-line post-column fluorimetry and ICP-MS detectors. Analyst, 124 (1) (1999), pp. 27-31

E. Bazrafshan, D. Balarak, A.H. Panahi, H. Kamani, A.H. Mahvi. Fluoride removal from aqueous solutions by cupricoxide nanoparticles. Fluoride, 49 (3) (2016), p. 233

Behbahani, M., ALAVI, M. M., Arami, M., 2011. A comparison between aluminum and iron electrodes on removal of phosphate from aqueous solutions by electrocoagulation process.

E. Bellack. . Simplified Fluoride Distillation Method. Journal (american Water Works Association), 50 (4) (1958), pp. 530-536

K.E. Bergmann, R.L. Bergmann. Salt fluoridation and general health. Adv. Dent. Res., 9 (2) (1995), pp. 138-143

A. Bhatnagar, E. Kumar, M. Sillanpää. Fluoride removal from water by adsorption—a review. Chem. Eng. J., 171 (3) (2011), pp. 811-840

P. Bhattacharya, M. Claesson, J. Bundschuh, O. Sracek, J. Fagerberg, G. Jacks, R.A. Martin, A.D.R. Storniolo, J.M. Thir. Distribution and mobility of arsenic in the Rio Dulce alluvial aquifers in Santiago del Estero Province. Argentina. Science of the Total Environment, 358 (1–3) (2006), pp. 97-120

K. Biswas, S.K. Saha, U.C. Ghosh. Adsorption of fluoride from aqueous solution by a synthetic iron (III)− aluminum (III) mixed oxide. Ind. Eng. Chem. Res., 46 (16) (2007), pp. 5346-5356

P.S. Blanes, E.E. Buchhamer, M.C. Giménez. Natural contamination with arsenic and other trace elements in groundwater of the Central-West region of Chaco, Argentina. J. Environ. Sci. Health A, 46 (11) (2011), pp. 1197-1206

L. Borgnino, M.G. Garcia, G. Bia, Y.V. Stupar, P. Le Coustumer, P.J. Depetris. Mechanisms of fluoride release in sediments of Argentina's central region. Sci. Total Environ., 443 (2013), pp. 245-255

D.R. Boyle, M. Chagnon. An incidence of skeletal fluorosis associated with groundwaters of the maritime carboniferous basin, Gaspé region, Quebec, Canada. Environ. Geochem. Health, 17 (1995), pp. 5-12

K. Brindha, L. Elango. Fluoride in groundwater: causes, implications and mitigation measures. Fluoride Properties, Applications and Environmental Management, 1 (2011), pp. 111-136

K. Brindha, G. Jagadeshan, L. Kalpana, L. Elango. Fluoride in weathered rock aquifers of southern India: managed aquifer recharge for mitigation. Environ. Sci. Pollut. Res., 23 (2016), pp. 8302-8316

D. Browne, H. Whelton, D. O'Mullane. Fluoride metabolism and fluorosis. J. Dent., 33 (3) (2005), pp. 177-186

E.E. Buchhamer, P.S. Blanes, R.M. Osicka, M.C. Giménez. Environmental risk assessment of arsenic and fluoride in the Chaco Province, Argentina: Research advances. J. Toxic. Environ. Health A, 75 (22–23) (2012), pp. 1437-1450

J. Bundschuh, B. Farias, R. Martin, A. Storniolo, P. Bhattacharya, J. Cortes, G. Bonorino, R. Albouy. Groundwater arsenic in the Chaco-Pampean plain, Argentina: case study from Robles County. Santiago Del Estero Province. Applied Geochemistry, 19 (2) (2004), pp. 231-243

J. Cai, D. Zhao, O. Varis. Match words with deeds: Curbing water risk with the Sustainable Development Goal 6 index. J. Clean. Prod., 318 (2021), Article 128509

J.A. Camargo. Fluoride toxicity to aquatic organisms: a review. Chemosphere, 50 (3) (2003), pp. 251-264

J. Cao, S.F. Luo, J.W. Liu, Y. Li. Safety evaluation on fluoride content in black tea. Food Chem., 88 (2) (2004), pp. 233-236

H. Cao, X. Xie, Y. Wang, H. Liu. Predicting geogenic groundwater fluoride contamination throughout China. J. Environ. Sci., 115 (2022), pp. 140-148

F.W. Carter. Czechoslovakia. Czechoslovakia. (1991), pp. 154-172

Cgwb.,. Ground water quality in shallow aquifers of India. Faridabad, unpublished report, Central Ground Water Board (2018), p. 108

G.T. Chae, S.T. Yun, B. Mayer, K.H. Kim, S.Y. Kim, J.S. Kwon, Y.K. Koh. Fluorine geochemistry in bedrock groundwater of South Korea. Sci. Total Environ., 385 (1–3) (2007), pp. 272-283

D. Chakraborti, M.M. Rahman, A. Chatterjee, D. Das, B. Das, B. Nayak, P.B. Kar. Fate of over 480 million inhabitants living in arsenic and fluoride endemic Indian districts: Magnitude, health, socio-economic effects and mitigation approaches. J. Trace Elem. Med Biol., 38 (2016), pp. 33-45

R. Chandrajith, S. Diyabalanage, C.B. Dissanayake. Geogenic fluoride and arsenic in groundwater of Sri Lanka and its implications to community health. Groundw. Sustain. Dev., 10 (2020), pp. 100-359

Chandrajith, R., Padmasiri, J. P., Dissanayake, C. B., Prematilaka, K. M., 2012. Spatial distribution of fluoride in groundwater of Sri Lanka. In: 20th International Forestry and Environment Symposium.

Y.X. Chen, M.Q. Lin, Z.L. He, Y.D. Xiao, C. Chen, D. Min, M.H. Yu. Relationship between total fluoride intake and dental fluorosis in areas polluted by airborne fluoride. Fluoride, 29 (1) (1996), pp. 7-12

J. Chen, H. Wu, H. Qian, Y. Gao. Assessing nitrate and fluoride contaminants in drinking water and their health risk of rural residents living in a semiarid region of Northwest China. Exposure and Health, 9 (2017), pp. 183-195

S.D. Chicas, K. Omine, M. Prabhakaran, T.G. Sunitha, V. Sivasankar. High fluoride in groundwater and associated non-carcinogenic risks at Tiruvannamalai region in Tamil Nadu, India. Ecotoxicol. Environ. Saf., 233 (2022), pp. 113-335

S. Chidambaram, B.K. Prasad, M., Manivannan, R., Karmegam, U., Singaraja, C., Anandhan, P., Manikandan, S.,. Environmental hydrogeochemistry and genesis of fluoride in groundwaters of Dindigul district, Tamilnadu (India). Environ. Earth Sci., 68 (2013), pp. 333-342

N.J. Chinoy, M.V. Narayana. In vitro fluoride toxicity in human spermatozoa. Reprod. Toxicol., 8 (2) (1994), pp. 155-159

A.L. Choi, G. Sun, Y. Zhang, P. Grandjean. Developmental fluoride neurotoxicity: a systematic review and meta-analysis. Environ. Health Perspect., 120 (10) (2012), pp. 1362-1368

S.L. Choubisa. A brief and critical review of endemic hydrofluorosis in Rajasthan. India. Fluoride, 51 (1) (2018), pp. 13-33

S.L. Choubisa, D. Choubisa, A. Choubisa. Fluoride contamination of groundwater and its threat to health of villagers and their domestic animals and agriculture crops in rural Rajasthan. India. Environmental Geochemistry and Health (2022), pp. 1-22

A. Chowdhury, M.K. Adak, A. Mukherjee, P. Dhak, J. Khatun, D. Dhak. A critical review on geochemical and geological aspects of fluoride belts, fluorosis and natural materials and other sources for alternatives to fluoride exposure. J. Hydrol., 574 (2019), pp. 333-359

H.V. Churchill. Occurrence of fluorides in some waters of the United States. Ind. Eng. Chem., 23 (9) (1931), pp. 996-998

D. Cinti, O. Vaselli, P.P. Poncia, L. Brusca, F. Grassa, M. Procesi, F. Tassi. Anomalous concentrations of arsenic, fluoride and radon in volcanic-sedimentary aquifers from central Italy: Quality indexes for management of the water resource. Environ. Pollut., 253 (2019), pp. 525-537

D.F. Cortes, R.P. Ellwood, D.M. O'Mullane, J.R. de Magalhaes Bastos. Drinking water fluoride levels, dental fluorosis, and caries experience in Brazil. J. Public Health Dent., 56 (4) (1996), pp. 226-228

M. Costantini, J. Colin, B. Decharme. Projected Climate-Driven Changes of Water Table Depth in the World's Major Groundwater Basins. Earth's Future, 11 (3) (2023), pp. 1-16

R.M. Coyte, A. Singh, K.E. Furst, W.A. Mitch, A. Vengosh. Co-occurrence of geogenic and anthropogenic contaminants in groundwater from Rajasthan, India. Sci. Total Environ., 688 (2019), pp. 1216-1227

L. Craig, A. Lutz, K.A. Berry, W. Yang. Recommendations for fluoride limits in drinking water based on estimated daily fluoride intake in the Upper East Region, Ghana. Sci. Total Environ., 532 (2015), pp. 127-137

