Fluoride Concentration Research Articles

Tooth brushing behavior and oral health care of people with early childhood autism in Germany

ObjectivesOnly a little is known about the tooth brushing behaviors and oral health care of people with early childhood autism (P-EA). To remedy this, a survey was carried out with P-EA of all ages.Materials and methodsIn summer 2021, an online survey questionnaire with 124 questions, addressed only at caregivers of P-EA, was sent to all members of the Bundesverband Autismus Deutschland e.V. Our present study evaluated the 20 survey questions related to dental self-care.ResultsIn total, 130 questionnaires were evaluated. The mean age of the P-EA was 22.7 years (min: 3y; max: 60y; SD ± 14.1y). Only 17.7% (n =23) of the P-EA were female, while 82.3%(n =107) were male. Overall, 54.6% (n = 71) of P-EA are always actively assisted in tooth brushing. Although 57.7% (n = 75) of P-EA brushed teeth twice daily, 39.2% brushed for one to two minutes (n = 51). P-EA younger than 18 years old selected toothpaste primarily for taste reasons (32.7%;n = 18). Only 9.3% (n = 7) of adult P-EA selected toothpaste because of the fluoride content. Manual toothbrushes were preferred by 40.8% (n = 53) of the P-EA, and electric toothbrushes by 34.6% (n = 45). Almost three quarters (71.5%;n = 93) did not use additional dental care implements. The same number (75.4%;n = 98) of P-EA had not practiced supervised brushing in a dental office.Conclusions/Clinical relevanceActive support in dental self-care is crucial for a majority of the P-EA in Germany, regardless of their age. Professional support needs to be fundamentally improved. Clinical concepts for practical instruction in dental hygiene should be developed for P-EA.

Fluoride in Groundwater of Chhattisgarh: A Comprehensive Review of Health Impacts on Humans, Mitigation Strategies and Sustainable Solutions

Fluorosis is a slowly progressing and often neglected disease that poses great health challenges by gradually affecting the human body. Although fluoride toxicity is theoretically reversible, such slow progression leaves with few choices of cure for these side effects, making prevention crucial. Inequitable access to safe sources of drinking water has worsened the prevalence of dental fluorosis, especially in regions where the concentration of fluoride in water is high. This review discusses the association between fluoride exposure, dental fluorosis, and skeletal fluorosis, bringing together an elaborate study of the negative effects that fluoride has on the human body. Skeletal fluorosis is one of the conditions that have received much attention lately. It remains the central theme in this study, which provides information about the latest discoveries made on this condition, detailing its prevalence, health effects, and the course it takes. It also reviews the latest developments in the prevention of fluorosis: new and cheap fluoride removal technologies and mitigation techniques. The conclusions are meant to stimulate further studies on the treatments of fluorosis and on ways to provide clean drinking water inexpensively and sustainably. Fluoride contamination of water is driven by geochemical reactions and natural as well as anthropogenic activities. Although fluoride is necessary for health, quantities over 1.5 mg L⁻¹ are toxic, and prolonged exposure through water has severe health effects, including skeletal fluorosis and oxidative damage to vital organs such as kidneys, the brain, thyroid gland, and liver. The review shows the need of prevention and intervention while shedding light on the multifaceted impacts from fluoride toxicity. By focusing on fluoride pollution, the article aims at unravelling the burden on human health and global water security in safeguarding human lives.

Determination of Fluoride and PH Concentration Among Different Brands of Packaged Alkaline Water – An Analytical Study

Abstract Background: People consuming alkaline water for health benefits should have optimum fluoride and pH. Water fluoridation prevents caries. Aim and Objectives: To determine the fluoride concentration, pH levels, and relation between them in six different brands of alkaline water. Materials and Methods: Randomly, six different alkaline water package bottles were selected for fluoride and pH analysis using an electrochemical probe method and electrometric method, respectively. Results: The mean fluoride concentration of tested samples was 0.212 ± 0.376 mg/L with the highest value in Aava alkaline water (1.03 mg/L) and the lowest in Kangen alkaline water (0.02 mg/L). The mean pH was 7.754 ± 0.672, much below the claimed values of the manufacturers. Kangen alkaline water had the highest pH (8.66), and Aava alkaline water had lowest pH (7.05). There was a statistically significant difference, P < 0.001, between different brands of fluoride and pH levels. There was a negative correlation between fluoride and pH in alkaline water samples (P = 0.032). Conclusion: Tested alkaline water bottles should adhere to its pH and should contain optimum fluoride. Concerned authorities should make sure the availability of optimum fluoride concentration and specify the pH level on the alkaline water bottle label for better consumer awareness and making an informed choice.

