Revealing drinking water quality issues and possible health risks based on water quality index (WQI) method in the Shanmuganadhi River basin of South India.

The aim of the study is to address the issues and associated health risks due to consumption of high-fluoride water supplied for drinking in a rural part of Shanmuganadhi River basin, Tamil Nadu, India. In this study, 61 groundwater samples were gathered from various tube and open wells and analysed for fluoride and other physicochemical parameters. The abundance of cations is Na+ > Ca2+ > Mg2+ > K+, and that of anions is HCO3- > SO42- > Cl- > F-. The fluoride concentration in drinking groundwater varied from 0.10 to 3.3 mg/l. According to the WHO standards, about 26% of the samples were unfit for drinking requirements (16 out of 61 samples) Water quality index (WQI) method was adopted to categorize the water into different classes to understand its suitability for drinking requirements. WQI signified that nearly 52% of the samples denoted poor, very poor and not suitable categories, whereas 48% of samples denoted good and excellent categories for consumption. Health risks associated with high-fluoride drinking water were assessed for various age groups of inhabitants such as children, teens and adults. The hazard quotient estimated based on the oral intake ranged from 0.00E+00 to 5.50E+00, from 0.00E+00 to 4.22E+00 and from 0.00E+00 to 3.45E+00 for children, teens and adults, respectively. It suggested that the health risks are associated with 75%, 59% and 43% of samples, respectively, among children, teens and adults. Therefore, children are more inclined towards risk than teens and adults in this region based on the intake of fluoride-rich drinking water. To improve the present scenario, groundwater should be either treated before drinking water supply or must be artificially recharged to lower the concentration of ions.

Appraisal of subsurface hydrogeochemical processes in a geologically heterogeneous semi-arid region of south India based on mass transfer and fuzzy comprehensive modeling.

The main aim of the present study was to examine the quality of the groundwater and decipher the sources of groundwater fluoride through mass balance modeling based on fluoride exposure in a geologically heterogeneous semi-arid region of southern India. This was achieved by hydrogeochemical analysis, graphical methods, and mass transfer modeling approaches. Fuzzy comprehensive technique was applied to evaluate the quality of groundwater for groundwater management. In this regard, 61 groundwater samples were obtained from open wells and bore wells and analyzed for different physicochemical parameters. The major cation and anion abundances follow the order Na+ > Ca2+ > Mg2+ > K+ and Cl- > HCO3- > SO42- > NO3- > PO43-. About 88.4% and 34.4% of the total water samples were dominated with Na+ and Cl- ions in this region, respectively. The fluoride level in groundwater ranged from 0.10 to 3.30 mg/l with a mean value of 1.04 mg/l. Nearly 25% of the groundwater samples collected from 15 villages showed fluoride concentrations exceeding the maximum permissible limit of 1.5 mg/l as per the World Health Organization recommendations for human intake. More than 85% of the samples fell under strong acid (Cl- and SO42-) type. The amount of groundwater salinization in this region was 70.5% since the Revelle index (RI) was excess in the groundwater samples (RI > 0.5 meq/l). Silicate weathering, cation exchange, and gypsum dissolution were the dominant geogenic processes in the aquifer system influencing groundwater chemistry and nullified the possibility of carbonate dissolution. Saturation indices revealed the contribution of sequestration of CaCO3 in F- enrichment. Total dissolved solids showed strong positive correlations with Na+, Ca2+, Mg2+, Cl-, SO42- and NO3- indicating the contribution of anthropogenic inputs to groundwater chemistry in addition to geogenic sources. The results of the fuzzy comprehensive method indicated that 33% of the groundwater samples fell under fair water type, 2% and 11% of the samples fell under poor and very poor quality water types, respectively. Therefore, this work will be helpful for the decision-makers to plan for the sustainable management of groundwater resources.

Evaluation of non-carcinogenic risks due to fluoride and nitrate contaminations in a groundwater of an urban part (Coimbatore region) of south India.