S.J. Cronin, V.E. Neall, J.A. Lecointre, M.J. Hedley, P. Loganathan. Environmental hazards of fluoride in volcanic ash: a case study from Ruapehu volcano, New Zealand. J. Volcanol. Geoth. Res., 121 (3–4) (2003), pp. 271-291

E. Cuoco, S. Viaroli, V. Paolucci, R. Mazza, D. Tedesco. Fe and As geochemical self-removal dynamics in mineral waters: evidence from the Ferrarelle groundwater system (Riardo Plain, Southern Italy). Environ. Geochem. Health (2021), pp. 1-18

M. Currell, I. Cartwright, M. Raveggi, D. Han. Controls on elevated fluoride and arsenic concentrations in groundwater from the Yuncheng Basin. China. Applied Geochemistry, 26 (4) (2011), pp. 540-552

R.W. Dabeka, A.D. Mckenzie. Survey of lead, cadmium, fluoride, nickel, and cobalt in food composites and estimation of dietary intakes of these elements by Canadians in 1986–1988. J. AOAC Int., 78 (4) (1995), pp. 897-909

L. Daniele, M. Corbella, A. Vallejos, M. Díaz-Puga, A. Pulido-Bosch. Geochemical simulations to assess the fluorine origin in Sierra de Gador groundwater (SE S pain). Geofluids, 13 (2) (2013), pp. 194-203

P.S. Datta, S.K. Tyagi, P. Mookerjee, S.K. Bhattacharya, N. Gupta, P.D. Bhatnagar. Groundwater NO3 and F contamination processes in Pushkar Valley, Rajasthan as reflected from 18O isotopic signature and 3H recharge studies. Environ. Monit. Assess., 56 (1999), pp. 209-219

H.T. Dean, F.S. McKay. Production of mottled enamel halted by a change in common water supply. American Journal of Public Health and the Nation’s Health, 29 (6) (1939), pp. 590-596

H.T. Dean, F.A. Arnold Jr, P. Jay, J.W. Knutson. Studies on mass control of dental caries through fluoridation of the public water supply. Public Health Rep., 1896–1970 (1950), pp. 1403-1408

M. del Pilar Alvarez, E. Carol. Geochemical occurrence of arsenic, vanadium and fluoride in groundwater of Patagonia, Argentina: sources and mobilization processes. J. S. Am. Earth Sci., 89 (2019), pp. 1-9

A.J. Desbarats. On elevated fluoride and boron concentrations in groundwaters associated with the Lake Saint-Martin impact structure. Manitoba. Applied Geochemistry, 24 (5) (2009), pp. 915-927

S. Dey, B. Giri. Fluoride fact on human health and health problems: a review. Med Clin Rev, 2 (1) (2015), p. 11, 10.21767/2471-299X.100011

R.K. Dey, S.K. Swain, S. Mishra, P. Sharma, T. Patnaik, V.K. Singh, R.K. Patel. Hydrogeochemical processes controlling the high fluoride concentration in groundwater: a case study at the Boden block area, Orissa, India. Environ. Monit. Assess., 184 (2012), pp. 3279-3291

H.A. Dharmagunawardhane, C.B. Dissanayake. Fluoride problems in Sri Lanka. Environ. Manag. Health, 4 (2) (1993), pp. 9-16

S.D. Dhiman, A.K. Keshari. Hydrogeochemical evaluation of high-fluoride groundwaters: a case study from Mehsana District, Gujarat. India. Hydrological Sciences Journal, 51 (6) (2006), pp. 1149-1162

A. Diro, T.G. Asere, D. Jado, F.. Melak. Spectroscopic determination of fluoride using eriochrome black T (EBT) as a spectrophotometric reagent from groundwater. International Journal of Analytical Chemistry, 2045491 (2021)

C.B. Dissanayake. Environmental geochemistry and its impact on humans. C.H. Fernando (Ed.), Ecology and Biogeography in Sri Lanka, Springer Dordrecht,pp (1984), pp. 65-97

C.B. Dissanayake. The fluoride problem in the ground water of Sri Lanka—environmental management and health. Int. J. Environ. Stud., 38 (2–3) (1991), pp. 137-155

C. Dissanayake. Of stones and health: medical geology in Sri Lanka. Science, 309 (5736) (2005), pp. 883-885

F.M. Ebrahim, T.N. Nguyen, S. Shyshkanov, A. Gładysiak, P. Favre, A. Zacharia, K.C. Stylianou. Selective, fast-response, and regenerable metal–organic framework for sampling excess fluoride levels in drinking water. J. Am. Chem. Soc., 141 (7) (2019), pp. 3052-3058

Edmunds, W. M., Smedley, P. L., 2012. Fluoride in natural waters. In Essentials of medical geology: Revised Edition, 311-336, Dordrecht: Springer Netherlands.

W.M. Edmunds, P.L. Smedley. Fluoride in natural waters. O. Selinus (Ed.), Essentials of Medical Geology, Springer, Dordrecht (2005), pp. 311-336

W.M. Edmunds, P.L. Smedley. Fluoride in natural waters. Revised Edition, Essentials of medical geology (2013), pp. 311-336

M. Egor, A.A. Kumar, T. Ahuja, S. Mukherjee, A. Chakraborty, C. Sudhakar, P. Srikrishnarka, S. Bose, S.J. Ravindran, T. Pradeep. Cellulosic ternary nanocomposite for affordable and sustainable fluoride removal. ACS Sustain. Chem. Eng., 9 (38) (2021), pp. 12788-12799

A.J. Ellis, W.A.J. Mahon. Natural hydrothermal systems and experimental hot water/rock interactions (Part II). Geochim. Cosmochim. Acta, 31 (4) (1967), pp. 519-538

M.M. Emamjomeh, M. Sivakumar. An empirical model for defluoridation by batch monopolar electrocoagulation/flotation (ECF) process. J. Hazard. Mater., 131 (1–3) (2006), pp. 118-125

C.P. Emenike, I.T. Tenebe, P. Jarvis. Fluoride contamination in groundwater sources in Southwestern Nigeria: Assessment using multivariate statistical approach and human health risk. Ecotoxicol. Environ. Saf., 156 (2018), pp. 391-402

A. Farooqi, H. Masuda, N. Firdous. Toxic fluoride and arsenic contaminated groundwater in the Lahore and Kasur districts, Punjab, Pakistan and possible contaminant sources. Environ. Pollut., 145 (3) (2007), pp. 839-849

F. Feng, Y. Jia, Y. Yang, H. Huan, X. Lian, X. Xu, Y. Jiang. Hydrogeochemical and statistical analysis of high fluoride groundwater in northern China. Environ. Sci. Pollut. Res., 27 (2020), pp. 34840-34861

T.K. Flaathen, S.R. Gislason. The effect of volcanic eruptions on the chemistry of surface waters: The 1991 and 2000 eruptions of Mt. Hekla, Iceland. J. Volcanol. Geoth. Res., 164 (4) (2007), pp. 293-316

F.M. Fordyce, K. Vrana, E. Zhovinsky, V. Povoroznuk, G. Toth, B.C. Hope, U. Iljinsky, J. Baker. A health risk assessment for fluoride in Central Europe. Environ. Geochem. Health, 29 (2007), pp. 83-102

S.J. Gaciri, T.C. Davies. The occurrence and geochemistry of fluoride in some natural waters of Kenya. J. Hydrol., 143 (3–4) (1993), pp. 395-412

S.Y. Ganyaglo, A. Gibrilla, E.M. Teye, E.D.G.J. Owusu-Ansah, S. Tettey, P.Y. Diabene, S. Asimah. Groundwater fluoride contamination and probabilistic health risk assessment in fluoride endemic areas of the Upper East Region, Ghana. Chemosphere, 233 (2019), pp. 862-872

M.G. García, K.L. Lecomte, Y. Stupar, S.M. Formica, M. Barrionuevo, M. Vesco, R. Gallará, R. Ponce. Geochemistry and health aspects of F-rich mountainous streams and groundwaters from sierras Pampeanas de Cordoba, Argentina. Environ. Earth Sci., 65 (2012), pp. 535-545

R.A. Garrott, L.L. Eberhardt, J.K. Otton, P.J. White, M.A. Chaffee. A geochemical trophic cascade in Yellowstone's geothermal environments. Ecosystems, 5 (2002), pp. 0659-0666

A.M. Gbadebo. Groundwater fluoride and dental fluorosis in southwestern Nigeria. Environ. Geochem. Health, 34 (2012), pp. 597-604

S. George, P. Pandit, A.B. Gupta. Residual aluminium in water defluoridated using activated alumina adsorption–Modeling and simulation studies. Water Res., 44 (10) (2010), pp. 3055-3064

P. Gevera, H. Mouri. Natural occurrence of potentially harmful fluoride contamination in groundwater: an example from Nakuru County, the Kenyan Rift Valley. Environ. Earth Sci., 77 (2018), pp. 1-19

G. Ghiglieri, D. Pittalis, G. Cerri, G. Oggiano. Hydrogeology and hydrogeochemistry of an alkaline volcanic area: the NE Mt. Meru slope (East African Rift-Northern Tanzania). Hydrol. Earth Syst. Sci., 16 (2) (2012), pp. 529-541

S. Ghorai, K.K. Pant. Investigations on the column performance of fluoride adsorption by activated alumina in a fixed-bed. Chem. Eng. J., 98 (1–2) (2004), pp. 165-173

