Fluoride Endemic Areas Research Articles

Spatial analysis and probabilistic risk assessment of exposure to fluoride in drinking water using GIS and Monte Carlo simulation.

Prevalence of fluorosis is a worldwide public health problem especially in many states of India. It is necessary to find out the fluoride endemic areas to adopt remedial measures to the people on the risk of fluorosis. The target goals of this research were to assess (a) the exposure of fluoride concentration; (b) probabilistic risk assessment, sensitivity analysis, and uncertainty through intake of groundwater among population of Agra City (infants, children and adults) by Crystal Ball software; and (c) spatial distribution of HQ and fluoride concentration. A total of sixty samples from standing tube wells/hand pumps were gathered from selected and identified fluoride prevalent areas in Agra City. The concentration of fluoride scrutinized was obtained to be ranging from 1.32 to 4.60 mg/L with mean value of 2.36 in Agra City, and more than 91% of samples investigated surpassed the allowable level set for fluoride concentration in potable water 1.5 mg/L, although 9% of the samples were well within the drinking water guidelines (0.5-1.5 mg/L). The hazard quotient (HQ) was obtained to an enormous difference in the exposure dose in infants (1.66-3.91), children (1.87-4.4), and adults (0.92-2.16), correspondingly. The non-carcinogenic HQ values in the group of infants, children, and more than 90% of adults were higher than those of the safety level (i.e., HQ >1). Consequently, the non-carcinogenic risks (HQ level) of fluoride vary from the most to the least: children, infant, and adults, respectively. With 87.41% certainty, the results indicated that the HQ values are between 1 and 3.42. So, infant is the most vulnerable group to fluoride consumption in study area. Uncertainty analysis results indicated that the children group's HQ level was between 1 and 1.90 with 38.48% certainty. To avoid further worsening of the situation as far as health is concerned, remedial actions like alternate sources of water supply and appropriate treatment of water need to be adopted besides required medical attention to affected people.

Relationship of fluoride in drinking water with blood pressure and essential hypertension prevalence: a systematic review and meta-analysis

Previous studies showed controversial results of the relationship between fluoride exposure through drinking water and elevated blood pressure. We conducted a systematic review and meta-analysis to assess the direct relationship of drinking water fluoride exposure with blood pressure and essential hypertension prevalence in general populations. We conducted a systematic search in databases including Web of Knowledge, PubMed, Scopus, and Embase by MeSH and non-MeSH terms for relevant studies with any design published until August 2019, with no limitation in time and language. The pooled effect measure was calculated within a 95% confidence interval (CI). Our search retrieved 630 journal articles, six of which were eligible for data extraction. The random-effects model found significantly higher systolic blood pressure (mean difference = 6.49mmHg; 95% CI 3.73-9.25; p value < 0.01) and diastolic blood pressure (mean difference = 4.33mmHg; 95% CI 1.39-7.26; p value < 0.01) in groups exposed to high-fluoride drinking water than in groups exposed to normal/low-fluoride drinking water. A significant relationship was also found between high-fluoride drinking water and essential hypertension (odds ratio = 2.14; 95% CI 1.02-4.49; p value = 0.045). The risk of elevated blood pressure increases in the general population of fluoride endemic areas. However, more research is needed to make a firm conclusion about the adverse effects of excess fluoride intake on the cardiovascular system at the individual level.

Identifying fluoride endemic areas and exposure pathways for assessment of non-carcinogenic human health risk associated with groundwater fluoride for Gujarat state, India.