Groundwater quality investigations were carried out in one of the urban parts of south India for fluoride and nitrate contaminations, with special focus on human health risk assessment for the rapidly growing and increasingly industrialized Coimbatore City. Twenty-five groundwater samples were collected and analyzed for physico-chemical parameters (EC, pH, TDS, Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3-, PO43-, NO3-, and F-) and the piper diagram characterized 60% of them as Ca-Mg-Cl type. Analysis of fluoride (0.1 to 2.4 mg/l) shows that 32% of the groundwater samples contain F- over the permissible limit, affecting a region of 122.10 km2. Nitrate (0.1 to 148 mg/l) is over the permissible limit in 44% of the groundwater samples spread over an area of 429.43 km2. The total hazard indices (THI) of non-carcinogenic risk for children (0.21 to 4.83), women (0.14 to 3.35), and men (0.12 to 2.90) shows some of the THI values are above the permissible limit of the US Environmental Protection Agency. The THI-based non-carcinogenic risks are 60%, 52%, and 48% for children, women, and men. This investigation suggests higher health risk for children and also recommends that proper management plan should be adopted to improve the drinking water quality in this region in order to avoid major health issues in the near future.

Eficácia do diamino fluoreto de prata em paralisar lesões de cárie em dentina: ensaios laboratorial e clínico controlado e randomizado / Efficacy of silver diamine fluoride in arresting dentin caries lesions: controlled randomized clinical tria

Este estudo objetivou: (1) investigar a eficácia in vitro do diamino fluoreto de prata (DFP) em paralisar lesões de cárie em dentina após diferentes concentrações e tempos de aplicação; (2) comparar o impacto do DFP e do tratamento restaurador atraumático (TRA) na qualidade de vida relacionada à saúde bucal (QVRSB) de préescolares; e (3) avaliar a eficácia do DFP comparado ao TRA, em paralisar lesões de cárie, por meio de um ensaio clínico controlado e randomizado após 2 anos de acompanhamento. Para o objetivo 1, blocos de dentina (n=42) foram fixados em placas de poliestireno. Um inóculo bacteriano misto (1,5x108 UFC/mL) foi adicionado ao meio de cultura com sacarose 5%, contido nas placas, que foram incubadas para a formação de biofilme. As amostras foram escaneadas em micro CT (M1) e tratadas com DFP de acordo com os grupos (n=6): DFP 30%, aplicação imediata; DFP 30%, 1'; DFP 30%, 3'; DFP 38%, aplicação imediata; DFP 38%, 1'; DFP 38%, 3'. Um grupo controle, sem tratamento, também foi preparado. Após o escaneamento (M2), os blocos foram submetidos a um desafio cariogênico (21 dias) e novamente escaneados (M3). O pH do meio de cultura e a profundidade das lesões inter e intra grupos foram comparados pelos testes de Kruskal-Wallis e Wilcoxon. Para os objetivos 2 e 3, préescolares com ao menos uma lesão de cárie ativa na oclusal de seus molares decíduos foram randomicamente alocados em dois grupos: DFP e TRA. Os índicesceo-d/CPO-DICDAS foram usados para detecção da presença e atividade de cárie. O B-ECOHIS foi usado para avaliar a QVRSB antes (M1), 15 dias (M2) e 3 meses (M3) após os tratamentos. O sucesso clínico foi avaliado após 6, 12, 18 e 24 meses. Foram ainda avaliados: tempo do procedimento, efeitos adversos/percepção estética e ansiedade. No estudo in vitro, em M1 e M2, não houve diferença na profundidade das lesões entre os grupos (p>0,05). Em M3, o DFP 38% apresentou menor pH do biofilme e os grupos que receberam aplicação por 1' e 3', em ambas as concentrações, não apresentaram aumento na profundidade da lesão em relação ao M1. DFP e TRA não diferiram quanto ao B-ECOHIS total, CIS e FIS em M2 e M3 e o B-ECOHIS total diminuiu de M1 para M2 e M3 em ambos os grupos (p<0,05). Após 2 anos, não houve diferença entre os tratamentos quanto à paralisação da cárie (p=0,072) e o tempo de tratamento para o DFP foi menor (p<0,001). Não houve diferença entre os grupos quanto aos efeitos adversos/percepção estética observados pelo operador (p=0,816) e pelos pais (p=1,000). A ansiedade não mudou após os tratamentos (p=0,583). Assim, o tempo mínimo de aplicação do DFP 30% para paralisar lesões de cárie foi de 1', enquanto o 38% paralisou com aplicação imediata, in vitro. Tanto o DFP quanto TRA melhoraram a QVRSB dos pré-escolares, sem diferença entre eles. Ainda, o DFP mostrou-se semelhante ao TRA na paralisação de cárie, ansiedade e efeitos adversos, requerendo menor tempo de cadeira. (AU)

