Adaptive responses of the ileum of NOD mice to low-dose fluoride: A proteomic exploratory study.

Fluoride (F) has been employed worldwide to control dental caries. More recently, it has been suggested that the consumption of low doses of F in the drinking water may reduce blood glucose levels, introducing a new perspective for the use of F for the management of blood glucose. However, the exact mechanism by which F affects blood glucose levels remains largely unexplored. Given that the small gut plays a pivotal role in glucose homeostasis, the aim of this study was to investigate the proteomic changes induced by low doses of F in the ileum of female nonobese-diabetic (NOD) mice. Forty-two female NOD mice were divided into two groups based on the F concentration in their drinking water for 14 weeks: 0 (control) or 10 mgF/L. At the end of the experimental period, the ileum was collected for proteomic and Western blot analyses. Proteomic analysis indicated an increase in isoforms of actin, gastrotropin, several H2B histones, and enzymes involved in antioxidant processes, as well as a decrease in enzymes essential for energy metabolism. In summary, our data indicates an adaptive response of organism to preserve protein synthesis in the ileum, despite significant alterations in energy metabolism typically induced by F, therefore highlighting the safety of controlled fluoridation in water supplies.

Silver nanopopcorns decorated on flexible membrane for SERS detection of nitrofurazone.

The synthesis of three-dimensional silver nanopopcorns (Ag NPCs) onto a flexible polycarbonate membrane (PCM) for the detection of nitrofurazone (NFZ) on the fish surface by surface-enhanced Raman spectroscopy (SERS) is presented. The proposed flexible Ag-NPCs/PCM SERS substrate exhibits significant Raman signal intensity enhancement with the measured enhancement factor of 2.36 × 106. This is primarily attributed to the hotspots created on Ag NPCs, including numerous nanoscale protrusions and internal crevices distributed across the surface of Ag NPCs. The detection of NFZ by this flexible SERS substrate demonstrates a low limit of detection (LOD) of 3.7 × 10-9 M and uniform and reproducible Raman signal intensities with a relative standard deviation below 8.34%. It also exhibits excellent stability, retaining 70% of its efficacy even after 10 days of storage. Notably, the practical detection of NFZ in tap water, honey water, and fish surfaces achieves LOD values of 1.35 × 10-8 M, 5.76 × 10-7 M, and 3.61 × 10-8 M, respectively,  which highlights its effectiveness across different sample types. The developed Ag-NPCs/PCM SERS substrate presents promising potential for sensitive SERS detection of toxic substances in real-world samples.

Mapping Microplastics in Humans: Analysis of Polymer Types, and Shapes in Food and Drinking Water-A Systematic Review.

Microplastics (MPs) pervade the environment, infiltrating food sources and human bodies, raising concerns about their impact on human health. This review is focused on three key questions: (i) What type of polymers are humans most exposed to? (ii) What are the prevalent shapes of MPs found in food and human samples? (iii) Are the data influenced by the detection limit on the size of particles? Through a systematic literature analysis, we have explored data on polymer types and shapes found in food and human samples. The data provide evidence that polyester is the most commonly detected polymer in humans, followed by polyamide, polyurethane, polypropylene, and polyacrylate. Fibres emerge as the predominant shape across all categories, suggesting potential environmental contamination from the textile industry. Studies in humans and drinking water reported data on small particles, in contrast to larger size MPs detected in environmental research, in particular seafood. Discrepancies in size detection methodologies across different reports were identified, which could impact some of the discussed trends. This study highlights the need for more comprehensive research on the interactions between MPs and biological systems and the effects of MPs on toxicity, together with standardised analytical methodologies to accurately assess contamination levels and human exposure. Understanding these dynamics is essential for formulating effective strategies to mitigate the environmental and health implications of MP pollution.

Health risk assessment in an area of dental fluorosis disease from high fluoride drinking water: a case study from southeastern Türkiye.