Analytical data of fluoride concentration in groundwater collected from various geological formations in Gujarat, India, have been studied to assess their spatial distribution characteristics and related potential chronic health risks. Decadal analysis of groundwater was attempted for precise quantification and a realistic ground representation of fluoride concentration in the entire state. This exercise involved collection of 6407 samples over a period of 10 years (2009-2018), from 641 representative locations, distributed evenly throughout the state (6407 = 641 locations × 10 years). The analytical results indicate that 19% of the sample locations have fluoride concentration higher than the permissible limit and 42% of the locations have fluoride concentration much below the desirable limit, thereby exposing children to a higher risk of associated dental morbidities. Monte Carlo simulation integrated with sensitivity and uncertainty analysis was applied for an accurate and realistic assessment of the non-carcinogenic health risk. Model results indicated that groundwater fluoride exposure through consumption is way higher than the exposure due to dermal absorption pathway. It is inferred that 94 locations (15%) have total hazard index greater than the unity value for all population groups, thereby increasing the vulnerability of the local populace to dental and skeletal fluorosis. Total hazard index in 210 locations (36%) and 188 locations (29%) are beyond the permissible limit for the population comprising infants and children. Populaces living in these locations are susceptible to health hazards that stems from high fluoride concentration. Children and infants are at greater risk due to groundwater fluoride toxicity when compared to the adult populace. The order of the geographic stratification of vulnerabilityis Mainland regions > Saurashtra region > Kachchh region. Ingestion rate and fluoride concentration are the sensitive parameters with high impact and residents of these vulnerable locations should be advised to abstain from direct intake of groundwater and resort to defluoridised groundwater.

English

BACKGROUND In addition to diet and nutrition, environmental changes may increase the incidence of diabetes mellitus and microvascular complication leading to ‘diabetic kidney disease (DKD)’. One such factor considered in this study is fluoride. Increased incidence of DKD lead to estimation of fluoride in fluoride endemic areas. Fluoride and advanced glycation end products lead to the development of microvascular complication in patients of diabetes leading to diabetic kidney disease or diabetic nephropathy which in turn leads to increase in expression of sirtuin 1; a regulatory protein mediating deacetylation of histone proteins which was analysed. METHODS Subjects recruited for this cross-sectional study were divided as - group 1 (healthy controls), group 2 (patients with type 2 diabetes) and group 3 (diabetic nephropathy patients) with 50 subjects in each group. Routine parameters were analysed in biochemistry section of central laboratory. RESULTS In patients with diabetic kidney disease, serum and urine fluoride levels were similar (0.2 and 0.28 ppm); whereas, in other two groups, urine fluoride values were more than the serum fluoride values indicating better renal function and fluoride clearance. Least sirtuin 1 median range was observed in group 1 [22.65 (11.78 - 91.10)] and 36.9 (27.38 - 56.23) in group 3 lesser than group 2 with a value of [42.7 (30.17 - 52.93)]. CONCLUSIONS Serum and urine fluoride estimation aids in assessing progression of disorder and hence helps in preventing complications. Fluoride may not be a cause of diabetes but may accelerate its microvascular complications as observed in this study. Sirtuin 1 levels in serum or plasma can be a marker for various damages caused by aging disorders. Sirtuin 1 correlation with diabetic parameters will help in health research to include it as a therapeutic target for various toxic conditions. KEY WORDS Advanced Glycation End product, Fluoride, Diabetic Kidney Disease, Sirtuin 1, Type 2 Diabetes Mellitus

Prevalence of Dental Caries in 11-14 Years Old School Children in Endemic Fluoride Areas of Haryana, India

Prevalence of Dental Caries in 11-14 Years Old School Children in Endemic Fluoride Areas of Haryana, India

Malocclusion index assessment in schoolchildren in the endemic fluorosis area (pilot study). Part I

Relevance . There are a lot of publications on the assessment of dental caries and fluorosis in children in the fluoride endemic areas. The studies on the analysis of the prevalence and severity of malocclusion in these children are few and contradictory. The aim of the study was to assess the prevalence and severity of malocclusion in schoolchildren in the endemic fluorosis areas. Materials and methods . A cross-sectional dental examination was performed according to the WHO method with a calibration expert in 361 schoolchildren aged 12 and 15 years old living in the areas with highly fluoridated drinking water (1.5-4.5 ppm). The clinical forms of dental fluorosis were assessed by the WHO classification and the prevalence and severity of malocclusion were evaluated by the DAI index. The obtained information was processed using the SPSS® Statistics 23.0 software. Results . A high prevalence of dental fluorosis was revealed in the examined schoolchildren with the predominance of mild forms of pathology. Most of the children had malocclusion; mild malocclusion was most often diagnosed. Conclusions. The study did not reveal any differences between the occurrence and severity of fluoride induced dental lesions, malocclusion in the studied age and sex groups. The prevalence and severity of malocclusion were comparable in the samples of students without dental fluorosis and with various clinical forms of this pathology.