Remineralising Effects of L-arginine Fluoride Mouthwash versus Sodium Fluoride Mouthwash: A Protocol of an In-vitro Study

Introduction: Preventing dental caries and maintaining oral health are important for children’s quality of life, as they profoundly impact overall well being, self-esteem and long-term health outcomes. Despite breakthroughs in preventive dentistry, oral infections and tooth decay remain common among children, highlighting the need for novel and efficient preventive interventions. Although fluoride is a proven preventive measure against tooth decay, L-arginine, a naturally occurring amino acid, has shown promising results in enhancing remineralisation and has gained interest due to its role in maintaining oral health. The combination of L-arginine and fluoride in mouthwash may improve dental health. Need of the Study: L-arginine fluoride is utilised in oral care products such as varnishes and toothpastes; however, there are no studies examining the efficacy of L-arginine fluoride as a mouthwash. Aim: To assess the remineralising activity of L-arginine fluoride mouthwash compared to sodium fluoride mouthwash. Materials and Methods: The present in-vitro study will be conducted in the Department of Paediatric and Preventive Dentistry, Sharad Pawar Dental College, Wardha, Maharashtra, India from September 2024 to December 2025. Forty-two teeth with no white spot lesions or caries will be included, while teeth with lesions, fractures, or wear will be excluded from the study. The teeth will be randomly divided into six groups with different concentrations of L-arginine fluoride, and a control group with sodium fluoride will also be evaluated. The teeth will be assessed for Ca/P ratio using Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX), mineral density using micro-Computed Tomography (micro-CT), and for mineral gain and remineralisation using a specific formula. The data will be statistically analysed using Statistical Package for Social Sciences (SPSS) software version 22.0; a two-way Analysis of Variance (ANOVA) with Bonferroni post-hoc test, a one-way ANOVA with Student-Newman-Keuls (SNK) test, and Kruskal-Wallis one-way ANOVA will be used. A p-value of <0.05 will be considered statistically significant.

Update on Endemic Fluorosis in a Region of Europe (Tenerife, Canary Islands)

Fluoride is an anion that is widely distributed in nature whose main source is volcanic emissions. This anion reaches humans mainly through water and can produce beneficial effects at certain doses, with toxic effects occurring at high doses. There are regions of the world that stand out for their high concentrations of fluoride, as it has produced endemic fluorosis in their population. This is the case for Tenerife, one of the islands of the Canary archipelago of volcanic origin. The aims of this study are to perform a historical review of fluoride concentrations in this region and to assess the current levels. The determination of fluoride will be carried out by potentiometry using an ion-selective electrode. The high concentration of fluoride in the water supply continues to be a problem, since about 55% of the studied municipalities on the island of Tenerife exceed the parametric value for the concentration of fluoride in the water (1.5 mg/L). The municipalities with the highest fluoride concentrations in Tenerife are El Tanque (10.61 mg/L), Icod de los Vinos (5.28 mg/L), Tegueste (4.37 mg/L) and La Victoria de Acentejo (3.63 mg/L). The child population aged from 1 to 3 years with a daily water consumption of 1.5 L exceeds the ULs in 21 of the 31 studied municipalities of the island. Meanwhile, the child population aged from 4 to 8 years (daily water consumption of 1.5 L) greatly exceeds the ULs in 13 of 31 of these municipalities. In the case of the adult population (consumption of 2 L/day), it exceeds the ULs in 3 of the 31 studied localities. In addition, since only exposure induced from one type of food has been studied, and not in regard to overall diet, it can be concluded that there may be a risk of overexposure to fluoride for the population aged 1 to 3 years in all the municipalities studied, as well as for the population aged 4 to 14 years and the adult population in most of them. Thus, it can be determined that, currently, with the recommended water consumption, the population could be exposed to a toxicological risk depending on the municipality and age.

In vitro cytotoxicity (irritant potency) of toothpaste ingredients.

