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Natural fruit beverages are popular drinks worldwide. In particular, watermelon juice is highly consumed in the Middle East because the geographical conditions are suitable for its cultivation. However, the innocuity of these beverages is poorly studied in the region. In this study, the fluoride concentration in natural watermelon juice from 3 different provinces of Iran was determined. The toxicological risk of fluoride for watermelon consumers with an age range of 4-65 years old was also determined. The fluoride content in 30 watermelon samples was analyzed. The mean values of triplicate fluoride measurements were reported in this study. The health risk assessment was evaluated by using the hazard quotient (HQ). Overall, the mean fluoride content in natural watermelon juice was 0.007 mg/L. The mean fluoride concentration in samples from Fars province (with the highest value of 0.037 mg/L) was statistically higher than that from Khuzestan and Isfahan provinces. The hazard quotient value in all age groups was <1 and indicated no significant risk for watermelon consumers of the different age groups. Although watermelon alone may not present an apparent health risk, fluoride intake by consuming other sources of drinks and food should be considered to provide a comprehensive fluoride risk assessment. [ABSTRACT FROM AUTHOR]

To investigate the relationship between fluoride exposure and Osteochondroma (OC) prevalence, a cross-sectional study was conducted in drinking water endemic fluorosis areas of Heilongjiang Province, China. Our study first reported that the prevalence of OC was 2.3% in drinking water endemic fluorosis areas of Heilongjiang Province, China, and no difference in gender. Logistic regression analysis found that compared to 1st quartile participants, the prevalence of OC was 73% lower in the 2nd quartile participants of WF (Water fluoride), and 3.4 times higher among the 2nd quartile UF (Urinary fluoride) participants. Our study suggests that 0.259–0.420 mg/L of WF may be considered an appropriate level for reducing OC prevalence, while UF (≥0.750 mg/L) could slightly increase the prevalence of OC. In summary, the link between fluoride and OC prevalence is complicated and needs to be further investigated in a cohort population. [ABSTRACT FROM AUTHOR]

Emerging scientific studies have supported the hypothesis that exposure to environmental chemicals increases the incidence of diverse human metabolic disorders. Therefore, this study aimed to evaluate the association between fluoride exposure and metabolic syndrome (MetS) prevalence in people from the Central Region of Mexico. This research included 575 adult individuals. Urinary fluoride concentrations were determined using a potentiometric method. Anthropometric measurements and blood pressure were also acquired. Serum fasting glucose and lipid levels were quantified. For the MetS screening, we used the International Diabetes Federation (IDF) and National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. The mean urinary fluoride levels were 3.50 ± 2.50 mg/L. The prevalence of MetS was approximately 27 and 25% according to NCEP ATP III and IDF criteria, respectively. A multivariate logistic regression analysis showed significant associations (p < 0.05) between urinary fluoride concentrations and MetS occurrence using NCEP ATP III criteria (OR = 1.60; 95% CI 1.05–2.10) and IDF criteria (OR = 1.35; 95% CI 0.95–1.45). These findings emphasize the need to discover the underlying mechanisms that fluoride exposure has on MetS pathogenesis. [ABSTRACT FROM AUTHOR]

Maternal and prenatal exposure to organochlorine pesticides (OCP), arsenic (As), and fluoride (F−) is a critical public health concern. The present study assessed serum OCP residues and urinary As and F− levels in mother and newborn pairs who are residents of rural areas of Durango State, Mexico, from August 2018 to February 2019. Levels of OCP, As, and F− were measured in serum and urine samples by Gas chromatography – Tandem mass spectrometry (GC – MS/MS), Hydride generation – Atomic fluorescent spectrometry (HG-AFS, and ion-selective electron analysis (ISE), respectively, in 60 binomial mothers – newborns. Dieldrin, endrin aldehyde, and endosulfan-II were significantly higher in newborns than in mothers (p ˂0.05). Meanwhile, no significant differences were observed for As and F− concentrations between mother – newborn pairs. Differences were observed in ∑Dienes and ∑DDTs comparing newborns with normal and low birth weights and a positive relationship in ƩDienes, ƩChlordanes, and ƩDDTs between mother and newborn pairs (p ˂ 0.05). These findings highlight the importance of extensive research regarding the influence of pollution. [ABSTRACT FROM AUTHOR]

Fluoride has become a globally concerning pollutant due to its potential toxicity and negative health impacts. Adsorption has been regarded as the most promising approach for the elimination of fluoride contamination owing to its cost-effectiveness and high efficiency. Nanomaterials are excellent adsorbents for defluoridation due to their high specific surface area, high adsorption properties, and ease of self-assembly. However, there are still some challenges in the application of nanoadsorbents for wastewater treatment. Therefore, this review summarizes the research progress of nanoadsorbents for fluoride removal and develops a fundamental understanding of the structure and adsorption properties of nanoadsorbents in different dimensions. It studies the synergistic effects of different nano- components in adsorption capabilities. In addition, challenges related to the engineering applications of nanoadsorbents and some suggestions to address these issues are presented to promote their practical application prospects. [ABSTRACT FROM AUTHOR]

Hydrotalcite-type compounds (HTs) are crystalline ion-exchange materials formed by positively charged sheets of metal hydroxides stabilized with interlayer anions. The synthesis methods significantly influence their crystallographic and morphological properties. Alternative methods, such as microwave or ultrasound irradiation, can reduce the synthesis time and obtain materials with specific characteristics. HT with the interlayer anion of NO3− was synthesized via conventional aging (hydrothermal), microwave, ultrasound, and combined (microwave/ultrasound) methods. The obtained compounds were characterized via X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDS), N2 adsorption-desorption, Fourier-transform infrared spectroscopy (FTIR), and point of zero charge. A larger crystal size ( t = 5.9 nm) and a higher surface area ( S = 6.70 m2 g−1) were obtained when HT was irradiated by microwaves/ultrasound compared to the synthesized compound via hydrothermal aging ( t = 5.5 nm, S = 1.83 m2 g−1). Although the removal capacity of the combined-mode irradiated compound was slightly lower ( q max = 41.7 ± 4.8 mg g−1) than the conventionally aged sample ( q max = 44.4 ± 6.8 mg g−1), the synthesis time was drastically decreased from 24 h to 5 min, and the combined-mode irradiated compound could remove fluoride as efficiently as the compounds obtained conventionally. [ABSTRACT FROM AUTHOR]

