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Sample records for water fluoride levels

  1. Fluoridated Water

    Science.gov (United States)

    ... Genetics Services Directory Cancer Prevention Overview Research Fluoridated Water On This Page What is fluoride, and where is it found? What is water fluoridation? When did water fluoridation begin in the ...

  2. Spatial distribution mapping of drinking water fluoride levels in Karnataka, India: fluoride-related health effects.

    Science.gov (United States)

    Chowdhury, Chitta R; Shahnawaz, Khijmatgar; Kumari, Divya; Chowdhury, Avidyuti; Bedi, Raman; Lynch, Edward; Harding, Stewart; Grootveld, Martin

    2016-11-01

    (1) To estimate the concentrations of fluoride in drinking water throughout different zones and districts of the state of Karnataka. (2) To investigate the variation of fluoride concentration in drinking water from different sources, and its relationships to daily temperature and rainfall status in the regional districts. (3) To develop an updated fluoride concentration intensity map of the state of Karnataka, and to evaluate these data in the context of fluoride-related health effects such as fluorosis and their prevalence. Aqueous standard solutions of 10, 100 and 1,000 ppm fluoride (F - ) were prepared with analytical grade Na + /F - and a buffer; TISAB II was incorporated in both calibration standard and analysis solutions in order to remove the potentially interfering effects of trace metal ions. This analysis was performed using an ion-selective electrode (ISE), and mean determination readings for n = 5 samples collected at each Karnataka water source were recorded. The F - concentration in drinking water in Karnataka state was found to vary substantially, with the highest mean values recorded being in the north-eastern zone (1.61 ppm), and the lowest in the south-western one (only 0.41 ppm). Analysis of variance (ANOVA) demonstrated that there were very highly significant 'between-zone' and 'between-districts-within-zones' sources of variation (p water source F - levels within this state. The southern part of Karnataka has low levels of F - in its drinking water, and may require fluoridation treatment in order to mitigate for dental caries and further ailments related to fluoride deficiency. However, districts within the north-eastern region have contrastingly high levels of fluoride, an observation which has been linked to dental and skeletal fluorosis. This highlights a major requirement for interventional actions in order to ensure maintenance of the recommended range of fluoride concentrations (0.8-1.5 ppm) in Karnataka's drinking water

  3. Data on fluoride concentration level in villages of Asara (Alborz, Iran) and daily fluoride intake based on drinking water consumption.

    Science.gov (United States)

    Akhavan, Giti; Dobaradaran, Sina; Borazjani, Jaleh Mohajeri

    2016-12-01

    In the present data article, fluoride concentration levels of drinking water (with spring or groundwater sources) in 10 villages of Asara area located in Alborz province were determined by the standard SPADNS method using a spectrophotometer (DR/2000 Spectrophotometer, USA). Daily fluoride intakes were also calculated based on daily drinking water consumption. The fluoride content were compared with EPA and WHO guidelines for drinking water.

  4. Level of Fluoride in Soil, Grain and Water in Jalgaon District, Maharashtra, India.

    Science.gov (United States)

    Naik, Rahul Gaybarao; Dodamani, Arun Suresh; Vishwakarma, Prashanth; Jadhav, Harish Chaitram; Khairnar, Mahesh Ravindra; Deshmukh, Manjiri Abhay; Wadgave, Umesh

    2017-02-01

    Fluoride has an influence on both oral as well as systemic health. The major source of fluoride to body is through drinking water as well as through diet. Staple diet mainly depends on local environmental factors, food grains grown locally, its availability etc. Determination of fluoride level in these food grains is important. So, estimation of the amount of fluoride in grains and its relation to the sources of fluoride used for their cultivation viz., soil and water is important. To estimate the relation of fluoride concentration in grains (Jowar) with respect to that of soil and water used for their cultivation. Fifteen samples each of soil, water and grains were collected using standardized method from the same farm fields of randomly selected villages of Jalgaon district. Fluoride ion concentration was determined in laboratory using SPADNS technique. Mean difference in fluoride levels in between the groups were analyzed using ANOVA and Post-Hoc Tukey test. Linear regression method was applied to analyse the association of the fluoride content of grain with water and soil. There was a significant difference in between mean fluoride levels of soil and water (pwater and grain was found to be non significant (p=0.591). Also fluoride levels in all the three groups showed significant association with each other. Fluoride level of soil, grains and water should be adjusted to an optimum level. Soil has positive correlation with respect to uptake of fluoride by Jowar grains. So, Jowar grains with optimum fluoride content should be made available in the commercial markets so that oral and general health can be benefitted.

  5. Bottled Water and Fluoride

    Science.gov (United States)

    ... Private Wells Infant Formula Fluorosis Public Health Service Recommendation Water Operators & Engineers Water Fluoridation Additives Shortages of Fluoridation Additives Drinking Water Pipe Systems CDC-Sponsored Water Fluoridation Training Links to Other ...

  6. Fluoride concentration level in rural area in Poldasht city and daily fluoride intake based on drinking water consumption with temperature.

    Science.gov (United States)

    Mohammadi, Ali Akbar; Yousefi, Mahmood; Mahvi, Amir Hossein

    2017-08-01

    Long-term exposure to high level of fluoride can caused several adverse effects on human health including dental and skeletal fluorosis. We investigated all the drinking water source located in rural areas of Poldasht city, west Azerbaijan Province, North West Iran between 2014 and 2015. Fluoride concentration of water samples was measured by SPADNS method. We found that in the villages of Poldasht the average of fluoride concentration in drinking water sources (well, and the river) was in the range mg/l 0.28-10.23. The average daily received per 2 l of drinking water is in the range mg/l 0.7-16.6 per day per person. Drinking water demands cause fluorosis in the villages around the area residents and based on the findings of this study writers are announced suggestions below in order to take care of the health of area residents.

  7. Monitoring of fluoride and iodide levels in drinking water using ion selective electrodes

    International Nuclear Information System (INIS)

    Ahmed, R.; Viqar-Un-Nisa; Hussain, M.; Tanwir, R.; Qureshi, S.A.

    2004-01-01

    Fluoride and iodide, the most important constituents of drinking water are essential as well as toxic depending on their levels. For their analysis in water mostly ion-selective electrodes, spectrophotometry, titrimetry and coulometry etc; have been used and literature has been briefly reviewed. Ion-selective electrodes offer an efficient method for the measurement of the two halides and were mostly used during this work. Fabrication of these electrodes is briefly described. Comparison of results obtained by ion selective electrode and coulometry is given. Recoveries of the added fluoride ions from the samples were good. A large number of water samples from Rawalpindi-Islamabad area were analyzed for fluoride and iodide. Levels of fluoride and iodide from two main water reservoirs of Rawalpindi and Islamabad are reported before and after treatment. Both surface and ground water samples were analyzed and results are compared and discussed. Some samples from northern areas were also analyzed for iodide and fluoride and compared. Intake of fluoride and iodide from water of different areas is also compared. Water samples, which caused bone deformation in certain areas in Punjab due to excess fluoride, were also analyzed for fluoride and results are presented. (author)

  8. Association of Down's syndrome and water fluoride level: a systematic review of the evidence

    Directory of Open Access Journals (Sweden)

    McDonagh Marian

    2001-07-01

    Full Text Available Abstract Background A review of the safety and efficacy of drinking water fluoridation was commissioned by the UK Department of Health to investigate whether the evidence supported a beneficial effect of water fluoridation and whether there was any evidence of adverse effects. Down's syndrome was one of the adverse effects reported. The aim of this review is to examine the evidence for an association between water fluoride level and Down's syndrome. Methods A systematic review of research. Studies were identified through a comprehensive literature search, scanning citations and online requests for papers. Studies in all languages which investigated the incidence of Down's syndrome in areas with different levels of fluoride in their water supplies were included. Study inclusion and quality was assessed independently by 2 reviewers. A qualitative analysis was conducted. Results Six studies were included. All were ecological in design and scored poorly on the validity assessment. The estimates of the crude relative risk ranged from 0.84 to 3.0. Four studies showed no significant associations between the incidence of Down's syndrome and water fluoride level and two studies by the same author found a significant (p Conclusions The evidence of an association between water fluoride level and Down's syndrome incidence is inconclusive.

  9. Fluoride absorption: independence from plasma fluoride levels

    International Nuclear Information System (INIS)

    Whitford, G.M.; Williams, J.L.

    1986-01-01

    The concept that there are physiologic mechanisms to homeostatically regulate plasma fluoride concentrations has been supported by results in the literature suggesting an inverse relationship between plasma fluoride levels and the absorption of the ion from the gastrointestinal tract of the rat. The validity of the relationship was questioned because of possible problems in the experimental design. The present work used four different methods to evaluate the effect of plasma fluoride levels on the absorption of the ion in rats: (i) the percentage of the daily fluoride intake that was excreted in the urine; (ii) the concentration of fluoride in femur epiphyses; (iii) the net areas under the time-plasma fluoride concentration curves after intragastric fluoride doses; and (iv) the residual amounts or fluoride in the gastrointestinal tracts after the intragastric fluoride doses. None of these methods indicated that plasma fluoride levels influence the rate or the degree or fluoride absorption. It was concluded that, unless extremely high plasma fluoride levels are involved (pharmacologic or toxic doses), the absorption of the ion is independent of plasma levels. The results provide further evidence that plasma fluoride concentrations are not homeostatically regulated

  10. Association between water fluoride and the level of children's intelligence: a dose-response meta-analysis.

    Science.gov (United States)

    Duan, Q; Jiao, J; Chen, X; Wang, X

    2018-01-01

    Higher fluoride concentrations in water have inconsistently been associated with the levels of intelligence in children. The following study summarizes the available evidence regarding the strength of association between fluoridated water and children's intelligence. Meta-analysis. PubMed, Embase, and Cochrane Library databases were systematically analyzed from November 2016. Observational studies that have reported on intelligence levels in relation to high and low water fluoride contents, with 95% confidence intervals (CIs) were included. Further, the results were pooled using inverse variance methods. The correlation between water fluoride concentration and intelligence level was assessed by a dose-response meta-analysis. Twenty-six studies reporting data on 7258 children were included. The summary results indicated that high water fluoride exposure was associated with lower intelligence levels (standardized mean difference : -0.52; 95% CI: -0.62 to -0.42; P intelligence (P intelligence levels. Greater exposure to high levels of fluoride in water was significantly associated with reduced levels of intelligence in children. Therefore, water quality and exposure to fluoride in water should be controlled in areas with high fluoride levels in water. Copyright © 2017. Published by Elsevier Ltd.

  11. Private Well Water and Fluoride

    Science.gov (United States)

    ... Private Wells Infant Formula Fluorosis Public Health Service Recommendation Water Operators & Engineers Water Fluoridation Additives Shortages of Fluoridation Additives Drinking Water Pipe Systems CDC-Sponsored Water Fluoridation Training Links to Other ...

  12. Low-Cost, Robust, and Field Portable Smartphone Platform Photometric Sensor for Fluoride Level Detection in Drinking Water.

    Science.gov (United States)

    Hussain, Iftak; Ahamad, Kamal Uddin; Nath, Pabitra

    2017-01-03

    Groundwater is the major source of drinking water for people living in rural areas of India. Pollutants such as fluoride in groundwater may be present in much higher concentration than the permissible limit. Fluoride does not give any visible coloration to water, and hence, no effort is made to remove or reduce the concentration of this chemical present in drinking water. This may lead to a serious health hazard for those people taking groundwater as their primary source of drinking water. Sophisticated laboratory grade tools such as ion selective electrodes (ISE) and portable spectrophotometers are commercially available for in-field detection of fluoride level in drinking water. However, such tools are generally expensive and require expertise to handle. In this paper, we demonstrate the working of a low cost, robust, and field portable smartphone platform fluoride sensor that can detect and analyze fluoride concentration level in drinking water. For development of the proposed sensor, we utilize the ambient light sensor (ALS) of the smartphone as light intensity detector and its LED flash light as an optical source. An android application "FSense" has been developed which can detect and analyze the fluoride concentration level in water samples. The custom developed application can be used for sharing of in-field sensing data from any remote location to the central water quality monitoring station. We envision that the proposed sensing technique could be useful for initiating a fluoride removal program undertaken by governmental and nongovernmental organizations here in India.

  13. Statistical analysis of fluoride levels in human urine and drinking water samples of fluorinated area of punjab (pakistan)

    International Nuclear Information System (INIS)

    Qayyum, M.; Zaman, W.U.; Rehman, R.; Ahmad, B.; Ahmad, M.; Ali, S.; Murtaza, S

    2013-01-01

    Increasing fluoride levels in drinking water of fluorinated areas of world leading to fluorosis. For bio-monitoring of fluorosis patients, fluoride levels were determined in drinking water and human urine samples of different individuals having dental fluorosis and bony deformities from fluorotic area of Punjab (Sham Ki Bhatiyan, Pakistan) and then compared with reference samples of non fluorotic area (Queens Road, Lahore, Pakistan) using ion selective electrode methodology. Fluoride levels in fluorinated area differ significantly from control group (p < 0.05). In drinking water and human urine samples, fluoride levels in fluorinated areas were: 136.192 +- 67.836 and 94.484 +- 36.572 micro molL/sup -1/ respectively, whereas in control samples, fluoride concentrations were: 19.306 +- 2.109 and 47.154 +- 22.685 micro molL/sup -1/ in water and urine samples correspondingly. Pearson's correlation data pointed out the fact that that human urine and water fluoride concentrations have a significant positive dose response relationship with the prevalence of dental and skeletal fluorosis in fluorotic areas having higher fluoride levels in drinking water. (author)

  14. Water Fluoridation Statistics - Percent of PWS population receiving fluoridated water

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2000-2014. Water Fluoridation Statistics is a biennial report of the percentage and number of people receiving fluoridated water from 2000 through 2014, originally...

  15. Water Fluoridation Statistics - Percent of PWS population receiving fluoridated water

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2000-2014 Water Fluoridation Statistics is a biennial report of the percentage and number of people receiving fluoridated water from 2000 through 2014, originally...

  16. Fluoride and Water (For Parents)

    Science.gov (United States)

    ... risk of tooth decay" on the label. The Controversy Over Fluoride Opponents of water fluoridation have questioned ... Us Contact Us Partners Editorial Policy Permissions Guidelines Privacy Policy & Terms of Use Notice of Nondiscrimination Visit ...

  17. Determination of water fluoride levels in the vicinities of the nuclear fuel plant in Resende, Rio de Janeiro

    International Nuclear Information System (INIS)

    Carneiro, L.A.; Castro Faria, M.V. de

    1983-01-01

    The water fluoride levels in rivers and lakes, in a total of 26 different collection points placed within a circle of 10 km in diameter having the Nuclear Fuel Plant of Resende, Rio de Janeiro, as the center, were determined. (E.G.) [pt

  18. Fluoride levels in commercially available rice in Ethiopia | Tegegne ...

    African Journals Online (AJOL)

    Alkaline fusion was used for sample preparation of six varieties for both the raw rice and rice cooked with tap water and fluoridated water. Fluoride levels ranged from 0.1-5.5 mg/kg in raw rice sample. Rice which was cooked with different fluoride levels of water showed increment depending on the method of cooking.

  19. Water Fluoridation Reporting System (Public Water Systems)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Water Fluoridation Reporting System (WFRS) has been developed to provide tools to assist states in managing fluoridation programs. WFRS is designed to track all...

  20. Health impact of supplying safe drinking water containing fluoride below permissible level on flourosis patients in a fluoride-endemic rural area of West Bengal.

    Science.gov (United States)

    Majumdar, Kunal Kanti

    2011-01-01

    The problem of high fluoride concentration in groundwater resources has become one of the most important toxicological and geo-environmental issues in India. Excessive fluoride in drinking water causes dental and skeletal fluorosis, which is encountered in endemic proportions in several parts of the world. World Health Organization (WHO) guideline value and the permissible limit of fluoride as per Bureau of Indian Standard (BIS) is 1.5 mg/L. About 20 states of India, including 43 blocks of seven districts of West Bengal, were identified as endemic for fluorosis and about 66 million people in these regions are at risk of fluoride contamination. Studies showed that withdrawal of sources identified for fluoride often leads reduction of fluoride in the body fluids (re-testing urine and serum after a week or 10 days) and results in the disappearance of non-skeletal fluorosis within a short duration of 10-15 days. To determine the prevalence of signs and symptoms of suspected dental, skeletal, and non-skeletal fluorosis, along with food habits, addictions, and use of fluoride containing toothpaste among participants taking water with fluoride concentration above the permissible limit, and to assess the changes in clinical manifestations of the above participants after they started consuming safe drinking water. A longitudinal intervention study was conducted in three villages in Rampurhat Block I of Birbhum district of West Bengal to assess the occurrence of various dental, skeletal, and non-skeletal manifestations of fluorosis, along with food habits, addictions, and use of fluoride containing toothpaste among the study population and the impact of taking safe water from the supplied domestic and community filters on these clinical manifestations. The impact was studied by follow-up examination of the participants for 5 months to determine the changes in clinical manifestations of the above participants after they started consuming safe drinking water from supplied

  1. Well Waters Fluoride in Enugu, Nigeria

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    ISI Ogbu

    2012-03-01

    Full Text Available Abnormal fluoride levels in drinking water have been associated with adverse health effects. To determine the fluoride content of well waters in Enugu, southeastern Nigeria, water samples from 50 artisan wells chosen by multistage sampling procedure from the 5 zones of Enugu municipality were analyzed in duplicates for their fluoride content. The zonal mean values were 0.60, 0.70, 0.62, 0.62, and 0.63 mg/L for Abakpa Nike, Achara Layout, Obiagu/ Ogui, Trans Ekulu and Uwani, respectively (p<0.05. The mean value for the whole city was 0.63 mg/L. Although, the mean level of fluoride recorded in this study is currently within safe limits (1.5 mg/L, WHO 2011, it is important to monitor continuously the fluoride content of well waters in the municipality in view of the increasing industrial activities going on in the city and heavy reliance on well water for domestic purposes and the widespread use of consumer products containing fluoride.