This study aimed to determine the cytotoxicity (irritant potency) of toothpaste ingredients, of which some had known to have sensitizing properties. From the wide variety of toothpaste ingredients, Xylitol, Propylene glycol (PEG), Sodium metaphosphate (SMP), Lemon, Peppermint, Fluoride, Cinnamon, and Triclosan and Sodium dodecyl sulphate (SDS) have been selected for evaluation of their cytotoxic properties. Reconstructed human gingiva (RHG) were topically exposed to toothpaste ingredients at different concentrations. The compound concentration resulting in 50% cell death (EC50) and 10% cell death (EC10) was determined by the MTT assay. Detrimental effects in tissue histology were observed by hematoxylin & eosin staining of tissue sections followed by microscopy. While Xylitol, PEG, and SMP did not appear to affect cell viability or tissue histology, the concentrations of Lemon, Peppermint, Cinnamon and SDS present in toothpastes exceeded the EC50 value and resulted in clear detrimental effects in tissue histology, indicating that they could harm the oral mucosa. Triclosan and Fluoride concentrations in the tested toothpastes exceeded the EC10 value but remained below the EC50 value with no clear detrimental effects in tissue histology. Manufacturers are encouraged to comply with higher standards of quality and safety for toothpaste.

The Dual Edge of Fluoride ; Effects of Fluoride on Oral Health

Fluoride is vital for dental health, promoting enamel remineralization and reducing decay risk. However, both low and high fluoride levels in drinking water pose health risks. Jhunjhunu district, Rajasthan, exhibits significant spatial variability in fluoride concentrations (0.3–1.4 ppm), resulting in dental health issues. Study Area and Methodology: • Conducted in Udaipurwati, Chirawa, and Pilani blocks across 68 villages. • Villages categorized into four groups based on fluoride levels (<0.5, 0.5–1, 1–1.05, ≥2 ppm). • Data collected through groundwater sampling, fluoride analysis (ion-selective electrodes), and dental health surveys among 480

Association between fluoride exposure and the risk of serum CK and CK-MB elevation in adults: a cross-sectional study in China

BackgroundThis study aimed to investigate the relationship between urinary fluoride concentration and myocardial disease.MethodsThis is a cross-sectional study that was conducted in three villages in Wenshui County, Shanxi Province. A total of 737 villagers were included in this analysis. Urinary fluoride was detected using a fluoride-ion selective electrode. Myocardial enzymes were detected using an automatic biochemical analyzer. Myocardial ischemia and arrhythmia were diagnosed using 12-lead electrocardiogram.ResultsThe median level of urinary fluoride concentration was 1.32 mg/L. Urinary fluoride was associated with serum creatine kinase (CK) elevation (odds ratio [OR] = 1.39 [95% confidence interval (CI)]: 1.09–1.78) and CK isoenzyme (CK-MB) elevation (OR = 1.49 [95% CI: 1.12–1.97]). Stratified analysis revealed that urinary fluoride concentration was associated with CK elevation in villagers under the age of 60 years (OR = 1.80 [95% CI: 1.26–2.59]). This study found that there was a positive association between urinary fluoride concentration and the risk of CK-MB elevation in participants under the age of 60 years(OR = 2.18 [95% CI: 1.39–3.42]), those who were of female gender (OR = 1.53 [95% CI: 1.07–2.19]), those who were overweight/obese (OR = 1.96 [95% CI: 1.28–2.99]), those who had central obesity (OR = 1.59 [95% CI: 1.12–2.25]), consumed alcohol (OR = 1.49 [95% CI: 1.09–2.05]), and smoked (OR = 1.50 [95% CI: 1.10–2.04]).ConclusionOur study suggests that fluoride exposure is associated with the risk of serum CK and CK-MB elevation; however, it is not associated with myocardial ischemia, arrhythmia, serum lactate dehydrogenase (LDH), serum alpha-hydroxybutyrate dehydrogenase (α-HBD), or serum aspartate aminotransferase (AST). Further investigations are needed to substantiate our findings and explore the potential underlying mechanisms.