T. Gleeson, Y. Wada, M.F. Bierkens, L.P. Van Beek. Water balance of global aquifers revealed by groundwater footprint. Nature, 488 (7410) (2012), pp. 197-200

N. Gómez, M. Licursi, J. Cochero. Seasonal and spatial distribution of the microbenthic communities of the Rio de la Plata estuary (Argentina) and possible environmental controls. Mar. Pollut. Bull., 58 (6) (2009), pp. 878-887

P. Grandjean, P.J. Landrigan. Developmental neurotoxicity of industrial chemicals. Lancet, 368 (9553) (2006), pp. 2167-2178

S.K. Gupta, R.D. Deshpande, M. Agarwal, B.R. Raval. Origin of high fluoride in groundwater in the North Gujarat-Cambay region, India. Hydrgeol. J., 13 (2005), pp. 596-605

M. Habuda-Stanić, M. Ergović Ravančić, A. Flanagan. A review on adsorption of fluoride from aqueous solution. Materials, 7 (9) (2014), pp. 6317-6366

B.K. Handa. Geochemistry and genesis of Fluoride-Containing ground waters in india. Groundwater, 13 (3) (1975), pp. 275-281

Y. Hang, C. Wu. Ion chromatography for rapid and sensitive determination of fluoride in milk after headspace single-drop microextraction with in situ generation of volatile hydrogen fluoride. Anal. Chim. Acta, 661 (2) (2010), pp. 161-166

R.E. Hannah. An HPLC anion exclusion method for fluoride determinations in complex effluents. J. Chromatogr. Sci., 24 (8) (1986), pp. 336-339

A. Heikens, S. Sumarti, M. Van Bergen, B. Widianarko, L. Fokkert, K. Van Leeuwen, W. Seinen. The impact of the hyperacid Ijen Crater Lake: risks of excess fluoride to human health. Sci. Total Environ., 346 (1–3) (2005), pp. 56-69

K.E. Heller, S.A. Eklund, B.A. Burt. Dental caries and dental fluorosis at varying water fluoride concentrations. J. Public Health Dent., 57 (3) (1997), pp. 136-143

D. Hermides, D. Kyriazis, P. Makri, A. Ermidou. Geochemical evolution of the Thriassion Plain groundwaters, Attica, Greece. Environ. Monit. Assess., 192 (2020), pp. 1-21

F. Hernandez, J. Bakker, L. Bijlsma, J. De Boer, A.M. Botero-Coy, Y.B. de Bruin, E.A. Hogendoorn. The role of analytical chemistry in exposure science: Focus on the aquatic environment. Chemosphere, 222 (2019), pp. 564-583

B. Hitchon. Fluorine in formation waters, Alberta Basin. Canada. Applied Geochemistry, 10 (3) (1995), pp. 357-367

S. Hossain, T. Hosono, H. Yang, J. Shimada. Geochemical processes controlling fluoride enrichment in groundwater at the western part of Kumamoto area, Japan. Water Air Soil Pollut., 227 (2016), pp. 1-14

K. Hu, J.M. Dickson. Nanofiltration membrane performance on fluoride removal from water. J. Membr. Sci., 279 (1–2) (2006), pp. 529-538

L. Huang, Z. Sun, A. Zhou, J. Bi, Y. Liu. Source and enrichment mechanism of fluoride in groundwater of the Hotan Oasis within the Tarim Basin, Northwestern China. Environ. Pollut., 300 (2022), pp. 118-962

P.F. Hudak, S. Sanmanee. Spatial patterns of nitrate, chloride, sulfate, and fluoride concentrations in the woodbine aquifer of North-Central Texas. Environ. Monit. Assess., 82 (2003), pp. 311-320

J. Ijumulana, F. Ligate, P. Bhattacharya, F. Mtalo, C. Zhang. Spatial analysis and GIS mapping of regional hotspots and potential health risk of fluoride concentrations in groundwater of northern Tanzania. Sci. Total Environ., 735 (2020), pp. 139-584

E. Indermitte, A. Saava, E. Karro. Exposure to high fluoride drinking water and risk of dental fluorosis in Estonia. Int. J. Environ. Res. Public Health, 6 (2) (2009), pp. 710-721

E. Indermitte, A. Saava, E. Karro. Reducing exposure to high fluoride drinking water in Estonia—A countrywide study. Int. J. Environ. Res. Public Health, 11 (3) (2014), pp. 3132-3142

M.E. Irigoyen-Camacho, A.G. Pérez, A.M. González, R.H. Alvarez. Nutritional status and dental fluorosis among schoolchildren in communities with different drinking water fluoride concentrations in a central region in Mexico. Sci. Total Environ., 541 (2016), pp. 512-519

T. Ish, G. Suckling. The severity of dental fluorosis in children exposed to water with a high fluoride content for various periods of time. J. Dent. Res., 70 (6) (1991), pp. 952-956

M.R. Islam, S.S. Gupta, S.K. Jana, T. Pradeep. Industrial utilization of capacitive deionization technology for the removal of fluoride and toxic metal ions (As3+/5+ and Pb2+). Global Chall., 6 (4) (2022), p. 2100129

A.I. Ismail, J.G. Messer. The risk of fluorosis in students exposed to a higher than optimal concentration of fluoride in well water. J. Public Health Dent., 56 (1) (1996), pp. 22-27

J.A. Izbicki, R.L. Michel. Movement and age of ground water in the western part of the Mojave Desert, southern California, USA. Water-Resources Investigations Report, 3 (2004), p. 4314

G. Jacks, P. Bhattacharya, V. Chaudhary, K.P. Singh. Controls on the genesis of some high-fluoride groundwaters in India. Appl. Geochem., 20 (2) (2005), pp. 221-228

S.V. Jadhav, E. Bringas, G.D. Yadav, V.K. Rathod, I. Ortiz, K.V. Marathe. Arsenic and fluoride contaminated groundwaters: a review of current technologies for contaminants removal. J. Environ. Manage., 162 (2015), pp. 306-325

G. Jagadeshan, L. Kalpana, L. Elango. Hydrogeochemistry of high fluoride groundwater in hard rock aquifer in a part of Dharmapuri district, Tamil Nadu, India. Geochem. Int., 53 (2015), pp. 554-564

S. Jagtap, M.K. Yenkie, N. Labhsetwar, S. Rayalu. Fluoride in drinking water and defluoridation of water. Chem. Rev., 112 (4) (2012), pp. 2454-2466

D.T. Jayawardana, H.M.T.G.A. Pitawala, H. Ishiga. Geochemical assessment of soils in districts of fluoride-rich and fluoride-poor groundwater, north-central Sri Lanka. J. Geochem. Explor., 114 (2012), pp. 118-125

S.K. Jha, A.K. Nayak, Y.K. Sharma. Fluoride toxicity effects in onion (Allium cepa L.) grown in contaminated soils. Chemosphere, 76 (3) (2009), pp. 353-356

P.K. Jha, P. Tripathi. Arsenic and fluoride contamination in groundwater: a review of global scenarios with special reference to India. Groundw. Sustain. Dev., 13 (2021), Article 100576

H. Jia, H. Qian, W. Qu, L. Zheng, W. Feng, W. Ren. Fluoride occurrence and human health risk in drinking water wells from southern edge of Chinese Loess Plateau. Int. J. Environ. Res. Public Health, 16 (10) (2019), p. 1683

W.J. Johnson, D.R. Taves, J. Jowsey. Fluoridation and bone disease in renal patients. Continuing Evaluation of the Use of Fluorides, CRC Press (2019), pp. 275-293

S. Kage, K. Kudo, N. Nishida, H. Ikeda, N. Yoshioka, N. Ikeda. Determination of fluoride in human whole blood and urine by gas chromatography-mass spectrometry. Forensic Toxicol., 26 (2008), pp. 23-26

E. Kalisińska, M. Palczewska-Komsa. Teeth of the red fox Vulpes vulpes (L., 1758) as a bioindicator in studies on fluoride pollution. Acta Theriol., 56 (2011), pp. 343-351

L.S. Kaminsky, M.C. Mahoney, J. Leach, J. Melius, M. Jo Miller. Fluoride: benefits and risks of exposure. Crit. Rev. Oral Biol. Med., 1 (4) (1990), pp. 261-281

S. Kanisawa. Content and behaviour of fluorine in granitic rocks, Kitakami Mountains, northeast Japan. Chem. Geol., 24 (1–2) (1979), pp. 57-67

S. Karavoltsos, A. Sakellari, N. Mihopoulos, M. Dassenakis, M.J. Scoullos. Evaluation of the quality of drinking water in regions of Greece. Desalination, 224 (1–3) (2008), pp. 317-329

E. Karro, M. Uppin. The occurrence and hydrochemistry of fluoride and boron in carbonate aquifer system, central and western Estonia. Environ. Monit. Assess., 185 (2013), pp. 3735-3748

C.A. Kashyap, A. Ghosh, S. Singh, S. Ali, H.K. Singh, T. Chandrasekhar, D. Chandrasekharam. Distribution, genesis and geochemical modeling of fluoride in the water of tribal area of Bijapur district, Chhattisgarh, central India. Groundw. Sustain. Dev., 11 (2020), pp. 100-403