This study focuses on identifying fluoride (F‒) concentrations and its health risk assessment (HRA) in drinking water sources in south-eastern Türkiye. Groundwater quality was assessed using some graphical approaches such as Schoeller and Piper diagrams and GIS mapping. Average daily exposure dosages through oral and dermal contact exposure routes were considered to determine the potential health risk of F‒ in groundwater. Groundwater samples were taken from 53 points in spring, summer, autumn, and winter seasons. The results showed that the average annual F‒ concentrations in water resources in the study area were 0.26‒3.62 mg/L. According to the HRA results, the highest F‒ health risk in this region was observed in children, followed by teenagers and adults. This study indicated that there is a strong relationship between the high health risk (4.28 > 3.5) in children and dental fluorosis caused by high F‒ concentration in groundwater.

Potential risk of dental fluorosis associated with different baby formulas and water brands marketed in Spain.

Despite efforts to promote breastfeeding, many babies aged <6 months receive only baby formula reconstituted with bottled water. The intake of high levels of fluoride during amelogenesis has been associated with hypomineralization of the tooth enamel, with aesthetic and mechanical repercussions. The objective of this study was to determine the potential risk of dental fluorosis associated with baby formulas marketed in Spain. We measured 26 baby formulas frequently consumed in Spain; 17 brands for babies aged <6 months, 5 for those aged >6 months, and 4 ready-to-use brands. They were prepared with 4 types of water: distilled water and three brands of bottled water with different levels of fluoride. The fluoride concentration (mg/L or ppm F) was measured with an ion-specific electrode coupled to an ion analyzer. Each sample was prepared according to the manufacturer's instructions and analyzed in triplicate. A descriptive analysis was carried out. The minimum fluoride level found was 0.04 mg/L and the maximum was 1.02 mg/L. Considering the daily intake of these formulas, none exceeded the clinically-acceptable daily dose limit risk for fluorosis (0.07 mg F/day/kg body weight) when mixed with bottled water with a low level of fluoride (0.1 mg/L). However, when the same brands of formula were reconstituted with bottled water with a higher fluoride content (0.99 mg/L), they all exceeded the daily dose limit for the risk of fluorosis. As the potential risk of dental fluorosis associated with the formulas tested depends exclusively on the fluoride concentration of the waters used for reconstitution, formula packaging should contain a warning.

Analysis of indicators of caries of permanent teeth in children according to the endemic features of the Poltava region, Ukraine.

OBJECTIVE: Aim: This research is focused at analyzing the indicators and substantiating the peculiarities of caries prevention in permanent teeth in schoolchildren of Poltava region, taking into account the endemic features of the Poltava region. PATIENTS AND METHODS: Materials and Methods: A comparative study was conducted among 608 pupils of secondary schools in Kremenchuk, who consumed drinking water with fluoride concentrations in the lower limits of the norm, and 1214 pupils of secondary schools in Poltava, who consumed drinking water with fluoride concentrations in the optimal upper limits of the norm. RESULTS: Results: The rates of caries in permanent teeth in children living in a region with fluoride concentrations in drinking water in the optimal-upper normal range are several times lower than in children of the same age living in a region with fluoride concentrations in drinking water in the lower normal range, and a significant increase in the prevalence and intensity of caries is observed from 7 to 9 to 12 years of age, as teeth after eruption are most vulnerable to caries. In a region where the fluoride concentration in drinking water is in the optimal-upper range of the norm, children with early forms of fluorosis have the lowest prevalence and intensity of caries. CONCLUSION: Conclusions: Endemic features of the region directly affect the prevalence and intensity of the caries process. In regions with a fluoride concentration in drinking water within the optimal upper limits of the norm, prevention of caries in permanent teeth in children should be carried out taking into account the presence of fluorosis.

Identification of Poly(ethylene terephthalate) Nanoplastics in Commercially Bottled Drinking Water Using Surface-Enhanced Raman Spectroscopy.