  2. Water fluoridation in 40 Brazilian cities: 7 year analysis

    Directory of Open Access Journals (Sweden)

    Suzely Adas Saliba MOIMAZ

    2013-01-01

    Full Text Available Objectives Fluoride levels in the public water supplies of 40 Brazilian cities were analyzed and classified on the basis of risk/benefit balance. Material and Methods Samples were collected monthly over a seven-year period from three sites for each water supply source. The samples were analyzed in duplicate in the laboratory of the Center for Research in Public Health - UNESP using an ion analyzer coupled to a fluoride-specific electrode. Results A total of 19,533 samples were analyzed, of which 18,847 were artificially fluoridated and 686 were not artificially fluoridated. In samples from cities performing water fluoridation, 51.57% (n=9,720 had fluoride levels in the range of 0.55 to 0.84 mg F/L; 30.53% (n=5,754 were below 0.55 mg F/L and 17.90% (n=3,373 were above 0.84 mg F/L (maximum concentration=6.96 mg F/L. Most of the cities performing fluoridation that had a majority of samples with fluoride levels above the recommended parameter had deep wells and more than one source of water supply. There was some variability in the fluoride levels of samples from the same site and between collection sites in the same city. Conclusions The majority of samples from cities performing fluoridation had fluoride levels within the range that provides the best combination of risks and benefits, minimizing the risk of dental fluorosis while preventing dental caries. The conduction of studies about water distribution systems is suggested in cities with high natural fluoride concentrations in order to optimize the use of natural fluoride for fluoridation costs and avoid the risk of dental fluorosis.

  3. Fluoride exposure and indicators of thyroid functioning in the Canadian population: implications for community water fluoridation.

    Science.gov (United States)

    Barberio, Amanda M; Hosein, F Shaun; Quiñonez, Carlos; McLaren, Lindsay

    2017-10-01

    There are concerns that altered thyroid functioning could be the result of ingesting too much fluoride. Community water fluoridation (CWF) is an important source of fluoride exposure. Our objectives were to examine the association between fluoride exposure and (1) diagnosis of a thyroid condition and (2) indicators of thyroid functioning among a national population-based sample of Canadians. We analysed data from Cycles 2 and 3 of the Canadian Health Measures Survey (CHMS). Logistic regression was used to assess associations between fluoride from urine and tap water samples and the diagnosis of a thyroid condition. Multinomial logistic regression was used to examine the relationship between fluoride exposure and thyroid-stimulating hormone (TSH) level (low/normal/high). Other available variables permitted additional exploratory analyses among the subset of participants for whom we could discern some fluoride exposure from drinking water and/or dental products. There was no evidence of a relationship between fluoride exposure (from urine and tap water) and the diagnosis of a thyroid condition. There was no statistically significant association between fluoride exposure and abnormal (low or high) TSH levels relative to normal TSH levels. Rerunning the models with the sample constrained to the subset of participants for whom we could discern some source(s) of fluoride exposure from drinking water and/or dental products revealed no significant associations. These analyses suggest that, at the population level, fluoride exposure is not associated with impaired thyroid functioning in a time and place where multiple sources of fluoride exposure, including CWF, exist. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Risk perception, psychological heuristics and the water fluoridation controversy.

    Science.gov (United States)

    Perrella, Andrea M L; Kiss, Simon J

    2015-04-29

    Increasingly, support for water fluoridation has come under attack. We seek an explanation, focusing on the case of Waterloo, Ontario, where a 2010 referendum overturned its water fluoridation program. In particular, we test whether individuals perceive the risks of water fluoridation based not on 'hard' scientific evidence but on heuristics and cultural norms. A sample of 376 residents in Waterloo were surveyed in June 2012 using random digit dialing. We use factor analysis, OLS regression, as well as t-tests to evaluate a survey experiment to test the credibility hypothesis. Perceptions of fluoride as a risk are lower among those who perceive fluoride's benefits (B = .473, p < 0.001) and those whose cultural view is 'egalitarian' (B = .156, p < 0.05). The experiment shows a lower level of perception of fluoride's benefits among respondents who are told that water fluoridation is opposed by a national advocacy group (Group A) compared to those who are told that the government and the World Health Organization support fluoridation (Group B) (t = 1.6547, p < 0.05), as well as compared to the control group (t = 1.8913, p < 0.05). There is no difference between Group B and the control, possibly because people's already general support for fluoridation is less prone to change when told that other public organizations also support fluoridation. Public health officials should take into account cultural norms and perceptions when individuals in a community appear to rise up against water fluoridation, with implications for other public health controversies.

  5. ADSORPTIVE REMOVAL OF FLUORIDE FROM WATER USING ...

    African Journals Online (AJOL)

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    Currently available treatment methods for removal of excess fluoride from water are broadly divided into three ... the application of nanoparticles as sorbents for fluoride removal. Sundaram [26] studied the ... Characterization of adsorbent.

  6. Evaluation and modeling of the parameters affecting fluoride toxicity level in aquatic environments by bioassay method

    OpenAIRE

    Hamid Reza Shamsollahi; Hadi asady; Amir Hossein Mahvi; Zahra zolghadr

    2014-01-01

    Background: Fluoride exists in various forms in nature and water resources. , The rising level of fluoride in water resources due to discharge of industrial effluents can cause toxicity in aquatic organisms. To prevent toxicity, it is necessary to determine maximum fluoride toxicity as well as effluent discharge limits. The aim of this study was to determine the maximum fluoride toxicity and the factors affecting fluoride toxicity to provide a model in order to determine the effluent discha...

  7. The effect of water purification systems on fluoride content of drinking water

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2008-03-01

    Full Text Available Objective: The purpose of the present study was to determine the effect of different water purification systems on the fluoride content of drinking water and to compare the efficacy of these water purification systems in reducing the fluoride content. Materials and Methods: Five different water purification systems were tested in this study. They were reverse osmosis, distillation, activated carbon, Reviva ® , and candle filter. The water samples in the study were of two types, viz, borewell water and tap water, these being commonly used by the people of Davangere City, Karnataka. The samples were collected before and after purification, and fluoride analysis was done using fluoride ion-specific electrode. Results: The results showed that the systems based on reverse osmosis, viz, reverse osmosis system and Reviva ® showed maximum reduction in fluoride levels, the former proving to be more effective than the latter; followed by distillation and the activated carbon system, with the least reduction being brought about by candle filter. The amount of fluoride removed by the purification system varied between the system and from one source of water to the other. Interpretation and Conclusion: Considering the beneficial effects of fluoride on caries prevention; when drinking water is subjected to water purification systems that reduce fluoride significantly below the optimal level, fluoride supplementation may be necessary. The efficacy of systems based on reverse osmosis in reducing the fluoride content of water indicates their potential for use as defluoridation devices.

  8. Fluoride level in saliva after bonding orthodontic brackets with a fluoride containing adhesive

    NARCIS (Netherlands)

    Ogaard, B; Arends, J; Helseth, H; Dijkman, G; vanderKuijl, M

    The fluoride level in saliva is considered an important parameter in caries prevention. Elevation of the salivary fluoride level by a fluoride-releasing orthodontic bonding adhesive would most likely be beneficial in the prevention of enamel caries. In this study, the fluoride level in saliva was

  9. Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention

    Science.gov (United States)

    2014-01-01

    Fluorine is the world's 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed. PMID:24719570

  10. Drinking Water Fluoride Levels for a City in Northern Mexico (Durango Determined Using a Direct Electrochemical Method and Their Potential Effects on Oral Health

    Directory of Open Access Journals (Sweden)

    Nelly Molina Frechero

    2013-01-01

    Full Text Available Fluoride is ingested primarily through consuming drinking water. When drinking water contains fluoride concentrations >0.7 parts per million (ppm, consuming such water can be toxic to the human body; this toxicity is called “fluorosis.” Therefore, it is critical to determine the fluoride concentrations in drinking water. The objective of this study was to determine the fluoride concentration in the drinking water of the city of Durango. The wells that supply the drinking water distribution system for the city of Durango were studied. One hundred eighty-nine (189 water samples were analyzed, and the fluoride concentration in each sample was quantified as established by the law NMX-AA-077-SCFI-2001. The fluoride concentrations in such samples varied between 2.22 and 7.23 ppm with a 4.313 ± 1.318 ppm mean concentration. The highest values were observed in the northern area of the city, with a 5.001 ± 2.669 ppm mean value. The samples produced values that exceeded the national standard for fluoride in drinking water. Chronic exposure to fluoride at such concentrations produces harmful health effects, the first sign of which is dental fluorosis. Therefore, it is essential that the government authorities implement water defluoridation programs and take preventative measures to reduce the ingestion of this toxic halogen.

  11. Drinking Water Fluoride Levels for a City in Northern Mexico (Durango) Determined Using a Direct Electrochemical Method and Their Potential Effects on Oral Health

    Science.gov (United States)

    Molina Frechero, Nelly; Sánchez Pérez, Leonor; Castañeda Castaneira, Enrique; Oropeza Oropeza, Anastasio; Gaona, Enrique; Salas Pacheco, José; Bologna Molina, Ronell

    2013-01-01

    Fluoride is ingested primarily through consuming drinking water. When drinking water contains fluoride concentrations >0.7 parts per million (ppm), consuming such water can be toxic to the human body; this toxicity is called “fluorosis.” Therefore, it is critical to determine the fluoride concentrations in drinking water. The objective of this study was to determine the fluoride concentration in the drinking water of the city of Durango. The wells that supply the drinking water distribution system for the city of Durango were studied. One hundred eighty-nine (189) water samples were analyzed, and the fluoride concentration in each sample was quantified as established by the law NMX-AA-077-SCFI-2001. The fluoride concentrations in such samples varied between 2.22 and 7.23 ppm with a 4.313 ± 1.318 ppm mean concentration. The highest values were observed in the northern area of the city, with a 5.001 ± 2.669 ppm mean value. The samples produced values that exceeded the national standard for fluoride in drinking water. Chronic exposure to fluoride at such concentrations produces harmful health effects, the first sign of which is dental fluorosis. Therefore, it is essential that the government authorities implement water defluoridation programs and take preventative measures to reduce the ingestion of this toxic halogen. PMID:24348140

  12. Drinking water fluoride levels for a city in northern Mexico (durango) determined using a direct electrochemical method and their potential effects on oral health.

    Science.gov (United States)

    Molina Frechero, Nelly; Sánchez Pérez, Leonor; Castañeda Castaneira, Enrique; Oropeza Oropeza, Anastasio; Gaona, Enrique; Salas Pacheco, José; Bologna Molina, Ronell

    2013-01-01

    Fluoride is ingested primarily through consuming drinking water. When drinking water contains fluoride concentrations>0.7 parts per million (ppm), consuming such water can be toxic to the human body; this toxicity is called "fluorosis." Therefore, it is critical to determine the fluoride concentrations in drinking water. The objective of this study was to determine the fluoride concentration in the drinking water of the city of Durango. The wells that supply the drinking water distribution system for the city of Durango were studied. One hundred eighty-nine (189) water samples were analyzed, and the fluoride concentration in each sample was quantified as established by the law NMX-AA-077-SCFI-2001. The fluoride concentrations in such samples varied between 2.22 and 7.23 ppm with a 4.313±1.318 ppm mean concentration. The highest values were observed in the northern area of the city, with a 5.001±2.669 ppm mean value. The samples produced values that exceeded the national standard for fluoride in drinking water. Chronic exposure to fluoride at such concentrations produces harmful health effects, the first sign of which is dental fluorosis. Therefore, it is essential that the government authorities implement water defluoridation programs and take preventative measures to reduce the ingestion of this toxic halogen.

  13. State and National Water Fluoridation System (Public Water Systems)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Water Fluoridation Reporting System (WFRS) has been developed to provide tools to assist states in managing fluoridation programs. WFRS is designed to track all...

  14. Fluoride uptake into the developing enamel and dentine of sheep incisors following daily ingestion of fluoridated milk or water

    International Nuclear Information System (INIS)

    Cuttress, T.W.; Suckling, G.W.; Gao, J.; Coote, G.E.

    1996-01-01

    The caries preventive action of fluoride is common knowledge, although some of the mechanisms involved remain equivocal. At present, raised local levels of fluoride at, or in, the surface of tooth enamel is the most commonly accepted explanation of the anti-cariogenic action of fluoride. However, fluoride incorporated as fluorapatite into the tooth during its formation remains a possible alternative or complementary anti-cariogenic mechanism. If so, regular ingestion of fluoride during tooth formation is beneficial. Although use of fluoridated water is the preferred method in public health programmes, access to suitable potable water is required, and often this in not feasible. Fresh, preserved, or dried cow's milk products are widely used as nutritional and dietary items in most populations, particularly for young children. Milk is a practical, controllable means for regular delivery of fluoride. Processing of milk is commonly centralised and uses standardised conditions, allowing easy supplementation of fluoride for distribution to communities. The purpose of this study was to resolve the question of availability of fluoride ingested in milk compared with fluoride ingested in water by measuring fluoride deposition in the developing permanent incisors of young sheep. Incisors were analysed using a proton microprobe. (author). 18 refs., 1 tabs., 3 figs

  15. Water fluoridation for the prevention of dental caries.

    Science.gov (United States)

    Iheozor-Ejiofor, Zipporah; Worthington, Helen V; Walsh, Tanya; O'Malley, Lucy; Clarkson, Jan E; Macey, Richard; Alam, Rahul; Tugwell, Peter; Welch, Vivian; Glenny, Anne-Marie

    2015-06-18

    fluoridated) or non-fluoridated water. We used an adaptation of the Cochrane 'Risk of bias' tool to assess risk of bias in the included studies.We included the following caries indices in the analyses: decayed, missing and filled teeth (dmft (deciduous dentition) and DMFT (permanent dentition)), and proportion caries free in both dentitions. For dmft and DMFT analyses we calculated the difference in mean change scores between the fluoridated and control groups. For the proportion caries free we calculated the difference in the proportion caries free between the fluoridated and control groups.For fluorosis data we calculated the log odds and presented them as probabilities for interpretation. A total of 155 studies met the inclusion criteria; 107 studies provided sufficient data for quantitative synthesis.The results from the caries severity data indicate that the initiation of water fluoridation results in reductions in dmft of 1.81 (95% CI 1.31 to 2.31; 9 studies at high risk of bias, 44,268 participants) and in DMFT of 1.16 (95% CI 0.72 to 1.61; 10 studies at high risk of bias, 78,764 participants). This translates to a 35% reduction in dmft and a 26% reduction in DMFT compared to the median control group mean values. There were also increases in the percentage of caries free children of 15% (95% CI 11% to 19%; 10 studies, 39,966 participants) in deciduous dentition and 14% (95% CI 5% to 23%; 8 studies, 53,538 participants) in permanent dentition. The majority of studies (71%) were conducted prior to 1975 and the widespread introduction of the use of fluoride toothpaste.There is insufficient information to determine whether initiation of a water fluoridation programme results in a change in disparities in caries across socioeconomic status (SES) levels.There is insufficient information to determine the effect of stopping water fluoridation programmes on caries levels.No studies that aimed to determine the effectiveness of water fluoridation for preventing caries in adults

  16. Occurrence of fluoride in ground waters of Saudi Arabia

    Science.gov (United States)

    Alabdulaaly, Abdulrahman I.; Al-Zarah, Abdullah I.; Khan, Mujahid A.

    2013-09-01

    The presence of elevated levels of fluoride in groundwater is considered a global problem. Fluoride in water derives mainly from dissolution of natural minerals in the rocks and soils with which water interacts. The most common fluorine-bearing minerals are fluorite, apatite and micas. Anthropogenic sources of fluoride include agricultural fertilizers and combustion of coal. In the present research, a survey of wells ( n = 1,060) was undertaken in all the 13 regions of the Kingdom of Saudi Arabia to assess the contained fluoride (F) levels. The results indicated variation in fluoride levels from 0.10 to 5.4 mg/L as F throughout the kingdom. The average fluoride levels in milligrams per liter as F were as follows in descending order: 1.80 (Hadwood Shamalyah), 1.37 (Hail), 1.33 (Eastern Province), 1.16 (Al Jouf), 1.11 (Qassim), 1.01 (Riyadh), 0.90 (Madina Al Munnawara), 0.81 (Tabouk), 0.74 (Makkah Al- Mukaramma), 0.73 (Jizan), 0.66 (Asir), 0.64 (Najran), and 0.60 (Al Baha). The results indicated that fluoride levels exceeded the USEPA maximum contaminant limits for drinking water (4 mg/L) in several wells ( n = 7) in different regions of the kingdom and that 13.96 % of the wells exceeded the World Health Organization recommended levels (1.5 mg/L). The results were also compared with the secondary USEPA contaminant standards of 2.0 mg/L for fluorides.

  17. Fluoride removal from water by nano filtration

    International Nuclear Information System (INIS)

    Bejaoui, Imen; Mnif, Amine; Hamrouni, Bechir

    2009-01-01

    As any oligo element, fluoride is necessary and beneficial for human health to low concentrations, but an excess amount of fluoride ions in drinking water has been known to cause undesirable effects, especially tooth and bones fluoro sis. The maximum acceptable concentration of fluoride in drinking water was fixed by the World Health Organization according to the climate in the range of 1 mg.L -1 to 1,2 mg.L -1 . Many methods have been used to remove fluoride from water such as precipitation, adsorption, electrocoagulation and membrane processes. Technologies using membrane processes are being used in many applications, particularly for brackish water desalination. Nano filtration seems to be the best process for a good selective defluorination of fluorinated waters. The main objective of this work was to investigate the retention of fluoride anions by nano filtration. The first part of this study deals with the characterisation of the NF HL2514TF membrane. The influence of various experimental parameters such as initial fluoride content, feed pressure, permeate flux, ionic strength, type of cation associated to fluoride and pH were studied in the second part. Results show that the retention order for the salts tested was TR(Na 2 SO 4 ) > TR(CaCl 2 ) > TR(NaCl), showing a retention sequence inversely proportional to the salt diffusion coefficients in water. It was also shown that charge effects could not be neglected, and a titration experiments confirmed that the NF membrane carry a surplus of negatively charged groups. Fluoride retention exceeds 60 pour cent, and increases with increasing concentration, where the rejection mechanism is related to the dielectric effects. Speigler-Kedem model was applied to experimental results in the aim to determine phenomenological parametersσand P s respectively, the reflexion coefficient of the membrane and the solute permeability of ions. The convective and diffusive parts of the mass transfer were quantified with

  18. Evaluation and modeling of the parameters affecting fluoride toxicity level in aquatic environments by bioassay method

    Directory of Open Access Journals (Sweden)

    Hamid Reza Shamsollahi

    2014-04-01

    Full Text Available Background: Fluoride exists in various forms in nature and water resources. , The rising level of fluoride in water resources due to discharge of industrial effluents can cause toxicity in aquatic organisms. To prevent toxicity, it is necessary to determine maximum fluoride toxicity as well as effluent discharge limits. The aim of this study was to determine the maximum fluoride toxicity and the factors affecting fluoride toxicity to provide a model in order to determine the effluent discharge limits. Methods: Daphnia magna bioassay in the absence of confounding factors was used to determine the maximum level of fluoride toxicity. Then, bioassay was repeated in the presence of the confounding factors (hardness, temperature and exposure time to determine their effects. Results: In the absence of intervening factors, fluoride LC50 levels determined after 24, 48 and 72 hours exposure were 4.9, 46.5 and 38.7 mg/l, respectively.. Also, the influence of confounding factors on LC50 values was reported significant by Minitab software. Conclusion: Increasing the water hardness reduced fluoride toxicity, and increasing the water temperature and exposure time increased fluoride toxicity in aquatic environments. Therefore, while determining the wastewater discharge limit in terms of fluoride concentration, it is essential to take the effect of confounding factors on fluoride toxicity into account in order to prevent toxicity in the open water resources.