L. Kaur, M.S. Rishi, A.U. Siddiqui. Deterministic and probabilistic health risk assessment techniques to evaluate non-carcinogenic human health risk (NHHR) due to fluoride and nitrate in groundwater of Panipat, Haryana. India. Environmental Pollution, 259 (2020), Article 113711

M. Kavisri, M. Abraham, M. Moovendhan. Effective removal of fluoride ions from aqueous solution by marine microalgae as natural biosorbent. Chemosphere, 313 (2023), Article 137312

M. Kaykhaii, M.H. Ghalehno. Rapid and sensitive determination of fluoride in toothpaste and water samples using headspace single drop microextraction-gas chromatography. Anal. Methods, 5 (20) (2013), pp. 5622-5626

R. Kechiched, I.E. Nezli, A. Foufou, M.S. Belksier, S.A. Benhamida, R. Djeghoubbi, O. Ameur-zaimeche. Fluoride-bearing groundwater in the complex terminal aquifer (a case study in Hassi Messaoud area, southern Algeria): hydrochemical characterization and spatial distribution assessed by indicator kriging. Sustainable Water Resources Management, 6 (2020), pp. 1-14

T. Keesari, D. Pant, A. Roy, U.K. Sinha, A. Jaryal, M. Singh, S.K. Jain. Fluoride geochemistry and exposure risk through groundwater sources in northeastern parts of Rajasthan, India. Arch. Environ. Contam. Toxicol., 80 (2021), pp. 294-307

B. Keshavarzi, F. Moore, A. Esmaeili, F. Rastmanesh. The source of fluoride toxicity in Muteh area, Isfahan. Iran. Environmental Earth Sciences, 61 (2010), pp. 777-786

B. Khan, H. Khan, M.L. Brusseau, I. Ahmada. ASSESSMENT OF FLUORIDE CONTAMINATION IN GROUNDWATER OF DISTRICT MARDAN IN PAKISTAN. Fluoride, 50 (4) (2017)

A.F. Khan, K. Srinivasamoorthy, R. Prakash, S. Gopinath, K. Saravanan, F. Vinnarasi, C. Rabina. Human health risk assessment for fluoride and nitrate contamination in the groundwater: a case study from the east coast of Tamil Nadu and Puducherry, India. Environ. Earth Sci., 80 (2021), pp. 1-17

Z. Kheradpisheh, M. Mirzaei, A.H. Mahvi, M. Mokhtari, R. Azizi, H. Fallahzadeh, M.H. Ehrampoush. Impact of drinking water fluoride on human thyroid hormones: a case-control study. Sci. Rep., 8 (1) (2018), pp. 1-7

K. Kim, G.Y. Jeong. Factors influencing natural occurrence of fluoride-rich groundwaters: a case study in the southeastern part of the Korean Peninsula. Chemosphere, 58 (10) (2005), pp. 1399-1408

S.H. Kim, K. Kim, K.S. Ko, Y. Kim, K.S. Lee. Co-contamination of arsenic and fluoride in the groundwater of unconsolidated aquifers under reducing environments. Chemosphere, 87 (8) (2012), pp. 851-856

V. Kimambo, P. Bhattacharya, F. Mtalo, J. Mtamba, A. Ahmad. Fluoride occurrence in groundwater systems at global scale and status of defluoridation–state of the art. Groundw. Sustain. Dev., 9 (2019), Article 100223

H. Kinnunen, T. Holopainen, M.L. Räisänen, L. Kärenlampi. Fluoride in birch leaves, ground vegetation, litter and humus in the surroundings of a fertilizer plant and apatite mine in Siilinjärvi, eastern Finland. Boreal Environ. Res., 8 (2) (2003), p. 185

L. Kirkeskov, E. Kristiansen, H. Bøggild, F. Von Platen-Hallermund, H. Sckerl, A. Carlsen, M.J. Larsen, S. Poulsen. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers. Commun. Dent. Oral Epidemiol., 38 (3) (2010), pp. 206-212

Y. Kitano, Y. Furukawa. Distribution of fluoride in waters of Tokyo Bay. J. Oceanogr., 28 (1972), pp. 121-125

H. Kloos, R.T. Haimanot. Distribution of fluoride and fluorosis in Ethiopia and prospects for control. Trop. Med. Int. Health, 4 (5) (1999), pp. 355-364

I.M. Kolthoff, M.E. Stansby. Detection and estimation of small amounts of fluorine. Ind. Eng. Chem. Anal. Ed., 6 (2) (1934), pp. 118-121

S. Koritnig. Fluorine. K.H. Wedepohl (Ed.), Handbook of Geochemistry Chapter 9, Springer, Berlin (1972)

M. Kovács, M.H. Nagy, J. Borszéki, P. Halmos. Indirect determination of fluoride in aqueous samples by inductively coupled plasma atomic emission spectrometry following precipitation of CeF3. J. Fluor. Chem., 130 (6) (2009), pp. 562-566

J. Kravchenko, T. Rango, I. Akushevich, B. Atlaw, P.G. McCornick, R.B. Merola, C. Paul, E. Weinthal, C. Harrison, A. Vengosh, M. Jeuland. The effect of non-fluoride factors on risk of dental fluorosis: Evidence from rural populations of the Main Ethiopian Rift. Sci. Total Environ., 488 (2014), pp. 595-606

O. Krunić, S. Parlić, D. Polomčić, M. Jovanović, S. Erić. Origin of fluorine in mineral waters of Bujanovac valley (Serbia, Europe). Geochem. Int., 51 (3) (2013), pp. 205-220

S. Kumar, K. Gopal. A review on fluorosis and its preventive strategies. Indian J. Environ. Prot., 20 (6) (2000), pp. 430-440

M. Kumar, R. Goswami, A.K. Patel, M. Srivastava, N. Das. Scenario, perspectives and mechanism of arsenic and fluoride co-occurrence in the groundwater: a review. Chemosphere, 249 (2020), Article 126126

P. Kumar, C.K. Singh, C. Saraswat, B. Mishra, T. Sharma. Evaluation of aqueous geochemistry of fluoride enriched groundwater: a case study of the Patan district, Gujarat. Western India. Water Science, 31 (2) (2017), pp. 215-229

M.C. Kundu, B. Mandal. Assessment of potential hazards of fluoride contamination in drinking groundwater of an intensively cultivated district in West Bengal. India. Environmental Monitoring and Assessment, 152 (1) (2009), pp. 97-103

Kunu, P. J., Talakua, S., Pesulima, Y., Uyara, L., Laimeheriwa, S., Osok, R. M., 2021. Carrying capacity and environmental capacity of water resources analysis in Maluku Province of Indonesia. In IOP Conference Series: Earth and Environmental Science (Vol. 883, No. 1, p. 012062). IOP Publishing.

K.M.K. Kut, A. Sarswat, A. Srivastava, C.U. Pittman Jr, D. Mohan. A review of fluoride in African groundwater and local remediation methods. Groundw. Sustain. Dev., 2 (2016), pp. 190-212

D.J. Lapworth, A.M. MacDonald, S. Kebede, M. Owor, G. Chavula, H. Fallas, P. Wilson, J.S.T. Ward, M. Lark, weillo, J.J.E.R.L., Mwathunga, E.. Drinking water quality from rural handpump-boreholes in Africa. Environ. Res. Lett., 15 (6) (2020), Article 064020

M.J. Larsen, S.J. Jensen. Solubility, unit cell dimensions and crystallinity of fluoridated human dental enamel. Arch. Oral Biol., 34 (12) (1989), pp. 969-973

S.S. Latha, S.R. Ambika, S.J. Prasad. Fluoride contamination status of groundwater in Karnataka. Curr. Sci., 76 (6) (1999), pp. 730-734

Y. Li, C. Liang, C.W. Slemenda, R. Ji, S. Sun, J. Cao, C.L. Emsley, F. Ma, Y. Wu, P.O. Ying, Y.A.N. Zhang. Effect of long-term exposure to fluoride in drinking water on risks of bone fractures. J. Bone Miner. Res., 16 (5) (2001), pp. 932-939

J. Li, Y. Wang, C. Zhu, X. Xue, K. Qian, X. Xie, Y. Wang. Hydrogeochemical processes controlling the mobilization and enrichment of fluoride in groundwater of the North China Plain. Sci. Total Environ., 730 (2020), Article 138877

H. Liu, J. Li, H. Cao, X. Xie, Y. Wang. Prediction modeling of geogenic iodine contaminated groundwater throughout China. J. Environ. Manage., 303 (2022), Article 114249

Y. Liu, W.H. Zhu. Environmental characteristics of regional groundwater in relation to fluoride poisoning in North China. Environ. Geol. Water Sci., 18 (1) (1991), pp. 3-10

W. Luo, X. Gao, X. Zhang. Geochemical processes controlling the groundwater chemistry and fluoride contamination in the Yuncheng Basin, China—An area with complex hydrogeochemical conditions. PLoS One, 13 (7) (2018), p. 0199082

P. Madhnure, D.Y. Sirsikar, A.N. Tiwari, B. Ranjan, D.B. Malpe. Occurrence of fluoride in the groundwaters of Pandharkawada area, Yavatmal district, Maharashtra. India. Current Science (2007), pp. 675-679