Micro/nanoplastics have emerged as global contaminants of serious concern to human and ecosystem health. However, identification and visualization of microplastics and particularly nanoplastics have remained elusive due to the lack of feasible and reliable analytical approaches, particularly for trace nanoplastics. Here, an efficient surface-enhanced Raman spectroscopy (SERS)-active substrate with triangular cavity arrays is reported. The fabricated substrate exhibited high SERS performance for standard polystyrene (PS) nanoplastic detection with size down to 50 nm and a detection limit of 0.001% (1.5 × 1011 particles/mL). Poly(ethylene terephthalate) (PET) nanoplastics collected from commercially bottled drinking water were detected with an average mean size of ∼88.2 nm. Furthermore, the concentration of the collected sample was estimated to be about 108 particles/mL by nanoparticle tracking analysis (NTA), and the annual nanoplastic consumption of human beings through bottled drinking water was also estimated to be about 1014 particles, assuming water consumption of 2 L/day for adults. The facile and highly sensitive SERS substrate provides more possibilities for detecting trace nanoplastics in an aquatic environment with high sensitivity and reliability.

Toothbrushing practices as risk factors for dental fluorosis in an area with varying fluoride levels in drinking water.

BACKGROUND: Despite contributing to a reduction in dental caries, improper use of fluoridated toothpaste could add to the burden of dental fluorosis in children. AIM: To assess the association between tooth-brushing practices such as the type and amount of toothpaste used, frequency of tooth brushing, parental assistance in tooth brushing, timing of tooth brushing and dental fluorosis in school children in Kurunegala district, an endemic area for dental fluorosis in Sri Lanka. METHODS: For this case-control study, a sex-matched sample of 15-year-old school children attending government schools in Kurunegala district and who were lifetime residents of the district was selected. Dental fluorosis was measured using the Thylstrup and Ferjeskov (TF) Index. Those children with a TF⟩1 were considered as cases and those with a TF score of 0 or 1 served as controls. An interview of parents/caregivers of the participants was used to assess risk factors for dental fluorosis. The fluoride concentration in drinking water was measured using spectrophotometry. Data analysis used chi-square tests and conditional logistic regression. RESULTS: Tooth brushing ≥ twice/day, brushing after breakfast and parent/care giver brushing the child's teeth reduced the likelihood of developing fluorosis. CONCLUSION: Use of fluoridated toothpaste adhering to the recommended guidelines could prevent dental fluorosis in children in this endemic area.

Continuous Sizing and Identification of Microplastics in Water.

The pollution of the environment with microplastics in general, and in particular, the contamination of our drinking water and other food items, has increasingly become the focus of public attention in recent years. In order to better understand the entry pathways into the human food chain and thus prevent them if possible, a precise characterization of the particles concerning their size and material is indispensable. Particularly small plastic particles pose a special challenge since their material can only be determined by means of large experimental effort. In this work, we present a proof of principle experiment that allows the precise determination of the plastic type and the particle size in a single step. The experiment combines elastic light scattering (Mie scattering) with inelastic light scattering (Raman scattering), the latter being used to determine the plastic type. We conducted Monte Carlo simluations for the elastically scattered light for different kinds of plastics in a microfluidic cuvette which we could reproduce in the experiment. We were able to measure the Raman signals for different microplastics in the same measurement as the elastically scattered light and thereby determine their material. This information was used to select the appropriate Monte Carlo simulation data and to assign the correct particle size to different materials with only one calibration measurement.

Antimony in Polyethylene Terephthalate-Bottled Beverages: The Migration Puzzle.