To evaluate and compare the bond strength of bulk fill composite when bonded to enamel or dentin pretreated with different concentrations of fluoride (F) compounds using a universal adhesive. A total of 120 teeth were used, including 40 enamel specimens and 80 dentin specimens. Enamel specimens were ground flat, while dentin specimens were prepared by cutting until mid-coronal dentin. The teeth were divided into four groups (n = 30) to test the F-based agents: 1.23% acidulated phosphate fluoride (APF), 1.1% neutral sodium fluoride (NSF), 0.4% stannous fluoride (SF), and a control group without F pretreatment. Each agent was applied for 30 s and rinsed before bonding. Enamel specimens underwent phosphoric acid etching (ER), while dentin specimens were bonded using either ER or self-etch (SE) protocols. Microtensile bond strength testing (μTBS) was performed after 24 h or 10,000 thermal cycles, and failure patterns were assessed. The study variables did not significantly affect μTBS values of enamel specimens. However, all study variables had a significant effect on μTBS values of dentin specimens. The ER protocol, after both control and SF pretreatment, exhibited the highest μTBS values. Pretreatment of enamel with different concentrations of F prior to bonding appears to be safe in terms of bond durability. However, pretreatment with F concentrations higher than 1000 ppm adversely affected bonding to dentin. Pretreating tooth structure with F-based agents at concentrations below 1000 ppm prior to bonding shows promise as a viable option without compromising bond durability. [ABSTRACT FROM AUTHOR]

To investigate the association between mtDNA genetic information and the risk of SF, individuals were conducted in the drinking water endemic fluorosis area in northern China, sequenced the whole genome of mtDNA, identified the SNPs and SNVs, analyzed the haplogroups, and diagnosed SF, and then, the effect of mtDNA genetic information on the risk of SF was evaluated. We find that, D5 haplogroup and its specific SNPs reduced the risk, while the D4 haplogroup and its specific SNPs increased the risk of SF. The number of SNVs in coding regions of mitochondrial respiratory chain (MRC) is different between the controls and cases. This suggests that D5 haplogroup may play a protective role in the risk of SF, while the opposite is observed for the D4 haplogroup, this may relate to their specific SNPs. And SNVs that encode the MRC complex may also be associated with the risk of SF. [ABSTRACT FROM AUTHOR]

Recently, Subwavelength Grating Waveguides (SWG WG) attract a lot of attention for sensing applications because it offers better sensitivity than conventional WGs. The sensitivity of SWG WG is greatly improved due to the interaction between the analyte and guiding mode in the SWG segments. In this study, a highly sensitive sensor based on a silicon SWG slot waveguide (SWGSW) is proposed for detecting low-concentration fluoride contaminations in water. The gap called as "slot" between the silicon slab along with cladding and the spaces between the segmented silicon rail waveguide is filled with fluoride ion-contaminated water samples as analyte for strong light–matter interaction between guiding modes of the SWG structure, resulting in greater sensitivity of the proposed sensor. The sensitivity of the proposed structure is estimated by numerical simulations as S = 615.38 nm/RIU which is comparable to the existing reported optical sensor structures based on optical waveguide and optical fibre with a smaller footprint. Additionally, the effect of variation of geometrical parameters on the transmission resonances of the proposed structure is also analyzed for the optimization of a SWG WG structure. The obtained results will be helpful to realize and design highly sensitive sensors based on the SOI platform. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the posts published with the #preventivedentistry on Instagram. In this cross-sectional retrospective study, the #preventivedentistry was searched on Instagram. Data were collected between 01/10/2023 and 01/20/2023. A total of 940 posts were analyzed for type, purpose, and source. The number of likes of the posts and the number of video views were determined. Of the posts examined, 869 were images, and 71 were videos. Of the posts, 19.7% (n = 185) with the #preventivedentistry were about preventive dentistry. The content of 80.3% (n = 755) included advertisements, celebrations, information about other dental practices, patient satisfaction, and personal sharing. Among specialist dentists, pediatric dentists shared the most posts about preventive dentistry. Regardless of content, most of the posts had 0-25 likes, and only a small percentage had above 300 likes. People searching with #preventivedentistry on Instagram cannot find sufficient information about preventive dentistry. Dental professionals should use Instagram more actively to increase awareness of preventive dentistry. [ABSTRACT FROM AUTHOR]

A simple and intuitive symmetry-based method for deriving the vibration–rotation kinetic energy operator (in polyspherical coordinates) for a general polyatomic molecule using the kinetic energy of a triatomic molecule was considered. Two vectors define the molecule-fixed coordinate system. For example, those vectors can determine positions of two atoms with respect to the third atom. By rotating the coordinate system, it is possible to obtain expressions that relate coefficients determining the kinetic energy in two coordinate systems. Those expressions let us obtain formulas for kinetic energy of general polyatomic molecules from kinetic energy of the triatomic molecules. Vibrational Energy levels of COF2 molecules were calculated from new ab initio potential energy surface. The comparison of the calculated and experimental vibrational energy levels is also reported. [ABSTRACT FROM AUTHOR]

Groundwater contamination from geogenic and anthropogenic sources is a significant concern for the public health across the globe. In India, fluoride and nitrate contamination are the most prevalent contaminants in the groundwater. This study evaluated groundwater quality in four over-exploited sub-districts of Tumkur district in Karnataka by collecting 143 samples from post and pre-monsoon seasons and using different hydrogeochemical, statistical and bivariate graphical approaches. Comparison with Drinking Water Standard guidelines revealed elevated levels of fluoride, nitrate, and total dissolved solids (TDS), rendering the groundwater unsuitable for drinking. According to Chadha's diagram, the predominant groundwater type is Na-Cl, and Gibbs diagram suggested the influence of rock dissolution and weathering. Bivariate plots indicated that hydrogeochemical characteristics were primarily influenced by silicate weathering of minerals, cation ion exchange processes, and anthropogenic factors. A non-carcinogenic health risk assessment was conducted using two different hazard index (HI) approaches from United States Environmental Protection Agency (USEPA) and Agency for Toxic Substances and Disease Registry (ATSDR). It was found that health risk associated with fluoride is more significant than the health risk from nitrate, with children being the most affected, followed by adolescents and adults. A holistic approach to assess cumulative health risks from fluoride and nitrate contamination in groundwater, as demonstrated in this study, promotes the synergistic advancement of SDG 3: Good health and well-being and SDG 6: Clean water and sanitation. [ABSTRACT FROM AUTHOR]

With the increasing demand for self-adaptive electronics, stretchable and conformable sensors with high sensitivity, stretchability, and self-adhesive are significant intelligent devices. Here a novel tactile sensor is demonstrated that maintains conformal contact to the object for efficient movement monitoring. The device, which was composed of the "H" well-manicured thermoplastic elastomer (TPE), a rectangular polyvinylidene fluoride (PVDF) film coupled with a silver electrode and clamped into the copper-clad signal line ends, and a "U" shaped super-elastic silica gel layer, provided satisfactory performance. The device was investigated as a dynamic monitoring sensor due to its stretchable and conformal configuration. The mechanical stability and high sensitivity suggested that, when attached to the skin of participants, the sensor detected motion induced strain which was experimentally demonstrated. The results show that the novel biomimetic sensor is effective in monitoring human dynamics, with an accuracy exceeding than 98.3%. The stretchable and conformable sensor is low-cost and nontoxic with potential applications in clinical, conformal detection, and artificial intelligence. [ABSTRACT FROM AUTHOR]