P.B. Maithani, R. Gurjar, R. Banerjee, B.K. Balaji, S. Ramachandran, R. Singh. Anomalous fluoride in groundwater from western part of Sirohi district, Rajasthan and its crippling effects on human health. Curr. Sci. (1998), pp. 773-777

J.P. Maity, M. Vithanage, M. Kumar, A. Ghosh, D. Mohan, A. Ahmad, P. Bhattacharya. Seven 21st century challenges of arsenic-fluoride contamination and remediation. Groundw. Sustain. Dev., 12 (2021), Article 100538

J. Malago, E. Makoba, A.N. Muzuka. Fluoride levels in surface and groundwater in Africa: a review. American Journal of Water Science and Engineering, 3 (1) (2017), pp. 1-17

M. Malakootian, M. Moosazadeh, N. Yousefi, A. Fatehizadeh. Fluoride removal from aqueous solution by pumice: case study on Kuhbonan water. Afr. J. Environ. Sci. Technol., 5 (4) (2011), pp. 299-306

E. Malcuit, O. Atteia, F. Larroque, M. Franceschi, A. Pryet. On the role of low-permeability beds in the acquisition of F and SO4 concentrations in a multi-layer aquifer, South-West France. J. Contam. Hydrol., 169 (2014), pp. 37-49

S.M. Maliyekkal, S. Shukla, L. Philip, I.M. Nambi. Enhanced fluoride removal from drinking water by magnesia-amended activated alumina granules. Chem. Eng. J., 140 (1–3) (2008), pp. 183-192

P. Mamatha, S.M. Rao. Geochemistry of fluoride rich groundwater in Kolar and Tumkur Districts of Karnataka. Environ. Earth Sci., 61 (2010), pp. 131-142

Z. Mandinic, M. Curcic, B. Antonijevic, M. Carevic, J. Mandic, D. Djukic-Cosic, C.P. Lekic. Fluoride in drinking water and dental fluorosis. Sci. Total Environ., 408 (17) (2010), pp. 3507-3512

H.W.T. Mapoma, X. Xie, Y. Liu, Y. Zhu, F.P. Kawaye, T.M. Kayira. Hydrochemistry and quality of groundwater in alluvial aquifer of Karonga, Malawi. Environ. Earth Sci., 76 (2017), pp. 1-18

A. Martsev, O. Selivanov. The research of fluoride ions concentration in household water supply. E3S Web of Conferences, Vol. 164, EDP Sciences (2020), p. p. 01016).

R. Masciale, S. Amalfitano, E. Frollini, S. Ghergo, M. Melita, D. Parrone, E. Preziosi, M. Vurro, A. Zoppini, G. Passarella. Assessing natural background levels in the groundwater bodies of the Apulia Region (Southern Italy). Water, 13 (7) (2021), p. 958

N. Masood, S. Batool, A. Farooqi. Groundwater pollution in Pakistan. Global Groundwater, Elsevier (2021), pp. 309-322

R. Melian, N. Myrlian, A. Gouriev, C. Moraru, F. Radstake. Groundwater quality and rural drinking-water supplies in the Republic of Moldova. Hydrgeol. J., 7 (1999), pp. 188-196

K.Y. Mikhaylichenko, A.Y. Dorontsova, O.A. Maksimova, I.A. Adarchenko, A.I. Kurbatova. Determining the geochemical hazard of drinking water: Case studies from the Novogorsk and the Aprelevka districts, Moscow Region, Russia. E3S Web of Conferences, Vol. 98, EDP Sciences (2019), p. 09019).

Mishra, S. P., Das, M., Dash, U. N., 2010. Review on adverse effects of water contaminants like arsenic, fluoride and phosphate and their remediation.

R. Misstear, L. Brown, P.M. Johnston. Estimation of groundwater recharge in a major sand and gravel aquifer in Ireland using multiple approaches. Hydrgeol. J., 17 (3) (2009), p. 693

M. Mohapatra, S. Anand, B.K. Mishra, D.E. Giles, P. Singh. Review of fluoride removal from drinking water. J. Environ. Manage., 91 (1) (2009), pp. 67-77

P.F. Møller, S.V. Gudjonsson. Massive fluorosis of bones and ligaments. Acta Radiol., 3–4 (1932), pp. 269-294

L.I. Moran Ayala, M. Paquet, K. Janowska, P. Jamard, C.A. Quist-Jensen, G.N. Bosio, V. Boffa. Water defluoridation: nanofiltration vs membrane distillation. Ind. Eng. Chem. Res., 57 (43) (2018), pp. 14740-14748

A. Motahhari, H. Abdolmohammad-Zadeh, K. Farhadi. Development of a new fluoride colorimetric sensor based on anti-aggregation of of modified silver nanoparticles. Analytical and Bioanalytical Chemistry Research, 8 (1) (2020), pp. 79-89

Moussa, D. T., El-Naas, M. H., Nasser, M., Al-Marri, M. J., 2017. A comprehensive review of electrocoagulation for water treatment: Potentials and challenges. Journal of environmental management, 186, 24-41.Mukherjee, I., and Singh, U. K. (2018). Groundwater fluoride contamination, probable release, and containment mechanisms: a review on Indian context. Environmental geochemistry and health, 40(6), 2259-2301.

S. Mukherjee, G. Halder. A review on the sorptive elimination of fluoride from contaminated wastewater. J. Environ. Chem. Eng., 6 (1) (2018), pp. 1257-1270

S. Mukherjee, T. Pradeep. Nanomaterials-enabled Technologies for Clean Water and their Sustainability Aspects. Industrial Applications of Nanoparticles, CRC Press (2023), pp. 16-31

S. Mukherjee, M. Shah, K. Chaudhari, A. Jana, C. Sudhakar, P. Srikrishnarka, T. Pradeep. Smartphone-based fluoride-specific sensor for rapid and affordable colorimetric detection and precise quantification at sub-ppm levels for field applications. ACS (2020)

I. Mukherjee, U.K. Singh. Exploring a variance decomposition approach integrated with the Monte Carlo method to evaluate groundwater fluoride exposure on the residents of a typical fluorosis endemic semi-arid tract of India. Environ. Res., 203 (2022), Article 111697

N. Mumtaz, G. Pandey, P.K. Labhasetwar. Global fluoride occurrence, available technologies for fluoride removal, and electrolytic defluoridation: a review. Crit. Rev. Environ. Sci. Technol., 45 (21) (2015), pp. 2357-2389

J.J. Murray, L. Shaw. A 3-year clinical trial into the effect of fluoride content and toothpaste abrasivity on the caries inhibitory properties of a dentifrice. Commun. Dent. Oral Epidemiol., 8 (1) (1980), pp. 46-51

A.A. Nadiri, H. Norouzi, R. Khatibi, M. Gharekhani. Groundwater DRASTIC vulnerability mapping by unsupervised and supervised techniques using a modelling strategy in two levels. J. Hydrol., 574 (2019), pp. 744-759

A. Nagar, T. Pradeep. Clean water through nanotechnology: needs, gaps, and fulfillment. ACS Nano, 14 (6) (2020), pp. 6420-6435

B. Nagudi, C. Koeberl, G. Kurat. Petrography and geochemistry of the Singo granite, Uganda, and implications for its origin. J. Afr. Earth Sc., 36 (1–2) (2003), pp. 73-87

K.R. Nair, F. Manji, J.N. Gitonga. The occurrence and distribution of fluoride in groundwaters of Kenya. East Afr Med J, 61 (7) (1984), pp. 503-512

J. Narbutaitė, M.M. Vehkalahti, S. Milčiuvienė. Dental fluorosis and dental caries among 12-yr-old children from high-and low-fluoride areas in Lithuania. Eur. J. Oral Sci., 115 (2) (2007), pp. 137-142

A. Narsimha, V. Sudarshan. Contamination of fluoride in groundwater and its effect on human health: a case study in hard rock aquifers of Siddipet, Telangana State, India. Appl Water Sci, 7 (2017), pp. 2501-2512

M. Naseem, Z. Khurshid, H.A. Khan, F. Niazi, S. Zohaib, M.S. Zafar. Oral health challenges in pregnant women: Recommendations for dental care professionals. The Saudi Journal for Dental Research, 7 (2) (2016), pp. 138-146

O. Navarro, J. González, H.E. Júnez-Ferreira, C.F. Bautista, A. Cardona. Correlation of arsenic and fluoride in the groundwater for human consumption in a semiarid region of Mexico. Procedia Eng., 186 (2017), pp. 333-340

W.G. Nawlakhe, K.R. Bulusu. Nalgonda Technique; A Process for removal of excess fluoride from water. Water. Qual. Bull., 14 (1989), pp. 218-220

E.J. Ncube, C.F. Schutte. The occurrence of fluoride in South African groundwater: A water quality and health problem. Water SA, 31 (1) (2005), pp. 35-40

O. Neves, M.J. Matias. Assessment of groundwater quality and contamination problems ascribed to an abandoned uranium mine (Cunha Baixa region, Central Portugal). Environ. Geol., 53 (2008), pp. 1799-1810

H.B. Nicolli, J.M. Suriano, M.A. Gomez Peral, L.H. Ferpozzi, O.A. Baleani. Groundwater contamination with arsenic and other trace elements in an area of the Pampa, Province of Córdoba, Argentina. Environ. Geol. Water Sci., 14 (1989), pp. 3-16