This study aimed to: (1) investigate the in vitro efficacy of silver diamine fluoride (SDF) in arresting dentin caries lesions after different concentrations and application times; (2) compare the impact of SDF and atraumatic restorative treatment (ART) on the oral health-related quality of life (QHRQoL) in preschoolers; and (3) to evaluate the effectiveness of SDF compared to ART, in arresting caries lesions, through a controlled randomized clinical trial after 2 years of follow-up. For objective 1, dentin blocks (n=42) were fixed in polystyrene plates. A mixed bacterial inoculum (1.5x108 CFU/mL) was added to the culture medium with 5% sucrose, in the plates; that were incubated for biofilm formation. The samples were scanned on micro CT (M1) and treated with SDF according to the groups (n=6): SDF 30%, immediate application; SDF 30%, 1'; SDF 30%, 3'; SDF 38%, immediate application; SDF 38%, 1'; SDF 38%, 3'. A control group, without treatment, was also prepared. After scanning (M2), the blocks were submitted to a cariogenic challenge (21 days) and scanned again (M3). The pH of the culture medium and the depth of lesions between and within the groups were compared using the Kruskal-Wallis and Wilcoxon tests. For objectives 2 and 3, preschoolers with at least one active caries lesion on the occlusal surface of their primary molars were randomly allocated into two groups: SDF and ART. The indexes dmft/DMFT and ICDAS were used to detect the presence and activity of caries. B-ECOHIS was used to assess the QHRQoL of children before (M1), 15 days (M2) and 3 months (M3) after treatments. Clinical success was assessed after 6, 12, 18 and 24 months. Were also evaluated: time of the procedure, adverse effects/aesthetic perception and the child's anxiety. In the in vitro study, in M1 and M2, there was no difference in the depth of the lesions between the groups (p>0.05). In M3, SDF 38% had a lower pH of the biofilm and the groups that received application for 1' and 3', in both concentrations, did not present an increase in the depth of the lesion in relation to M1. SDF and ART did not differ in total B-ECOHIS, CIS and FIS in M2 and M3; and the total B-ECOHIS decreased from M1 to M2 and M3 for both groups (p<0.05). After 2 years, there was no difference between treatments regarding caries arrest (p=0.072) and the treatment time for SDF was shorter (p<0.001). There was no difference regarding the adverse effects/aesthetic perception observed by the operator (p=0.816) and reported by the parents (p=1.000), according to the groups. Anxiety did not change either before or after treatments (p=0.583). Thus, the minimum time of application of SDF 30% to arrest dentin caries was 1', while SDF 38% arrested with immediate application, in vitro. Both SDF and ART improved the QHRQoL of preschoolers, with no difference between them. Still, SDF was similar to ART in arresting caries, anxiety and adverse effects, requiring less chair time. (AU)

Fluorometric selective detection of fluoride ions in aqueous media using Ag doped CdS/ZnS core/shell nanoparticles.

The presence of fluoride ions in drinking water plays an important role in human health. For that reason, maintaining the optimum concentration of fluoride ions in drinking water is essential, as both low and excess (above the permissible level) concentrations can cause different health problems, such as fluorosis, urolithiasis, kidney failure, cancer, and can even lead to death. So, development of a simple and low cost method for the detection of fluoride ions in water is highly desirable. In this study, a fluorometric method based on Ag-CdS/Ag-ZnS core/shell nanoparticles is developed for fluoride ion detection. The method was tested in aqueous solution at different pH values. The selectivity and sensitivity of the fluorescence probe was checked in the presence of other anions (Cl(-), Br(-), I(-), NO3(-) SO4(2-), HCO3(-), HPO4(2-), CH3COO(-), and H2PO4(-)) and found there is no significant interference of these associated ions. The fluoride ion concentration was varied in the range 190-22 800 µg L(-1) and a lower detection limit was obtained as 99.7 µg L(-1).