  19. High fluoride and low calcium levels in drinking water is associated with low bone mass, reduced bone quality and fragility fractures in sheep.

    Science.gov (United States)

    Simon, M J K; Beil, F T; Rüther, W; Busse, B; Koehne, T; Steiner, M; Pogoda, P; Ignatius, A; Amling, M; Oheim, R

    2014-07-01

    Chronic environmental fluoride exposure under calcium stress causes fragility fractures due to osteoporosis and bone quality deterioration, at least in sheep. Proof of skeletal fluorosis, presenting without increased bone density, calls for a review of fracture incidence in areas with fluoridated groundwater, including an analysis of patients with low bone mass. Understanding the skeletal effects of environmental fluoride exposure especially under calcium stress remains an unmet need of critical importance. Therefore, we studied the skeletal phenotype of sheep chronically exposed to highly fluoridated water in the Kalahari Desert, where livestock is known to present with fragility fractures. Dorper ewes from two flocks in Namibia were studied. Chemical analyses of water, blood and urine were executed for both cohorts. Skeletal phenotyping comprised micro-computer tomography (μCT), histological, histomorphometric, biomechanical, quantitative backscattered electron imaging (qBEI) and energy-dispersive X-ray (EDX) analysis. Analysis was performed in direct comparison with undecalcified human iliac crest bone biopsies of patients with fluoride-induced osteopathy. The fluoride content of water, blood and urine was significantly elevated in the Kalahari group compared to the control. Surprisingly, a significant decrease in both cortical and trabecular bones was found in sheep chronically exposed to fluoride. Furthermore, osteoid parameters and the degree and heterogeneity of mineralization were increased. The latter findings are reminiscent of those found in osteoporotic patients with treatment-induced fluorosis. Mechanical testing revealed a significant decrease in the bending strength, concurrent with the clinical observation of fragility fractures in sheep within an area of environmental fluoride exposure. Our data suggest that fluoride exposure with concomitant calcium deficit (i) may aggravate bone loss via reductions in mineralized trabecular and cortical bone

  20. Western Australian schools access to dentally optimal fluoridated water.

    Science.gov (United States)

    Desai, P; Kruger, E; Trolio, R; Tennant, M

    2015-03-01

    This study examined water fluoride levels at schools across Western Australia. The aim was to identify schools where levels of water fluoride appeared to be below dental health thresholds (0.5-1.0 mg/L) as recommended by the National Health and Medical Research Council (NHMRC). The objective is to provide health organizations with the knowledge for a more targeted approach to schools with greater risk of decay. Population data, school location, enrolment data and water quality data were integrated into geographic databases for analysis using Quantum GIS, Lisboa 1.8. The results indicated that 46% of school attendees in the northern half of Western Australia were at schools where there was the potential that the water was not dentally optimally fluoridated while in the southern half of Western Australia this was about 10%. Of these attendees (north and south), 45% were at primary school. Similarly, there was an association between socio-economic decile and proportion of school attendees in non-dentally optimally fluoridated schools. Lower deciles (i.e. poorer attendees) had a greater risk of being in schools outside dentally optimally fluoridated areas. This study clearly highlights areas where more prevention (and probably) treatment needs are present and provides a framework for targeted service planning. © 2015 Australian Dental Association.

  1. Fluoride Intake through Consumption of Tap Water and Bottled Water in Belgium

    Directory of Open Access Journals (Sweden)

    Herman van Oyen

    2009-05-01

    Full Text Available There is a tendency to align higher levels of fluoride in natural mineral water with the existing higher levels in tap water. Treatment of natural mineral waters could harm the preservation of their natural character. In this study fluoride intake through bottled and tap water consumption in the Belgian adult population was assessed, taking into account regional differences. A deterministic approach was used whereby consumption quantities of tap water and different brands of bottled water were linked with their respective fluoride concentrations. Data from the national food consumption survey (2004 were used and the Nusser methodology was applied to obtain usual intake estimates. Mean intake of fluoride through total water consumption in Flanders was 1.4±0.7 mg/day (97.5th percentile: 3.1 mg/day, while in the Walloon region it was on average 0.9±0.6 mg/day (97.5th percentile: 2.4 mg/day. The probability of exceeding the UL of 7 mg per day via a normal diet was estimated to be low. Consequently, there is no need to revise the existing norms, but higher fluoride concentrations should be more clearly indicated on the labels. Reliable data about total dietary fluoride intake in children, including intake of fluoride via tooth paste and food supplements, are needed.

  2. Fluoride levels in tef [Eragrostis tef (Zucc.) Trotter] and enjera and its ...

    African Journals Online (AJOL)

    The main objective of this study was to estimate the fluoride levels in tef grain and in enjera, its fermentation product in different regions of Ethiopia, especially in the regions where tef is dominantly cultivated. The effect of water used to bake the enjera was assessed by preparing fluoride-containing water in the laboratory.

  3. Application of Titanium Compounds to Reduce Fluoride Ion in Water Resources with High Fluoride Ion Contents

    Directory of Open Access Journals (Sweden)

    Fariborz Riahi

    2005-06-01

    Full Text Available The present work describes studies on the sorption of fluoride ions from water by titanium compounds used in water treatment to reduce fluoride content in water resources. There are different methods of reducing fluoride ion in water, each associated with specific problems such as secondary contamination, environmental contamination, high costs, or the need for primary and secondary treatment. In this study, application of titanium sulfate and Metatitanic acid produced from titanium ore concentrate (ileminite is investigated in the removal of fluoride ion and the possibility of complete purification of fluorine containing wastewater is examined to determine the optimal conditions. Metatitanic acid has a great sorption property for fluoride ion. Also titanium sulfate is a suitable and more effective material for this purpose. Efficiency of this material in reducing fluoride ion content is 99.9% and it is possible to refresh sorbet material for reuse without problems arising from Ti+4 ion contamination.

  4. Fluoride in the drinking water of Pakistan and the possible risk of crippling fluorosis

    Directory of Open Access Journals (Sweden)

    M. A. Tahir

    2013-02-01

    Full Text Available To explore the possibility of fluoride toxicity, 747 water samples were collected from surface water and groundwater sources of 16 major cities of Pakistan, adopting a uniform sampling design with distribution of samples: Lahore (79, Kasur (46, Faisalabad (30, Khushab (50, Chakwal (51, Mianwali (30, Jhelum (53, Bahawalpur (60, Karachi (60, Mirpur Khas (55, Peshawar (38, Risalpur (35, Quetta (81, Ziarat (21, Loralai (21, and Mastung (37. Comparison of analytical findings with WHO Guidelines of Drinking Water for Fluoride (i.e., 1.5 ppm has concluded that 16% of the monitored water sources have fluoride concentration beyond the permissible safe limit of 1.5 mg L−1 falling in the concentration range of 1.6–25 mg L−1. The highest fluoride contamination (22% is detected in the Balochistan province followed by 19% in Punjab province. Comparatively higher fluoride levels of > 20% in the groundwater sources like hand pumps supported the possibility of increased groundwater contamination as excessive fluoride concentrations are expected to come from calcium-poor aquifers and in areas where fluoride-bearing minerals are common or where cation exchange of sodium for calcium occurs. Field observations have also indicated the prevalence of fluoride-associated health implications in the study areas with excessive fluoride in water sources. Findings of this study have provided bidirectional vision for the epidemiological investigations as well as to mitigate the issues in the affected vicinities of fluoride-rich areas.

  5. Fluoride Removal From Drinking Water by Electrocoagulation Using Iron and Aluminum Electrodes

    OpenAIRE

    Takdastan; Emami Tabar; Neisi; Eslami

    2014-01-01

    Background Existence of fluoride in drinking water above the permissible level causes human skeletal fluorosis. Objectives Electrocoagulation by iron and aluminum electrodes was proposed for removing fluoride from drinking water. Materials and Methods Effects of different operating conditions such as treatment time, initial pH, applied voltage, type and number of electrodes, the sp...

  6. [Fluoride intake through consumption of water from municipal network in the INMA-Gipuzkoa cohort].

    Science.gov (United States)

    Jiménez-Zabala, Ana; Santa-Marina, Loreto; Otazua, Mónica; Ayerdi, Mikel; Galarza, Ane; Gallastegi, Mara; Ulibarrena, Enrique; Molinuevo, Amaia; Anabitarte, Asier; Ibarluzea, Jesús

    2017-05-22

    To estimate fluoride intake through consumption of water from the municipal network in pregnant women and their children from the INMA-Gipuzkoa cohort and to compare these intakes with recommended levels. In Euskadi (Spain), fluoridation of drinking water is compulsory in water supplies for more than 30,000 inhabitants. 575 pregnant women (recruitment, 2006-2008) and 424 4-year-old children (follow-up, 2010-2012) have been included. Fluoride levels in drinking water were obtained from the water consumption information system of the Basque Country (EKUIS). Water consumption habits and socioeconomic variables were obtained by questionnaire. 74.9% and 87.7% of women and children consumed water from the municipal network. Average fluoride levels in fluoridated water were 0.805 (SD: 0.194) mg/L during baseline recruitment and 0.843 (SD: 0.080) mg/L during follow up, at 4 years old of the children. Average and 95th percentile of fluoride intake were 0.015 and 0.026mg/kg per day in women and 0.033 and 0.059mg/kg per day in children. Considering only fluoride provided by drinking water, 8.71% of children living in fluoridated areas exceeded intake level recommended by the European Food Safety Authority, consisting in 0.05mg/kg per day. The results show that ingested levels of fluoride through consumption of municipal water can exceed the recommended levels in children and encourages further studies that will help in fluoridation policies of drinking water in the future. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Impact of Dental Fluorosis, Socioeconomic Status and Self-Perception in Adolescents Exposed to a High Level of Fluoride in Water.

    Science.gov (United States)

    Molina-Frechero, Nelly; Nevarez-Rascón, Martina; Nevarez-Rascón, Alfredo; González-González, Rogelio; Irigoyen-Camacho, María Esther; Sánchez-Pérez, Leonor; López-Verdin, Sandra; Bologna-Molina, Ronell

    2017-01-12

    Objective : To identify adolescents' self-perception of dental fluorosis from two areas with different socioeconomic levels. Methods : A cross-sectional, descriptive study was conducted with 15-year-old youths by applying a questionnaire designed and validated to assess self-perceptions of dental fluorosis in two areas with different socioeconomic statuses (SESs). Fluorosis was clinically evaluated by applying the Thylstrup and Fejerkov (TF) index on the upper front teeth. Results : A total of 308 adolescents were included in the study. The medium-SES population, which was exposed to 2.5 ppm of fluoride in water, and the low-SES population, which was exposed to 5.1 ppm, presented the following levels of dental fluorosis: TF 2-3 (50%), TF 4-5 (45.6%) and TF 6-7 (4.4%) for medium SES and TF 2-3 (12.3%), TF 4-5 (67.1%) and TF 67 (20.6%) for low SES. A significant association was found between self-perception and dental fluorosis in those with medium and low SESs ( p self-perception, with a 6-7 TF level for concerns about color (OR = 1.6), smile (OR = 1.2) and appearance (OR = 3.36). Conclusions : Self-perceptions of dental fluorosis affect adolescents such that adolescents with a medium SES have more negative perceptions than those with a low SES. Such perceptions increase as the TF index increases.

  8. Opinion of residents from the Gold Coast, Queensland, on community water fluoridation.

    Science.gov (United States)

    Kroon, Jeroen; Reid, Kate Emily; Cutting, Jenna Renae; Lalloo, Ratilal; Chiu, Kandy Chien

    2014-02-01

    To investigate opinions and concerns of Gold Coast residents regarding fluoridation of community water supplies. Anonymous data were collected in four major shopping centers from approximately 500 Gold Coast residents. Eighty-one percent of participants were aware of the addition of fluoride to the water supply. More than half obtained information on water fluoridation through the print and electronic media. Sixty percent of respondents supported water fluoridation. The majority preferred the public and/or health professionals to have made the decision on water fluoridation rather than the government. The percentage of residents supporting water fluoridation was lower than that found in other Queensland, Australian, and worldwide surveys. In this study, only age and the highest level of education attained were factors significantly related to levels of support for water fluoridation. The Queensland Government's decision to implement water fluoridation without a referendum caused disquiet amongst some Gold Coast residents. Future public health initiatives therefore may be assisted by more consultation with, and involvement from, health professionals in the relevant fields. Public health campaigns may benefit more from interaction with the community in order to address their specific concerns. © 2012 Wiley Publishing Asia Pty Ltd.

  9. Effect of high fluoride concentration in drinking water on children’s intelligence

    Directory of Open Access Journals (Sweden)

    Seraj B

    2006-07-01

    Full Text Available Background and Aim: Human and animal studies linking fluoride with diminished intelligence have been published. Although adverse effects of high intake of fluoride on intelligence and mental acuity continue to be reported, they are still controversial. The aim of this research was to investigate the relationship between fluoride in drinking water and children's intelligence. Materials and Methods: In this cross sectional study, 41 children were selected from the high fluoride area with 2.5mg/l (ppm fluoride in the drinking water and 85 children were selected from low fluoride area with 0.4mg/l (ppm fluoride in the drinking water. The intelligence quotient (IQ of each child was measured by the Raven's test. The history of illnesses affecting the nervous system, head trauma, birth weight (2.5kg or  2.5kg, residental history, age and sex of children were investigated by questionnaires completed by the children's parents. Data were analyzed by Chi-Square test with p<0.05 as the limit of significance. Results: In the high fluoride area the mean IQ of children (87.911 was significantly lower than in the low fluoride area (98.912.9 (P=0.025. Conclusion: Based on the findings of this study, exposure of children to high levels of fluoride may carry the risk of impaired development of intelligence.

  10. An Investigation of Fluoride Concentration in Drinking Water of Sanganer Tehsil, Jaipur District, Rajasthan, India and Defluoridation from Plant Material

    Directory of Open Access Journals (Sweden)

    Mohammed Arif

    2014-01-01

    Full Text Available Forty water samples of 20 villages of Sanganer tehsil, Jaipur district were analyzed for determining fluoride ion concentrations. High fluoride containing regions were identified on the basis of fluoride levels of the water samples and also on the prevalence rate of dental and skeletal fluorosis of the study area. Fluoride maps, which distinguish the regions containing the water sources of different ranges of fluoride ion concentrations, were also prepared by isopleth’s technique, a statistical method. Water samples containing high fluoride levels were defluoridated with low-cost materials prepared from plant byproducts. These materials successfully decrease the fluoride ions concentration to an acceptable limit (from 0.5 to 1.5 mg/L without disturbing drinking water quality standards.

  11. Fluoride Removal From Drinking Water by Electrocoagulation Using Iron and Aluminum Electrodes

    Directory of Open Access Journals (Sweden)

    Takdastan

    2014-07-01

    Full Text Available Background Existence of fluoride in drinking water above the permissible level causes human skeletal fluorosis. Objectives Electrocoagulation by iron and aluminum electrodes was proposed for removing fluoride from drinking water. Materials and Methods Effects of different operating conditions such as treatment time, initial pH, applied voltage, type and number of electrodes, the spaces between aluminum and iron electrodes, and energy consumption during electrocoagulation were investigated in the batch reactor. Variable concentrations of fluoride solution were prepared by mixing proper amounts of sodium fluoride with deionized water. Results Experimental results showed that aluminum electrode is more effective in fluoride removal than iron, as in 40 minutes and initial pH of 7.5 at 20 V, the fluoride removal process reached to 97.86%. The final recommendable limit of fluoride (1.5 mg/L was obtained in 10 minutes at 20 V with the aluminum electrode. Conclusions In electrocoagulation with iron and aluminum electrodes, increase of voltage, number of electrodes and reaction time as well as decrease of the spaces between electrodes, enhanced the fluoride removal efficiency from drinking water. In addition the effect of pH and initial concentration of fluoride varied with types of electrodes.

  12. Atmospheric fluoride levels in some Ontario peach orchards

    Energy Technology Data Exchange (ETDEWEB)

    Drowley, W B; Rayner, A C; Jephcott, C M

    1963-10-01

    As a result of suture injury to peaches, a survey was taken to determine monthly atmospheric fluoride levels in the soft fruit-growing area of the Niagara Peninsula of Ontario. Although the injury was confined to a few orchards, it was found necessary to locate stations for fluoride sampling over a wide area. The limed-paper candle method was used for fluoride collection. Unwashed and washed peach leaves were analyzed for fluoride content. Fluoride was separated from all samples by the Willard-Winter distillation procedure and estimated colorimetrically. It was found that a general background level of atmospheric fluoride existed in the whole surveyed area and that the levels were highest in and near the area of peach injury. The fluoride content of peach leaves was also highest in this area. The coincidence of high fluoride levels and suture injury to peaches suggests that atmospheric fluoride was the causal agent. When lime sprays were applied to peach trees in the damaged area, a reduction in the incidence of suture injury was observed.