This study was to investigate the prevalence and severity of children's dental fluorosis (DF) in Shandong and identified the potential risk factors for DF. A total of 87 villages in Shandong were investigated to calculate the prevalence of DF and Community Fluorosis Index (CFI) in 2018–2019. Six hundred and seventy children were enrolled to identify the potential risk factors using univariate and multivariate logistic regressions. Goodman–Kruskal Gamma was used to explore the factors related to the severity of DF. In 87 villages, 1249 of 8700 (14.36%) children still have DF. The prevalence of DF in most villages was below 40% in 2018–2019. Water fluorine concentration when selected for the study and urinary fluorine concentration were related to the risk of DF (P < 0.001). Some eating habits, like lower frequency of eating fresh vegetables, eggs, and beans, were associated with the risk of DF (P < 0.001). The high water fluorine concentration, and lower frequency of eating fresh vegetables, eggs, and beans were also related to the severity of DF (P < 0.001). DF in children in Shandong province is still a common endemic disease. This study tries to provide a useful guide for the prevention and control of DF. [ABSTRACT FROM AUTHOR]

To evaluate the association between ATP2B1 gene polymorphisms and skeletal fluorosis, a cross-sectional study was conducted. In China, 962 individuals were recruited, including 342 cases of skeletal fluorosis. Four TP2BA1 polymorphisms (rs2070759, rs12817819, rs17249754, and rs7136259) were analysed. The results suggested that rs17249754 and rs7136259 were associated with skeletal fluorosis. After controlling confounders, the protective effect of GG genotype in rs17249754 was apparent in individuals over 45 years old, female, with urine fluoride concentration below 1.6 mg/L, serum calcium above 2.25 mmol/L or serum phosphorus between 1.1 and 1.3. Heterozygote TC in rs7136259 increased the risk of skeletal fluorosis in subjects who are elderly, female, with urinary fluoride more than 1.6 mg/L, serum calcium more than 2.25 mmol/L and blood phosphorus between 1.1 and 1.3 mmol/L. Four loci were found to be tightly related by linkage disequilibrium analysis, and the frequency of distribution of haplotype GCGT was lower in the skeletal fluorosis group. [ABSTRACT FROM AUTHOR]

The goal of this study was to perform systematic review (SR) to investigate the scientific literature regarding the genotoxicity effects of fluoride exposure (FE). The search of databases used for this study was PubMed/Medline, SCOPUS and Web of Science. The quality of included studies was assessed using the EPHPP (Effective Public Health Practice Project). A total of 20 potentially relevant studies were selected for evaluating the genotoxicity induced by fluoride. Few studies have revealed that FE induces genotoxicity. A total of 14 studies demonstrated negative results whereas 6 studies did not. After reviewing the twenty studies, 1 was classified as weak, 10 were considered moderate and 9 were considered strong, according to the EPHPP. Taken together, it has been established that genotoxicity of fluoride is limited. [ABSTRACT FROM AUTHOR]

To investigate the potential association between LRP5 rs648438 polymorphism and the risk of skeletal fluorosis (SF) was evaluated in a cross-sectional case–control study conducted in Shanxi, China, in 2019. A total of 973 individuals were enrolled in this study, in which cases and controls were 346 and 627, respectively. SF was diagnosed according to the standard WS/192–2008 (China). The LRP5 rs648438 was detected by the multiple PCR and sequencing. LRP5 rs648438 was found to follow a dominant genetic model using a web-based SNP-STATS software. Logistic regression analysis found that the TC/CC genotype of LRP5 rs648438 might be a protective factor for SF. When stratified by gender, this protective effect of TC/CC genotype in rs648438 was pronounced in males. There was an interaction between gender and rs648438 on risk of SF. Our study suggested that TC/CC genotype of rs648438 might be a protective factor for water-drinking-type skeletal fluorosis, especially in male participants. [ABSTRACT FROM AUTHOR]

The present research work approaches the accumulation of fluoride ions from contaminated water using an aquatic plant Monochoria hastate L. in hydroponic culture. A design of experiment (DOE) has been adopted and an analysis of variance has been conducted to establish the statistical significance of various process parameters. The different experimental factors are root and shoot (Factor A), fluoride concentration (Factor B), and experimental days (Factor C) largely influence the output response. Plants treated with 5 mg/L of fluoride solutions accumulated the highest concentration in root biomass 1.23 mg/gm, and shoot biomass 0.820 mg/gm, dry weight after 21 days' experimentation. The accumulation mechanism and potentiality of treated plants depend on root cells of the plasma membrane and energy-capturing molecules of adenosine triphosphate. Monochoria hastate L. root biomass was characterized to confirm the accumulation of fluoride ions in the experimented plants using scanning electron micrographs-energy dispersive spectrum (SEM-EDS), and Fourier transforms infrared analysis (FTIR) analysis. The novelty of this study is the high fluoride accumulation efficiency in hydroponic treatment by Monochoria hastate L an excellent choice for phytoremediation technique. The Design of Experiment (DOE) has a good approach for the optimization of fluoride in the accumulation process. The maximum absorption of fluoride ions in root biomass is 1.23 mg/gm, and shoot biomass is 0.820 mg/gm, dry weight after 21 days of treatment. To know the fluoride ions in shoot and root biomass are characterized using scanning electron micrographs-energy dispersive spectrum (SEM-EDS), and Fourier transforms infrared analysis (FTIR). [ABSTRACT FROM AUTHOR]

Fluoride is a naturally occurring substance that is also added to drinking water, dental hygiene products, and food supplements for preventing dental caries. Concerns have been raised about several other potential health risks of fluoride. To conduct a robust synthesis of evidence regarding human health risks due to exposure to fluoride in drinking water, and to develop a point of departure (POD) for setting a health-based value (HBV) for fluoride in drinking water. A systematic review of evidence published since recent reviews of human, animal, and in vitro data was carried out. Bradford Hill considerations were used to weigh the evidence for causality. Several key studies were considered for deriving PODs. The current review identified 89 human studies, 199 animal studies, and 10 major in vitro reviews. The weight of evidence on 39 health endpoints was presented. In addition to dental fluorosis, evidence was considered strong for reduction in IQ scores in children, moderate for thyroid dysfunction, weak for kidney dysfunction, and limited for sex hormone disruptions. The current review identified moderate dental fluorosis and reduction in IQ scores in children as the most relevant endpoints for establishing an HBV for fluoride in drinking water. PODs were derived for these two endpoints, although there is still some uncertainty in the causal weight of evidence for causality for reducing IQ scores in children and considerable uncertainty in the derivation of its POD. Given our evaluation of the overall weight of evidence, moderate dental fluorosis is suggested as the key endpoint until more evidence is accumulated on possible reduction of IQ scores effects. A POD of 1.56 mg fluoride/L for moderate dental fluorosis may be preferred as a starting point for setting an HBV for fluoride in drinking water to protect against moderate and severe dental fluorosis. Although outside the scope of the current review, precautionary concerns for potential neurodevelopmental cognitive effects may warrant special consideration in the derivation of the HBV for fluoride in drinking water. [ABSTRACT FROM AUTHOR]