Recommendations for fluoride limits in drinking water based on estimated daily fluoride intake in the Upper East Region, Ghana.

Both dental and skeletal fluorosis caused by high fluoride intake are serious public health concerns around the world. Fluorosis is particularly pronounced in developing countries where elevated concentrations of naturally occurring fluoride are present in the drinking water, which is the primary route of exposure. The World Health Organization recommended limit of fluoride in drinking water is 1.5 mg F(-) L(-1), which is also the upper limit for fluoride in drinking water for several other countries such as Canada, China, India, Australia, and the European Union. In the United States the enforceable limit is much higher at 4 mg F(-) L(-1), which is intended to prevent severe skeletal fluorosis but does not protect against dental fluorosis. Many countries, including the United States, also have notably lower unenforced recommended limits to protect against dental fluorosis. One consideration in determining the optimum fluoride concentration in drinking water is daily water intake, which can be high in hot climates such as in northern Ghana. The results of this study show that average water intake is about two times higher in Ghana than in more temperate climates and, as a result, the fluoride intake is higher. The results also indicate that to protect the Ghanaian population against dental fluorosis, the maximum concentration of fluoride in drinking water for children under 6-8 years should be 0.6 mg F(-) L(-1) (and lower in the first two years of life), and the limit for older children and adults should be 1.0 mg F(-) L(-1). However, when considering that water treatment is not cost-free, the most widely recommended limit of 1.5 mg F(-) L(-1) - which is currently the limit in Ghana--may be appropriate for older children and adults since they are not vulnerable to dental fluorosis once the tooth enamel is formed.

An evaluation of the frequency shift caused by collisions with background gas in the primary frequency standard NPL-CsF2.

Collisions between cold cesium atoms and background gas atoms at ambient temperature reduce the cold atom signal in a fountain clock and at the same time produce a shift in the measured clock frequency. We evaluate the shift in the NPL-CsF2 cesium fountain primary frequency standard based on measurements of the fractional loss of cold atoms from the atomic cloud during the interrogation time combined with a model by Gibble that quantifies the relationship between the loss and the frequency shift.

Physicochemical quality evaluation of groundwater and development of drinking water quality index for Araniar River Basin, Tamil Nadu, India.

Groundwater is the most important natural resource which cannot be optimally used and sustained unless its quality is properly assessed. In the present study, the spatial and temporal variations in physicochemical quality parameters of groundwater of Araniar River Basin, India were analyzed to determine its suitability for drinking purpose through development of drinking water quality index (DWQI) maps of the post- and pre-monsoon periods. The suitability for drinking purpose was evaluated by comparing the physicochemical parameters of groundwater in the study area with drinking water standards prescribed by the World Health Organization (WHO) and Bureau of Indian Standards (BIS). Interpretation of physicochemical data revealed that groundwater in the basin was slightly alkaline. The cations such as sodium (Na(+)) and potassium (K(+)) and anions such as bicarbonate (HCO3 (-)) and chloride (Cl(-)) exceeded the permissible limits of drinking water standards (WHO and BIS) in certain pockets in the northeastern part of the basin during the pre-monsoon period. The higher total dissolved solids (TDS) concentration was observed in the northeastern part of the basin, and the parameters such as calcium (Ca(2+)), magnesium (Mg(2+)), sulfate (SO4 (2-)), nitrate (NO3 (-)), and fluoride (F(-)) were within the limits in both the seasons. The hydrogeochemical evaluation of groundwater of the basin demonstrated with the Piper trilinear diagram indicated that the groundwater samples of the area were of Ca(2+)-Mg(2+)-Cl(-)-SO4 (2-), Ca(2+)-Mg(2+)-HCO3 (-) and Na(+)-K(+)-Cl(-)-SO4 (2-) types during the post-monsoon period and Ca(2+)-Mg(2+)-Cl(-)-SO4 (2-), Na(+)-K(+)-Cl(-)-SO4 (2-) and Ca(2+)-Mg(2+)-HCO3 (-) types during the pre-monsoon period. The DWQI maps for the basin revealed that 90.24 and 73.46% of the basin area possess good quality drinking water during the post- and pre-monsoon seasons, respectively.