A novel strategy to assess the main variables that potentially affect the migration of antimony from PET bottles to beverages, including mineral waters and juices, is herein proposed. In a preliminary step, an LC-ICP-MS method previously used for water analysis was optimized to correct identify Sb species present in the studied matrices using HRMS. Subsequently, the influence of temperature and storage time up to 30 days on Sb migration from PET bottles into peach and pineapple juices of the same brand was studied. Storing PET bottled drinks at elevated temperatures (i.e., in a hot car or in summer) can cause antimony migration to exceed the limits allowed in the EU or USA. Because the behavior observed differed from the results reported for Sb migration in mineral waters, a second approach was proposed: three mineral water and two juice samples were kept in different PET containers and stored at an elevated temperature (up to 60 °C) to understand the role of the PET type and matrix simultaneously. This study demonstrated that both matrix characteristics and type of PET bottle greatly influence antimony leaching, highlighting the need to consider these variables together when conducting migration experiments. The obtained results can be helpful for developing future legislation concerning migration of pollutants from packing to food commodities.

Use of agricultural bio-wastes to remove arsenic from contaminated water.

Arsenic (As) is a highly toxic metalloid. High As levels have been recorded in groundwater aquifers at a global scale. This study investigated As level in groundwater of District Vehari and assessed the potential of different agricultural by-products (sugarcane bagasse, cottonseed hulls, soybean hulls, corncobs and rice husk) to remove As from water. The study was carried out in two steps. In the first step, a total of 38 groundwater samples were obtained from Vehari. Groundwater samples were analyzed for total As contents and physicochemical parameters. Results indicated that As content ranged from below detection limit to 49 µg/L in the groundwater samples. The values of hazard quotient and cancer risk were up to 1.5 and 0.0004, respectively, which delineated severe risk of As poisoning. During the second step, six As-contaminated groundwater samples (total As contents: 49, 40, 29, 24, 18, 16 µg/L) were selected to remove As using agricultural by-products. Furthermore, four As solutions (200, 100, 50 and 25 µg/L) were prepared in the laboratory. Results revealed that corncobs and soybean hulls removed, respectively, 98% and 71% As from aqueous mediums after 120 min. Moreover, agricultural by-products were less effective in removing As from groundwater samples than synthetic solutions. The adsorption/removal capacity of by-products was lower at low initial As concentration compared to high initial levels, which needs further studies to explore the underlying mechanisms. Overall, the As removal efficiency of agriculture by-products differed significantly with respect to initial As level, contamination category, type of agricultural by-products and interaction duration. Therefore, these aspects need to be optimized before the possible use of an agricultural by-product as a potential biosorbent.

Epidemiological analysis of drinking water-type fluorosis areas and the impact of fluorosis on children's health in the past 40 years in China.

This study analyzed the effect of China's fluorosis prevention and control program, which has been in effect for more than 40 years, and the impact of fluorosis on children's health. Relevant research studies were retrieved from the following online databases from the time of their inception to May 2022: PubMed, ScienceDirect, Embase, Cochrane, China National Knowledge Infrastructure, and Wanfang. The Review Manager 5.3 software was used in statistical analyses. This article included seventy studies: Thirty-eight studies reported the effect of improving water quality and reducing fluoride content, the incidence rate of dental fluorosis in children, and the level of urinary fluoride, and thirty-two studies reported the intelligence quotient (IQ) and health status of children. Following water improvement strategies, the fluoride levels in drinking water decreased significantly; urinary fluoride levels and dental fluorosis decreased significantly in children. With regard to the effect of fluorosis on the IQ of children, the results showed that the IQ of children in areas with a high fluoride of fluorosis was lesser than that in areas with a low fluoride, and this difference was significant. Based on the prevalence of dental fluorosis and its effect on the intelligence of children, it appears that reducing fluoride levels in drinking water and monitoring water quality are important strategies for the prevention and treatment of fluorosis.

Evaluation of the impact of fluoride in drinking water and tea on the enamel of deciduous and permanent teeth.