The main objective of this research paper was to find out the major governing factors controlling fluoride enrichment in groundwater resources in the Jaipur region of India. Chemical analysis of collected water samples revealed that 36% of the collected groundwater samples exhibit fluoride concentration of more than 1.5 mg/L as per BIS, 10,500 and WHO, 2017. An attempt has been made to discuss occurrence of fluoride alongside its spatial distribution in the study area with respect to geology and groundwater flow direction. Chloroalkaline indices, Gibb's plot, Piper diagram and various inter-ionic bivariant plots have been applied to recognize hydrochemical processes and dissolution trends resulting in high concentration of fluoride in groundwater. There exist five water types in the study area: Ca-HCO3, Na-HCO3, Na-Cl, Ca-Mg-Cl and Ca-Na-HCO3. Due to ion association of excess Cl− emanating from wastewater, Na-HCO3 type water finally gets changed as Na-Cl type in aquifer. In the study area, 82% of water samples enriched in F− concentration (>1 ppm) pertain to Na-Cl type. Geochemical modelling confirms that reduced Ca2+ ion activity due to oversaturation of calcite with respect to fluorite might have triggered the favourable condition for dissolution of fluoride bearing minerals leading to fluoride enrichment in groundwater. To further assess the extent of natural and anthropogenic processes, the data was subjected to multivariate statistical analysis by performing correlation analysis, principal component analysis and hierarchical cluster analysis. [ABSTRACT FROM AUTHOR]

The presence of fluoride ions is considered a threat to public health and the environment due to health challenges. Graphene, as an adsorbent with a porous structure and high surface area, has been used on a large scale to effectively remove organic and inorganic contaminants from aqueous media. Therefore, the present study aimed to use magnetic chitosan/graphene oxide (MCGO) composite in fluoride adsorption and study adsorption isotherms and kinetics. At first, a magnetic chitosan/graphene oxide compound was synthesised and its characteristics were determined by SEM, XRD and FTIR. Then, fluoride adsorption process experiments were performed by studying the effect of pH, contact time, adsorbent mass, and fluoride initial concentration. TheLangmuir, Freundlich, Temkin, and Dubinin and Radushkevich isotherm models were also studied to describe the equilibrium of the adsorbate between the solid and fluid phases, and the pseudo-first-order, pseudo-second-order, Intraparticle diffusion, and Elovich kinetic models were analyzed to investigate the adsorption behaviour. To evaluate the effect of each parameter, R software based on Response Surface Methodology (RSM) was used. All experiments were repeated three times and the average was considered as presented as the final results. The results showed that the maximum fluoride adsorption was at pH5. The equilibrium time was reported at 136 minutes and the maximum removal percentage obtained 91% in optimal conditions. Investigation of the isotherm and kinetics showed that the results of fluoride adsorption process were correlated with Langmuir isotherm model (R2 > 0.99) and Elovich kinetic model (R2 > 0.989), respectively. It can be concluded that theMCGOcomposite is an effective adsorbent for fluoride removal from water resources. [ABSTRACT FROM AUTHOR]

The increase in hazardous substances in drinking water is an eye-catching problem of modern world. Where the urban life style is setting new goals, the environment safety of living beings is in poor hands. Almost each and every living thing depends on water for basic survival, but the pollution makes it difficult for health and growth. Fluoride is an ion present in nature and also essential for our body. It helps to strengthen the bone and teeth. But the rapid industrialisation increases the amount of fluoride in natural sources, this increased level tends to decline the health of human, water animals, and plants. So our focus should be to remove the excess fluoride, make water drinkable as per the quality standards for a better future. Various techniques are discussed like coagulation, ion-exchange, membrane separation, adsorption, and electrocoagulation for fluoride removal with advantages and disadvantages. An analysis was performed keeping various criteria for the removal of fluoride ion from water. Adsorption was found to be most suitable compared to others. [ABSTRACT FROM AUTHOR]

Presence of fluoride in drinking water resources is one of the most important challenges related to water management and health issues. This study aimed to monitor the fluoride concentration in rural areas of North Khorasan province, Iran. During a seven-year sampling period, the water quality of over 500 points was assessed annually, based on SPADNS colorimetric method. The geostatistical analyses and spatial distribution of fluoride were performed through global Moran's I index (spatial autocorrelation), and inverse distance weighting (IDW). In addition, the health impact probabilities of fluoride were evaluated via comparing concentrations with Iran national standard and the health risk assessment method recommended by EPA. According to the results, the measured concentrations of fluoride were in the range of 0–8.73 mg/L (average ± SD = 0.855 ± 0.458 mg/L). The lowest fluoride concentrations were determined in Esfarayen and Farouj counties (0.63 mg/L) and highest ones in Maneh Samalghan (0.9 mg/L). Moreover, Global Moran's I was calculated to be close to zero, indicating a random distribution of fluoride throughout the province. The average THQs for adult and children age groups were 4.94 and 3.61, respectively, which showed a high non-carcinogenic risk for both adult and children age groups. However, the concentration of fluoride in all studied water resources has not exceeded the standard and was in a good condition. Therefore, it is necessary to control the excessive concentrations, especially in areas with higher amounts. [ABSTRACT FROM AUTHOR]

A visible-light-mediated fluorosulfonylation reaction of thianthrenium salts has been developed to prepare various sulfonyl fluorides with 1,4-diazabicyclo [2.2.2] octane bis (sulfur dioxide) (DABSO) as sulfonyl source and cheap KHF2 as fluorine source based on radical sulfur dioxide insertion and fluorination strategy. This operationally simple protocol proceeds with high functional-group tolerance under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Rapeseed, the second-most-important vegetable oil source, is cultivated in various areas of India where both groundwater and soil are contaminated with fluoride (F–). Furthermore, the frequent use of F– contaminated groundwater for irrigation leads to accumulation of F– in surface and sub-surface soil. The study aims to compare the morphological and biochemical changes in Brassica juncea L., the variations in its fatty acids (FAs) composition and oil yield, under two regimes of F– contaminated soils: (i) pre-contaminated soil (Tr) and (ii) irrigation with F– contaminated water (Ir). The level of F– (µg g−1) in the plant tissues (root, leaf, and grain) was significantly higher in Ir_10 (18.3, 14.7, and 2.8, respectively) than in Tr_10 (4.3, 2.6, and 0.77, respectively), while the oil yield was significantly lower with Ir_10 (19.5%) than with Tr_10 (44.9%). The phytoremediation potential of F– by Brassica juncea L. is greater in Tr regime than in the Ir regime. The erucic acid content (%), which is detrimental to cardiac health, increased to 67.37% (Ir_10) and 58.3% (Tr_10) from 57.73% (control). Thus, the present study shows that irrigation with F– contaminated water results in greater toxicity and accumulation in plants and is not safe for human health. Irrigation with F– contaminated water results in a greater accumulation of F– in mustard than cultivated on pre-contaminated soil. The level of erucic acid in mustard oil enhances against F– exposure. [ABSTRACT FROM AUTHOR]