[Risk and prevention of teeth fluorosis in infants by feeding pattern changes].

Effect of fluorides in drinking water on fluorine content in breast milk, the food for infants of the 1-sty year of life, was investigated. On determining fluorine concentration in urine and its excretion, fluorine intake by the infants was calculated under various alternatives (breast, mixed and artificial) of feeding. It has been found the in mixed and especially in artificial feeding, fluorine intake by the infants acquires uncontrollable character exceeding several times the dose of fluorine intake with breast milk under natural feeding. That was predominantly fluorine of drinking water. Mathematical formula for calculation of fluorine content in the food cooked for feeding of infants was elaborated. A computer program was formed be means of which calculation, control and management of fluorine intake are carried out in feeding alteration.

Total and free available fluoride in toothpastes in Brunei, Cambodia, Laos, the Netherlands and Suriname.

OBJECTIVES: This study assessed total and free fluoride concentrations in samples of toothpaste from Brunei, Cambodia, Laos, the Netherlands and Suriname, and investigated the labelling practices of the respective manufacturers. MATERIALS AND METHODS: Convenience samples were bought in the five countries and sent for analysis to the Netherlands. Levels of total and free available fluoride were measured. Details of the information declared on the packaging about type of fluoride and abrasives were recorded, and manufacturing and expiry dates were noted. RESULTS: A total of 119 samples of toothpaste were analysed. With one exception, all samples from the Netherlands complied with ISO (International Organisation for Standardisation) labelling requirements and there were no differences between the fluoride content declared and that found to be present on analysis. In samples purchased in the other countries, sodium monofluorophosphate (SMFP) toothpastes predominantly showed a low percentage of free available fluoride and the majority of toothpastes did not follow standard labelling guidelines. DISCUSSION: This study is not representative of any of the brands analysed, yet it highlights problematic discrepancies in products across countries. These may be related to the lack of a generally accepted methodology for analysing total and free fluoride content, absence of an agreement on the minimum concentration of fluoride required to ensure efficacy, weak regulating institutions that are unable to control labelling and consumer information, as well as a possible influx of counterfeit low-quality toothpaste. CONCLUSIONS: Renewed international focus should be directed towards closing gaps in guidelines and standards. Consumers should use only non-expired toothpaste, which should preferably be silica-based fluoride toothpaste that does not include abrasives containing calcium and that is properly labelled.

The electrocoagulation/advanced oxidation treatment of the groundwater used for human consumption.

The purpose of this work was development and application of the purification system suitable for the treatment of groundwater used for human consumption, satisfying following criteria: (a) no need for external addition of the chemicals; (b) simultaneous removal of wide range of contaminants present in the treated water; (c) low sensitivity to the changes in the composition of the treated water; (d) high quality of treated water with regards to all measured parameters. Therefore the well water from the 60 m deep water layer situated near the city of Osijek (Eastern Croatia) with elevated values of heavy metals, color, turbidity, suspended solids, ammonia and organic contaminants was processed. Due to the complex composition of the treated water, the purification system required the combination of electroreduction/electrocoagulation, using iron and aluminum electrode plates followed by the simultaneous ozonation/UV treatment. The electroreduction/electrocoagulation approach was used for the removal of heavy metals, suspended solids, color and turbidity, while the organic contaminants and ammonia were removed by the ozonation/UV treatment. All measured parameters in the purified water were significantly lower compared to the regulated values. Under the optimum treatment conditions, the removal efficiencies for color, turbidity, nickel and arsenic were 100%. The removal efficiencies of V, Cr, Mn, Fe, Cu, Zn, Pb, ammonia, fluorides, sulfates and COD were 94.5%, 96.0%, 98.3%, 99.6%, 99.7%, 97.8%, 96.7%, 96,7%, 93.4%, 51.4%, 72.2% and 93.8%, respectively, increasing with the increased initial concentrations.