Prevalence of dental fluorosis and treatment needs among 11-14 years old school children in endemic fluoride areas of Haryana, India.

Dental fluorosis is a major endemic oral disease characterized by hypo mineralization of enamel caused due to consumption of water containing high concentration of fluoride during developmental stages of teeth. To assess the prevalence of dental fluorosis among 11-14 years old school children in endemic fluoride areas of Haryana and to find their treatment needs. A cross-sectional study was conducted among 2200 school children in endemic fluoride areas of Haryana (India) for a period of six months. Dental fluorosis was recorded by the Thylstrup-Fejerskov index (TF index) given by Thylstrup A, Fejerskov O. Data entry and analysis were performed using Statistical Package of Social Sciences (SPSS) software version 18.0. Chi square test was used to find association between TFI scores and gender, age categories. The level of significance was set at 0.05. Prevalence of dental fluorosis (TFI) reached 96.6% with most children falling in TFI score 2, 3, 4 and 5 categories. Mean TFI score of study population was found to be 3.19 ± 1.551. There was significant difference found between gender and prevalence of dental fluorosis (P = 0.00). Our findings showed the increased prevalence of dental fluorosis in endemic fluoride areas with mild to moderate level of dental fluorosis.

Therapeutic application of fluoride varnish

Fluoride is the safest, economical, and effective tool for the prevention of dental caries. Food and Drug Administration has listed fluoride as an essential nutrient for human health. The World Health Organization (WHO) expert committee has included fluoride in its list of 14 trace elements that are essential for normal growth and development. Approximately half the population of the USA is consuming optimally fluoridated water since 1980 and countries like the UK, New Zealand, and Australia are protected by water fluoridation. In India, the preventive measures are not so effective and the caries incidence is still on the rise. The average DMFT in India by the age of 15 years is about 3. This high incidence could also be attributed to a low dentist–population ratio of 1:80,000 in India. According to WHO, the DMFT of 2 by the age of 15 should cause alarm. The answer for this health problem is prevention. Although many measures are available, the best option is to use systemic and topical fluorides. Approximately 5% of the population lives in endemic fluoride areas and 3% lives in optimal fluoride areas. About 85%–90% of the population lives in fluoride deficient areas and preventive measures should be directed toward this segment of the population. The use of fluoride in communal water supply and dentifrices does not interfere with normal oral hygiene measures. Fluorides in dentifrices had led to the decrease in the incidence of dental caries in the US, UK and Scandinavia.

Impact of dental fluorosis on the oral health related quality of life among 11- to 14-year-old school children in endemic fluoride areas of Haryana (India)

Objective: This study investigates the impact of dental fluorosis on the oral health-related quality of life (OHRQoL) among 11- to 14-year-old school children in endemic fluoride areas of Haryana (India). Materials and methods: A cross-sectional survey was conducted among 2,200 school children in endemic fluoride areas of Haryana. Using cluster random sampling, three districts out of 14 endemic fluoride districts were selected, and children 11–14 years of age were examined. A child perception questionnaire (CPQ11–14) (Hindi version) evaluated the impact of dental fluorosis on OHRQoL. The Thylstrup-Fejerskov index (TFI) was used for assessing dental fluorosis. The data were analysed using SPSS version 18, and non-parametric tests were used to assess the significance. The regression analysis was used to determine the effect of change in CPQ scores with dental fluorosis at P < 0.05. Results: The study participants included 45.3% males and 54.7% females among which mild to moderate level of dental fluorosis was identified with mean mean TFI Scores being 3.19 ± 1.55. Children without dental fluorosis had 1.17 times more odd of percieving their oral health as excellent/good when compared to children with dental fluorosis (P < 0.05). Study subjects with dental fluorosis did not have higher mean CPQ11–14 domain and total scores when compared with subjects without dental fluorosis. Conclusion: It can be concluded that mild dental fluorosis did not affect the OHRQoL of the children in the endemic fluoride areas of Haryana in India.