Fluoride overexposure, especially through drinking water, poses a severe risk to people all over the world. There are several ways to get rid of fluoride, but adsorption technologies are typically seen to be the most appealing in view of their efficiency, practicality, simplicity of operation, and attractiveness from an economic and environmental standpoint. In the current work, Zirconia and activated carbon nanocomposite (Zr-AC) were researched for the adsorption of fluoride from water. The impact of the various factors, viz. Zr-AC dosage (0.25-2.5 g/L), initial concentration of fluoride (2-32 ppm), pH (2.0-7.0) and contact time (30-180 min) and their effect on adsorption of fluoride was examined by using central composite design (CCD) of response surface methodology (RSM). At pH 7, initial fluoride concentration of 2 ppm, contact time of 180 min, and Zr-AC dosage of 2.5 g/L, fluoride removal was around 95% using Zr-AC composite. Surface characterisation of the prepared adsorbent was done using SEM-EDS and FTIR. The obtained results indicate that Zr-AC gave good results and therefore could be used for treating fluoride-contaminated water. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the spatial distribution and zoning of nitrate and fluoride concentrations in the drinking water distribution network of Behbahan city and the health risk caused by their concentration using sensitivity analysis and the Monte Carlo simulation during 2018 to 2019.In this cross-sectional study, 90 samples were collected from 45 points of the city's drinking water distribution network in the two high-rainy and low-rainy seasons.Nitrate and fluoride concentration was measured byDR 5000 spectrophotometer and its non-carcinogenic impacts were calculated using EDI and HQ.The results showed that the average nitrate concentrations in high and low rainy seasons in the study area were 15.05 and 13.35 mg l−1, respectively.Also, the average concentrations of fluoride in high and low-rainy seasons were 0.67 and 0.76 mg L−1, respectively.The fluoride concentration in the high-rainy season showed a decreasing trend from north to south.The nitrate concentration decreased from north to south and southwest.The amount of nitrate HQ in the age groups corresponding to children, adolescents, adults and infants were 0.5, 0.4, 0.34, and 0.07, respectively.The fluoride HQ levels in the age groups corresponding to children, adolescents, adults and infants were 0.7, 0.5, 0.05, and 0.1, respectively.These results showed that children were the significant at-risk group due to these ions.According to the Monte Carlo simulator, 95th percentile caused by exposure to nitrate and fluoride ions in all age groups was more than one.Based on the sensitivity analysis, the most efficient factor in the health risk caused by nitrate and fluoride ions was the concentration of these ions in the drinking water distribution network. [ABSTRACT FROM AUTHOR]

Groundwater with excess fluoride content is a major issue in most of the states in India. Mineral ions and its seasonal fluctuations are influencing fluoride contamination in groundwater sources to a greater extent. Reports on health issues from several regions of south India have instigated detailed studies on groundwater fluoride contamination and the geo-environmental reasons underlying it. Fluoride contamination in the groundwater sources of Palakkad district, a semi-arid tropical region in South India, was assessed along with major anions and cations. The study revealed that 89% of Po, 88% of Pr, and 52% of Mo samples exceeded the BIS limit of fluoride concentration of 1.0 mg/L. The piper plot and correlation studies affirm that fluoride contamination is accelerated by a higher concentration of magnesium, sodium ions and a lower concentration of calcium and dissolved iron. The negative correlation of fluoride with nitrates supports its geological origin. Fluoride contamination is highly linked with the hornblende biotite gneiss (~ 42%) distributed in the central-eastern part of the district. IDW interpolation defines a maximum of 3.4 mg/L of fluoride in the groundwater sources. The overdose of fluoride in drinking water, which exceeded the OFC level, is noted to be the reason for the prevalence of fluorosis in the study area. The study recommends 0.61 mg/L of fluoride as an OFC limit for drinking purposes. [ABSTRACT FROM AUTHOR]

An ion chromatography (IC) method for the separation of fluoride in presence of large concentrations of organic acid anions was developed with a view to determine trace level concentration of fluoride in plant samples. Present study deals with determination of fluoride in dry black gram seeds. Pyrohydrolysis was employed for extracting fluoride from the seeds. Organic acid anions are produced during pyrohydrolysis of seeds/plant materials and these organic anions show similar retention behavior of fluoride in IC. Separation of fluoride from organic acids and common anions was investigated. An IC method involving the appropriate dilution of pyrohydrolysis distillate of the sample followed by a large volume injection through a pre-concentrator column is proposed to circumvent the interference due to organic acids. Fluoride recovery of the pre-concentrator column is found to be more than 90%. The method provides a precision better than 7% (RSD). The limit of detection of the method is 0.5ppmw whereas the LOD for fluoride by IC method alone is 10 ppb. Results obtained are validated by analyzing the samples by using fluoride ion selective electrode method. [ABSTRACT FROM AUTHOR]

A colorimetric anion sensor (E)-3-((2-((4-(4-Methoxyphenyl)thiophen-2- yl)methyl)hydrazono)methyl)-1 H-indole ATH was synthesised and confirmed by different spectroscopic methods, such as 1 H NMR, 13 C NMR, ESI-Mass and FT-IR spectroscopy. The ATH sensor revealed the spectral change and detection in the presence of fluoride ion over the other anions such as OH−, Cl−, AcO−, I−, HSO4−, NO3−, Br−, S2-, CN− & NO2−. Interestingly, sensor ATH exhibited highly selective fluoride ion detection with significant changes in the colour from light yellow to dark yellow in ACN and ACN: H2O (8:2, v/v) medium. The colorimetric sensor effectively responds to fluoride ion stimulation through deprotonation and (ICT) intramolecular charge transfer sensing mechanism. The fluoride sensing mechanism was confirmed by 1 H NMR titration and was supported by density functional theory (DFT) and electrochemical studies. In this study, the B–H plot calculates the stoichiometry and binding constant (Ka) of the host-guest complex and strong interaction between the probe ATH with fluoride ions forming a 1:2 binding ratio. Furthermore, the test strips based on the probe ATH were used to detect F- ions qualitatively and quantitatively in 100% aqueous solution. [ABSTRACT FROM AUTHOR]

Fluoro-aluminates with pyrochlore-type structures such as Cs2KAl3F12 & Cs2NaAl3F12 could have very useful industrial applications but despite of having much significance, very less exploration on these kinds of compounds has been accomplished. Although some experiments related to luminescence studies on Ce3+ activated phosphors have been achieved on these fluorides long ago, since then very less considerable work on investigating such compounds was done so far. Therefore further work has been carried out by adding rare-earth gadolinium (Gd) as an activator in these complexes. Gadolinium in its trivalent form showed encouraging luminescence results. Additionally, the effect of dopant concentration on photoluminescence intensities has been studied. Decay characteristics showed long lifetimes (in ms) that vary with Gd3+ concentrations. Also, respective values for quantum efficiency (Ø)% and non-radiative rates (AnR) have been evaluated. Phase-purity was confirmed with the help of XRD and Rietveld analysis. [ABSTRACT FROM AUTHOR]