Safe use of fluoride-containing toothpastes for caries prevention in children

Relevance. Following environmental rehabilitation efforts in Chapayevsk, Samara Region, an increase in the prevalence and severity of dental caries has been observed, particularly among preschool-aged children.Objective. To evaluate the safety of fluoride use for preventing dental caries in children.Material and methods. A survey was conducted among 124 parents of children aged 5–6 years attending preschools and 361 adolescents aged 12 and 15 years, using the WHO questionnaire (2013). Responses regarding oral hygiene habits were analyzed. Fluoride ion concentrations were measured in drinking water using the potentiometric method (GOST 4386-89 S.6), in urine according to GOST 8.563-96, and in toothpastes following GOST 7983-2016. The availability and popularity of fluoride-containing toothpastes in pharmacies and supermarkets were also assessed. Statistical analysis was performed using IBM SPSS Statistics v.26 (IBM Corporation).Results. Over the past 15 years, the fluoride content in drinking water decreased from 0.78–0.91 mg/L to 0.49– 0.71 mg/L following the city’s environmental rehabilitation efforts, remaining suboptimal for caries prevention. Analysis of fluoride excretion via the kidneys indicated low overall fluoride intake from water, toothpaste, and food. A weak correlation was found between the DMFT (decayed, missing, and filled teeth) index and urinary fluoride levels (ρ = 0.35), as well as estimated systemic fluoride levels (ρ = 0.36). These results indicate low fluoride intake, eliminating concerns about toxic effects on health. An analysis of toothpaste preferences showed that the population primarily chooses fluoride-free toothpastes or those with fluoride levels below 1000 ppm. This trend is influenced by the product range available, low adherence to preventive dental care, and misinformation from online sources that often attribute negative effects to fluoridation or raise safety concerns. The actual fluoride content in toothpastes was found to be within acceptable technological limits.

Fluoride-Mediated Immune Damage Through Cytokine Network Regulation of Tregs

Long-term fluoride exposure can induce inflammatory responses in various tissues of the body, thereby affecting the inflammatory microenvironment. To explore how fluoride induces changes in immune function within this microenvironment, this study collected baseline information and biological samples from participants in areas with the drinking water type of fluorosis, and simultaneously established Wistar rat models with a 12-week and 24-week fluoride exposure, as well as a 12-week fluoride exposure followed by 12-week pure water feeding regimen. Luminex multiplex assays and enzyme-linked immunosorbent assays (ELISAs) were used to measure cytokine expression levels. Subsequently, correlation analysis, multiple linear regression, and mediation analysis were employed to explore the long-term effects induced by the complex cytokine network during fluoride exposure. The population survey results indicated that fluoride suppressed the expression of pro-inflammatory factors such as Interleukin-2 (IL-2), Interleukin-12 (IL-12), Interferon-γ (IFN-γ), Tumor necrosis factor-α (TNF-α), and anti-inflammatory factors such as Interleukin-4 (IL-4), Interleukin-13 (IL-13), and Interleukin-37 (IL-37), while promoting an increase in the proportion of regulatory T cells (Tregs) in peripheral blood. Among these, IL-2 and IFN-γ mediated the fluoride-induced peripheral Tregs expansion. Animal experiments indicate that the proportion of Tregs in peripheral blood and immune organs increases in a time-dependent manner with fluoride exposure. After reducing the fluoride concentration in the drinking water of rats, the number of Tregs remained significantly elevated. The changes in Treg numbers in the 12-week fluoride feeding group, 24-week fluoride feeding group, and 12-week fluoride feeding followed by 12-week water improvement group were related to the cytokine levels. Therefore, the impact of fluoride on the immune homeostasis has cumulative and long-term effects, and may be related to the accumulation and migration of Tregs induced by fluoride in an inflammatory environment, mediated by cytokines.

Assessment of natural fluoride contamination in water intended for human consumption from various regions in Tunisia

ABSTRACT Fluoride is a naturally occurring element present in the Earth's crust, which is released from rocks into the soil and water. Elevated levels of fluoride have been reported in phreatic groundwater worldwide, posing significant health risks to animals, plants, and humans. This study aims to assess the fluoride content in water intended for human consumption from both public networks and groundwater sources in various regions of Tunisia. A total of 46 water samples were collected between 2020 and 2021. The fluoride levels were determined using potentiometry with a combined Fluoride perfectION™ ISE selective electrode. The analysis revealed that fluoride content ranged from 0.351 to 6.016 mg/L. Samples exceeding the regulated limit of 1.5 mg/L were predominantly found in the southern areas of the country (64.3%, averaging 1.755 mg/L), regions known by hydrogeological fluoride deposits (54.8%, averaging 1.715 mg/L), and groundwater sources (75%, averaging 2.103 mg/L). Exposure of animals and humans to such high levels of fluoride poses a serious public health concern. Consequently, the implementation of a national strategy for the monitoring and control of public water resources intended for consumption is essential in mitigating the risks associated with fluoride contamination.