Evaluating the Association Between Dental Fluorosis and Polymorphisms in Bone Development and Mineralization Genes Among Population from a Fluoride Endemic Region of Eastern India.

Close to 12 million people in India are affected by more than the desirable level of fluoride in drinking water that could lead to dental, skeletal, and non-skeletal fluorosis. Dental fluorosis is a developmental defect that results in hypo-mineralization and pronounced porosity of enamel in the affected individuals. As estrogen receptor 1 (ESR1), collagen type 1 alpha 2 (COL1A2), bone γ-carboxyglutamic acid protein (BGLAP), and secreted protein acidic and cysteine rich (SPARC) genes are involved in bone development and mineralization, polymorphisms in these genes could be determining factors in influencing the risk to fluorosis among the exposed individuals in fluoride endemic areas. A case-control study was carried out among a total of 87 individuals (case = 36, control = 51) to examine the association between selected polymorphisms in the ESR1, COL1A2, BGLAP, and SPARC genes and risk of dental fluorosis from a fluoride endemic region of Eastern India. Altogether, 10 single nucleotide polymorphisms (SNPs) in ESR1 (rs2234693, rs2228480, rs3798577, rs2077647, and rs9340799), COL1A2 (rs42524, rs412777), BGLAP (rs1800247), and SPARC (rs6579885, rs4958278) genes were genotyped through PCR-RFLP in these subjects. The association of the SNPs for disease risk estimation was measured by odds ratio with 95% confidence interval. The risk genotypes of none of the 10 SNPs showed statistically significant association with risk of dental fluorosis. Frequencies of the haplotypes in the intragenic SNPs of the ESR1, COL1A2, and SPARC genes did not reveal any statistically significant difference between the case and control groups. The present study is the first of its kind from India that has attempted to investigate possible involvement of genetic factors in influencing the risk to fluorosis among the population from a fluoride endemic region.

Health risk in children to fluoride exposure in a typical endemic fluorosis area on Loess Plateau, north China, in the last decade.

Excessive and inadequate intake of fluoride may cause adverse effects in children, such as dental caries and dental fluorosis. This study reports the results of monitoring fluoride concentrations in drinking water from an endemic fluorosis region during the ten-year period (2008 through 2017). The fluoride concentration had a range of 0.03-9.42mgL-1 (mean=0.55±0.01mgL-1). Approximately 10%, 1.3% and 0.06% children are at risk for dental decay, dental fluorosis and skeletal fluorosis, respectively. Probabilistic risks for children were assessed and the fluoride endemic areas were marked by GIS mapping system. On several water consumption points, the hazard quotient (HQ) values for children were higher than 1, indicating potential non-cancer health risks due to fluoride exposure. The results of this study will help governmental agencies to develop better policies for protecting children from exposure to fluoride.

Groundwater fluoride contamination and probabilistic health risk assessment in fluoride endemic areas of the Upper East Region, Ghana

Groundwater fluoride contamination has long been recognized as a water-related health issue in some parts of Ghana. However, the extent of fluoride contamination and the related human health risk to the communities in the fluoride endemic areas are not adequately studied. In this paper, fluoride concentrations in existing and newly drilled wells were assessed. Probabilistic non carcinogenic human health risk assessment, uncertainty and sensitivity analysis for three age groups (Group A: 0–10 years; Group B: 11–20 years; Group C: 21–72 years) was also carried out using Monte Carlo simulation technique. The results showed that, 27.27% and 15.38% of the existing wells in the Bongo and Kassena Nankana West districts have fluoride values above the guideline value 1.5 mg L−1 respectively. The non-carcinogenic risk of fluoride associated with oral ingestion recorded a mean Hazard Quotient (HQ) > 1 for younger age group (0–10 years) in all the study areas signifying potential health risk to this age group. Additionally, when the upper 95th percentile is used for the HQ, the oral ingestion for all the age categories recorded an HQ > 1. Sensitivity analyses indicated that fluoride concentration in the drinking water and ingestion rate were the most relevant variables in the model to reduce the potential health effect. The study established the basis for a strong advocacy and public awareness on the effect of water quality on human health and proposed some management strategies to guide future groundwater resources management to reduce the potential health risk to the population.