Pollution level and noncarcinogenic health risks due to fluoride and nitrate in the groundwater samples from Ramanathapuram district during pre-monsoon (September 2016) were calculated. One hundred and fifty-two groundwater samples collected were analysed for various physicochemical parameters such as major cations (Ca2+, Mg2+, Na+, K+) and major anions (CO32-, HCO3−, SO42-, Cl−, NO3−, PO43-). The fluoride ion concentrations in the collected samples were measured using the fluoride ion-selective electrode. Noncarcinogenic risks were calculated based on fluoride and nitrate concentrations (fluoride – 0.02–1.00 and nitrate – 0.0–4.9). The calculated risk values exceed the United States Environmental Production Agency (USEPA) recommended value of 1. The habitants from the study area are under the health risk due to fluoride and nitrate. Water quality index (WQI) values of the analysed samples indicate that 52% poor, 14% very poor, and 4% unsuitable for drinking purposes. Piper plot shows that 58% of mixed Ca2+-Mg2+-Cl− and 16% of Na+-Cl− groundwater types are predominant in the study area. Gibbs plot reveals that 91% of the samples have rock-water interaction, and it is a principal process that controls the dissolution of minerals from the subsurface into groundwater. Statistical analysis (correlation analysis, factor analysis) reveals that the natural process (rock-water interaction, leaching of sediments) and anthropogenic activities (domestic sewage, untreated effluents from industries) are the reason for the high fluoride and nitrate concentration in the groundwater. High noncarcinogenic health risk places were marked in spatial distribution maps. [ABSTRACT FROM AUTHOR]

A method for synthesizing microspheres of the zeolite gmelinite (GME) with mean diameter 8 µm, and narrow dispersion, has been developed and establishes the key role of aging the gel prior to heating to produce a narrow size distribution. Fluoride adsorption from acidic media has been evaluated for GME microspheres following post-synthetic modifications by calcium ion exchange, iron(III) surface modification, and dealumination. In each instance, the post-synthetic modification leads to appreciable equilibrium fluoride loadings, with the highest loadings observed for dealuminated GME microspheres, capable of 97.4% fluoride removal from acidified 22 ppm fluoride solutions at equilibrium. Accordingly, dealuminated GME microspheres show promise as a potential adsorbent for reducing the aqueous fluoride content in dangerously high natural sources (up to 30 ppm) to safe drinking levels (≤1.5 ppm) in one treatment. [ABSTRACT FROM AUTHOR]

This article discusses the use of anti-interleukin-17 treatment in a case of ankylosing spondylitis (AS), a chronic inflammatory disease that primarily affects the spinal joints. The formation of new bone is a hallmark of advanced AS, leading to loss of flexibility in the vertebrae. The study used 18F-sodium fluoride positron emission tomography/computed tomography (PET/CT) to assess osteoblastic activity before and after treatment with an interleukin-17 inhibitor (IL-17i). The results showed a decrease in osteoblastic activity and new bone formation after treatment, indicating the effectiveness of IL-17i in reducing abnormal bone growth in AS. The study suggests that 18F-NaF PET/CT may be a useful tool for evaluating disease activity in AS. However, the use of this imaging modality may be limited due to increased radiation exposure compared to conventional methods, and further validation in larger patient populations is needed. [Extracted from the article]

In this research study, a new bio adsorbent has been developed by synthesis of zirconium nanoparticles using Zingiber officinale rhizome extract and its subsequent entrapment in calcium alginate-carrageenin hydro gel beads. The characterisation of synthesised nanoparticles were carried out using SEM, TEM, SAED, EDAX and FT-IR. The resulting Zr-alginate-carrageenin, hydrogel beads were further subjected to batch sorption studies. Various physicochemical parameters such as pH, contact time, biomass doses were optimised for maximum removal of fluoride from aqueous solution. Results revealed that composite so prepared could remove fluoride from aqueous solution up to 98.5%.The equilibrium study has been carried out to investigate the capacity of adsorption by applying the Langmuir and Freundlich model, respectively. The nature of adsorption was found to be endothermic, spontaneous and belonged to chemisorption as supported by Temkin and D-R isotherm studies. [ABSTRACT FROM AUTHOR]

To examine the association between fluoride exposure and childhood blood pressure (BP), we used data involving 3260 subjects participating in the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016. Both plasma and water fluoride concentrations were measured using the ion-specific electrode. Outcome variables were systolic blood pressure (SBP) and diastolic blood pressure (DBP). For a 1-mg/L increase in water fluoride concentration, the participantsʻ SBP decreased by 0.473 mm Hg (95% CI: −0.860, −0.087). Specifically, inverse associations were found between water fluoride and SBP in girls (β= −0.423, 95% CI: −0.886, −0.021), adolescents (β= −0.623, 95% CI: −0.975, −0.272), and non-Hispanic whites (β= −0.694, 95% CI: −1.237, −0.151). Also, every 1-μmol/L increase in plasma fluoride concentration was associated with a 1.183 mm Hg decrease in SBP among other races (95% CI: −2.258, −0.108). This study suggested that fluoride exposure may affect childhood blood pressure. [ABSTRACT FROM AUTHOR]

Asymmetric minimal receptors based on 4-nitrophenylurea, 1, and 4-nitrophenylthiourea, 2, were shown to bind a range of anions and are deprotonated by both fluoride and hydroxide to give a colorimetric response. A 4-trifluoromethylphenylurea receptor, 3, was deprotonated by fluoride but not hydroxide but was not discernible by the naked eye. Deprotonation of 1 by fluoride ultimately resulted in the formation of its bicarbonate complex as determined by X-ray crystallography in agreement with DFT calculations. Fluorescence spectroscopy revealed that emission of 2 reaches a maximum at two equivalents of anions except for fluoride where it continues to increase with increasing addition of TBAF allowing 2 to give a fluoride-specific response. [ABSTRACT FROM AUTHOR]

To meet the Kairos Power (KP) Fluoride Salt-Cooled High-Temperature Reactor (FHR) (KP-FHR) development and commercialization schedules, the System Analysis Module (SAM), which is an advanced systems code for Generation IV liquid-cooled reactors developed at Argonne National Laboratory (ANL), has been selected as the basis for the development of the KP-FHR systems code KP-SAM. This allows for an accelerated joint development effort between the KP and ANL teams. This paper presents a general overview of the KP-SAM development process, its current status, completed verification, and ongoing validation efforts. KP-SAM development follows the U.S. Nuclear Regulatory Commission Evaluation Model Development and Assessment Process framework. SAM is a high-order fully implicit transient systems code written in C++. The SAM software design, major physical models, and Jacobian Free Newton Krylov–based numerical methods are briefly discussed. KP-SAM has matured enough to be used for the unvalidated demonstration safety analysis for the low-power KP-FHR test reactor (Hermes) as part of Preliminary Safety Analysis Report work. By following the guidance of an internal KP-FHR thermal fluid Phenomena Identification and Ranking Table report, some of the most important separate-effects-test validations were completed for the first iteration. A scaled integral-effects test is under detailed design and will be built in 2022 to provide key data to validate KP-SAM for licensing safety analysis. [ABSTRACT FROM AUTHOR]