Natural contamination with arsenic and other trace elements in groundwater of the Central-West region of Chaco, Argentina.

This study covered the central agricultural region of the Chaco province, which lacks a permanent river networks. However, during the rainy period there is localized groundwater recharge. About 84 groundwater samples were taken during the period April-December 2007. These groundwater samples were collected from two different depths: 62 samples from shallow wells (4 to 20 m) and 24 samples from deep wells (20 to 100 m). Chemical variables were determined: pH, specific conductance, total dissolved solid, hardness, alkalinity, HCO(3)-, CO(3)(2-), SO(4)(2-), Cl-, NO(3)-, NO(2) -, NH(4)+, F-, As((tot)), Na+, K+, Ca2+, Mg2+, Fe, Cu, Ni, Pb and Zn. The chemical composition of groundwater in the study area is dominantly sodium bicarbonate and sodium chloride bicarbonate, comprising more than 60% (52/86) of shallow and deep groundwater samples. Of the 86 analyzed groundwater samples, 88% exceeded the WHO (World Health Organization) and CAA (Código Alimentario Argentino) standards (10 µg/L) for As (arsenic) and 9% exceeded the WHO standard (1.5 mg/L) for F(-).Groundwater highly contaminated with As (max. 1,073 µg/L) and F- (max. 4.2 mg/L) was found in shallow aquifer. The contaminated groundwater is characterized by high pH (max. 8.9), alkalinity (max. HCO(3)- 1,932 mg/L), SO(4)(2-) (max. 11,862 mg/L), Na(+) (max. 3,158 mg/L), Cl(-) (max. 10,493 mg/L) and electric conductivity greater than 33.3 µS/cm. Other associated elements (Ni, Pb, Cu and Zn) are present in low concentrations, except for Fe that in 32% of samples exceeded the guideline value of 0.3 mg/L suggested by the CAA.

Density functional theory study on aqueous aluminum-fluoride complexes: exploration of the intrinsic relationship between water-exchange rate constants and structural parameters for monomer aluminum complexes.

Density functional theory (DFT) calculation is carried out to investigate the structures, (19)F and (27)Al NMR chemical shifts of aqueous Al-F complexes and their water-exchange reactions. The following investigations are performed in this paper: (1) the microscopic properties of typical aqueous Al-F complexes are obtained at the level of B3LYP/6-311+G**. Al-OH(2) bond lengths increase with F(-) replacing inner-sphere H(2)O progressively, indicating labilizing effect of F(-) ligand. The Al-OH(2) distance trans to fluoride is longer than other Al-OH(2) distance, accounting for trans effect of F(-) ligand. (19)F and (27)Al NMR chemical shifts are calculated using GIAO method at the HF/6-311+G** level relative to F(H(2)O)(6)(-) and Al(H(2)O)(6)(3+) references, respectively. The results are consistent with available experimental values; (2) the dissociative (D) activated mechanism is observed by modeling water-exchange reaction for [Al(H(2)O)(6-i)F(i)]((3-i)+) (i = 1-4). The activation energy barriers are found to decrease with increasing F(-) substitution, which is in line with experimental rate constants (k(ex)). The log k(ex) of AlF(3)(H(2)O)(3)(0) and AlF(4)(H(2)O)(2)(-) are predicted by three ways. The results indicate that the correlation between log k(ex) and Al-O bond length as well as the given transmission coefficient allows experimental rate constants to be predicted, whereas the correlation between log k(ex) and activation free energy is poor; (3) the environmental significance of this work is elucidated by the extension toward three fields, that is, polyaluminum system, monomer Al-organic system and other metal ions system with high charge-to-radius ratio.

Evidence-based clinical recommendations on the prescription of dietary fluoride supplements for caries prevention: a report of the American Dental Association Council on Scientific Affairs.