Exploring a multi-exposure-pathway approach to assess human health risk associated with groundwater fluoride exposure in the semi-arid region of east India

Human health risks associated with groundwater fluoride have been assessed using USEPA method in few parts of India, but those assessments were conducted based on a single value for each parameter, which may lead to certain inaccuracy and uncertainties in results. In this study, a higher degree of accuracy in health risk assessment was achieved through Monte Carlo simulations, sensitivity analysis and uncertainty analysis. As fluoride hazards to human health are chronic, a total of 4560 water samples (N = 4560) were collected during consecutive four seasons (2 pre-monsoon and 2 post-monsoon seasons; 1140 samples/season) from the entire Birbhum district, covering all the blocks and geological settings to obtain the spatiotemporal variation of fluoride level. The Empirical Bayesian Kriging geostatistical model was employed to determine fluoride endemic areas. Amongst all blocks, Nalhati-1 had exhibited the highest fluoride level (18.25 mg/L). The study revealed that most of the blocks are vulnerable to groundwater fluoride due to its occurrences in excess level. The average and 95th percentile values of total hazard index indicate that the infants and children populations of the district are more susceptible than the adults and teens. The sensitivity analysis revealed that water ingestion rate and fluoride concentration are the most influential parameters for higher risk of fluoride-related health hazards. Health risks were evaluated through ingestion and dermal exposure routes for infants, children, teens, and adult residents. The exposure was much higher through ingestion than dermal contacts. Ingestion of defluoridated water will reduce the health risks associated with groundwater fluoride exposure.

Geospatial Analysis of Fluoride Concentration in Groundwater in Puruliya District, West Bengal

Fluoride contamination in groundwater is a major geo-environmental issue. In India, groundwater sources contribute more than 85 per cent of the drinking water requirement in rural areas, 76 per cent of irrigation requirements and more than 50 per cent of the urban and industrial water supplies. Many studies have reported fluoride-related health problems such as dental and skeletal fluorosis in humans due to drinking of fluoride-rich water which has severe socio-economic implications. The permissible limit of fluoride in drinking water is 1.5 mg/l according to the World Health Organisation (WHO, 2004) and the Bureau of Indian Standards (BIS, 2012). Puruliya is the westernmost district of West Bengal and located on the eastern slope of the Chotanagpur plateau. The intensive and prolonged dry spell, semi-arid climate, long-term withdrawal of groundwater for irrigation, alkaline nature of sub-surface circulating water, a long residence time of water in fractured aquifers and low chances of dilution are favourable for fluoride enrichment in the Puruliya District. Eighteen out of 20 blocks of the district have high fluoride level in groundwater. This paper attempts to examine the status of fluoride concentration in groundwater, its distribution including the causative factors for its occurrence. It also tries to draw a comparative view of the change in fluoride pattern for the period 2005-06 and 2015-16 and estimate population under threat. Data collected from Physical Health & Engineering Department (PHED) is superimposed over topographical maps and Google Earth. Mapping of fluoride endemic areas in Puruliya district is attempted to delineate areas and the extent of fluoride contamination in the study area.

Hydrothermal synthesis of magnetic iron oxide encrusted hydrocalumite-chitosan composite for defluoridation studies.

A magnetic adsorbent namely magnetic iron oxide encrusted hydrocalumite-chitosan (Fe3O4@HCCS) composite was prepared by the fabrication of magnetic iron oxide (Fe3O4) particles on hydrocalumite-chitosan (HCCS) composite for fluoride sorption studies in batch mode. The prepared magnetic Fe3O4@HCCS composite possesses an enhanced defluoridation capacity (DC) of 6.8mg/g compared to hydrocalumite (HC) which possesses the DC of 2.4mg/g. The various physico-chemical parameters such as contact time, pH, co-existing anions, initial fluoride concentration and temperature were optimized for the maximum fluoride removal. The structural changes of the sorbent, before and after fluoride sorption were studied using FTIR and SEM with EDAX techniques. The equilibrium data was well modeled by Freundlich and Langmuir isotherms. The thermodynamic parameters revealed the feasibility, spontaneity and endothermic nature of fluoride sorption. The field performance and efficiency of Fe3O4@HCCS composite was examined with the waste-water sample collected from a fluoride endemic area of Dindigul district, Tamilnadu, India using standard protocols.