  13. Impact of Dental Fluorosis, Socioeconomic Status and Self-Perception in Adolescents Exposed to a High Level of Fluoride in Water

    Science.gov (United States)

    Molina-Frechero, Nelly; Nevarez-Rascón, Martina; Nevarez-Rascón, Alfredo; González-González, Rogelio; Irigoyen-Camacho, María Esther; Sánchez-Pérez, Leonor; López-Verdin, Sandra; Bologna-Molina, Ronell

    2017-01-01

    Objective: To identify adolescents’ self-perception of dental fluorosis from two areas with different socioeconomic levels. Methods: A cross-sectional, descriptive study was conducted with 15-year-old youths by applying a questionnaire designed and validated to assess self-perceptions of dental fluorosis in two areas with different socioeconomic statuses (SESs). Fluorosis was clinically evaluated by applying the Thylstrup and Fejerkov (TF) index on the upper front teeth. Results: A total of 308 adolescents were included in the study. The medium-SES population, which was exposed to 2.5 ppm of fluoride in water, and the low-SES population, which was exposed to 5.1 ppm, presented the following levels of dental fluorosis: TF 2–3 (50%), TF 4–5 (45.6%) and TF 6–7 (4.4%) for medium SES and TF 2–3 (12.3%), TF 4–5 (67.1%) and TF 67 (20.6%) for low SES. A significant association was found between self-perception and dental fluorosis in those with medium and low SESs (p < 0.05). The multiple regression model found differences between TF levels and self-perception, with a 6–7 TF level for concerns about color (OR = 1.6), smile (OR = 1.2) and appearance (OR = 3.36). Conclusions: Self-perceptions of dental fluorosis affect adolescents such that adolescents with a medium SES have more negative perceptions than those with a low SES. Such perceptions increase as the TF index increases. PMID:28085102

  14. Impact of Dental Fluorosis, Socioeconomic Status and Self-Perception in Adolescents Exposed to a High Level of Fluoride in Water

    Directory of Open Access Journals (Sweden)

    Nelly Molina-Frechero

    2017-01-01

    Full Text Available Objective: To identify adolescents’ self-perception of dental fluorosis from two areas with different socioeconomic levels. Methods: A cross-sectional, descriptive study was conducted with 15-year-old youths by applying a questionnaire designed and validated to assess self-perceptions of dental fluorosis in two areas with different socioeconomic statuses (SESs. Fluorosis was clinically evaluated by applying the Thylstrup and Fejerkov (TF index on the upper front teeth. Results: A total of 308 adolescents were included in the study. The medium-SES population, which was exposed to 2.5 ppm of fluoride in water, and the low-SES population, which was exposed to 5.1 ppm, presented the following levels of dental fluorosis: TF 2–3 (50%, TF 4–5 (45.6% and TF 6–7 (4.4% for medium SES and TF 2–3 (12.3%, TF 4–5 (67.1% and TF 67 (20.6% for low SES. A significant association was found between self-perception and dental fluorosis in those with medium and low SESs (p < 0.05. The multiple regression model found differences between TF levels and self-perception, with a 6–7 TF level for concerns about color (OR = 1.6, smile (OR = 1.2 and appearance (OR = 3.36. Conclusions: Self-perceptions of dental fluorosis affect adolescents such that adolescents with a medium SES have more negative perceptions than those with a low SES. Such perceptions increase as the TF index increases.

  15. [Exposure to fluorides from drinking water in the city of Aguascalientes, Mexico].

    Science.gov (United States)

    Trejo-Vázquez, R; Bonilla-Petriciolet, A

    2001-08-01

    Determine the fluoride content in all the wells that supply drinking water to the city of Aguascalientes, Mexico, in order to establish the population's degree of exposure. The fluoride content of the 126 wells that supply drinking water to the city of Aguascalientes was determined, using the SPADNS method, in accordance with two Mexican regulations, NMX-AA-77-1982 and NMX-014-SSAI-1993. Using that data, we created fluoride isopleth maps showing the distribution of fluoride concentrations in the water supplies for the city of Aguascalientes. We also estimated exposure doses for the city's inhabitants. The mean analysis uncertainty was 3.9%. Seventy-three wells had a fluoride concentration of" 1.5 mg/L, which was the maximum permissible value set by the Mexican standards then in effect. All the maximum exposure doses surpassed the minimum risk level set by Agency for Toxic Substances and Disease Registry (ATSDR) of the Department of Health and Human Services of the United States of America. In the children under 1 year of age, even the minimum does was slightly higher than the ATSDR risk level. From estimating the fluoride exposure doses caused by water consumption in the city of Aguascalientes and comparing those doses with ones from other states in Mexico, we concluded that the fluoride intake in Aguascalientes represents a potential risk for inhabitants' health. The fluoride content of the city's drinking water should be reduced to 0.69 mg/L.

  16. FLUORIDE LEVELS IN COMMERCIALLY AVAILABLE RICE IN ...

    African Journals Online (AJOL)

    Preferred Customer

    2013-05-05

    May 5, 2013 ... Rice is one of the commonly consumed cereals for more than half of the ... also used as flour, for making rice wine, as ingredient for beer and liquor, ... Fluoride is a necessary element to human health, and a moderate amount of fluoride intake ... For Ethiopian red rice (ERR) Fogera was selected to collect.

  17. The effects of water filtration systems on fluoride: Washington, D.C. metropolitan area.

    Science.gov (United States)

    Jobson, M D; Grimm, S E; Banks, K; Henley, G

    2000-01-01

    According to the U.S. Environmental Protection Agency (EPA), approximately one in eight Americans is exposed to potentially harmful microbes, pesticides, lead, or radioactive radon whenever they drink a glass of tap water or take a shower. One reason for this exposure is that the water plants are aging or ill equipped to process the huge amounts of raw sewage and agricultural pollutants that are still being discharged into our drinking-water sources. Other compounds such as fluoride and chloride have been added to the community water supplies for health benefits. Water filtration systems are becoming more popular as people become concerned with pollutants in the public water supply and questions are being raised as to whether fluoride is affected by these filters. The aim of this pilot study was to assess the efficacy of three types of water filtration systems and to determine their impact on fluoride content of the water in the Washington, D.C. metropolitan area. One sample of water was collected daily for fourteen days, from one location. The sample was divided to use as a control and the test samples which were processed through various filter systems. With the use of a fluoride ion specific electrode, the fluoride concentration level was tested in all samples in order to determine the percentage of fluoride removed. This study was intended to prove that the water filtration systems did not affect the advantage offered by optimum water fluoride levels. The experimental samples were ascertained and compared to the control group, resulting in three of the four carbon filters showing statistically significant amounts of fluoride removed from the water. Both Reverse Osmosis and Distillation, as expected, removed the fluoride at a high rate.

  18. Fluoride Removal from Water by Reverse Osmosis Membrane

    Directory of Open Access Journals (Sweden)

    Sara Namavar

    2013-09-01

    Full Text Available As fluoride concentration in drinking water is one of the effective parameters in human health, finding the way to remove excess amount of fluoride from drinking water is very important in water supply projects. Today, with developing in technology and finding new methods, the use of membrane technology for producing fresh water get improved. In this study the efficiency of reverse osmosis method to remove fluoride from water was investigated. Initial concentration of fluoride, sulfate and electrical conductivity in feed water and the effect of associated cation with fluoride ion were studied. All tests adapted from “Standard Methods for Examination of Water and Wastewater”. Determination of fluoride concentration was done according the standard SPANDS method by using a spectrophotometer DR/5000. Obtain results show that with increasing in concentration of fluoride and sulfate and electrical conductivity in feed water the efficiency of RO membrane to remove fluoride reduced. In addition, this efficiency for CaF2 was higher than NaF.

  19. The prevalence of fluorosis in children is associated with naturally occurring water fluoride concentration in Mexico.

    Science.gov (United States)

    Mariño, Rodrigo

    2013-09-01

    Fluorosis and dental caries in Mexican schoolchildren residing in areas with different water fluoride concentrations and receiving fluoridated salt. Garcia-Perez A, Irigoyen-Carnacho ME, Borges-Yanez A. Caries Res 2013;47(4):299-308. Rodrigo Mariño Is there an association between the presence of dental fluorosis and fluoride concentration in drinking water? and Is there an association between the severity of fluorosis and dental caries experience in schoolchildren residing in two rural towns in Mexico (with water fluoride concentrations of 0.70 and 1.50 ppm) that also receive fluoridated salt? Government: National Council of Science and Technology (Consejo Nacional de Ciencia y Tecnologia, CONACYT) Other: Autonomous University, Xochimilco (Universidad Autonoma Metropolitana, UAM-X) TYPE OF STUDY/DESIGN: Cross-sectional Level 3: Other evidence Not applicable. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Risk Assessment of Fluoride Intake from Tea in the Republic of Ireland and its Implications for Public Health and Water Fluoridation

    Science.gov (United States)

    Waugh, Declan T.; Potter, William; Limeback, Hardy; Godfrey, Michael

    2016-01-01

    The Republic of Ireland (RoI) is the only European Country with a mandatory national legislation requiring artificial fluoridation of drinking water and has the highest per capita consumption of black tea in the world. Tea is a hyperaccumulator of fluoride and chronic fluoride intake is associated with multiple negative health outcomes. In this study, fifty four brands of the commercially available black tea bag products were purchased and the fluoride level in tea infusions tested by an ion-selective electrode method. The fluoride content in all brands tested ranged from 1.6 to 6.1 mg/L, with a mean value of 3.3 mg/L. According to our risk assessment it is evident that the general population in the RoI is at a high risk of chronic fluoride exposure and associated adverse health effects based on established reference values. We conclude that the culture of habitual tea drinking in the RoI indicates that the total cumulative dietary fluoride intake in the general population could readily exceed the levels known to cause chronic fluoride intoxication. Evidence suggests that excessive fluoride intake may be contributing to a wide range of adverse health effects. Therefore from a public health perspective, it would seem prudent and sensible that risk reduction measures be implemented to reduce the total body burden of fluoride in the population. PMID:26927146

  1. Exposure to High Fluoride Drinking Water and Risk of Dental Fluorosis in Estonia

    Directory of Open Access Journals (Sweden)

    Ene Indermitte

    2009-02-01

    Full Text Available The purpose of this study was to assess exposure to drinking water fluoride and evaluate the risk of dental fluorosis among the Estonian population. The study covered all 15 counties in Estonia and 93.7% of population that has access to public water supplies. In Estonia groundwater is the main source for public water supply systems in most towns and rural settlements. The content of natural fluoride in water ranges from 0.01 to 7.20 mg/L. The exposure to different fluoride levels was assessed by linking data from previous studies on drinking water quality with databases of the Health Protection Inspectorate on water suppliers and the number of water consumers in water supply systems. Exposure assessment showed that 4% of the study population had excessive exposure to fluoride, mainly in small public water supplies in western and central Estonia, where the Silurian-Ordovician aquifer system is the only source of drinking water. There is a strong correlation between natural fluoride levels and the prevalence of dental fluorosis. Risk of dental fluorosis was calculated to different fluoride exposure levels over 1.5 mg/L.

  2. Fluoride Concentration in Water, Cow Milk and Cow Urine from Smallholder Dairy Farms in Kiambu- Kenya

    International Nuclear Information System (INIS)

    Gikunju, J.K.; Maitho, T.E.; Kyule, M.N.; Mitema, E.S.; Mugera, G.M.

    1999-01-01

    Kiambu district is situated in central part of Kenya. most of the available land is suitable for agricultural use. majority of the farmers are small scale or subsistence farmers and they are involve in a variety of livestock activities e.g. dairy production, pig production and others in combination or as separate operations. excessive fluoride ingestion can cause specific dental and skeletal lesions and in severe cases adversely influence the health and productivity performance of domestic animals.therefore a study was designed to investigate the levels of flouride in urine, milk and water samples from small scale dairy farms in Kiambu. Water, cow urine and milk samples were collected in clean plastic containers from 84 small scale farms belonging to 6 dairy farmers co-operative societies (DFCs). The DFCs in this study were Kiambaa, Lari, Nderi, Kikuyu, Chania and Limuru. The fluoride concentration in water milk and urine were analysed using the potentiometric method of fluoride ion specific electrode. overall urine contained the highest fluoride concentration while milk contained the lowest fluoride levels. Fluoride levels in water, milk and urine were significantly different, (P>0.05). The mean fluoride concentration in water from all societies was 0.29 ppm while the mean fluoride concentration in milk 0.05 ppm. urine samples had the highest fluoride concentration, (1.5 ppm). The cooperative specific mean fluoride concentrations arranged in descending order were as follow: Nderi (2.8 ppm), Kikuyu (2.4 ppm), Kiambaa(1.9 ppm), Chania (1.6 ppm), Limuru (1.3 ppm) and Lari (1.0 ppm). The maximum fluoride concentration encountered in water in this study was 3.4 ppm, however adverse productivity has been reported in dairy animals consuming as low as 2.15 ppm in drinking water. The mean milk production in in kilograms per day per cow ranged from 2.5 to 6.9 when all six dairy co-operative societies were taken into consideration. this is far below the expected production

  3. Spectrophotometric determination of fluorides in water with Hach equipment

    International Nuclear Information System (INIS)

    Acosta L, E.

    1994-11-01

    The spectrophotometric method for the determination of the fluoride ion in water, demineralized water, raw waters, laundry waters and waters treated with ion exchange resins , using the technique and the SPADNS coloring indicated in the operation manual of the Hach equipment is described. This method covers the determination of the fluoride ion in the range from 0 to 2 mg/l on 25 ml. of radioactive base sample. These limits can be variable if the size of the used aliquot one is changed for the final determination of the fluoride ion. (Author)

  4. Data on daily fluoride intake based on drinking water consumption prepared by household desalinators working by reverse osmosis process.

    Science.gov (United States)

    Karbasdehi, Vahid Noroozi; Dobaradaran, Sina; Esmaili, Abdolhamid; Mirahmadi, Roghayeh; Ghasemi, Fatemeh Faraji; Keshtkar, Mozhgan

    2016-09-01

    In this data article, we evaluated the daily fluoride contents in 20 household desalinators working by reverse osmosis (RO) process in Bushehr, Iran. The concentration levels of fluoride in inlet and outlet waters were determined by the standard SPADNS method using a spectrophotometer (M501 Single Beam Scanning UV/VIS, UK). The fluoride content in outlet waters were compared with EPA and WHO guidelines for drinking water.

  5. Urinary fluoride as a monitoring tool for assessing successful intervention in the provision of safe drinking water supply in five fluoride-affected villages in Dhar district, Madhya Pradesh, India.

    Science.gov (United States)

    Srikanth, R; Gautam, Anil; Jaiswal, Suresh Chandra; Singh, Pavitra

    2013-03-01

    Endemic fluorosis was detected in 31 villages in the Dhar district of Madhya Pradesh, Central India. Out of the 109 drinking water sources that were analyzed, about 67 % were found to contain high concentration of fluoride above the permissible level of 1.0 mg/l. Dental fluorosis among the primary school children in the age between 8 and 15 served as primary indicator for fluoride intoxication among the children. Urinary fluoride levels among the adults were found to be correlated with drinking water fluoride in 10 villages affected by fluoride. Intervention in the form of alternate safe water supply in five villages showed significant reduction in the urinary fluoride concentration when compared to the control village. Urinary fluoride serves as an excellent marker for assessing the effectiveness of intervention program in the fluoride-affected villages.

  6. Purification of Drinking Water from Fluorides by Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    Aleksander A.

    2018-03-01

    Full Text Available Introduction: An important task in the sphere of sanitary and epidemiological welfare of the population of the Russian Federation is provision of drinking water. Tap water must not contain pathogenic bacteria and dangerous chemicals. Purification systems regulate the concentration of fluoride ions in drinking water. The aim of this paper is to study the possibility of purifying tap water from fluoride ions by reverse osmosis. Materials and Methods: We used the Alfa Laval PilotUnit 2.5 "RO/NF with a set of spiral-type membrane elements RO99-2517/48 to remove fluoride ions. We measured the concentration of fluoride ions by the potentiometric method using the Hanna HI 2211 (pH/mV/T. Fluoride-selective electrode ELIS 131 F was used as an indicator electrode and the standard chloride-silver electrode EVL-1M3 was used as a reference electrode. Both the calibration and buffer solutions were prepared from chemically pure reagents and A. R. purity for analysis reagents according to GOST 4386-89. Results: A single passage of water through the reverse osmosis membrane reduced the concentration of fluoride ions from 2.29 ± 0.02 to 0.240 ± 0.015 mg/l. Double passage of water reduced the concentration by a factor of two. As the concentration of fluoride ions increased in the retentate, the concentration in the filtrate slightly increased too. Purification of water reduced the concentration of fluoride ions from 20 mg/l, to 0.5 mg/l. Discussion and Conclusions: Thus, using the Alfa Laval PilotUnit 2.5" RO/NF with a set of spiral-type membrane elements RO99-2517/48 filters tap water of ions of fluoride to the maximum allowable concentration. This study opens the perspective of using reverse osmosis to purify tap water with high concentration of fluoride ions.

  7. Community water fluoridation on the Internet and social media.

    Science.gov (United States)

    Mertz, Aaron; Allukian, Myron

    2014-01-01

    In the United States, 95 percent of teens and 85 percent of adults use the Internet. Two social media outlets, Facebook and Twitter, reach more than 150 billion users. This study describes anti-fluoridation activity and dominance on the Internet and social media, both of which are community water fluoridation (CWF) information sources. Monthly website traffic to major fluoridation websites was determined from June 2011 to May 2012. Facebook, Twitter, and YouTube fluoridation activity was categorized as "proCWF" or "anti-CWF." Twitter's anti-CWF tweets were further subcategorized by the argument used against CWF. Anti-CWF website traffic was found to exceed proCWF activity five- to sixty-fold. Searching "fluoride" and "fluoridation" on Facebook resulted in 88 to 100 percent anti-CWF groups and pages; "fluoridation" on Twitter and YouTube resulted in 64 percent anti-CWF tweets and 99 percent anti-CWF videos, respectively. "Cancer, " "useless, " and "poisonous" were the three major arguments used against fluoridation. Anti-fluoridation information significantly dominates the Internet and social media. Thousands of people are being misinformed daily about the safety, health, and economic benefits of fluoridation.

  8. Fluoride Content of Bottled Drinking Waters in Qatar.

    Science.gov (United States)

    Almulla, Hessa Ibrahim; King, Nigel M; Alnsour, Hamza Mohammad; Sajnani, Anand K

    2016-12-01

    Fluoridation of drinking water has been recognized as one of the most effective ways of achieving community-wide exposure to the caries prevention effects of fluoride (F). A vast majority of people in Qatar use bottled water for drinking. Use of bottled water without knowing the F level may expose children to dental caries risk if the F level is lower than optimal or to dental fluorosis if the F level is too high. The aim of this study was to determine the F concentration of bottled water available in Qatar. A total of 32 brands of bottled water were evaluated. The F concentrations displayed on the labels were recorded. The F ion-selective electrode method was used to measure the F concentration in water samples, and three measurements were taken for every sample to ensure reproducibility. The p value was set at 0.05. The F concentration ranged from 0.06 to 3.0 ppm with a mean value of 0.8 ppm (±0.88). The F levels were provided by the manufacturers on the labels of 60 % of the samples, but this was significantly lower than the measured F levels (p < 0.0001). Moreover, bottled water that was produced in Saudi Arabia had significantly higher levels of F when compared to those produced in other countries (p < 0.05). There was a wide variation in the F levels in the different brands of bottled water. Furthermore, there was a significant disparity between the F levels which were measured and those that were provided on the labels.

  9. Spectrophotometric determination of fluoride in drinking water using ...

    African Journals Online (AJOL)

    2011-03-14

    Mar 14, 2011 ... Fluoride (F-) occurs in almost all waters from trace to high con- centration ... in drinking water can give rise to a number of adverse effects. (WHO ..... amended activated alumina granules. Chem. ... coal in Southwestern China.

  10. Fluoride ions sorption of the water using natural and modified hematite with aluminium hydroxide

    International Nuclear Information System (INIS)

    Teutli S, E. A.