The structures, bonding and stability of (MF2)m:(M´F3)n (M = Be, Mg; M´ = B, Al; m = 0,1,2; n = 0,1,2) clusters were obtained at the B3LYP/aug-cc-pVTZ level of theory. To understand trends across this set of closely related atoms, an analysis of the results obtained using atoms in molecules (AIM), electron localisation function (ELF) and electron density shift (EDS) approaches, permits to identify subtle dissimilarities when the first-row elements, Be and B, are replaced by the second-row counterparts, Mg and Al. For dimers this replacement involves an increase in the bonding enthalpies as a direct consequence of a much larger ionic character of the derivatives including second-row elements. For trimers and tetramers, rather stable structures involving penta-coordinated aluminium atoms are formed, which are not found for the B-containing analogues. In all clusters investigated the electronic environment around each monomer does not change significantly neither with nature of the monomers interacting with it or with the size of the cluster, though some small cooperative effects are observed when analyzing the binding enthalpies. The important consequence is that the stability of larger clusters can be easily predicted through a statistical treatment of the values obtained for the smaller ones. [ABSTRACT FROM AUTHOR]

Radiolytic fluorine gas production at temperatures of 40°C to 60°C was investigated for the fluoride salts LiF, BeF2, UF4, ThF4, and 71.7LiF-16BeF2-12.3UF4 (FliBe-UF4) by gamma irradiation of powdered samples using spent fuel elements from the High Flux Reactor (HFR) Petten as the irradiation source; work of a similar nature was previously performed at Oak Ridge National Laboratory in the period 1965 to 1995. Gamma irradiation was conducted for just over 41 days, with total absorbed gamma dose ranging from ~45 MGy for the lightest salts to ~170 MGy for ThF4 and UF4. By measuring the gas pressure within salt-filled capsules during irradiation, it was possible to quantify radiolytic gas production for all salt samples except UF4. Production rates are reported as the salt G-values, measured as number of fluorine molecules produced per 100 eV of energy absorbed (molecules F2/100 eV). The G-values of the salts were found to be G(LiF) ~0.004, G(BeF2) ~0.009, G(ThF4) ~0.021, and G(FLiBe-UF4) ~0.005. [ABSTRACT FROM AUTHOR]

High fluoride intake via groundwater is a very serious problem for human health, especially in children. The present study focused on the health risk in children between 5–15 years due to higher consumption of fluoride in water used for potable purposes. A total of 195 samples of groundwater were analyzed for water parameters like pH, EC, TDS, fluoride, etc. On the basis of the primary data on the quality of drinking water, non-carcinogenic health risks of excessive fluoride intake in children were evaluated. Findings showed that the concentration of fluoride in Munger lies from 0.029 to 12 (mg/l) and 13.8% of total samples contain fluoride exceeding the allowable limit (1.5 mg/l). Hazard quotient value through ingestion of drinking water with high-level fluoride content varies from 0.625 to 8.571 whereas via dermal exposure hazard, quotient value lies in between 0.001 to 0.012. Therefore, the total hazard quotient obtained in Munger varied from 0.626 to 8.58. This indicates that children in Munger are highly vulnerable to non-carcinogenic health risks via prolonged fluoride intake mainly through the drinking water pathway. The outcome of the sensitivity analysis revealed that the concentration of fluoride is the most influential parameter in non-carcinogenic health risk. [ABSTRACT FROM AUTHOR]

In this study N-methyl-D-glucamine selective functional group is bound to magnetic nanoparticles (M-TACA) with click chemistry, which is fast, simple to use, easy to purify, versatile, region-specific and gives high product yield. The synthesized M-TACA nano-sorbent was characterized by SEM and VSM techniques. The parameters effecting sorption of As(V) onto M-TACA such as dosage, initial concentration of As(V), contact time and pH were studied. Sorption of As(V) onto M-TACA nano-sorbent is pH dependent and the maximum sorption capacity was obtained at pH 6 as 76.54 ± 1.21mg/g. The effects of fluoride, sulfate and phosphate ions, which compete with As(V) to hold active groups, on the sorption of As(V) were investigated. Fluoride has minimal effect on arsenic uptake. It is sulfate that has the most negative effect on intake and phosphorus has had a less negative effect. Sorption is more compatible with the Langmuir isotherm model than any other applied isotherm model. Results obtained from intra particle diffusion model shown the two sorption stages indicating that both surface and intra-particle sorption occurs. At the same time, sorption percentages for five times reusability were determined as 99.6 ± 2.5%, 99.0 ± 3.0%, 98.6 ± 3.1%, 97.0 ± 3.5% and 96.6 ± 3.8%, respectively. The reusability results showed that the MTACA nano-sorbent can be reused at least 5 times in removal of As(V). [ABSTRACT FROM AUTHOR]

This study evaluated the antimicrobial and anticaries effects of toothpaste containing hydroxyapatite nanoparticles (nanoHAP − 5 or 10%), xylitol (2 or 3%) and propolis (1 or 2%), associated or not with 1500 ppm fluoride (F). An in vitro model was used with microcosm biofilm produced from a pool of human saliva and McBain saliva (1:50) in the first 8 h of culture on 162 bovine enamel specimens. At the end of the experimental period, analyses of metabolic activity, colony forming units (CFU) and transverse microradiography (TMR) were performed. This study showed a possible decrease in demineralization and increase in remineralization by the commercial toothpaste (1500 ppm F) and for the experimental toothpaste containing the highest concentration of all agents, combined with F. In addition, a reduction in antimicrobial activity possibly caused by propolis and xylitol, mainly in relation to cariogenic bacteria, was observed. [ABSTRACT FROM AUTHOR]

In this study, the concentration of fluoride in water resources and its associated health risks were investigated by collecting water samples from 43 villages around the city of Divandarreh during the rainy and dry seasons. The results showed that fluoride concentration in drinking water ranged from 0.23 to 2.08 mg L−1 for the rainy season and 0.1 to 1.95 mg L−1 for the dry season. Based on the results, 51.16% of the analysed samples from the rainy season and 58.13% from the dry season were within the standard range required by WHO (0.5–1.5 mg/l). The results from the health risk assessment showed that children were exposed to the higher levels of risk in most of the studied villages. The hazard quotient (HQ) values for all groups of the studied population was higher than 1 in Alijan, Babarar, Gheshlagh sefid and Abbareh villages. In conclusion, the reduction of fluoride content in the drinking water and regular monitoring of water resources can play a vital role in preventing non-carcinogenic fluoride adverse health effects. [ABSTRACT FROM AUTHOR]

The development of simple and cost-effective photocatalytic materials in the treatment of effluents containing organic compounds is of extreme importance. This work evaluated the influence of fluoride ions on the synthesis of spray-dried Nb2O5/Carbon Xerogel composites. The material processed in the system with high fluoride concentration showed the presence of hexagonal NbO2F and Nb2O5 crystalline phases, whereas the material synthesized in lower fluoride concentration showed mainly the Nb2O5 phase. The higher content of the fluoride was detrimental to the adsorption capacity of the material and resulted in a significant reduction in the photocatalytic activity of spray-dried materials, probably due to the significant reduction in the specific surface area observed. [ABSTRACT FROM AUTHOR]