FIMAR: A new Fluoride Index to mitigate geogenic contamination by Managed Aquifer Recharge

The objective of this study is to develop a Fluoride Index for mitigation of geogenic contamination by Managed Aquifer Recharge (FIMAR). This index was tested by applying to the Pambar river basin in southern India. About 40% of the study area had fluoride >1.5 mg/L, contributed from the dissolution of fluorite, fluorapatite, biotite and hornblende. The relationship between groundwater level and fluoride concentration exhibited two types of relationship. In shallow wells, groundwater recharge during monsoon increases the groundwater level and dilutes the fluoride concentration. During summer, evaporation decreases the groundwater levels and increases the fluoride content. In deep wells, the fluoride-rich salts that is deposited in the unsaturated zone due to evaporation in the pre-monsoon season is flushed during groundwater recharge and thus, the fluoride concentration increases with increase in groundwater level. This relationship was used as a key layer in FIMAR. Overlay analysis including the well type derived from the groundwater level and fluoride fluctuation, average fluoride concentration, geology, geomorphology, soil, drainage density, land use, lineament density and thickness of the weathered zone indicated 30% of the area was suitable for MAR to mitigate fluoride contamination. Since the construction of new MAR structures is cost-intensive, it is proposed to rejuvenate the existing ponds in the areas identified by FIMAR to induce recharge and dilute fluoride concentration. The positive impact was confirmed using numerical and geochemical modelling. This proves that FIMAR can be used as a planning tool in fluoride endemic areas and that the future MAR methods will be beneficial to mitigate geogenic fluoride contamination.

Association of Hypertension, Body Mass Index, and Waist Circumference with Fluoride Intake; Water Drinking in Residents of Fluoride Endemic Areas, Iran.

Hypertension is becoming a global epidemic for both rural and urban populations; it is a major public health challenge in Iran. Fluoride can be a risk factor for hypertension. Cross-sectional analysis was conducted in two study areas to assess the relation of fluoride with blood pressure prevalence, BMI, waist circumference, and waist-to-hip ratio (WHR) among different age groups in both sexes. The mean value of fluoride concentration in the drinking water from the four study villages varied from 0.68 to 10.30mg/L. The overall prevalence of HTN and prehypertension in all subjects was 40.7%. The prevalence of isolated systolic hypertension, isolated diastolic hypertension, systolic-diastolic hypertension, and prehypertension in the total sample population was 1.15, 0.28, 9.53, and 29.76%, respectively. The odd ratio of hypertension in residents who drank water with high fluoride levels was higher than that in residents who drank water with lower level of fluoride (OR 2.3, 1.03-5.14). Logistic regression results showed that age (P < 0.001), sex (P = 0.018), BMI (P = 0.015), and the fluoride level in drinking water (P = 0.041) had a significant relationship with increased blood pressure. There were no statistically significant correlations between fluoride and BMI, hip circumference, and waist to hip ratio (WHR). The findings of this study are important for health care personnel and policymakers.

Effects of high fluoride content in livestock drinking water on milk samples of different cattle in endemic area of Pakistan: risk assessment for children.

Fluoride in trace quantity is beneficial for human beings, serving to strengthen the apatite matrix of skeletal tissues and teeth, whereas high intake causes adverse impacts. In the present study, the effect of fluoride-contaminated drinking water of livestock on the milk samples of different cattle, belonging to a fluoride-endemic area (Tharparkar, Pakistan), was studied. In milk samples of different cattle (cows, camels, sheep, and goats), free and bound fluoride forms and its total (free (F-) + bound (F-)) contents were measured by ion-selective electrode. The concentration of fluoride in drinking water of livestock was also analyzed, as found in the range of 11.8-33.5mg/L. The concentration of total fluoride in the milk samples of sheep, goats, cows, and camels were observed in the range of 1.72-2.43, 1.40-2.03, 0.835-1.41, and 0.425-0.897mg/L, respectively. The resulted data indicated that the concentration of fluoride was higher in the milk samples of smaller cattle (sheep and goat), as compared to cow and camel. The fluoride in milk samples of all cattle appeared dominantly in free form. The percentage values of bound fluoride in the milk samples of sheep, goats, and cows were found to be 6.76, 11.6, and 19.7% in total, respectively, while in camel milk, the percentage was below the detection limit. The estimated daily intake of fluoride contents on consuming different types of milk by children age ranged 1.0 to 3.0years was evaluated. Graphical abstract ᅟ.