    2011-01-01

    Fluorine is a mineral known for its dental benefits, but fluoride ions can cause fluoro sis in excessive quantities. There are many epidemiological studies on possible adverse effects resulting from prolonged ingestion of fluoride through drinking water. These studies demonstrate that fluoride mainly affects the bone tissue (bones and teeth), may produce an adverse effect on tooth enamel and can cause mild dental fluoro sis at concentrations from 0.9 to 1.2 mg/L in drinking water. In several states of Mexico, water contaminated with fluoride ions can be found, such as Aguascalientes, Chihuahua, Coahuila, Durango, Guanajuato, Sonora, Zacatecas, San Luis Potosi and Jalisco, where the fluoride ions levels are higher than 1.5 mg/L, established by the Mexican Official Standard (NOM-127-Ssa-2000) which sets the permissible limits of water for human use and consumption. Currently, several technologies have been proposed to remove fluoride ions from water such as precipitation methods which are based on the addition of chemicals to water and sorption methods to removed fluoride ions by sorption or ion exchange reactions by some suitable substrate capable of regenerate and reuse. In this work, the sorption of fluoride ions using unmodified and modified hematite with aluminum hydroxide to remove fluoride ions from water by bath experiments was studied. The hematite was modified by treating it with aluminum hydroxide, NaOH and Al 2 (SO 4 ) 3 solutions. The characterization of hematite before and after modification with aluminum hydroxide was studied by X-ray diffraction, scanning electron microscopy, EDS and Bet. The effect of ph, contact time, concentration of fluoride ions, and the dose of sorbent on the sorption of fluoride ions by the modified hematite were studied. Equilibrium was reached within 48 hours of contact time and the maximum sorption of fluoride ions were in the range pH eq between 2.3 and 6.2. Sorption capacities of fluoride ions as a function of dose of

  11. Fluoride removal studies in water using natural materials : technical ...

    African Journals Online (AJOL)

    Excess fluoride in water causes health hazards to the natural environment. The removal of fluoride was attempted using natural materials such as red soil, charcoal, brick, fly-ash and serpentine. Each material was set up in a column for a known volume and the defluoridation capacities of these materials were studied with ...

  12. The occurrence of fluoride in South African groundwater: A water ...

    African Journals Online (AJOL)

    The fluoride data were obtained by extracting fluoride groundwater quality data from DWAF's Water Management Systems (WMS) database. STATISTICA and ARCVIEW were used to process the data. The dental fluorosis data were obtained from a field study conducted by the Department of Health. The degree of dental ...

  13. Fluoride

    Science.gov (United States)

    Opalescence® ... Fluoride is used to prevent tooth decay. It is taken up by teeth and helps to strengthen ... and block the cavity-forming action of bacteria. Fluoride usually is prescribed for children and adults whose ...

  14. Estimation of fluoride concentration in drinking water and common beverages in United Arab Emirates (UAE).

    Science.gov (United States)

    Walia, Tarun; Abu Fanas, Salem; Akbar, Madiha; Eddin, Jamal; Adnan, Mohamad

    2017-07-01

    To assess fluoride concentration in drinking water which include tap water of 4 emirates - Abu Dhabi, Dubai, Sharjah and Ajman plus bottled water, commonly available soft drinks & juices in United Arab Emirates. Five different samples of tap water collected from each of the four emirates of UAE: Ajman, Sharjah, Abu Dhabi and Dubai; twenty-two brands of bottled water and fifteen brands of popular cold beverages, purchased from different supermarkets in U.A.E were tested using ion selective electrode method and the fluoride concentration was determined. The mean fluoride content of tap water samples was 0.14 mg F/L with a range of 0.04-0.3 mg F/L; with Ajman tap water samples showing the highest mean fluoride content of 0.3 mg F/L. The mean fluoride content for both bottled drinking water and beverages was 0.07 mg F/L with a range of 0.02-0.50 mg F/L and 0.04-0.1 mg F/L respectively. Majority (68.2%) of the bottled water are produced locally within U.A.E while a few (31.8%) are imported. The tap water, bottled water and beverages available in U.A.E show varying concentrations of fluoride, however none showed the optimal level necessary to prevent dental caries. Dental professionals in U.A.E should be aware of the fluoride concentrations before prescribing fluoride supplements to children.

  15. Evaluating the Performance of Iron Nano-particle Resin in Removing Fluoride from Water

    Directory of Open Access Journals (Sweden)

    Amir Hossein Mahvi

    2011-01-01

    Full Text Available Excessive amounts of fluoride in drinking water pose serious health problems. It is, therefore, essential to remove it from drinking water by appropriate water treatment processes down to standard levels for preventing the health risks associated. The aim of this study was to determine the performance of a kind of hybrid sorbent resin in removing fluoride from water. Batch experiments were performed to investigate adsorption isotherms and the effects of experimental parameters such as contact time (5-120 min and pH (3-9. Results revealed that fluoride adsorption rate was initially rapid but continued at a slower rate before it reached equilibrium in 120 min. Optimum fluoride removal was observed at a pH range of 3-5.5. The data obtained from the experiments were fitted with Langmiur model.

  16. Readying Community Water Fluoridation Advocates through Training, Surveillance, and Empowerment.

    Science.gov (United States)

    Veschusio, C; Jones, M K; Mercer, J; Martin, A B

    2018-05-30

    This paper describes the Community Water Fluoridation Advocacy Training Project that was designed to develop networks of community water fluoridation advocates in rural communities. The South Carolina (SC) Department of Health and Environmental Control Division of Oral Health staff and the SC Dental Association were responsible for developing and facilitating the training sessions for key policy influencers, which included medical and dental providers, early childhood educators, and water system operators and managers. Findings from the post-training survey indicate that participants increased their knowledge and skills to discuss the impact of water fluoridation on the dental health of community residents. Participants identified a need for online access to water fluoridation education and advocacy materials. Dental public health competencies illustrated: communication and collaboration with groups and individuals, and advocate, implement and evaluate public health policy, legislation and regulations. Copyright© 2018 Dennis Barber Ltd.

  17. The occurrence and geochemistry of fluoride in some natural waters of Kenya

    Science.gov (United States)

    Gaciri, S. J.; Davies, T. C.

    1993-03-01

    In recent years the acquisition of considerable additional data on the hydrogeochemical behaviour of fluoride in natural waters of Kenya has been made possible by extensive surface-water and groundwater sampling campaigns as well as by improvements in analytical techniques. Ultimately, the principal source of fluoride relates to emissions from volcanic activity associated with the East African Rift System. Through various intermediate steps, but also directly, fluoride passes into the natural water system and components of the food chain. Ingestion by man is mainly through drinking water and other beverages. River waters in Kenya generally have a fluoride concentration lower than the recommended level (1.3 ppm) for potable water, thus promoting susceptibility to dental caries. Groundwaters and lake waters show considerably higher fluoride contents, resulting in the widespread incidence of fluorosis in areas where groundwater is the major source of drinking water, and lake fish is a regular component of the diet. This paper presents a synthesis of the data so far obtained on the sources and distribution of fluoride in the hydrological system of Kenya, examines the extent of fluorine toxicity and puts forward recommendations to combat or minimise the problem.

  18. Fluoride Concentration of Drinking-Water of Qom, Iran

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Yari

    2016-03-01

    Full Text Available Background and Purpose: Fluoride is a natural element essential for human nutrition due to its benefits for dental enamel. It is well-documented that standard amounts of fluoride in drinkingwater can decrease the rate of dental caries. This study was conducted with the aim of measuring fluoride concentration of drinking-water supplies and urban distribution system in Qom, Iran. Materials and Methods: Results were subsequently compared against national and international standards. All sources of drinking-water of rural and urban areas were examined. To measure fluoride, the standard SPADNS method and a DR/4000s spectrophotometer were used. Results: Results showed that the mean of fluoride concentration in rural areas, mainly supplied with groundwater sources, was 0.41 mg/L, that of the urban distribution system 0.82 mg/L, that of Ali-Abad station 0.11 mg/L, and that of the private water desalination system 0.24 mg/L. Due to the hot climate of Qom, fluoride concentration means of all sources were lower than the permissible standards set by Iranian Standards and the WHO guidelines (except those of some of the groundwater sources and urban distribution systems. Conclusion: It seems that in most of the drinking-water sources the average fluoride concentration is not enough to prevent dental caries or strengthen dental enamel. It is concluded that Qom’s drinkingwater would require at least 0.4 mg/L to reach the minimum desirable standard.

  19. Lithological Influences on Occurrence of High-Fluoride Waters in The Central Kenya Rift

    Science.gov (United States)

    Olaka, L. A.; Musolff, A.; Mulch, A.; Olago, D.; Odada, E. O.

    2013-12-01

    Within the East African rift, groundwater recharge results from the complex interplay of geology, land cover, geomorphology, climate and on going volcano-tectonic processes across a broad range of spatial and temporal scales. The interrelationships between these factors create complex patterns of water availability, reliability and quality. The hydrochemical evolution of the waters is further complex due to the different climatic regimes and geothermal processes going on in this area. High fluoridic waters within the rift have been reported by few studies, while dental fluorosis is high among the inhabitants of the rift. The natural sources of fluoride in waters can be from weathering of fluorine bearing minerals in rocks, volcanic or fumarolic activities. Fluoride concentration in water depends on a number of factors including pH, temperature, time of water-rock formation contact and geochemical processes. Knowledge of the sources and dispersion of fluoride in both surface and groundwaters within the central Kenya rift and seasonal variations between wet and dry seasons is still poor. The Central Kenya rift is marked by active tectonics, volcanic activity and fumarolic activity, the rocks are majorly volcanics: rhyolites, tuffs, basalts, phonolites, ashes and agglomerates some are highly fractured. Major NW-SE faults bound the rift escarpment while the rift floor is marked by N-S striking faults We combine petrographic, hydrochemistry and structural information to determine the sources and enrichment pathways of high fluoridic waters within the Naivasha catchment. A total of 120 water samples for both the dry season (January-February2012) and after wet season (June-July 2013) from springs, rivers, lakes, hand dug wells, fumaroles and boreholes within the Naivasha catchment are collected and analysed for fluoride, physicochemical parameters and stable isotopes (δ2 H, δ18 O) in order to determine the origin and evolution of the waters. Additionally, 30 soil and

  20. Risk assessment of fluoride exposure in drinking water of Tunisia.

    Science.gov (United States)

    Guissouma, Wiem; Hakami, Othman; Al-Rajab, Abdul Jabbar; Tarhouni, Jamila

    2017-06-01

    The presence of fluoride in drinking water is known to reduce dental cavities among consumers, but an excessive intake of this anion might leads to dental and skeletal fluorosis. This study reports a complete survey of the fluoridated tap water taken from 100 water consumption points in Tunisia. The fluoride concentrations in tap water were between 0 and 2.4 mg L -1 . Risk assessment of Fluoride exposure was assessed depending on the age of consumers using a four-step method: hazard identification, toxicity reference values selection (TRVs), daily exposure assessment, and risk characterization. Our findings suggest that approximately 75% of the Tunisian population is at risk for dental decay, 25% have a potential dental fluorosis risk, and 20% might have a skeletal fluorosis risk according to the limits of fluoride in drinking water recommended by WHO. More investigations are recommended to assess the exposure risk of fluoride in other sources of drinking water such as bottled water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. SITUATION OF FLUORIDES RATE IN WATERS AND MAJOR ...

    African Journals Online (AJOL)

    31 déc. 2010 ... by fluoride ions in the waters of the region (Fluorosis Dental and skeletal). This study proposes, the estimated daily intake of fluoride from its water .... Le fluor est dosé par la méthode potentiométrique (NF T 90-004) grâce à une électrode spécifique aux ions fluorures. La mesure du potentiel a été effectuée ...

  2. Correlation among fluoride and metals in irrigation water and soils of ...

    African Journals Online (AJOL)

    Correlation among fluoride and metals in irrigation water and soils of Ethiopian Rift Valley. ... The fluoride concentrations in water samples were found in the range of 0.14-8.0 mg/L which is below the WHO limit of fluoride concentration for irrigation (less than 10 mg/L). ... KEY WORDS: Fluoride, Metals, Water, Soil, Ethiopia.

  3. Monitoring of fluoride in water samples using a smartphone

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Saurabh [Akvo Foundation (Netherlands); Krishnan, Sunderrajan [INREM Foundation (India); Rajkumar, Samuel; Halery, Nischal; Balkunde, Pradeep [Akvo Foundation (Netherlands)

    2016-05-01

    In several parts of India, groundwater is the only reliable, year round source for drinking water. Prevention of fluorosis, a chronic disease resulting from excess intake of fluoride, requires the screening of all groundwater sources for fluoride in endemic areas. In this paper, the authors present a field deployable colorimetric analyzer based on an inexpensive smartphone embedded with digital camera for taking photograph of the colored solution as well as an easy-fit, and compact sample chamber (Akvo Caddisfly). Phones marketed by different smartphone makers were used. Commercially available zirconium xylenol orange reagent was used for determining fluoride concentration. A software program was developed to use with the phone for recording and analyzing the RGB color of the picture. Linear range for fluoride estimation was 0–2 mg l{sup −1}. Around 200 samples, which consisted of laboratory prepared as well as field samples collected from different locations in Karnataka, India, were tested with Akvo Caddisfly. The results showed a significant positive correlation between Ion Selective Electrode (ISE) method and Akvo Caddisfly (Phones A, B and C), with correlation coefficient ranging between 0.9952 and 1.000. In addition, there was no significant difference in the mean fluoride content values between ISE and Phone B and C except for Phone A. Thus the smartphone method is economical and suited for groundwater fluoride analysis in the field. - Highlights: • Fluoride is an inorganic pollutant in ground water, affecting human health. • A colorimetric method for measurement of fluoride in drinking water with smartphone • Measurement is by mixing water with zirconyl xylenol orange complex reagent. • Results are comparable with laboratory-based ion selective fluoride electrode method.

  4. Monitoring of fluoride in water samples using a smartphone

    International Nuclear Information System (INIS)

    Levin, Saurabh; Krishnan, Sunderrajan; Rajkumar, Samuel; Halery, Nischal; Balkunde, Pradeep

    2016-01-01

    In several parts of India, groundwater is the only reliable, year round source for drinking water. Prevention of fluorosis, a chronic disease resulting from excess intake of fluoride, requires the screening of all groundwater sources for fluoride in endemic areas. In this paper, the authors present a field deployable colorimetric analyzer based on an inexpensive smartphone embedded with digital camera for taking photograph of the colored solution as well as an easy-fit, and compact sample chamber (Akvo Caddisfly). Phones marketed by different smartphone makers were used. Commercially available zirconium xylenol orange reagent was used for determining fluoride concentration. A software program was developed to use with the phone for recording and analyzing the RGB color of the picture. Linear range for fluoride estimation was 0–2 mg l"−"1. Around 200 samples, which consisted of laboratory prepared as well as field samples collected from different locations in Karnataka, India, were tested with Akvo Caddisfly. The results showed a significant positive correlation between Ion Selective Electrode (ISE) method and Akvo Caddisfly (Phones A, B and C), with correlation coefficient ranging between 0.9952 and 1.000. In addition, there was no significant difference in the mean fluoride content values between ISE and Phone B and C except for Phone A. Thus the smartphone method is economical and suited for groundwater fluoride analysis in the field. - Highlights: • Fluoride is an inorganic pollutant in ground water, affecting human health. • A colorimetric method for measurement of fluoride in drinking water with smartphone • Measurement is by mixing water with zirconyl xylenol orange complex reagent. • Results are comparable with laboratory-based ion selective fluoride electrode method.

  5. A model to determine the economic viability of water fluoridation.

    Science.gov (United States)

    Kroon, Jeroen; van Wyk, Philippus Johannes

    2012-01-01

    In view of concerns expressed by South African local authorities the aim of this study was to develop a model to determine whether water fluoridation is economically viable to reduce dental caries in South Africa. Microsoft Excel software was used to develop a model to determine economic viability of water fluoridation for 17 water providers from all nine South African provinces. Input variables for this model relate to chemical cost, labor cost, maintenance cost of infrastructure, opportunity cost, and capital depreciation. The following output variables were calculated to evaluate the cost of water fluoridation: per capita cost per year, cost-effectiveness and cost-benefit. In this model it is assumed that the introduction of community water fluoridation can reduce caries prevalence by an additional 15 percent and that the savings in cost of treatment will be equal to the average fee for a two surface restoration. Water providers included in the study serve 53.5 percent of the total population of South Africa. For all providers combined chemical cost contributes 64.5 percent to the total cost, per capita cost per year was $0.36, cost-effectiveness was calculated as $11.41 and cost-benefit of the implementation of water fluoridation was 0.34. This model confirmed that water fluoridation is an economically viable option to prevent dental caries in South African communities, as well as conclusions over the last 10 years that water fluoridation leads to significant cost savings and remains a cost-effective measure for reducing dental caries, even when the caries-preventive effectiveness is modest. © 2012 American Association of Public Health Dentistry.

  6. Fluoride in drinking water and diet: the causative factor of chronic kidney diseases in the North Central Province of Sri Lanka.

    Science.gov (United States)

    Dharmaratne, Ranjith W

    2015-07-01

    A significant number of people in the North Central Province of Sri Lanka suffer from chronic kidney diseases (CKD), and the author revisits existing literature related to CKD to find its causative factor. There is a direct connection between high fluoride levels in drinking water and kidney disease, and there are unhealthy levels of fluoride in the groundwater in Sri Lanka's CKD-affected areas. Based on the following observations, the author believes with confidence that excess fluoride in drinking water and in the locally grown food in the affected areas are the culprits of CKD in Sri Lanka. Fluoride excretion rate is considerably lower in children than adults, leading to renal damage of children living in areas with high fluoride. Adults who had renal damage due to fluoride in childhood are vulnerable to CKD with continued consumption of water from the same source. Patients with chronic renal insufficiency are at an increased risk of chronic fluoride toxicity. High content of fluoride in groundwater paves the way to excess fluoride in local food crops, consequently adding more fluoride to the systems of the consumers. People who work outdoors for prolonged periods consume excess water and tea, and are subjected to additional doses of fluoride in their system. In the mid-1980s, the increase in water table levels of the affected areas due to new irrigation projects paved the way to adding more fluorides to their system through drinking water and locally grown foods.

  7. [Influence of water fluoride exposure on sex hormone binding globulin and testosterone in adult male].