BACKGROUND: Systemic fluoride intake is predominantly derived from drinking water and tea. It's been noted that water and tea containing fluoride, within the boundaries set by the World Health Organization, can lessen the prevalence of dental caries. A review of the literature did not uncover any study that has examined the impact of fluoride in bottled drinking water and tea on enamel of deciduous and permanent teeth. Thus, we assessed the effects of fluoride present in seven different brands of bottled water from distinct geographical regions of Turkey, and a type of tea produced and packaged in Turkey, on the enamel of deciduous and permanent teeth. MATERIALS AND METHODS: Fluoride analysis was performed on drinking water sourced from seven different regions of Turkey and a brand of tea brewed with these waters. The tea was harvested and packaged in Turkey. The analysis was conducted using an ion-selective electrode. In total, 112 tooth enamel samples (56 deciduous molars and 56 permanent molars) were randomly divided into eight distinct groups. These were kept in water for 15 min and tea for 15 min every day for a month. The eighth group was treated with fluoride gel prior to tea and water applications. The amount of fluoride in the tooth enamel structure was evaluated using an SEM EDX device before and after the experiment. RESULTS: Statistically significant differences were found in fluoride content of enamel between water brands and tooth type (deciduous and permanent teeth). Fluoride levels were higher in the enamel of deciduous teeth than in permanent teeth. CONCLUSION: Regular exposure of enamel samples to black tea and water led to an increase in fluoride levels in the enamel; thus, regular consumption of black tea and fluoride water could help reduce the prevalence of dental caries.

Simultaneous determination of phthalates and bisphenols from plastic bottled water samples by dispersive solid-phase extraction with multiwalled carbon nanotubes and liquid chromatography/atmospheric pressure photoionization/high-resolution mass spectrometry.

RATIONALE: Phthalates and bisphenols were reported as endocrine disrupting chemicals and hence a potential threat to human health. Polyethylene terephthalate bottles are being used to store drinking water and the probability of migration of phthalates and bisphenols from the bottles into the water is high. The migration of analytes with respect to different storage conditions need to be studied. METHOD: A sensitive analytical method for simultaneous determination of seven phthalates and three bisphenols from packaged drinking water was developed using liquid chromatography/atmospheric pressure photoionization/high-resolution mass spectrometry. The analytes were extracted by dispersive solid-phase extraction by multiwalled carbon nanotubes. RESULTS: The developed method showed linearity from 0.5 to 5000 µg/L with the limit of detection and limit of quantification ranging from 0.5 to 1 µg/L and 1 to 2 µg/L, respectively, for phthalates and bisphenols. The inter- and intraday variations were below 10%. The recoveries were in the range of 79.5% to 112%. The migration of phthalates and bisphenols increased with storage time and temperature. Maximum migration was observed for diisobutyl phthalate of 1209.7 ng/L followed by dibutyl phthalate at 777.8 ng/L on 180 days of analysis at room temperature. Migration of bis(2-ethylhexyl) phthalate was observed to be higher at elevated temperatures, increasing from 14.9 to 514 ng/L. Similarly, migration of bisphenol-A was increased at 45°C. The results were subjected to analysis of variance (ANOVA) studies and the results showed significant variations of phthalates and bisphenols with respect to storage temperature and time. CONCLUSION: The use of atmospheric pressure photoionization facilitated simultaneous determination of phthalates and bisphenols. The migration of phthalates and bisphenols increased with increasing temperature and storage time. Maximum migration was observed for diethyl, diisobutyl, dibutyl and bis(2-ethylhexyl) phthalates. This may be attributed to the type of plastic, the processing parameters and recycling.

Groundwater antibiotics and microplastics in a drinking-water source area, northern China: Occurrence, spatial distribution, risk assessment, and correlation.