BACKGROUND: This article presents evidence-based clinical recommendations for the prescription of dietary fluoride supplements. The recommendations were developed by an expert panel convened by the American Dental Association (ADA) Council on Scientific Affairs (CSA). The panel addressed the following questions: when and for whom should fluoride supplements be prescribed, and what should be the recommended dosage schedule for dietary fluoride supplements? TYPES OF STUDIES REVIEWED: A panel of experts convened by the ADA CSA, in collaboration with staff of the ADA Center for Evidence-based Dentistry, conducted a MEDLINE search to identify publications that addressed the research questions: systematic reviews as well as clinical studies published since the systematic reviews were conducted (June 1, 2006). RESULTS: The panel concluded that dietary fluoride supplements should be prescribed only for children who are at high risk of developing caries and whose primary source of drinking water is deficient in fluoride. CLINICAL IMPLICATIONS: These recommendations are a resource for practitioners to consider in the clinical decision-making process. As part of the evidence-based approach to care, these clinical recommendations should be integrated with the practitioner's professional judgment and the patient's needs and preferences. Providers should carefully monitor the patient's adherence to the fluoride dosing schedule to maximize the potential therapeutic benefit.

Potable groundwater quality in some villages of Haryana, India: focus on fluoride.

The fluoride concentration in ground water was determined in ten villages of Rohtak district of Haryana state (India). The fluoride concentration in the underground water of these villages varied from 0.034-2.09 mg/l. Various other water quality parameters, viz., pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity sodium, potassium, calcium, magnesium, carbonate, bicarbonate, chloride and sulfate were also measured. A systematic calculation of correlation coefficients among different physicochemical parameters indicated considerable variations among the analyzed samples with respect to their chemical composition. Majority of the samples do not comply with Indian as well as WHO standards for most of the water quality parameters measured. Overall water quality was found unsatisfactory for drinking purposes. Fluoride content was higher than permissible limit in 50% samples.

Hydro-chemical survey of groundwater of Hisar city and assessment of defluoridation methods used in India.

Ground water quality of Hisar city was assessed for its suitability for drinking purposes. Samples collected from the Bore-wells (forms a part of municipal water supply) and handpumps (direct consumption) were analyzed for the various physico-chemical parameters including pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity, sodium, potassium, calcium, magnesium, carbonate, bicarbonate, chloride and sulfate. The concentrations of magnesium, sodium, potassium, sulfate and especially of chloride were found moderately higher than the WHO standards for the drinking water. Further a comparison of fluoride (F-) levels in groundwater of various cities and towns of Haryana state was performed. The relatively higher concentrations of F- in groundwater of Haryana raise the risk of fluorosis and hence groundwater must be used with proper treatment. Promising defluoridation methods using locally available materials and technologies are discussed for the prevention and control of fluorosis. Data were assessed statistically to find the suitable markers of ground water quality as an aid to monitoring groundwater quality.

Fluoride in drinking water and human urine in Southern Haryana, India.

The objective of this study was to determine the fluoride content in drinking water and urine samples of adolescent males aged 11-16 years living in Southern Haryana, India. A total of 30 drinking water sources in the studied habitations were assessed for fluoride contamination. Fluoride was estimated in the urine of 400 male children randomly selected from these habitations. The fluoride concentration in drinking water and urine samples was determined using USEPA fluoride ion selective electrode method. The mean fluoride concentration in drinking water samples of Pataudi, Haily Mandi and Harsaru villages was 1.68+/-0.35, 3.22+/-1.18 and 1.78+/-0.12 mg/l, respectively. The mean urinary fluoride concentration was 2.26+/-0.024 mg/l at Pataudi, 2.48+/-0.77 mg/l at Haily Mandi and 2.43+/-0.84 mg/l at Harsaru village. The higher fluoride levels in the urine of children may be associated to higher fluoride levels in drinking water. The accuracy of measurements was assessed with known addition method in water and urine. Mean fluoride recovery was 98.0 and 99.1% in water and urine. The levels obtained were reproducible with in +/-3% error limit.