The amount of fluoride in drinking water sources is very important for public health. This study was conducted to evaluate the fluoride concentration in drinking water and compare the results with national and international standards, health risk assessment in non-cancerous diseases in East Azerbaijan province. This cross-sectional study was conducted in 20 large cities of East Azerbaijan province (West North of Iran) in warm (spring and summer) and cold (autumn and winter) seasons in 2017–2018.The results showed that the mean fluoride concentration in drinking water during cold and warm seasons was variable in the range of 0.19–0.65 and 0.18–0.62 mg/L, respectively. The Fluoride concentration in 80% of samples was lower than the standards. Also, the fluoride concentration in drinking water of studied cities was lower than calculated optimum concentration by Galagan and Vermillion equation. The estimated daily intake of fluoride (EDI) for infants, children, teenagers, and adults were 3.06, 2.15, 12 and 12.5 µg/kg/day, respectively. The hazard quotient (HQ) values for four age groups (infants, children, teenagers, and adults) for both seasons were lower than 1.Fluoridation and adjusting its concentrations in drinking water could be useful to compensate for its deficiency and prevent tooth decay. Based on the results, the non-carcinogenic risks of fluoride for the four exposed populations were below the safe limit. [ABSTRACT FROM AUTHOR]

To investigate groundwater quality in the north of Jazmourian (Roudbar plain), 30 samples were collected and analyzed for evaluating drinking and irrigation status and associated health risks. In addition to major anions and cations, the fluoride and nitrate content of samples were analyzed using standard procedures. Nitrate levels range between 6.6 and 131 mg/L and exceed the WHO permissible limit in more than 23% and 80% of samples for adults and children, respectively. Fluoride amounts ranged from 0.4 to 4.8 mg/L in samples. The F- level exceeded the WHO standard limit in 10% of samples. The EC level increases in fine-grained deltaic deposits toward the south. The concentrations of major ions (HCO3, Cl, SO4, Mg, Na, K) increase southwards, following the flow direction. There are, however, lateral (east-west) differences in water quality due to the influence of such factors as the rate of recharge and the type of bedrock. Wherever the redbeds comprise the bedrock and the recharge rate is weaker, the dissolved salts are higher in amount. The water quality index (IWQ) indicated that 13, 13, and 4 samples are in "good," "poor," and "very poor" quality classes, respectively. By using the irrigation water quality index (IWQI), eight samples were at "low restriction," nine samples at "moderate restriction," twelve samples at "high restriction," and one sample at "severe restriction" classes. The acquired findings revealed that the mean oral hazard quotient of nitrate was 1.14, 1.0, and 0.84, and for fluoride, it was 0.82, 0.72, and 0.61 for children, females, and males, respectively. The total hazard index for cumulative NO3- and F- toxicity exceeded the acceptable level in 76.67%, 66.67%, and 56.67% of samples for children, females, and males, respectively. [ABSTRACT FROM AUTHOR]

The fluoride with high-concentration in industrial wastewater will cause great harm to the environment and calcium-modified biochar is an effective adsorbent for the removal of fluoride. Biochar composites were prepared from mature and dried dead leaves and eggshell to remove fluoride from the aqueous solution. The effects of raw material ratio, pH, contact time, adsorbent dosage, temperature, initial concentration of fluoride, and the coexisting ions on the removal efficiency of fluoride were explored. The biochar composites before and after fluoride removal were characterized by the SEM, FTIR, XRD, and XPS, which showed CaF2 precipitation was formed during the adsorption. The kinetics and isotherm study showed that chemical adsorption was the primary step for the fluoride adsorption of the biochar composites. The removal efficiency of fluoride can reach 98.53% when the amount of adsorbent was 1.6 g/L and the fluoride concentration was 500 mg/L. The BET-specific surface area of platanus acerifoli leaves biochar was 410.14 m2/g, which was suitable for the adsorption carrier. The adsorption capacity of the biochar composite materials was as high as 308 mg/g. The platanus acerifoli leaves-eggshell biochar composite with large pore size and high removal efficiency may be used as an efficient and low-cost adsorbent for treating high-concentration fluoride-containing wastewater. [ABSTRACT FROM AUTHOR]

This study presents a comparison among different-bottled drinking water commercially available in Lahore Pakistan. For that, five locally produced drinking water brands and four national brands were selected. Different physical, chemical and microbiological parameters like EC, pH, salinity, TDS, Na+, K+, Ca2+, Mg2+, Cl−, F−, Fe3+, SO42-, NO3-, PO43-, Arsenic (As), total coliforms and faecal coliforms/Escherichia coli were analysed. Results showed that there was a remarkable difference in the quality. Analysed data exposed that EC range was 141–298.3 μS/cm, pH 7.35–7.95, Salinity 0.1 ± 0.02 ppt, turbidity 2.13–2.45 NTU, TDS 85–182 mg/L, sodium 12–71.2 mg/L, potassium 0.1–2.4 mg/L, calcium 16–40 mg/L, mag- 30 magnesium 2.5–35 mg/L, chloride 35–95 mg/L, fluoride 0.29–0.94 mg/L,Iron below detectable limits to 0.17 mg/L, sulphate s 22–120 mg/L, phosphates 0.023–0.17 mg/L, nitrates 0.9–3.6 mg/L and arsenic were 0.0005–0.01 mg/L in these brands of drinking water. The analysed data was compared with the PSQCA, US–EPA and WHO standards. In only one brand of water, the concentration of sodium (71.2 mg/L) and arsenic (0.01 mg/L) was higher than permissible limits. For microbiological contamination brand E (80 colonies/100 mL sample), C (25 colonies/100 mL sample), S (100 colonies/100 mL sample) and K (15 colonies/100 mL sample) were.Some of these water brands examined were deficient in essential minerals like S brand in which Magnesium was only 2.5 mg/L and K and G brands in which calcium was 16 mg/L and 20 mg/L, respectively It was observed that treatment plants having raw water of low TDS 60 or those whose process based on 50% mineral dosing and 50% blending were cost-effective. Data presented in this study are important because it can be considered as baseline data for future. [ABSTRACT FROM AUTHOR]

The present study makes an attempt to mainly design to analyze the impact of fluoride in plain tropical central India and affecting health conditions of the school children. Fluoride naturally, a toxic material for the human beings but its more concentration in the body due to anthropogenic activities increases the risk of more dangerous outcomes. We utilized ionic concentration, hydrochemistry, fluoride content and health risk assessed from the different collected water samples in the month of June, 2017. This study shows the concentration of fluoride content in water sample ranged from 0.08-2.4 mg/l (mean = 0.6 mg/l) and had positive relation with the pH (r= 0.49), HCO3 - (r= 0.29) and Naþ (r = 0.20). Few, 9.18% water sample out of total collected samples were exceeding the permissible limit (> 1.5 mg/l) of fluoride content in groundwater which was not suitable for drinking purpose due to the heavy loading of fluoride content. [ABSTRACT FROM AUTHOR]