In recent years, antibiotics and microplastics have both received increasing attention. However, the contamination and correlation between the two pollutants in the groundwater of drinking-water source areas has not yet been considered. In this study, eight antibiotics were detected in 81 groundwater samples from a drinking-water source area. These were trimethoprim (TMP), sulfadimidine (SDD), sulfadiazine (SDZ), sulfamethoxazole (SMX), sulfachloropyridazine (SCP), norfloxacin (NOR), ciprofloxacin (CIP) and enrofloxacin (ENRO). Detection rates ranged from 1.23% to 95.06% and the maximum concentration ranged from 0.44 ng/L to 45.40 ng/L. Antibiotics in the groundwater pose no threat to human health, while only ENRO, CIP, NOR, SMX, and SDZ posed medium to low risks to the aquatic ecosystem. In contrast, the detection rate of microplastics was 100% with abundance values ranging from 4 n/L to 72 n/L, with an average of 29 n/L. Microplastic polymers were identified as polyamide, polyethylene, polypropylene, polyvinyl chloride and polystyrene. These also occurred in surface water but the particle sizes in groundwater were lower than those in the surface water. Through correlation analysis, it was found that NOR, ENRO and total antibiotic concentrations were significantly correlated with microplastic abundances. This study revealed the contamination and potential risks of antibiotics and microplastics in the groundwater of a drinking-water source area and found a correlation between them, indicating that risk management of antibiotics and microplastics in groundwater should be highly concerned.

Health risk assessment of fluoride exposure due to groundwater consumption in Romania.

Fluoride has both beneficial and detrimental effects on human health. Concentrations of fluoride less than 1.0 mg/L in ingested water are beneficial for the rate of tooth decay, especially in children. The aims of the paper are as follows: (i) to monitor fluoride concentrations in drinking water samples (well water and tap water from the rural district of Valea Râmnicului, Romania); (ii) to study and select the optimal buffer solution and the optimal volume used in the analyses and (iii) to validate the potentiometric method for determining fluoride ions with a selective ion electrode. The values of fluoride ion concentrations in the groundwater samples and in tap water varied from 0.01 to 0.138 mg/L. The values for the hazard quotient for the studied samples varied from 0.01 to 0.13.

Impact of diseases of the hard tissues of teeth on oral health-related quality of life of schoolchildren in area with a high concentration of fluoride in drinking water.

OBJECTIVE: To assess the impact of caries, Molar Incisor Hypomineralization (MIH), and fluorosis on the Oral Health-Related Quality of Life (OHRQoL) of schoolchildren aged 8-10 years living in area with different fluoride levels in the drinking water. SUBJECT AND METHODS: The prevalence of caries and fluorosis were assessed among 663 Mexican schoolchildren using the International Caries Detection and Assessment System (ICDAS II) and the Thylstrup and Fejerskov Index (TFI), respectively. MIH was recorded using the European Academy of Pediatric Dentistry (EAPD) criteria and OHRQoL using the Child Perceptions Questionnaire (CPQ8-10). Poisson regression models were used in data analysis. RESULTS: Schoolchildren presenting two of the three conditions (cavitated lesions and TFI≥4, cavitated lesions and MIH or TFI≥4 and MIH) experienced worse quality of life than children who did not [RR=4.18; (95% CI 3.83, 4.56)]. Children with all three conditions had worse quality of life than children who did not [RR=5.64; (95% CI 5.13, 6.20)]. CONCLUSIONS: Fluorosis, MIH, and caries have a negative impact on the OHRQoL of schoolchildren living in area with a high concentration of fluoride in their drinking water.

Novel machine learning techniques based hybrid models (LR-KNN-ANN and SVM) in prediction of dental fluorosis in groundwater.

Studies have shown that excessive intake of fluoride into human body from drinking water may cause fluorosis adversely affects teeth and bones. Fluoride in water is mostly of geological origin and the amounts depend highly on many factors such as availability and solubility of fluoride minerals as well as hydrogeological and geochemical conditions. Chemical methods usually accomplish fluoride analysis in drinking water. The chemical methods are expensive, labor-intensive and time-consuming in general although accurate and reliable results are obtained. An alternative cost-effective approach based on machine learning (ML) technique is investigated in this study. Furthermore, most effective input parameters are selected via proposed Simulated Annealing (SA) search scheme. Selected subset (SAR, K+, NO3-, NO2-, Mn, Ba and Fe) by SA algorithm exhibited high correlation coefficient values of 0.731 and strong t test scores of 5.248. On the other hand, most frequently selected individual features were identified as NO3-, NO2-, Fe and SAR by vote map. The results of experiments revealed that selected feature subset improves the prediction performance of the learning models while feature size is reduced substantially. Thus it eventually enabled determination of fluoride in a cheap, fast and feasible way.