Mononuclear Aluminum-Fluoride Ions, AlFx(+/-)-Study of Plausible Frameworks of Complexes with Biomolecules and Their In Vitro Toxicity.

The importance of fluorine and aluminum in all aspects of daily life has led to an enormous increase in human exposure to these elements in their various forms. It is therefore important to understand the routes of exposure and to investigate and understand the potential toxicity. Of particular concern are aluminum-fluoride complexes (AlFx), which are able to mimic the natural isostructural phosphate group and influence the activity of numerous essential phosphoryl transferases. Our review of salts of ionic AlFx species, which plausibly form the framework of complexes with biomolecules, revealed that the octahedral configuration of aluminum in the active site of the enzyme is preferred over the trigonal-bipyramidal structure. The effects of varying concentrations of fluoride, aluminum and AlFx-from micromolar to millimolar levels-on the viability and apoptosis rate of THP-1 monocytes were investigated using phosphate buffer solution as a culture media to simulate physiological conditions. Our results suggest that aluminum can reduce the direct toxicity of fluoride through the formation of AlFx. In view of the results found, further in vitro studies are required to clarify the toxicity mechanisms of these species.

Urinary Fluoride Levels Among Youth in the National Health and Nutrition Examination Survey (NHANES) 2015-2016: Potential Differences According to Race.

Urinary fluoride (UF) is the most well-established biomarker for fluoride exposure, and understanding its distribution can inform risk assessment for potential adverse systemic health effects. To our knowledge, this study is the first to report distributions of UF among youth according to sociodemographic factors in a nationally representative United States (US) sample. The study included 1191 children aged 6-11 years and 1217 adolescents aged 12-19 years from the National Health and Nutrition Examination Survey (NHANES) 2015-2016. We examined UF according to sociodemographic variables as well as Spearman correlations between UF and plasma fluoride. Survey-weighted quantile regression examined associations between tap water fluoride and UF levels adjusted for covariates. The average age of participants was 12.5 years. The median (IQR) UF and water fluoride concentrations were 0.52 (0.50) mg/L and 0.39 (0.54) mg/L, respectively. Children had higher UF levels than adolescents and males had higher UF levels than females. UF differed according to race/ethnicity among both children and adolescents. Specifically, non-Hispanic Black youth tended to have higher UF levels than all participants except for those classified as other race/multiracial. UF and plasma fluoride were moderately correlated for children and adolescents. Higher water fluoride levels were associated with higher UF levels, and the magnitudes of association were larger at higher quantiles of UF (β = 0.14, p < 0.001; β = 0.20, p< 0.001 at the 25th and 50th quantiles, respectively). The magnitude of association between water fluoride and UF was the largest for non-Hispanic Black participants (predictive margin = 0.3, p < 0.001). Non-Hispanic Black youth in the US may have greater fluoride exposure and receive more of their fluoride intake from tap water than youth of other races/ethnicities. Factors contributing to potential racial/ethnic disparities in fluoride exposure within the US warrant further investigation so that they can be mitigated to reduce the potential for harm.

Aqueous Binder with Self-Emulsifying Characteristics for Practical Si/C Anode in Lithium-Ion Batteries.

Silicon/carbon (Si/C) materials have achieved commercial applications as a solution to the problems of large volume expansion and short lifespan of silicon-based anodes in lithium-ion batteries. However, the potential risk of structural fracture and localized differences in surface adsorption properties lead to difficulties in maintaining the structural integrity of Si/C anodes using conventional binders during repeated lithiation/delithiation. Herein, an aqueous binder (PVA-g-M) based on polyvinyl alcohol (PVA) grafted methacrylic acid (MAA) obtained by self-emulsifyingemulsion polymerization is reported. The introduction of carboxyl groups of MAA enables PVA-g-M to form more hydrogen bonds, thereby enhancing both the cohesion of the binder film and its adhesion to silicon-based surface. Simultaneously, the methyl-containing segments of MAA can wet the carbon-based surface, thereby enhancing the adhesion of PVA-g-M to carbonaceous materials. In addition, the hydroxyl groups on both the PVA segments and the silicon surface can be esterified with the carboxyl groups during the heat treatment, thus further improving the bonding strength. As-prepared Si/C anodes with PVA-g-M binder can significantly inhibit the electrode volume expansion and maintain high structural integrity during cycling as well as form SEIs with high lithium fluoride content, showing excellent cycling stability (81.1% capacity retention after 300 cycles).