Implementing a geographical information system to assess endemic fluoride areas in Lamphun, Thailand.

IntroductionMany studies have shown that fluoride can cross the placenta and that exposure to high fluoride during pregnancy may result in premature birth and/or a low birth weight. Lamphun is one of six provinces in Thailand where natural water fluoride (WF) concentrations >10.0 mg/L were found, and it was also found that >50% of households used water with high fluoride levels. Nevertheless, geographical information system (GIS) and maps of endemic fluoride areas are lacking. We aimed to measure the fluoride level of village water supplies to assess endemic fluoride areas and present GIS with maps in Google Maps.MethodsA cross-sectional survey was conducted from July 2016 to January 2017. Purpose sampling was used to identify villages of districts with WF >10.0 mg/L in the Mueang Lamphun, Pasang, and Ban Thi districts. Water samples were collected with the geolocation measured by Smart System Info. Fluoride was analyzed with an ion-selective electrode instrument using a total ionic strength adjustment buffer. WF >0.70 mg/L was used to identify unsafe drinking water and areas with high endemic fluoride levels. Descriptive statistics were used to describe the findings, and MS Excel was used to create the GIS database. Maps were created in Google Earth and presented in Google Maps.ResultsWe found that WF concentrations ranged between 0.10–13.60 mg/L. Forty-four percent (n=439) of samples were at unsafe levels (>0.70 mg/L), and. 54% (n=303) of villages and 46% (n=79,807) of households used the unsafe drinking water. Fifty percent (n=26) of subdistricts were classified as being endemic fluoride areas. Five subdistricts were endemic fluoride areas, and in those, there were two subdistricts in which every household used unsafe drinking water.ConclusionThese findings show the distribution of endemic fluoride areas and unsafe drinking water in Lamphun. This is useful for health policy authorities, local governments, and villagers and enables collaboration to resolve these issues. The GIS data are available at https://drive.google.com/open?id=1mi4Pvomf5xHZ1MQjK44pdp2xXFw&usp=sharing.

Scalp Hair as Biomarker for Chronic Fluoride Exposure among Fluoride Endemic and Low Fluoride Areas: A Comparative Study.

Objective:To investigate scalp hair as biomarker for chronic fluoride exposure among fluoride endemic and low fluoride areas.Methodology:Two areas were identified in Vadodara district, Ajod, as a low fluoride area (Fluoride content of drinking water = 0.11 ppm) and Karsan, a high fluoride area (fluoride content in drinking water = 3.43 ppm). The study was performed on a total of 36 participants from the two villages, 18 from Ajod and 18 from Karsan. Thylstrup Fejerskov Index (TFI) was recorded for each of the participants and sample of hair was collected from the occipital region. Analysis of hair samples was done for assessing the fluoride content.Results:The study consisted of total 36 participants, ranging from the age of 34–60 years and a mean age of 46.53 years. The mean TFI score for the participants in Karsan was 3.39 (±0.979) and in Ajod was 0.83 (±0.786). The difference in this mean score between the two groups was found to be statistically significant. Furthermore, the average fluoride content in hair of the participants in Karsan was 3.40(±1.043) and that in Ajod was 0.35 (±0.063). This difference was statistically significant between the two groups. The TFI scores were found to be positively correlated with the fluoride content in hair.Conclusion:Hair can be used as a useful biomaterial for fluoride exposure monitoring. Having certain advantages over other biomaterials such as easy to collect, store, and transport, hair also serves as a biomarker of chronic fluoride exposure. Hair analysis should thus play a greater role in routinely measuring the chronic exposure to fluorides.