    Science.gov (United States)

    Zhou, Tong; Yang, Rupu; Li, Shihong; Zheng, Guoqing; Xi, Yu; Cheng, Xuemin; Hou, Jiaxiang; Cui, Liuxin; Ba, Yue

    2013-03-01

    To explore the influence of water fluoride exposure on sex hormone binding globulin (SHBG) and testosterone in adult male. Cross-sectional study was conducted in three villages of Tongxu county including high fluoride group (HFG), defluoridation project group (DFPG) and control group (CG) based on the fluoride concentration in drinking water. Adult male who were born and raised in the village and aged 18 - 50 years old were recruited using cluster sampling. Fasting blood and morning urine samples were collected. The fluoride levels in drinking water and urine were detected by fluoride-ion selective electrode method. Serum SHBG level was determined using enzyme-linked immunosorbent assay (ELISA). The chemical luminescence immune analysis method was used to detect serum testosterone content. Serum SHBG level was 47.85 nmol/L in CG, 31.37 nmol/L in DFPG and 24.52 nmol/L in HFG respectively. There were significant difference among of three groups (P < 0.05). Serum testosterone level was 3.69 ng/ml in CG, 4.61 ng/ml in DFPG and 4.83 ng/ml in HFG respectively. Serum testosterone level in HFG was significantly higher than that in CG (P < 0.05). Serum SHBG level in HFG has positive correlation with serum testosterone (r = 0.230, P = 0.049), which has not been observed in DFPG and CG. Long-time fluorine exposure may affect serum SHBG and testosterone level in adult male.

  8. Data on fluoride concentration levels in semi-arid region of Medak, Telangana, South India

    Directory of Open Access Journals (Sweden)

    Adimalla Narsimha

    2018-02-01

    Full Text Available According to the World Health Organization recommendation, the optimal fluoride concentration levels in drinking water have to be in the range of 0.5 and 1.5 mg/L since this permissible range is essential for normal mineralization of bones and teeth as well as for dental enamel formation in human's body Bell and budwig, 1970; Adimalla and Venkatayogi, 2017; Narsimha and Sudarshan, 2013, 2016; 2017 [1,2,4,5,6]. If continues intake of high fluoride (>1.5 water can severely cause dental and skeletal fluorosis. The investigated area people majorly depend on groundwater for drinking purposes and fluoride concentration ranged from 0.2 to 7.4 mg/L with mean concentration of 2.7 mg/L and data was compared with WHO guidelines for drinking purposes. Overall, data reveals that the 57% of groundwater samples data was not safe for drinking purposes. Therefore, distribution of fluoride in the groundwater of Medak region in Telangana was suggested to intake drinking water, which are below level of fluoride concentration in the groundwater and take care about health implications.

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

    Science.gov (United States)

    Yousefi, Mahmood; Yaseri, Mehdi; Nabizadeh, Ramin; Hooshmand, Elham; Jalilzadeh, Mohsen; Mahvi, Amir Hossein; Mohammadi, Ali Akbar

    2018-03-14

    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 10.30 mg/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 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.

  10. Fluoride content in water in and around heavy water plant Manuguru colony

    International Nuclear Information System (INIS)

    Mohapatra, C.; Dubey, S.K.; Reddy, A.R.; Ravi Kumar, T.S.P.; Selvaraj, S.

    1996-01-01

    Fluoride concentration in water used for human consumption has significant importance with respect to its toxic effects. Hence there was a need for analysing fluoride concentration in drinking water primarily used at Heavy water Plant, Manuguru (HWP (M)) colony and its nearby villages. We found that at HWP (M) colony there is not much variation in the fluoride concentration. However, nearby villages are having wide variation from 0.79 to 5.1 ppm. (author). 5 refs., 1 tab

  11. Effect of fluoride in drinking water on children′s intelligence in high and low fluoride areas of Delhi

    Directory of Open Access Journals (Sweden)

    Hansa Kundu

    2015-01-01

    Full Text Available Introduction: Fluoride is one of the indispensable elements for the living being. However, the intake of F above the threshold level can affect the central nervous system even before causing dental or skeletal fluorosis. Aim: The aim was to assess the effect of fluoride in drinking water on the intelligence quotient (IQ of 8-12 years old school going children residing in high and low Fluoride (F areas of Delhi. Materials and Methods: A total of 200 school children were selected, 100 from low F area and 100 from high F area. The IQ of the children was assessed using Ravens Standardized Progressive Matrices Test. Information for each child′s sociodemographic data, mother′s diet during pregnancy, duration of residency in the village, source of drinking water, and duration of drinking water from the source was entered on a specially designed proforma from mothers of children. Height and weight were also recorded for each child to assess the nutritional status. Independent t-test and Chi-square test was used to compare mean IQ scores in high and low fluoridated areas. Pearson′s correlation and multivariate linear regression were used to appraise the issue of all the study variables on IQ. Results: Comparison of mean IQ of children in both high (76.20 ± 19.10 and low F (85.80 ± 18.85 areas showed a significant difference (P = 0.013. Multiple regression analysis between child IQ and all other independent variables revealed that mother′s diet during pregnancy (P = 0.001 along with F in drinking water (P = 0.017 were the independent variables with the greatest explanatory power for child IQ variance (r2 = 0.417 without interaction with other variables. Conclusion: Fluoride in the drinking water was significantly related with the IQ of children. Along with fluoride, mother′s diet during pregnancy was also found to be significantly related with IQ of children. Researches in the same field are further advocated with large sample size and over a

  12. Analysis of Ground Water Fluoride Content and its Association with Prevalence of Fluorosis in Zarand/Kerman: (Using GIS).

    Science.gov (United States)

    T, Malek Mohammadi; R, Derakhshani; M, Tavallaie; M, Raoof; N, Hasheminejad; Aa, Haghdoost

    2017-06-01

    The concentration of fluoride in water is usually higher in areas around the coal mines. Zarand region in the south-east of Iran is known for its coal mines. Some studies have shown the high prevalence of fluorosis and some studies reported high levels of fluoride in the region. This study aimed to use Geographic Information System (GIS) to assess the relationship between water fluoride content and the prevalence of fluorosis and its spatial distribution in Zarand region. This cross-sectional study aimed to recruit 550 people aged 7-40 years in Zarand. Dental examination for fluorosis was conducted based on the Dean's Index. The level of fluoride in the water was determined in samples of water taken from 35 areas. Information on fluorosis and fluoride content was mapped on GIS. Most participants lived in rural areas (87.25%) and had an educational status of high school level (66%). About 23% of the examined people had normal teeth, 10% had severe and 67% had mild to moderate fluorosis. Distribution of severe fluorosis was higher in areas with higher levels of fluoride in the water according to GIS map. GIS map clearly showed a positive relationship between the prevalence and severity of fluorosis with the level of fluoride in water in Zarand. The GIS analysis may be useful in the analysis of other oral conditions.

  13. Removal of fluoride from water using aluminium containing compounds

    Institute of Scientific and Technical Information of China (English)

    M. Karthikeyan; K. P. Elango

    2009-01-01

    Batch adsorption studies were undertaken to assess the suitability of aluminium titanate (AT) and bismuth aluminate (BA) to remove fluoride ions from water.The effect of pH,dose of adsorbent,contact time,initial concentration,co-ions and temperature on fluoride removal efficiency were studied.The amounts of fluoride ions adsorbed,at 30℃ from 4 mg/L of fluoride ion solution,by AT and BA are 0.85 and 1.55 mg/g,respectively.The experimental data fitted well to the Freundlich and Langmuir isotherms.Thermodynamic parameters such as △H~0,△S~0 and △G~0 indicated that the removal of fluoride ions by AT is exothermic and non-spontaneous while that by BA is endothermic and spontaneous.Furrier transform infrared (FT-IR) analysis and X-ray diffraction (XRD) patterns of the adsorbent before and after adsorption indicated that fluoride ions are chemisorbed by these adsorbents.

  14. Impact of Drinking Water Fluoride on Human Thyroid Hormones: A Case- Control Study.

    Science.gov (United States)

    Kheradpisheh, Zohreh; Mirzaei, Masoud; Mahvi, Amir Hossein; Mokhtari, Mehdi; Azizi, Reyhane; Fallahzadeh, Hossein; Ehrampoush, Mohammad Hassan

    2018-02-08

    The elevated fluoride from drinking water impacts on T 3 , T 4 and TSH hormones. The aim was study impacts of drinking water fluoride on T 3 , T 4 and TSH hormones inYGA (Yazd Greater Area). In this case- control study 198 cases and 213 controls were selected. Fluoride was determined by the SPADNS Colorimetric Method. T 3 , T 4 and TSH hormones tested in the Yazd central laboratory by RIA (Radio Immuno Assay) method. The average amount of TSH and T 3 hormones based on the levels of fluoride in two concentration levels 0-0.29 and 0.3-0.5 (mg/L) was statistically significant (P = 0.001 for controls and P = 0.001 for cases). In multivariate regression logistic analysis, independent variable associated with Hypothyroidism were: gender (odds ratio: 2.5, CI 95%: 1.6-3.9), family history of thyroid disease (odds ratio: 2.7, CI 95%: 1.6-4.6), exercise (odds ratio: 5.34, CI 95%: 3.2-9), Diabetes (odds ratio: 3.7, CI 95%: 1.7-8), Hypertension (odds ratio: 3.2, CI 95%: 1.3-8.2), water consumption (odds ratio: 4, CI 95%: 1.2-14). It was found that fluoride has impacts on TSH, T 3 hormones even in the standard concentration of less than 0.5 mg/L. Application of standard household water purification devices was recommended for hypothyroidism.

  15. THE USE OF FLUORIDE CONTAINING MINERAL WATER IN WORT PRODUCTION

    Directory of Open Access Journals (Sweden)

    Gunka Yonkova

    2011-12-01

    Full Text Available The present work aims to study the quality of wort produced using fluoride containing mineral water. The results show that the mineral water has a negative impact on the enzymatic destruction of starch, proteins, color intensity and pH of the wort. The changes of pH during mashing process using tap and mineral water was studied. The lower acidity of wort obtained using mineral water didn’t change during the brewing process. The fluoride content of beer is lower than 5 mg.L-1 when wort is produced using mineral and tap water in 1:1 ratio and citric acid for pH correction. At the same time, the final degree of fermentation, α-amine nitrogen content and the intensity of color of produced wort are close to the control sample. The changes in fluoride ion concentration are monitored using ion-selective potentiometry. The fluoride content is decreased from 5.7 to 4.75 mg.L-1, the most intense change is observed during the mashing process.

  16. Fluoride removal from rural spring water using wood ash

    CSIR Research Space (South Africa)

    Makhado, R

    2006-05-01

    Full Text Available This paper presents an overview of a report on an investigation on the use of cheap wood ash as an effective means of removing excess fluoride from drinking water used by an impoverished rural community of the Didi village in Limpopo province....

  17. Drinking water fluoride and blood pressure? An environmental study.

    Science.gov (United States)

    Amini, Hassan; Taghavi Shahri, Seyed Mahmood; Amini, Mohamad; Ramezani Mehrian, Majid; Mokhayeri, Yaser; Yunesian, Masud

    2011-12-01

    The relationship between intakes of fluoride (F) from drinking water and blood pressure has not yet been reported. We examined the relationship of F in ground water resources (GWRs) of Iran with the blood pressure of Iranian population in an ecologic study. The mean F data of the GWRs (as a surrogate for F levels in drinking water) were derived from a previously conducted study. The hypertension prevalence and the mean of systolic and diastolic blood pressures (SBP & DBP) of Iranian population by different provinces and genders were also derived from the provincial report of non-communicable disease risk factor surveillance of Iran. Statistically significant positive correlations were found between the mean concentrations of F in the GWRs and the hypertension prevalence of males (r = 0.48, p = 0.007), females (r = 0.36, p = 0.048), and overall (r = 0.495, p = 0.005). Also, statistically significant positive correlations between the mean concentrations of F in the GWRs and the mean SBP of males (r = 0.431, p = 0.018), and a borderline correlation with females (r = 0.352, p = 0.057) were found. In conclusion, we found the increase of hypertension prevalence and the SBP mean with the increase of F level in the GWRs of Iranian population.

  18. Factors affecting fluoride and natural organic matter (NOM) removal from natural waters in Tanzania by nanofiltration/reverse osmosis.

    Science.gov (United States)

    Shen, Junjie; Schäfer, Andrea I

    2015-09-15

    This study examined the feasibility of nanofiltration (NF) and reverse osmosis (RO) in treating challenging natural tropical waters containing high fluoride and natural organic matter (NOM). A total of 166 water samples were collected from 120 sources within northern Tanzania over a period of 16 months. Chemical analysis showed that 81% of the samples have fluoride levels exceeding the WHO drinking guideline of 1.5mg/L. The highest fluoride levels were detected in waters characterized by high ionic strength, high inorganic carbon and on some occasions high total organic carbon (TOC) concentrations. Bench-scale experiments with 22 representative waters (selected based on fluoride concentration, salinity, origin and in some instances organic matter) and 6 NF/RO membranes revealed that ionic strength and recovery affected fluoride retention and permeate flux. This is predominantly due to osmotic pressure and hence the variation of diffusion/convection contributes to fluoride transport. Different membranes had distinct fluoride removal capacities, showing different raw water concentration treatability limits regarding the WHO guideline compliance. BW30, BW30-LE and NF90 membranes had a feed concentration limit of 30-40 mg/L at 50% recovery. NOM retention was independent of water matrices but is governed predominantly by size exclusion. NOM was observed to have a positive impact on fluoride removal. Several mechanisms could contribute but further studies are required before a conclusion could be drawn. In summary, NF/RO membranes were proved to remove both fluoride and NOM reliably even from the most challenging Tanzanian waters, increasing the available drinking water sources. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Estimation of fluoride levels in various commercially available carbonated soft drinks in Chandigarh city, India

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    Mohit Bansal

    2015-01-01

    Full Text Available Introduction: Fluoride has a preventive action on dental caries. However, Excessive ingestion of fluoride from different sources can lead to the development of dental fluorosis. Aim: To estimate fluoride levels in various commercially available carbonated soft drinks available in Chandigarh city. Materials and Methods: Twelve different brands of commercially available soft drinks were purchased from three different places and divided into three groups. Fluoride levels were estimated using fluoride test strips Quantofix 37211 Fluka; Sigma-Aldrich. Results: Fluoride levels ranged from 0.12 to 0.42 mg/dl F with the maximum level in Thumbs up and least in Diet Pepsi. Conclusion: The levels of fluoride varied in various carbonated soft drinks analyzed. This could contribute significantly to the total fluoride intake from all sources and thus be an important risk factor for the development of dental fluorosis.

  20. Environmental evaluation of fluoride in drinking water at "Los Altos de Jalisco," in the central Mexico region.

    Science.gov (United States)

    Hurtado, Roberto; Gardea-Torresdey, Jorge

    Naturally occurring fluoride has been detected and quantified in drinking water in several cities of the "Los Altos de Jalisco" (LAJ) region. LAJ is located in the northeastern part of the state of Jalisco-Mexico, covering an area of 16,410 km2 with a population of 696,318 in 20 municipalities. Drinking water comes mainly from groundwater aquifers, located in the Trans-Mexican Volcanic Belt, which is a volcanic region characterized by hydrothermal activity. Results indicated that water supply from 42% of the municipalities had a fluoride concentration over the Mexican standards of 1.5 mg/L. It is important to notice that there are three cities, Lagos de Moreno (1.66-5.88 mg/L F(-)), Teocaltiche (3.82-18.58 mg/L F(-)), and Encarnación de Díaz (2.58-4.40 mg/L F(-)) where all water samples resulted in fluoride concentration over the maximum contaminant level. The total population from these three cities is over 122,000 inhabitants. Another important city with high levels of fluoride in the water supply was Tepatitlán de Morelos (2 wells with 6.54 and 13.47 mg/L F(-)). In addition to water supply, 30 samples of brand-name bottled water were tested. Surprisingly, 8 samples (27%) demonstrated fluoride level over the standards, mainly Agua de Lagos with 5.27 mg/L. Fluoridated table salt (200-300 mg/kg F(-)) is another important source of fluoride. A large number of people living in the region, mainly school children, might be under adverse health risk because they are consuming contaminated drinking water. It is well known that long-term exposure to water with high levels of fluoride produces severe health problems.

  1. Drinking water fluoridation: bone mineral density and hip fracture incidence.

    Science.gov (United States)

    Lehmann, R; Wapniarz, M; Hofmann, B; Pieper, B; Haubitz, I; Allolio, B

    1998-03-01

    The role of drinking water fluoride content for prevention of osteoporosis remains controversial. Therefore, we analyzed the influence of drinking water fluoridation on the incidence of osteoporotic hip fractures and bone mineral density (BMD) in two different communities in eastern Germany: in Chemnitz, drinking water was fluoridated (1 mg/L) over a period of 30 years; in Halle, the water was not fluoridated. BMD was measured in healthy hospital employees aged 20-60 years (Halle: 214 women, 98 men; Chemnitz: 201 women, 43 men, respectively) using dual-energy X-ray absorptiometry. Hip fractures in patients > or = 35 years admitted to the local hospitals in the years 1987-1989 were collected from the clinic registers. There was no difference in age, anthropometric, hormonal, or lifestyle variables between the two groups. Mean fluoride exposure in Chemnitz was 25.2 +/- 7.3 years. No correlation was found between fluoride exposure and age-adjusted BMD. We found no significant difference in spinal or femoral BMD between subjects living in Halle and Chemnitz [lumbar spine: 0.997 +/- 0.129 (g/cm2) vs. 1.045 + 0.171 (g/cm2), p = 0.08, for men; 1.055 +/- 0.112 (g/cm2) vs. 1.046 +/- 0.117 (g/cm2), p = 0.47, for women]. The fracture incidence showed an exponential increase with aging in men and women with an incidence about 3.5 times higher for women. In Chemnitz, we calculated an age-adjusted annual incidence of 142.2 per 100,000 for women and 72.5 per 100,000 for men, respectively. In Halle, the incidences were 178.5 per 100,000 for women and 89.2 per 100,000 for men. There was a lower hip fracture incidence after the age of 85 in women in Chemnitz (1391 per 100,000 in Chemnitz vs. 1957 per 100,000) in Halle, p = 0.006). Using the age-adjusted incidences, significantly fewer hip fractures occurred in Chemnitz in both men and women. In conclusion, our study suggests that optimal drinking water fluoridation (1 mg/L), which is advocated for prevention of dental caries, does

  2. Correlation among fluoride and metals in irrigation water and soils of Ethiopian Rift Valley

    Directory of Open Access Journals (Sweden)

    Elias Gizaw

    2014-05-01

    Full Text Available The levels of fluoride and selected metals in Ethiopian Rift Valley soils and irrigation water in the nearby sources were determined by fluoride ion selective electrode and flame atomic absorption spectrophotometer, respectively. The pH, conductivity, salinity and total dissolved solids in water and soil samples were also determined. Accuracy of the optimized procedure was evaluated using standard addition (spiking method and an acceptable percentage recovery was obtained. The fluoride concentrations in water samples were found in the range of 0.14-8.0 mg/L which is below the WHO limit of fluoride concentration for irrigation (less than 10 mg/L. The water soluble and total fluorides in soil were 2.3-16 µg/g and 209-1210 µg/g, respectively and are within the ranges recommended by FAO and WHO. The range of metal concentration in soil samples (µg/g dry weight basis and in water samples (mg/L respectively were: Na (684-6703, 8.6-67, Mg (1608-11229, 23-67, K (1776-4394, 1.1-20, Ca (7547-22998, 17-267, Cr (9.8-79, 0.07-0.17, Mn (143-700, 0.05-37, Co (50-112, 0.35-1.5, Ni (446-1288, 0.27-41, Fe (12180-32681, 6.0-48, Cu (8.9-45, 0.09-0.25 and Zn (31-89, 0.14-0.56. Fluoride was found to have significant correlation with major trace metals (Fe, Cu and Cr, but the correlation with other trace metals was not significant. DOI: http://dx.doi.org/10.4314/bcse.v28i2.7

  3. Health risk assessment to fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran.

    Science.gov (United States)

    Yousefi, Mahmood; Ghoochani, Mahboobeh; Hossein Mahvi, Amir

    2018-02-01

    This study analyzes the concentrations and health risks of fluoride in 112 drinking water samples collected from 28 villages of the Poldasht city, West Azerbaijan province in Iran. Results indicated that fluoride content in drinking water ranged from0.27 to 10.3mgL -1 (average 1.70mgL -1 ). The 57% of samples analyzed exceeded the limit set for fluoride in drinking water. Based on findings from health risk assessment this study, the highest fluoride exposure for different regions of Poldasht city was observed in young consumers, children and teenager's groups. Also, most of the rural residents suffered from fluoride contaminated drinking water. The calculated HQ value was > 1 for all groups of residents in Agh otlogh and Sari soo areas. Therefore, it is imperative to take measures to reduce fluoride concentration in drinking water and control of fluorosis. Action should be implemented to enhance monitoring of fluoride levels to avoid the potential risk to the population. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Caries status in 16 year-olds with varying exposure to water fluoridation in Ireland.