Synthesis of zirconium-based metal-organic framework/gelatin aerogel for removing phosphate and fluoride from aqueous solutions.

This study describes the preparation of novel hybrid aerogels derived from gelatin (Gel), incorporating Br-functionalized zirconium-based metal-organic framework (UiO-66-Br; MOF) as modifying agent to effectively eliminate phosphate and fluoride ions from aqueous environments. The adsorption performance of MOF decorated Gel (Gel-xMOF) hybrid aerogels was investigated under different conditions, including agitation time, adsorbent dosage, solution pH, initial phosphate and fluoride concentrations, coexisting ions, and temperature. The functional groups of the gelatin network, coupled with UiO-66-Br, enhanced the adsorption performance of phosphate and fluoride ions from aqueous solutions. The structural features and physicochemical parameters were evaluated using several characterization tools. The mesoporous Gel-1.5MOF aerogels exhibited Langmuir adsorption capacities of 20.81 and 7.42 mg/g for phosphate and fluoride, respectively. Reusability and coexisting experiment results suggest that the as-prepared Gel-1.5MOF aerogels have the potential for practical applications. Electrostatic attraction and ligand exchange primarily govern the adsorption mechanism of both ions, followed by hydrogen bonding and pore-filling mechanisms. This investigation offers new insights into the successful elimination of phosphate and fluoride ions across a broad pH range.

Evaluating major element hydrogeochemistry and fluoride occurrence in groundwater of crystalline bedrock aquifers and associated controlling factors of Eumseong basin area, South Korea.

Long-term intake of high-fluoride water can cause fluorosis in bones and teeth or damage to organs. Fluoride in groundwater is primarily derived from reactions with rocks containing fluorine-related minerals, and fluoride concentrations are elevated in groundwater that has been reacting with these rocks for a long time. The purpose of this study is to investigate the origin and distribution of fluoride in groundwater and to assess the influence of various factors, including geology, on fluoride concentrations in groundwater. The Eumseong basin and surrounding areas were selected as the study area due to the diversity of geologic factors. 139 groundwater samples and 14 rock samples were collected, with groundwater samples subjected to field water quality measurements, chemical analysis, and statistical analysis, and rock samples subjected to microscopic observation and chemical analysis. Fluoride concentration in groundwater increased with well depth, and was highest in groundwater associated with granitic rocks rich in biotite. The fluoride concentration in groundwater showed a negative correlation with the distance to the fault, suggesting that deep groundwater may preferentially flow along fault zones in certain areas. In addition, high-fluoride groundwater had depleted water-stable isotope values, which is likely to be resulted from higher degree of water-rock interaction in groundwater recharged at higher elevations. Calcite precipitation in most groundwater appears to weaken fluorite solubility control on fluoride concentration. Multivariate statistical analysis revealed that water-rock interactions generally governed fluoride and major element concentrations, with high-fluoride groundwater clearly distinguished. These findings can aid in assessing fluoride occurrence in groundwater and managing water quality in areas with similar geological characteristics.

Comparative Evaluation of the Fluoride Content in Plant-based and Animal-based Milk: An In Vitro Study

Comparative Evaluation of the Fluoride Content in Plant-based and Animal-based Milk: An In Vitro Study