S. Nizam, H.S. Virk, I.S. Sen. High levels of fluoride in groundwater from Northern parts of Indo-Gangetic plains reveals detrimental fluorosis health risks. Environmental Advances, 8 (2022), Article 100200

S. Noor, A. Rashid, A. Javed, J.A. Khattak, A. Farooqi. Hydrogeological properties, sources provenance, and health risk exposure of fluoride in the groundwater of Batkhela. Pakistan. Environmental Technology & Innovation, 25 (2022), Article 102239

D.K. Nordstrom, E.A. Jenne. Fluorite solubility equilibria in selected geothermal waters. Geochim. Cosmochim. Acta, 41 (2) (1977), pp. 175-188

J. O’Reilly, M.J. Watts, R.A. Shaw, A.L. Marcilla, N.I. Ward. Arsenic contamination of natural waters in San Juan and La Pampa, Argentina. Environ. Geochem. Health, 32 (2010), pp. 491-515

J.O. Odiyo, R. Makungo. Fluoride concentrations in groundwater and impact on human health in Siloam Village, Limpopo Province. South Africa. Water SA, 38 (5) (2012), pp. 731-736

L.A. Olaka, F.D. Wilke, D.O. Olago, E.O. Odada, A. Mulch, A. Musolff. Groundwater fluoride enrichment in an active rift setting: Central Kenya Rift case study. Sci. Total Environ., 545 (2016), pp. 641-653

T. Onipe, J.N. Edokpayi, J.O. Odiyo. A review on the potential sources and health implications of fluoride in groundwater of Sub-Saharan Africa. J. Environ. Sci. Health A, 55 (9) (2020), pp. 1078-1093

N. Ozbek, S. Akman. Determination of fluorine in milk samples via calcium-monofluoride by electrothermal molecular absorption spectrometry. Food Chem., 138 (1) (2013), pp. 650-654

D.L. Ozsvath. Fluoride concentrations in a crystalline bedrock aquifer Marathon County, Wisconsin. Environ. Geol., 50 (2006), pp. 132-138

D.L. Ozsvath. Fluoride and environmental health: a review. Reviews in Environmental Science and Bio/technology, 8 (2009), pp. 59-79

E. Pagliano, J. Meija, J. Ding, R.E. Sturgeon, A. D’Ulivo, Z. Mester. Novel ethyl-derivatization approach for the determination of fluoride by headspace gas chromatography/mass spectrometry. Anal. Chem., 85 (2) (2013), pp. 877-881

B. Palahouane, N. Drouiche, S. Aoudj, K. Bensadok. Cost-effective electrocoagulation process for the remediation of fluoride from pretreated photovoltaic wastewater. J. Ind. Eng. Chem., 22 (2015), pp. 127-131

D. Parrone, S. Ghergo, E. Frollini, D. Rossi, E. Preziosi. Arsenic-fluoride co-contamination in groundwater: Background and anomalies in a volcanic-sedimentary aquifer in central Italy. J. Geochem. Explor., 217 (2020), Article 106590

A. Parvaiz, J.A. Khattak, I. Hussain, N. Masood, T. Javed, A. Farooqi. Salinity enrichment, sources and its contribution to elevated groundwater arsenic and fluoride levels in Rachna Doab, Punjab Pakistan: Stable isotope (δ2H and δ18O) approach as evidence. Environ. Pollut., 268 (2021), Article 115710

K.S. Patel, B.L. Sahu, N.S. Dahariya, A. Bhatia, R.K. Patel, L. Matini, P. Bhattacharya. Groundwater arsenic and fluoride in Rajnandgaon District, Chhattisgarh, northeastern India. Appl Water Sci, 7 (2017), pp. 1817-1826

R. Perera, N. Johnson, U. Usgodaarachchi, T. Ariyananda. Prevention of dental fluorosis by harvesting rainwater in Sri Lanka. Prevention (2013)

T. Petrović Pantić, K. Atanasković Samolov, J. Štrbački, M. Tomić. Geothermal potential, chemical characteristics, and utilization of groundwater in Serbia. Environ. Earth Sci., 80 (22) (2021), p. 736

W.F. Pickering. The mobility of soluble fluoride in soils. Environ. Pollut. B., 9 (4) (1985), pp. 281-308

K.S. Pillai, V.A. Stanley. Implications of fluoride–an endless uncertainty. J. Environ. Biol., 23 (1) (2002), pp. 81-87

J. Podgorski, M. Berg. Global analysis and prediction of fluoride in groundwater. Nat. Commun., 13 (1) (2022), p. 4232

M. Polemio, K. Voudouris. Groundwater Resources Management: Reconciling Demand. High Quality Resources and Sustainability. Water, 14 (13) (2022), p. 2107

T. Poursaberi, M. Hassanisadi, K. Torkestani, M. Zare. Development of zirconium (IV)-metalloporphyrin grafted Fe3O4 nanoparticles for efficient fluoride removal. Chemical (2012)

R.W. Premathilaka, N.D. Liyanagedera. Fluoride in drinking water and nanotechnological approaches for eliminating excess fluoride. Journal of (2019)

M.L. Puntoriero, A.V. Volpedo, A. Fernández Cirelli. Arsenic, fluoride, and vanadium in surface water (Chasicó Lake, Argentina). Front. Environ. Sci., 2 (2014), p. 23

M. Qasemi, M. Afsharnia, M. Farhang, M. Ghaderpoori, A. Karimi, H. Abbasi, A.J.D.W.T. Zarei. Spatial distribution of fluoride and nitrate in groundwater and its associated human health risk assessment in residents living in Western Khorasan Razavi. Iran. Desalin Water Treat, 170 (2019), pp. 176-186

A. Queste, M. Lacombe, W. Hellmeier, F. Hillermann, B. Bortulussi, M. Kaup, K. Ott, W. Mathys. High concentrations of fluoride and boron in drinking water wells in the Muenster region-results of a preliminary investigation. Int. J. Hyg. Environ. Health, 203 (3) (2001), pp. 221-224

T. Rafique, S. Naseem, M.I. Bhanger, T.H. Usmani. Fluoride ion contamination in the groundwater of Mithi sub-district, the Thar Desert, Pakistan. Environ. Geol., 56 (2008), pp. 317-326

T. Rafique, S. Naseem, T.H. Usmani, E. Bashir, F.A. Khan, M.I. Bhanger. Geochemical factors controlling the occurrence of high fluoride groundwater in the Nagar Parkar area, Sindh. Pakistan. Journal of Hazardous Materials, 171 (1–3) (2009), pp. 424-430

T. Rafique, S. Naseem, D. Ozsvath, R. Hussain, M.I. Bhanger, T.H. Usmani. Geochemical controls of high fluoride groundwater in Umarkot sub-district, Thar Desert, Pakistan. Sci. Total Environ., 530 (2015), pp. 271-278

A.M. Raichur, M.J. Basu. Adsorption of fluoride onto mixed rare earth oxides. Sep. Purif. Technol., 24 (1–2) (2001), pp. 121-127

D. Raj, E. Shaji. Fluoride contamination in groundwater resources of Alleppey, southern India. Geosci. Front., 8 (1) (2017), pp. 117-124

N.J. Raju, S. Dey, W. Gossel, P. Wycisk. Fluoride hazard and assessment of groundwater quality in the semi-arid Upper Panda River basin, Sonbhadra district, Uttar Pradesh. India. Hydrological Sciences Journal, 57 (7) (2012), pp. 1433-1452

N. Ranasinghe, E. Kruger, R. Chandrajith, M. Tennant. Groundwater fluoride in Sri Lanka: opportunities to mitigate the risk at maximum contaminant level. Ceylon Med J, 63 (4) (2018), pp. 174-179

T. Rango, G. Bianchini, L. Beccaluva, T. Ayenew, N. Colombani. Hydrogeochemical study in the Main Ethiopian Rift: new insights to the source and enrichment mechanism of fluoride. Environ. Geol., 58 (2009), pp. 109-118

T. Rango, A. Vengosh, M. Jeuland, R. Tekle-Haimanot, E. Weinthal, J. Kravchenko, C. Paul, P. McCornick. Fluoride exposure from groundwater as reflected by urinary fluoride and children's dental fluorosis in the Main Ethiopian Rift Valley. Sci. Total Environ., 496 (2014), pp. 188-197

A. Rashid, A. Farooqi, X. Gao, S. Zahir, S. Noor, J.A. Khattak. Geochemical modeling, source apportionment, health risk exposure and control of higher fluoride in groundwater of sub-district Dargai. Pakistan. Chemosphere, 243 (2020), Article 125409

A. Rasool, A. Farooqi, T. Xiao, W. Ali, S. Noor, O. Abiola, S. Ali, W. Nasim. A review of global outlook on fluoride contamination in groundwater with prominence on the Pakistan current situation. Environ. Geochem. Health, 40 (2018), pp. 1265-1281

C. Reimann, G.E.M. Hall, U. Siewers, K. Bjorvatn, G. Morland, H. Skarphagen, T. Strand. Radon, fluoride and 62 elements as determined by ICP-MS in 145 Norwegian hard rock groundwater samples. Sci. Total Environ., 192 (1) (1996), pp. 1-19

B. Revich, E. Aksel, T. Ushakova, I. Ivanova, N. Zhuchenko, N. Klyuev, B. Brodsky, Y. Sotskov. Dioxin exposure and public health in Chapaevsk. Russia. Chemosphere, 43 (4–7) (2001), pp. 951-966

Richard-Ferroudji, A., Lassaube, G., 2020. The challenge of making groundwater visible: a review of communication approaches and tools in France. Sustainable Groundwater Management: A Comparative Analysis of French and Australian Policies and Implications to Other Countries, 191-209.