    LENUS (Irish Health Repository)

    Mullen, J

    2012-12-01

    Most of the Republic of Ireland\\'s public water supplies have been fluoridated since the mid-1960s while Northern Ireland has never been fluoridated, apart from some small short-lived schemes in east Ulster.

  5. Relationship between water, urine and serum fluoride and fluorosis in school children of Jhajjar District, Haryana, India

    Science.gov (United States)

    Kumar, Sunil; Lata, Suman; Yadav, Jyoti; Yadav, J. P.

    2017-10-01

    The present study was undertaken to determine the relationship between fluoride in water, urine and serum and dental fluorosis. The fluoride level in water and urine were measured spectrophotometrically by using acid zirconyl and SPADNS reagents, while the fluoride level in serum was determined by ion selective electrode meter. Dental fluorosis survey was conducted with the help of Performa prescribed by Rajiv Gandhi Drinking Water Mission and the use of Tooth Surface Index for Fluorosis. Mean fluoride values in water samples of Jhajjar City and Dadanpur and Dariyapur villages of Jhajjar District were measured to be 2.17 (range from 1.92 to 2.60 mg/L), 2.81 (range from 2.53 to 3.14 mg/L) and 2.22 mg/L (range from 1.63 to 3.33 mg/L), respectively. The mean fluoride values in the urine samples of children were found to be 1.51 (range from 0.05 to 2.64 mg/L), 1.71 (range from 0.69 to 2.80 mg/L) and 1.45 mg/L (range from 0.31 to 2.50 mg/L) at Jhajjar City and Dadanpur and Dariyapur sites, respectively. Serum fluoride was detected in the blood samples of children, who have high urinary fluoride at these three sites. The mean serum fluoride level was reported to be 0.15, 0.34 and 0.17 mg/L, respectively. A total of 842 children were also analyzed for dental fluorosis. The mean values of fluorosis-affected children in Jhajjar, Dadanpur and Dariyapur were 51.90, 94.63 and 36.84 %, respectively. A significantly positive correlation between water, urine, serum fluoride concentration and fluorosis was seen.

  6. Assessment of Fluoride Level in Groundwater and Prevalence of Dental Fluorosis in Didwana Block of Nagaur District, Central Rajasthan, India

    Directory of Open Access Journals (Sweden)

    M Arif

    2013-10-01

    Full Text Available Background: In India, for the high concentration of fluoride in groundwater, people are at risk of dental fluorosis. The problem is common in various states of India. The condition in Rajasthan is worse where all districts have such a problem. Objective: To study the fluoride concentration in groundwater and prevalence of dental fluorosis in Didwana block of Nagaur district, Central Rajasthan, India. Methods: The fluoride concentration in water of 54 villages was measured electrochemically, using fluoride ion selective electrode. Dental fluorosis was assessed in 1136 people residing in study area by Dean's classification for dental fluorosis. Results: The fluoride concentration in groundwater in studied sites ranged from 0.5 to 8.5 mg/L. The concentration of fluoride was more than the maximum permissible limit set by WHO and Bureau of Indian Standards (1 mg/L in 48 groundwater sources. Of 1136 people studied, 788 (69.4%; 95% CI: 66.7%–72.1% had dental fluorosis—252 had mild and 74 had severe dental fluorosis. Conclusion: High level of fluoride in drinking water of Didwana block of Nagaur district, Central Rajasthan, India, causes dental fluorosis in most people in the region and is an important health problem that needs prompt attention.

  7. Geochemistry of ground water and the source of contamination of fluoride in the drinking water of the Naranji area, district Swabi, NWFP, Pakistan

    International Nuclear Information System (INIS)

    Danishwar, S.; Shah, M.T.

    1997-01-01

    Inhabitants of the Naranji village are known for their yellow coloration of teeth throughout the Mardan division. A general survey of the area shows prevalence of dental and skeletal fluorosis of varied degree in the village. A detailed geochemical analysis of ground water of the village indicates fluoride concentration of 13.5 mg l-1 which is about 9 times more than WHO's maximum contaminant level. The source of high fluoride in drinking water is considered to be the alkaline rocks of Koga Complex. Tube well water should be supplied to the area in order to avoid the fluoride contamination. (author)

  8. Probabilistic risk assessment of Chinese residents' exposure to fluoride in improved drinking water in endemic fluorosis areas.

    Science.gov (United States)

    Zhang, Li E; Huang, Daizheng; Yang, Jie; Wei, Xiao; Qin, Jian; Ou, Songfeng; Zhang, Zhiyong; Zou, Yunfeng

    2017-03-01

    Studies have yet to evaluate the effects of water improvement on fluoride concentrations in drinking water and the corresponding health risks to Chinese residents in endemic fluorosis areas (EFAs) at a national level. This paper summarized available data in the published literature (2008-2016) on water fluoride from the EFAs in China before and after water quality was improved. Based on these obtained data, health risk assessment of Chinese residents' exposure to fluoride in improved drinking water was performed by means of a probabilistic approach. The uncertainties in the risk estimates were quantified using Monte Carlo simulation and sensitivity analysis. Our results showed that in general, the average fluoride levels (0.10-2.24 mg/L) in the improved drinking water in the EFAs of China were lower than the pre-intervention levels (0.30-15.24 mg/L). The highest fluoride levels were detected in North and Southwest China. The mean non-carcinogenic risks associated with consumption of the improved drinking water for Chinese residents were mostly accepted (hazard quotient risk of children in most of the EFAs at the 95th percentile exceeded the safe level of 1, indicating the potential non-cancer-causing health effects on this fluoride-exposed population. Sensitivity analyses indicated that fluoride concentration in drinking water, ingestion rate of water, and the exposure time in the shower were the most relevant variables in the model, therefore, efforts should focus mainly on the definition of their probability distributions for a more accurate risk assessment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Drinking water pollution with respective of fluoride in the semi-arid region of Basara, Nirmal district, Telangana State, India.

    Science.gov (United States)

    Narsimha, Adimalla; Sudarshan, Venkatayogi

    2018-02-01

    Fluoride is an essential microelement for human health. Statistically, smaller quantities (water are usually considered to have a beneficial effect on the rate of occurrence of dental caries, particularly among children, but excessive continuous exposure (>1.5 mg/L) to fluoride can give rise to a number of adverse effects, including dental fluorosis, skeletal fluorosis, increased rate of bone fractures, decreased birth rates, increased rate of urolithiasis (kidney stones), impaired thyroid function, and impaired development of intelligence in children [1], [2], [3], [4], [5]. The data suggested that the north-eastern part of the Basara region having high fluoride concentration, which is unsuitable for drinking purposes. Hence, this unsuitable drinking water cause fluorosis in this Basara and surrounding villages, and especially based on the findings suggests, where the fluoride levels are in below maximum permissible limits that water ingests to the people to avoid further fluorosis.

  10. Biosorption of fluoride ion from water using the seeds of the ...

    African Journals Online (AJOL)

    Biosorption of fluoride ion from water using the seeds of the cabbage tree ( Moringa ... The maximum fluoride sorption capacity was found to be 1.32 mg.g-1 of dry weight ... Key words: Biosorption, chemisorption, desorption, fluoride, isotherm, ...

  11. The concentration data of fluoride and health risk assessment in drinking water in the Ardakan city of Yazd province, Iran.

    Science.gov (United States)

    Mirzabeygi Rad Fard, Majid; Yousefi, Mahmood; Soleimani, Hamed; Mohammadi, Ali Akbar; Mahvi, Amir Hossein; Abbasnia, Abbas

    2018-06-01

    According to the World Health Organization (WHO) reports, Iran is located in the global fluoride belts, so that is why carrying out extended research on this contaminant anion in water supplies must be considered. Due to the various industries in the Ardakan city, this region is severely suffering from fluoride contamination. This study was designed to investigate the fluoride concentration and its distribution pattern as well as related health risk assessment in groundwater resources of 28 villages of the Ardakan city in Yazd province using SPADNS method according to standard instructions. Our results show that, the average concentration of fluoride was 2.92 mg/l (range: 0.9-6 mg/l), also in half of the villages, the concentration range of this element was over than standard level (1.5 mg/l) given by WHO rules. In addition, risk assessment results showed that HQ value is higher than 1 in 46.4% of samples of groundwater resources in age groups of infants, children, teenagers and adults. Therefore, it is necessary to take measures to reduce fluoride concentration in drinking water in order to control resultant fluorosis. Actions should be implemented to enhance monitoring of fluoride levels to avoid the potential risk of high Fluoride concentration.

  12. Quantification of trace level of fluoride content in uranium oxide produced by deconversion of HEX gas by ion chromatography

    International Nuclear Information System (INIS)

    Unnikrishnan, E.K.; Padmakumar, P.R.; Shanmugavelu, P.; Sudhakar, T.M.; Bhowmik, A.

    2015-01-01

    Fluoride content in nuclear fuel is detrimental due to its corrosion behavior with cladding material. It is essential to monitor and control the fluoride concentration in nuclear material at various processing stages. Deconversion of upgraded HEX gas is carried out to produce uranium oxide. The performance of the deconversion process of HEX gas is evaluated for which trace level of fluoride concentration accompanying uranium oxide is considered as a marker. An analytical method has been developed for testing the uranium oxide produced from deconversion process of HEX gas. The method involves sample pretreatment followed by analysis using ion chromatography. The test method was validated for its performance using in house synthetic uranyl fluoride (UO 2 F 2 ) standard solutions prepared with different level of fluoride content. The results are in agreement with the expected values with the recovery in the range of 80-95%. This method has been successfully implemented for routine analysis of samples at our lab. Since UO 2 F 2 reference material is not available to validate this method, in house UO 2 F 2 standards were prepared from U 3 O 8 prepared from nuclear grade uranyl nitrate solution. UO 2 F 2 standards were prepared by converting U 3 O 8 to UO 2 F 2 by the addition of HF followed by H 2 O 2 at 200°C on a hot plate. The entire yellow colored UO 2 F 2 was dissolved in nano pure water and recrystallised several times to ensure that all free HF is removed. The crystals dried in air oven at 120° for three hours. Samples containing 1000 mg kg -1 fluoride prepared from this UO 2 F 2 , and subsequently from this sample containing 5 mg kg -1 to 35 mg kg -1 fluoride samples were prepared and analysed against fluoride CRM and the fluoride concentration obtained was analysed

  13. Toxicity levels to humans during acute exposure to hydrogen fluoride

    International Nuclear Information System (INIS)

    Halton, D.M.; Dranitsaris, P.; Baynes, C.J.

    1984-11-01

    A literature review was conducted of the acute toxicity of hydrogen fluoride (HF) with emphasis on the effects of inhalation of gaseous HF. The data and findings of the relevant references were summarized under four categories: animal studies, controlled human studies, community exposure and industrial exposure. These were critically reviewed and then lethal concentration-time relationships were developed for humans, corresponding to LCsub(LO), LCsub(10) and LCsub(50) levels. The effects of age, health and other physiological variables on the sensitivity to HF were discussed, as well as antagonistic and synergistic effects with other substances

  14. The effects of fluoride concentration and the level of cariogenic challenge on caries development in desalivated rats.

    Science.gov (United States)

    Tabchoury, C M; Holt, T; Pearson, S K; Bowen, W H

    1998-12-01

    Dental caries is an infectious and transmissible disease that continues to affect the majority of people. The presence of carbohydrate, mainly sucrose in the diet, is an important factor in its occurrence. The amount of fluoride required for optimal protective effect where there is a high caries challenge is unclear. Differences in the intensity of cariogenic challenge, for whatever reason, may play a part in determining fluctuations in the effectiveness of fluoride. The purpose of this study was to evaluate the effect of different concentrations of fluoride on the development of caries and explore the cariostatic effect of fluoride under various levels of cariogenic challenge. The study comprises two experiments. In experiment I, 60 desalivated Sprague Dawley rats infected with Streptococcus sobrinus were offered the following to drink for 21 days: group (1), sterile distilled water (SDW); (2) 10 parts/10(6) F SDW; (3) 20 parts/10(6) F SDW; (4) 30 parts/10(6) F SDW; (5) 40 parts/10(6) F SDW. In experiment II, eight groups of 9 rats were placed in a König Höfer programmed feeder and were exposed to different levels of cariogenic challenge through varying frequency of eating and offered water containing 10 parts/10(6) F. In experiment I, exposure to 20, 30 and 40 parts/10(6) F reduced caries development significantly: fluoride, at 10 parts/10(6), reduced the severity of the carious lesions. In this model of severe cariogenic challenge, the results suggest that elevated concentrations of fluoride might be effective in patients at high caries risk. In experiment II, fluoride reduced the incidence and severity of smooth-surface caries in all groups. The protective effect of fluoride decreased as the number of exposures to sugar increased. It is concluded that the effectiveness of fluoride is influenced by the level of cariogenic challenge and that consideration should be given to adjusting the level of fluoride exposure based on perceived caries risk, and that there

  15. Drinking water pollution with respective of fluoride in the semi-arid region of Basara, Nirmal district, Telangana State, India

    Directory of Open Access Journals (Sweden)

    Adimalla Narsimha

    2018-02-01

    Full Text Available Fluoride is an essential microelement for human health. Statistically, smaller quantities (1.5 mg/L to fluoride can give rise to a number of adverse effects, including dental fluorosis, skeletal fluorosis, increased rate of bone fractures, decreased birth rates, increased rate of urolithiasis (kidney stones, impaired thyroid function, and impaired development of intelligence in children [1–5]. The data suggested that the north-eastern part of the Basara region having high fluoride concentration, which is unsuitable for drinking purposes. Hence, this unsuitable drinking water cause fluorosis in this Basara and surrounding villages, and especially based on the findings suggests, where the fluoride levels are in below maximum permissible limits that water ingests to the people to avoid further fluorosis.

  16. FLUORIDE REDUCTION FROM WATER BY PRECIPITATION WITH ...

    African Journals Online (AJOL)

    2013-12-31

    Dec 31, 2013 ... reduce it, we have chosen a sample with the highest content of ... from happening or reduce them, many techniques of defluoridation are used such as: ... 100 ml of Shuhada water was put in each cup of plastic then the pH ...

  17. Arsenic, Fluoride and Vanadium in surface water (Chasicó Lake, Argentina

    Directory of Open Access Journals (Sweden)

    Maria laura ePuntoriero

    2014-06-01

    Full Text Available Chasicó Lake is the main water body in the southwest of the Chaco-Pampean plain. It shows some differences from the typical Pampean shallow lakes, such as high salinity and high arsenic and fluoride levels. The aim of this paper is to analyze the trace elements [arsenic (As, fluoride (F- and vanadium (V] present in Chasicó Lake. Surface and groundwater were sampled in dry and wet periods, during 2010 and 2011. Fluoride was determined with a selective electrode. As and V were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES. Significant correlation in surface water was only found for As and F- (r=0.978, p<0.01. The As, F- and V concentration values were higher and more widely dispersed in surface water than in groundwater, as a consequence of evaporation. The fact that these elements do not correlate in surface water may also indicates that groundwater would not be the main source of origin of As, F- and V in surface water. The origin of these trace elements is from volcanic glass from Pampean loess. As, F- and V concentration were higher than in national and international guideline levels for the protection of aquatic biota. Hence, this issue is relevant since the silverside (Odontesthes bonariensis is the most important commercial species in Chasicó Lake. This fish is both consumed locally and exported to other South-American countries through commercial and sport fishing.

  18. Electrochemical behavior of molten fluoride-water system

    Energy Technology Data Exchange (ETDEWEB)

    Takenaka, Toshihide; Ito, Yasuhiko; Ishikawa, Takayasu; Oishi, Jun

    1984-11-01

    The cathodic behavior of a molten fluoride-water system was investigated by the potential sweep method. LiF-KF-NaF eutectic melt was used as an electrolyte and HF-H/sub 2/O gas mixture with Ar as a carrier was bubbled into it. Gold wire was used as a working electrode. The peak currents due to the reduction of HF and H/sub 2/O were clearly observed. The relations between peak currents and the square roots of the scanning rates were linear, strongly suggesting that the reduction reactions of the HF and H/sub 2/O dissolved in the melt were diffusion controlled. From the linearity of the relations between peak currents and partial pressures of HF and H/sub 2/O in the low partial pressure region, it was concluded that the concentrations of HF and H/sub 2/O in a fluoride melt are proportional to the partial pressure of each gas. The peak current due to the reduction of OH/sup -/ ion could not be observed, though a clear peak current was observed when OH/sup -/ ion was added to the melt and a cathodic scan was applied immediately. This indicates that OH/sup -/ ion is unstable in a fluoride melt under HF-H/sub 2/O atmosphere.

  19. Reduction in fluoride-induced genotoxicity in mouse bone marrow cells after substituting high fluoride-containing water with safe drinking water.