Waste PET bottle-derived carbon for defluorination of fluoride-polluted water

ABSTRACT This study synthesises expanded graphite (EG) from graphitised carbon from waste polyethylene terephthalate (PET) bottles. The adsorbent material was characterised using FTIR, XRF, XRD, SEM, Raman Spectroscopy, and BET surface area analysis. The synthesised EG defluorinated wastewater, utilising response surface methodology (RSM) for experimental design and optimisation. XRD patterns confirmed the successful synthesis of graphite and EG, demonstrating structural modifications. Raman spectra indicated higher crystalline order in EG, with D and G band shifts and an increased ID/IG intensity ratio from 0.89–1.04. BET analysis revealed a specific surface area of 247.1 m²/g. . FTIR analysis showed abundant functional groups, particularly hydroxyl (-OH) and alkene (C = C). Batch adsorption experiments revealed that fluoride adsorption onto EG depended on pH, time, and initial fluoride concentration. Optimal conditions for fluoride removal, determined using RSM with central composite design (CCD), demonstrated a maximum fluoride removal rate of 97%. Isotherm data fitted both Langmuir and Freundlich model, and kinetics data aligned well with the pseudo-first-order model. ANOVA showed significant effects of contact time, pH, adsorbent dose, and initial fluoride concentration on removal efficiency. The model's R² value of 0.98 and lack of fit value of 0.1554 confirmed the quality of the second-order polynomial model. Optimal conditions for maximum fluoride removal efficiency of 97% were validated at 5 mg/L fluoride concentration, pH 4, adsorbent dose of 5 g/L, and a contact time of 30 min. Therefore, the present study demonstrated efficient fluoride-polluted water treatment using waste-derived EG.

Memory Effect of Double Oxides Compared to Simple Ion Exchange for Controlled Fluoride Ion Capture and Release

A layered double hydroxide (LDH) containing Mg and Al was synthesized from a nitrate solution using a coprecipitation method. The resulting material exhibited a homogeneous structure, which, upon calcination at 450 °C, was converted into a layered double oxide (LDO). When rehydrated in a fluoride-containing aqueous solution, the original hydroxide structure was successfully regenerated, demonstrating the LDH’s memory effect. During this transformation, fluoride anions from the solution were incorporated into the interlayer galleries to maintain electroneutrality, as confirmed by energy-dispersive X-ray spectroscopy (EDS) analysis. Separately, the process was tested in the presence of ethanol, which significantly enhanced the incorporation of fluoride ions into the interlayer spaces. The material’s potential for controlled fluoride release was evaluated by monitoring its release into demineralized water. For comparison, a simple ion-exchange process was carried out using the as-synthesized MgAl LDH. The memory effect mechanism displayed a notably higher fluoride incorporation capacity compared to the ion-exchange process. Among all the specimens, the sample reconstructed in the presence of ethanol exhibited the highest fluoride ion content. Fluoride release studies revealed a two-phase pattern: an initial rapid release within the first three hours, followed by a substantially slower release over time.

Physicochemical Qualities and Health Risk Assessment of Heavy Metals in Drinking Water From Selected Areas of the Gofa Zone, Ethiopia

Spring and well waters are among the most important sources of drinking water in Gofa Zone rural areas; therefore, it is vital to evaluate the quality of these water sources. Hence, this study aims to determine the physicochemical parameters and metallic mineral concentration with its associated health risks of drinking water in selected rural areas of the Gofa zone, Ethiopia. The purposive sampling method was used for water sample collection. Standard analytical procedures were used to determine the physicochemical parameters and mineral contents. The average values of all physicochemical parameters of spring and well‐drinking water of the selected areas were obtained as temperature (20.73°C and 20.30°C), pH (7.2 and 6.07), electrical conductivity (481.13 µS/cm and 584.24 µS/cm), dissolved oxygen (4.09 and 6.07 mg/L), turbidity (1.60 NTU and 6.55 NTU), total dissolved solids (330.83 and 338.3 mg/L), total suspended solids (84.76 and 89.24 mg/L), chloride concentrations (58.15 and 60.47 mg/L), SO42− ion (68.50 mg/L and 5.58 mg/L), NO3+ ion (3.25 and 2.75 mg/L), and fluoride ion concentration (0.49 mg/L and 0.37 mg/L). Health risk assessment indicates that Co metal showed high hazard indices compared with Fe, Cu, and Zn. Additionally, the values of the heavy metal pollution index (MPI) and heavy metal evaluation index (HEI) indicate that the Sawla Kusti spring water (SSW5), Geze Gofa Mhirzho Wola spring water (GGSW7), and Geze Gofa Bulki Guya well water (BGWW8) sources are considered highly polluted and not recommended for drinking purposes.