Water quality and probabilistic non-carcinogenic health risk of groundwater: a half decadal scenario change in Vadodara.

Groundwater is essential to secure the safety of water supply in Vadodara, Gujarat. In this study, groundwater samples were collected from various part of the city which separated in 12 wards. The present study contains analyses of 720 groundwater samples gathered from various tube and open wells and analyzed for fluoride and other physicochemical parameters during 2014 and 2019. The results indicated that fluoride and TDS were high and the overall water quality was poor in the study area. Gastrointestinal and other health-related issues increased due to higher TDS in east, north and northeast regions. Likewise, hierarchical cluster analysis also indicated that TDS and chloride-rich water. Fluoride concentration was observed in the range of 0.66-1.61 mg/l (2014) and 0.86-1.77 mg/l (2019) which indicates that 62% samples are unfit for drinking purpose, which could cause dental and skeletal fluorosis. The water quality index (WQI) indicated lack of excellent water in the studied area in the last half-decade. As per WQI calculation suggest that 82.12% (2014) and 69.00% (2019) of groundwater samples represent poor, very poor and unsuitable categories, whereas remaining 17.85% (2014) and 31.00% (2019) of the samples represent good category for drinking purposes in entire Vadodara, Gujarat. Marginal improvement in the groundwater quality is reported due to good rainfall in 2019. Health risks associated with high fluoride drinking water were assessed for various age groups of inhabitants such as children, infants and adults. The non-carcinogenic hazard quotient estimated by oral intake was 1.38-3.36 (2014) and 1.79-3.70 (2019) for infants; 0.69-1.68 (2014) and 0.90-1.85 (2019) for children, whereas 0.07-0.18 (2014) and 0.10-0.20 (2019) for adults. Therefore, infant and children are relatively at higher health risk due to the intake of fluoride-rich drinking water than adult in the studied region. Both indices were indicated contaminated water or closer to contamination which induced non-carcinogenic health risk on citizens. Thus, the comprehensive results of present study can be used as a baseline data and valuable tool for government authorities for long-term monitoring, health monitoring and sustainable development of Vadodara, Gujarat.

Distributing and assessing fluoride health risk in urban drinking water resources in Fars Province, Iran, using the geographical information system.

Excessive fluoride intake has been reported in many studies, which can lead to diseases such as autism, mental retardation, low birth weight, reproductive disorder, as well as dental and bone fluorosis. The potential risk assessment of fluoride intake for the health of people living in Fars Province, Iran, is investigated. Hence, 1700 drinking water samples were taken from April 2018 to March 2020 in four seasons in 29 cities of Fars Province and were analyzed. Non-carcinogenic health risks of exposure to fluoride through drinking water were evaluated. Moreover, the spatial distribution maps of fluoride and hazard quotient (HQ) risk index were prepared using GIS software. The results showed that the concentration of fluoride in the drinking water of the studied area was in the range of 0.086 to 2.61 mg/L. Accordingly, in 48.27% of the cities, fluoride was in the range below the national and international standards, 34.48% of the cities were in the permissible range of 0.5 to 1.5 mg/L, and 17.24% of the urban areas of the province had fluoride contents above the permissible range. Hazard quotient index had the health risk of HQ > 1 in 27.58% of children, 17.24% of teenagers, and 10.34% of adults in the urban areas of Fars Province. In the cities with HQ > 1, there was risk of diseases associated with excessive fluoride intake. Therefore, it is necessary to replace water supply sources in these cities.