R. Rodríguez, I. Morales-Arredondo, I. Rodríguez. Geological differentiation of groundwater threshold concentrations of arsenic, vanadium and fluorine in El Bajío Guanajuatense. México. Geofísica Internacional, 55 (1) (2016), pp. 5-15

J.J. Rosso, M.L. Puntoriero, J.J. Troncoso, A.V. Volpedo, A. Fernández Cirelli. Occurrence of fluoride in arsenic-rich surface waters: a case study in the Pampa Plain, Argentina. Bull. Environ. Contam. Toxicol., 87 (2011), pp. 409-413

S. Routroy, R. Harichandan, J.K. Mohanty, C.R. Panda. A statistical appraisal to hydrogeochemistry of fluoride contaminated ground water in Nayagarh District, Odisha. J. Geol. Soc. India, 81 (2013), pp. 350-360

J. Ruiz, S.E. Kesler, L.M. Jones. Strontium isotope geochemistry of fluorite mineralization associated with fluorine-rich igneous rocks from the Sierra Madre Occidental. Mexico; Possible Exploration Significance. Economic Geology, 80 (1) (1985), pp. 33-42

Y.A. Rukah, K. Alsokhny. Geochemical assessment of groundwater contamination with special emphasis on fluoride concentration. North Jordan. Geochemistry, 64 (2) (2004), pp. 171-181

M. Ryazanov, I. Korsakov, N. Kuzmina. MOCVD of ferroelectric BaMgF4 thin films. Le Journal De Physique IV, 9 (PR8) (1999), pp. 8-471

P.K. Sahoo, S.B. Ray, A. Kerketta, P. Behera, G. Neogi, H.B. Sahoo. Geogenic enrichment of fluoride in groundwater of hard rock aquifer in fluorosis prevalent area of Balangir district, Odisha. India. Groundwater for Sustainable Development, 19 (2022), Article 100830

B.L. Sahu, G.R. Banjare, S. Ramteke, K.S. Patel, L. Matini. Fluoride contamination of groundwater and toxicities in dongargaon block, Chhattisgarh, India. Exposure and Health, 9 (2017), pp. 143-156

S. Sahu, L. Mallik, S. Pahi, B. Barik, U.K. Sahu, M. Sillanpää, R.K. Patel. Facile synthesis of poly o-toluidine modified lanthanum phosphate nanocomposite as a superior adsorbent for selective fluoride removal: a mechanistic and kinetic study. Chemosphere, 252 (2020), Article 126551

S. Samatya, Ü. Yüksel, M. Yüksel, N. Kabay. Removal of fluoride from water by metal ions (Al3+, La3+ and ZrO2+) loaded natural zeolite. Sep. Sci. Technol., 42 (9) (2007), pp. 2033-2047

W. Sanchez, B. Piccini, J.M. Ditche, J.M. Porcher. Assessment of seasonal variability of biomarkers in three-spined stickleback (Gasterosteus aculeatus L.) from a low contaminated stream: implication for environmental biomonitoring. Environ. Int., 34 (6) (2008), pp. 791-798

G.R. Satsangi, A. Lakhani, P. Khare, S.P. Singh, K.M. Kumari, S.S. Srivastava. Composition of rainwater at a semi-arid rural site in India. Atmos Environ, 32 (1998), pp. 3783-3793

V. Saxena, S. Ahmed. Dissolution of fluoride in groundwater: a water-rock interaction study. Environ. Geol., 40 (2001), pp. 1084-1087

V. Saxena, S. Ahmed. Inferring the chemical parameters for the dissolution of fluoride in groundwater. Environ. Geol., 43 (2003), pp. 731-736

B. Scaillet, R. Macdonald. Fluorite stability in silicic magmas. Contrib. Miner. Petrol., 147 (2004), pp. 319-329

R.G. Schamschula, P.S. Un, E. Sugar, J.L. Duppenthaler, K. Toth, D.E. Barmes. The fluoride content of selected foods in relation to the fluoride concentration of water. Acta Physiol. Hung., 72 (2) (1988), pp. 217-227

W.H. Schlesinger, E.M. Klein, A. Vengosh. Global biogeochemical cycle of fluorine. Global Biogeochem. Cycles, 34 (12) (2020)

R.D. Scott, A.E. Kimberly, A.L. Van Horn, L.F. Ey, F.H. Waring. Fluoride in Ohio water supplies—its effect, occurrence and reduction. Journal (american Water Works Association), 29 (1) (1937), pp. 9-25

F. Sedlacek, F. Zemek, M. Herman, H. Kierdorf, U. Kierdorf. Fluoride load on ecosystems in western part of Krusne hory Mts determined by bioindication. International Journal for Ecological Problems of the Biosphere. (2001)

S. Senarathne, J.M.C.K. Jayawardana, E.A.N.V. Edirisinghe, R. Chandrajith. Influence of regional climatic on the hydro geochemistry of a tropical river basin—a study from the Walawe River basin of Sri Lanka. Environ. Sci. Pollut. Res., 28 (2021), pp. 15701-15715

E. Shaji, V. Bindu, J., Thambi, D. S.,. High fluoride in groundwater of Palghat District, Kerala. Current Science (2007), pp. 240-245

E. Shaji, J.J. Gómez-Alday, S. Hussein, T.R. Deepu, Y. Anilkumar. Salinization and deterioration of groundwater quality by nitrate and fluoride in the Chittur block, Palakkad, Kerala. J. Geol. Soc. India, 92 (2018), pp. 337-345

E. Shaji, M. Santosh, K.V. Sarath, P. Prakash, V. Deepchand, B.V. Divya. Arsenic contamination of groundwater: A global synopsis with focus on the Indian Peninsula. Geosci. Front., 12 (3) (2021), Article 101079

K. Shalvi, N., Verma, K. L., Jain, V. K., Nagpal, S.. Integrated device for colorimetric detection of arsenite using polyethylene glycol capped gold nanoparticles—Lab-on-chip. Toxicol. Environ. Heal. Sci., 13 (4) (2021), pp. 351-362

J. Shen, A. Schäfer. Removal of fluoride and uranium by nanofiltration and reverse osmosis: a review. Chemosphere, 117 (2014), pp. 679-691

J.L. Shupe, A.E. Olson, H.B. Peterson, J.B. Low. Fluoride toxicosis in wild ungulates. J. Am. Vet. Med. Assoc., 185 (11) (1984), pp. 1295-1300

C.K. Singh, K. Rina, R.P. Singh, S. Shashtri, V. Kamal, S. Mukherjee. Geochemical modeling of high fluoride concentration in groundwater of Pokhran area of Rajasthan, India. Bull. Environ. Contam. Toxicol., 86 (2011), pp. 152-158

J. Singh, P. Singh, A. Singh. Fluoride ions vs removal technologies: a study. Arab. J. Chem., 9 (6) (2016), pp. 815-824

M. Skórka-Majewicz, M. Goschorska, W. Żwierełło, I. Baranowska-Bosiacka, D. Styburski, P. Kapczuk, I. Gutowska. Effect of fluoride on endocrine tissues and their secretory functions–review. Chemosphere, 260 (2020), Article 127565

P.L. Smedley, H.B. Nicolli, D.M.J. Macdonald, A.J. Barros, J.O. Tullio. Hydrogeochemistry of arsenic and other inorganic constituents in groundwaters from La Pampa. Argentina. Applied Geochemistry, 17 (3) (2002), pp. 259-284

E.T.D. Sousa, V.F. Alves, F.B.M. Maia, M. Nobre-dos-Santos, F.D.S. Forte, F.C. Sampaio. Influence of fluoridated groundwater and 1,100 ppm fluoride dentifrice on biomarkers of exposure to fluoride. Braz. Dent. J., 29 (2018), pp. 475-482

P.D. Sreedevi, S. Ahmed, B. Madé, E. Ledoux, J.M. Gandolfi. Association of hydrogeological factors in temporal variations of fluoride concentration in a crystalline aquifer in India. Environ. Geol., 50 (2006), pp. 1-11

S. Srivastava, S.J.S. Flora. Fluoride in drinking water and skeletal fluorosis: a review of the global impact. Current Environmental Health Reports, 7 (2020), pp. 140-146

N. Subba Rao. Groundwater quality: focus on fluoride concentration in rural parts of Guntur district, Andhra Pradesh. India. Hydrological Sciences Journal, 48 (5) (2003), pp. 835-847

V. Sunitha, R.B. Muralidhara, R.M. Ramakrishna. Variation of fluoride and correlation with alkalinity in groundwater of shallow and deep aquifers-A case study in and around Anantapur district, Andhra Pradesh. Int J Appl Sci Eng Res, 1 (4) (2012), pp. 569-575

E.D. Sunkari, M. Abu. Hydrochemistry with special reference to fluoride contamination in groundwater of the Bongo District, Upper East Region, Ghana. Sustainable Water Resources Management, 5 (2019), pp. 1803-1814

A.K. Susheela. Fluorosis management programme in India. Curr. Sci., 77 (10) (1999), pp. 1250-1256

A.K. Susheela, P. Jethanandani. Circulating testosterone levels in skeletal fluorosis patients. J. Toxicol. Clin. Toxicol., 34 (2) (1996), pp. 183-189

A. Susheela, A. Kumar, M. Bhatnagar, R. Bahudur. Prevalence of endemic fluorosis with gastro-intestinal manifestations in people living in some North-Indian villages. Fluoride, 26 (2) (1993), pp. 97-104

S. Suthar, V.K. Garg, S. Jangir, S. Kaur, N. Goswami, S. Singh. Fluoride contamination in drinking water in rural habitations of Northern Rajasthan, India. Environ. Monit. Assess., 145 (2008), pp. 1-6

X. Tang, C. Zhou, W. Xia, Y. Liang, Y. Zeng, X. Zhao, W. Xiong, M. Cheng, Z. Wang. Recent advances in metal–organic framework-based materials for removal of fluoride in water: Performance, mechanism, and potential practical application. Chem. Eng. J., 137299 (2022)

F. Tassi, F. Aguilera, T. Darrah, O. Vaselli, B. Capaccioni, R.J. Poreda, A.D. Huertas. Fluid geochemistry of hydrothermal systems in the Arica-Parinacota, Tarapacá and Antofagasta regions (northern Chile). J. Volcanol. Geoth. Res., 192 (1–2) (2010), pp. 1-15

R. Tekle-Haimanot, Z. Melaku, H. Kloos, C. Reimann, W. Fantaye, L. Zerihun, K. Bjorvatn. The geographic distribution of fluoride in surface and groundwater in Ethiopia with an emphasis on the Rift Valley. Sci. Total Environ., 367 (1) (2006), pp. 182-190

S.X. Teng, S.G. Wang, W.X. Gong, X.W. Liu, B.Y. Gao. Removal of fluoride by hydrous manganese oxide-coated alumina: performance and mechanism. J. Hazard. Mater., 168 (2–3) (2009), pp. 1004-1011

C.S. Teo. Fluoridation of public water supplies in Singapore. Ann Acad Med Singapore, 13 (2) (1984), pp. 247-251

P. Thapa, K.K. Aryal, S. Mehata, A. Vaidya, B.K. Jha, M. Dhimal, K.B. Karki. Oral hygiene practices and their socio-demographic correlates among Nepalese adult: evidence from non-communicable diseases risk factors STEPS survey Nepal 2013. BMC Oral Health, 16 (1) (2016), pp. 1-8

R. Thapa, S. Gupta, D.V. Reddy. Application of geospatial modelling technique in delineation of fluoride contamination zones within Dwarka Basin, Birbhum. India. Geoscience Frontiers, 8 (5) (2017), pp. 1105-1114

R. Thapa, S. Gupta, H. Kaur, R. Baski. Assessment of groundwater quality scenario in respect of fluoride and nitrate contamination in and around Gharbar village, Jharkhand, India. HydroResearch, 2 (2019), pp. 60-68

B. Thole. Ground water contamination with fluoride and potential fluoride removal technologies for East and Southern Africa. Perspectives in Water Pollution (2013), pp. 65-95

K. Tirumalesh, K. Shivanna, A.A. Jalihal. Isotope hydrochemical approach to understand fluoride release into groundwaters of Ilkal area, Bagalkot District, Karnataka, India. Hydrgeol. J., 15 (2007), pp. 589-598

K.K. Tiwari, G. Krishan, G. Prasad, N.C. Mondal, V. Bhardwaj. Evaluation of fluoride contamination in groundwater in a semi-arid region, Dausa District, Rajasthan. India. Groundwater for Sustainable Development, 11 (2020), Article 100465

A.K. Tiwari, A.K. Singh, M.K. Mahato. GIS based evaluation of fluoride contamination and assessment of fluoride exposure dose in groundwater of a district in Uttar Pradesh, India. Hum. Ecol. Risk Assess. Int. J., 23 (1) (2017), pp. 56-66

A.K. Tolkou, S. Trikalioti, O. Makrogianni, D.G. Trikkaliotis, E.A. Deliyanni, G.Z. Kyzas, I.A. Katsoyiannis. Magnesium modified activated carbons derived from coconut shells for the removal of fluoride from water. Sustain. Chem. Pharm., 31 (2023), Article 100898

G. Tomar, A. Thareja, S. Sarkar. Fluoride removal by a hybrid fluoride-selective adsorbent. Water Sci. Technol. Water Supply, 14 (6) (2014), pp. 1133-1141

G. Tomar, A. Thareja, S. Sarkar. Enhanced fluoride removal by hydroxyapatite-modified activated alumina. Int. J. Environ. Sci. Technol., 12 (2015), pp. 2809-2818

V. Ugran, N.N. Desai, D. Chakraborti, K.A. Masali, P. Mantur, S. Kulkarni, K.K. Das. Groundwater fluoride contamination and its possible health implications in Indi taluk of Vijayapura District (Karnataka State). Environmental geochemistry and health, India (2017), p. 39

L. Valdez-Jiménez, C.S. Fregozo, M.M. Beltrán, O.G. Coronado, M.P. Vega. Effects of the fluoride on the central nervous system. Neurología (english Edition), 26 (5) (2011), pp. 297-300

M. Vithanage, P. Bhattacharya. Fluoride in the environment: sources, distribution and defluoridation. Environ. Chem. Lett., 13 (2015), pp. 131-147

R. Vivona, E. Preziosi, B. Madé, G. Giuliano. Occurrence of minor toxic elements in volcanic-sedimentary aquifers: a case study in central Italy. Hydrgeol. J., 15 (2007), pp. 1183-1196

L. Wang, J. Huang. Outline of control practice of endemic fluorosis in China. Soc Sci Med, 41 (8) (1995), pp. 1191-1195

W. Wang, R. Li, J.A. Tan, K. Luo, L. Yang, H. Li, Y. Li. Adsorption and leaching of fluoride in soils of China. Fluoride, 35 (2) (2002), pp. 122-129

P. Wang, A.D. Verin, A. Birukova, G.-G. McClain, L. I., Jacobs, K., J. G.. Mechanisms of sodium fluoride-induced endothelial cell barrier dysfunction: role of MLC phosphorylation. American Journal of Physiology-Lung Cellular and Molecular Physiology, 281 (6) (2001), pp. L1472-L1483

D. Wen, F. Zhang, E. Zhang, C. Wang, S. Han, Y. Zheng. Arsenic, fluoride and iodine in groundwater of China. J. Geochem. Explor., 135 (2013), pp. 1-21

W.W. Wenzel, W.E. Blum. Fluorine speciation and mobility in F-contaminated soils. Soil Sci., 153 (5) (1992), pp. 357-364

G.M. Whitford, D.H. Pashley, R.H. Garman. Effects of fluoride on structure and function of canine gastric mucosa. Dig. Dis. Sci., 42 (1997), pp. 2146-2155

G.M. Whitford, J.E. Thomas, S.M. Adair. Fluoride in whole saliva, parotid ductal saliva and plasma in children. Arch. Oral Biol., 44 (10) (1999), pp. 785-788

C.L. Wilson, R. Belcher, A.M.G. Macdonald, J.C. Roberts, C.A. Johnson, P. Adams, J.A. Durant. Organic microchemistry and its applications. Proc. Soc. Anal. Chem., 8 (1) (1971), pp. 6-20

X. Wu, Y. Zhang, X. Dou, M. Yang. Fluoride removal performance of a novel Fe–Al–Ce trimetal oxide adsorbent. Chemosphere, 69 (11) (2007), pp. 1758-1764

B. Xu, S. Liu, J.L. Zhou, C. Zheng, J. Weifeng, B. Chen, W. Qiu. PFAS and their substitutes in groundwater: Occurrence, transformation and remediation. J. Hazard. Mater., 412 (2021), Article 125159

K.K. Yadav, S. Kumar, Q.B. Pham, N. Gupta, S. Rezania, H. Kamyab, J. Cho. Fluoride contamination, health problems and remediation methods in Asian groundwater: A comprehensive review. Ecotoxicol. Environ. Saf., 182 (2019), Article 109362

A. Yasar, T. Javed, F. Kausar, J. Shamshad, M.U. Hayat Khan, R. Iqbal. Ground water toxicity due to fluoride contamination in Southwestern Lahore, Punjab. Pakistan. Water Supply, 21 (6) (2021), pp. 3126-3140

T. Younos, K.E. Tulou. Overview of desalination techniques. Journal of Contemporary Water Research & Education, 132 (1) (2005), pp. 3-10

Zhang et al., 2020a H. Zhang, S. Cheng, H. Li, K. Fu, Y. Xu. Groundwater pollution source identification and apportionment using PMF and PCA-APCA-MLR receptor models in a typical mixed land-use area in Southwestern China. Sci. Total Environ., 741 (2020), Article 140383

Zhang et al., 2020b Q. Zhang, P. Xu, H. Qian, F. Yang. Hydrogeochemistry and fluoride contamination in Jiaokou Irrigation District, Central China: Assessment based on multivariate statistical approach and human health risk. Sci. Total Environ., 741 (2020), Article 140460