    Science.gov (United States)

    Podder, Santosh; Chattopadhyay, Ansuman; Bhattacharya, Shelley

    2011-10-01

    Treatment of mice with 15 mg l(-1) sodium fluoride (NaF) for 30 days increased the number of cell death, chromosomal aberrations (CAs) and 'cells with chromatid breaks' (aberrant cells) compared with control. The present study was intended to determine whether the fluoride (F)-induced genotoxicity could be reduced by substituting high F-containing water after 30 days with safe drinking water, containing 0.1 mg F ions l(-1). A significant fall in percentage of CAs and aberrant cells after withdrawal of F-treatment following 30 days of safe water treatment in mice was observed which was highest after 90 days, although their levels still remained significantly high compared with the control group. This observation suggests that F-induced genotoxicity could be reduced by substituting high F-containing water with safe drinking water. Further study is warranted with different doses and extended treatment of safe water to determine whether the induced damages could be completely reduced or not. Copyright © 2011 John Wiley & Sons, Ltd.

  20. Low-levels of fluoride in plaque and saliva and their effects on the demineralisation and remineralisation of enamel; role of fluoride toothpastes.

    Science.gov (United States)

    Lynch, R J M; Navada, R; Walia, R

    2004-01-01

    To summarise support for current consensus on the likely means by which fluoride toothpastes reduce caries and review some relevant studies of the effect of low levels of fluoride on the demineralisation and remineralisation of enamel. The major anti-caries effect of fluoride toothpastes is thought to result from small but protracted elevations in levels of fluoride in plaque and saliva. Fluoride incorporated into enamel systemically does not reduce enamel solubility sufficiently to exert an anti-caries effect. Fluoride has the potential to exert an anti-caries benefit largely through three mechanisms; inhibition of demineralisation, promotion of remineralisation and interference with bacterial growth and metabolism. However, the low levels of fluoride thought to influence caries are insufficient to have a significant effect via the latter mechanism. Thus reductions in caries resulting from the use of fluoride toothpastes can be linked to modification of the demineralisation/remineralisation balance by direct effects on dental mineral exerted topically by low levels of fluoride. Numerous in vitro studies have shown that low levels of fluoride, typical of those found after many hours in resting plaque and saliva, and resulting from the regular use of fluoride toothpastes, can have a profound effect on enamel demineralisation and remineralisation.

  1. Other Fluoride Products

    Science.gov (United States)

    ... Private Wells Infant Formula Fluorosis Public Health Service Recommendation Water Operators & Engineers Water Fluoridation Additives Shortages of Fluoridation Additives Drinking Water Pipe Systems CDC-Sponsored Water Fluoridation Training Links to Other ...

  2. Comparative study of fluoride concentration in human serum and drinking water in fluorinated endemic and non endemic areas of pakistan

    International Nuclear Information System (INIS)

    Qayyum, M.; Ahmad, B.; Ahmad, M.

    2013-01-01

    For comparing the human blood serum and drinking water fluoride levels of subjects with dental fluorosis and bony deformities, this study is carried out with individuals ranging 8-17 age group fluorinated Sham Ki Bhatiyan, Punjab (endemic) and Queens Road, Lahore, Punjab (non-endemic) areas. Fluoride concentrations were determined using ion selective electrode methodology and statistically compared. Both the groups showed a significant difference (p < 0.05). Subjects from fluorotic area showed high concentration of fluoride in water and blood serum samples (mean value: 135.587+-77.435 and 2.765+-0.469 micro molL/sup -1/ in water and blood serum samples respectively) as compared to controls (mean value: 19.509+-2.432 and 2.364+- 0.667 micro molL -1). These findings indicate that serum and water fluoride concentrations have a significant positive dose response relationship with the prevalence of dental fluorosis in an area associated with high fluoride level in drinking water. (author)

  3. Fluoride Increase in Saliva and Dental Biofilm due to a Meal Prepared with Fluoridated Water or Salt: A Crossover Clinical Study.

    Science.gov (United States)

    Lima, Carolina V; Tenuta, Livia M A; Cury, Jaime A

    2018-06-07

    Knowledge about fluoride delivery to oral fluids from foods cooked with fluoridated water and salt is scarce, and no study has evaluated fluoride concentrations in saliva or biofilm during meal consumption. In this randomized double-blind crossover study, 12 volunteers ingested meals (rice, beans, meat, and legumes) prepared with nonfluoridated water and salt (control group), fluoridated water (0.70 mg F/L; water group), and fluoridated salt (183.7 mg F/kg; salt group). Whole saliva was collected before meal ingestion, during mastication, and up to 2 h after meal ingestion. Dental biofilm was collected before and immediately after meal ingestion. Fluoride concentrations in saliva and dental biofilm were determined by an ion-specific electrode. The mean (±standard deviation; n = 4) fluoride concentrations in meals prepared for the control, water, and salt groups were 0.039 ± 0.01, 0.43 ± 0.04, and 1.71 ± 0.32 μg F/g, respectively. The three groups had significantly different fluoride concentrations in saliva collected during mastication (p water > control). The fluoride concentration in saliva returned to baseline 30 min after meal ingestion in the water group but remained high for up to 2 h in the salt group (p = 0.002). The fluoride concentration in biofilm fluid differed only between the salt and control groups (p = 0.008). The mastication of foods cooked with fluoridated water and salt increases fluoride concentrations in oral fluids and may contribute to the local effect of these community-based fluoride interventions on caries control. © 2018 S. Karger AG, Basel.

  4. Fluoride Levels in Urine, Blood Plasma and Serum of People Living in an Endemic Fluorosis Area in the Thar Desert, Pakistan

    International Nuclear Information System (INIS)

    Rafique, T.; Shirin, K.; Ahmed, I.; Khan, M. H.; Soomro, F.

    2015-01-01

    Fluoride (F/sup -/) levels in the urine, blood plasma and serum samples of people living in a village in the Thar Desert have been analysed where fluorosis is endemic and groundwater contains fluoride as high as 9.76 mg/L. Average values of fluoride levels in these human specimens i.e. urine, blood plasma and serum have been found to be 12.98 mg/L, 0.61 mg/L and 0.75 mg/L, respectively. These values are much higher than the normal values reported from other parts of the world. It was observed that urinary fluoride levels increase with age of an individual but with an insignificant correlation (r = 0.116), however, fluoride levels in plasma and serum samples did not vary considerably with age in male and female subjects. It has been found that after the age of 50 years the urinary fluoride decreases with its concomitant increase in serum fluoride level. Since groundwater is the only available source of water for human consumption and it contains higher fluoride (av. 7.09 mg/L) than WHO limit (1.5 mg/L), therefore, it is the main cause of fluorosis in the area. (author)

  5. Validating a High Performance Liquid Chromatography-Ion Chromatography (HPLC-IC) Method with Conductivity Detection After Chemical Suppression for Water Fluoride Estimation.

    Science.gov (United States)

    Bondu, Joseph Dian; Selvakumar, R; Fleming, Jude Joseph

    2018-01-01

    A variety of methods, including the Ion Selective Electrode (ISE), have been used for estimation of fluoride levels in drinking water. But as these methods suffer many drawbacks, the newer method of IC has replaced many of these methods. The study aimed at (1) validating IC for estimation of fluoride levels in drinking water and (2) to assess drinking water fluoride levels of villages in and around Vellore district using IC. Forty nine paired drinking water samples were measured using ISE and IC method (Metrohm). Water samples from 165 randomly selected villages in and around Vellore district were collected for fluoride estimation over 1 year. Standardization of IC method showed good within run precision, linearity and coefficient of variance with correlation coefficient R 2  = 0.998. The limit of detection was 0.027 ppm and limit of quantification was 0.083 ppm. Among 165 villages, 46.1% of the villages recorded water fluoride levels >1.00 ppm from which 19.4% had levels ranging from 1 to 1.5 ppm, 10.9% had recorded levels 1.5-2 ppm and about 12.7% had levels of 2.0-3.0 ppm. Three percent of villages had more than 3.0 ppm fluoride in the water tested. Most (44.42%) of these villages belonged to Jolarpet taluk with moderate to high (0.86-3.56 ppm) water fluoride levels. Ion Chromatography method has been validated and is therefore a reliable method in assessment of fluoride levels in the drinking water. While the residents of Jolarpet taluk (Vellore distict) are found to be at a high risk of developing dental and skeletal fluorosis.

  6. Performance of novel hydroxyapatite nanowires in treatment of fluoride contaminated water

    Energy Technology Data Exchange (ETDEWEB)

    He, Junyong; Zhang, Kaisheng [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wu, Shibiao [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Cai, Xingguo; Chen, Kai; Li, Yulian [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun, Bai; Jia, Yong; Meng, Fanli; Jin, Zhen [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Kong, Lingtao, E-mail: ltkong@iim.ac.cn [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Jinhuai [Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-02-13

    Highlights: • Novel ultralong hydroxyapatite (HAP) nanowires were developed for effective defluoridation. • High fluoride adsorption capacity, 40.65 mg/g at neutral pH. • The HAP nanowire membrane efficiently removed fluoride by dynamic adsorption. • The membrane could remove more than 98% fluoride, and filtered water amount reached 350 L/m{sup 2}. - Abstract: Novel ultralong hydroxyapatite (HAP) nanowires were successfully prepared for fluoride removal for the first time. The fluoride adsorption on the HAP nanowires was studied on a batch mode. The results revealed that the adsorption data could be well described by the Freundlich model, and the adsorption kinetic followed the pseudo-second-order model. The maximum of adsorption capacity was 40.65 mg/g at pH 7.0 when the fluoride concentration is 200 mg/L. The thermodynamic parameters suggested that the adsorption of fluoride was a spontaneous endothermic process. The FT-IR, XPS and Zeta potential analysis revealed that both anion exchange and electrostatic interactions were involved in the adsorption of fluoride. Furthermore, the HAP nanowires were made into HAP membrane through a simple process of suction filtration. Membrane filtration experiments revealed that the fluoride removal capabilities depended on the membrane thickness, flow rate and initial concentration of fluoride. The as-prepared membrane could remove fluoride efficiently through continues filtration. The filtered water amount could reach 350, 192, and 64 L/m{sup 2} when the fluoride concentrations were 4, 5 and 8 ppm, respectively, using the HAP membrane with only 150 μm thickness. The as-synthesized ultralong HAP nanowires were thus demonstrated to be very effective and biocompatible adsorbents for fluoride removal from contaminated water.

  7. Performance of novel hydroxyapatite nanowires in treatment of fluoride contaminated water.

    Science.gov (United States)

    He, Junyong; Zhang, Kaisheng; Wu, Shibiao; Cai, Xingguo; Chen, Kai; Li, Yulian; Sun, Bai; Jia, Yong; Meng, Fanli; Jin, Zhen; Kong, Lingtao; Liu, Jinhuai

    2016-02-13

    Novel ultralong hydroxyapatite (HAP) nanowires were successfully prepared for fluoride removal for the first time. The fluoride adsorption on the HAP nanowires was studied on a batch mode. The results revealed that the adsorption data could be well described by the Freundlich model, and the adsorption kinetic followed the pseudo-second-order model. The maximum of adsorption capacity was 40.65 mg/g at pH 7.0 when the fluoride concentration is 200mg/L. The thermodynamic parameters suggested that the adsorption of fluoride was a spontaneous endothermic process. The FT-IR, XPS and Zeta potential analysis revealed that both anion exchange and electrostatic interactions were involved in the adsorption of fluoride. Furthermore, the HAP nanowires were made into HAP membrane through a simple process of suction filtration. Membrane filtration experiments revealed that the fluoride removal capabilities depended on the membrane thickness, flow rate and initial concentration of fluoride. The as-prepared membrane could remove fluoride efficiently through continues filtration. The filtered water amount could reach 350, 192, and 64 L/m(2) when the fluoride concentrations were 4, 5 and 8 ppm, respectively, using the HAP membrane with only 150 μm thickness. The as-synthesized ultralong HAP nanowires were thus demonstrated to be very effective and biocompatible adsorbents for fluoride removal from contaminated water. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. [Public water supply fluoridation in Brazil according to health sector leaders].

    Science.gov (United States)

    Ferreira, Regina Glaucia Lucena Aguiar; Bógus, Cláudia Maria; Marques, Regina Auxiliadora de Amorim; Menezes, Léa Maria Bezerra de; Narvai, Paulo Capel

    2014-09-01

    Various groups have opposed water supply fluoridation in Brazil, while others have supported the measure based on scientific evidence. This article describes the perceptions of delegates to the 13th National Health Conference on mandatory fluoridation of the country's public water supply. Interviews were processed using collective subject discourse analysis. A certain degree of misinformation persists regarding basic characteristics of water fluoridation, which is frequently confused with chlorination. The delegates' discourses showed a continuing need for public awareness-raising regarding fluoridation and the delegates' desire that the National Congress not take measures impacting public health without consulting society's stakeholders. However, most of the interviewees agreed that to repeal mandatory water fluoridation or loosen the control of its implementation could increase the incidence of tooth decay in the population.

  9. Amelioration of chronic fluoride toxicity by calcium and fluoride-free water in rats.

    Science.gov (United States)

    Shankar, Priyanka; Ghosh, Sudip; Bhaskarachary, K; Venkaiah, K; Khandare, Arjun L

    2013-07-14

    The study was undertaken to explore the amelioration of chronic fluoride (F) toxicity (with low and normal Ca) in rats. The study was conducted in two phases. In phase I (6 months), seventy-six Wistar, weanling male rats were assigned to four treatment groups: normal-Ca (0·5 %) diet (NCD), Ca+F - ; low-Ca (0·25 %) diet (LCD), Ca - F - ; NCD +100 parts per million (ppm) F water, Ca+F+; LCD +100 ppm F water, Ca - F+. In phase II (reversal experiment, 3 months), LCD was replaced with the NCD. Treatment groups Ca+F+ and Ca - F+ were divided into two subgroups to compare the effect of continuation v. discontinuation along with Ca supplementation on reversal of chronic F toxicity. In phase I, significantly reduced food efficiency ratio (FER), body weight gain (BWG), faecal F excretion, serum Ca and increased bone F deposition were observed in the treatment group Ca - F+. Reduced serum 25-hydroxy-vitamin D3, increased 1,25-dihydroxy-vitamin D3 and up-regulation of Ca-sensing receptor, vitamin D receptor and S100 Ca-binding protein G (S100G) were observed in treatment groups Ca - F - and Ca - F+. In phase II (reversal phase), FER, BWG and serum Ca in treatment groups Ca - F+/Ca+F - and Ca - F+/Ca+F+ were still lower, as compared with other groups. However, other variables were comparable. Down-regulation of S100G was observed in F-fed groups (Ca+F+/Ca+F+ and Ca - F+/Ca+F+) in phase II. It is concluded that low Ca aggravates F toxicity, which can be ameliorated after providing adequate Ca and F-free water. However, chronic F toxicity can interfere with Ca absorption by down-regulating S100G expression irrespective of Ca nutrition.

  10. A cross-sectional study to assess the intelligence quotient (IQ of school going children aged 10-12 years in villages of Mysore district, India with different fluoride levels

    Directory of Open Access Journals (Sweden)

    Shibu Thomas Sebastian

    2015-01-01

    Full Text Available Introduction: Besides dental and skeletal fluorosis, excessive fluoride intake can also affect the central nervous system without first causing the physical deformities associated with skeletal fluorosis. With the existence of widespread endemic fluorosis in India, the possible adverse effect of elevated fluoride in drinking water on the Intelligence Quotient (IQ level of children is a potentially serious public health problem. Aims and Objectives: This study assessed the Intelligence Quotient (IQ of school going children aged 10-12 years in villages of Mysore district with different fluoride levels. Materials and Methods: In this cross-sectional study, 405 school children aged 10-12 years were selected from three villages in Mysore district with normal fluoride (1.20 mg F/l, low fluoride (0.40 mg F/l and high fluoride (2.20 mg F/l in their water supplies. A pre designed questionnaire was used to collect the required data for the survey which included socio demographic details, oral hygiene practices, diet history, body mass index and dental fluorosis. Intelligence Quotient was assessed using Raven′s colored Progressive Matrices Test. Results: In bivariate analysis, significant relationships were found between water fluoride levels and Intelligence Quotient of school children (P < 0.05. In the high fluoride village, the proportion of children with IQ below 90, i.e. below average IQ was larger compared to normal and low fluoride village. Age, gender, parent education level and family income had no significant association with IQ. Conclusion: School children residing in area with higher than normal water fluoride level demonstrated more impaired development of intelligence when compared to school children residing in areas with normal and low water fluoride levels. Thus, children′s intelligence can be affected by high water fluoride levels.

  11. Nutritional and water effect on fluoride uptake and respiration of bean seedlings. [Phaseolus vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Applegate, H G; Adams, D F

    1960-01-01

    Bean plants (Phaseolus vulgaris) were grown in an atmosphere containing 2.0 +/- 0.21 g F /mT (1.6 ppb). The effect of N, P, K, Fe, and Ca deficiencies and the effect of osmotic pressures of 0, 1.5, 3.0, 4.5, 6.0 and 7.5 pounds on fluoride uptake and fluoride-mediated respiration were studied. The data showed that P deficient plants took up more fluoride than plants deficient in any of the other elements studied. Fluoride-mediated respiration was phosphorous dependent, however. Plants low in Fe or K showed increased uptake of fluoride. Nitrogen had no effect on fluoride uptake under the conditions of this experiment. Plants low in Fe showed inhibition of oxygen uptake. This inhibition was accentuated by fluoride. The interactions of N, K and Ca with fluoride on respiration were complex. Neither fluoride uptake nor fluoride-mediated respiration appeared to be linked directly to the water economy of the plants. 14 references, 6 tables.

  12. A cross-sectional study to assess the intelligence quotient (IQ) of school going children aged 10-12 years in villages of Mysore district, India with different fluoride levels.

    Science.gov (United States)

    Sebastian, Shibu Thomas; Sunitha, S

    2015-01-01

    Besides dental and skeletal fluorosis, excessive fluoride intake can also affect the central nervous system without first causing the physical deformities associated with skeletal fluorosis. With the existence of widespread endemic fluorosis in India, the possible adverse effect of elevated fluoride in drinking water on the Intelligence Quotient (IQ) level of children is a potentially serious public health problem. This study assessed the Intelligence Quotient (IQ) of school going children aged 10-12 years in villages of Mysore district with different fluoride levels. In this cross-sectional study, 405 school children aged 10-12 years were selected from three villages in Mysore district with normal fluoride (1.20 mg F/l), low fluoride (0.40 mg F/l) and high fluoride (2.20 mg F/l) in their water supplies. A pre designed questionnaire was used to collect the required data for the survey which included socio demographic details, oral hygiene practices, diet history, body mass index and dental fluorosis. Intelligence Quotient was assessed using Raven's colored Progressive Matrices Test. In bivariate analysis, significant relationships were found between water fluoride levels and Intelligence Quotient of school children (P intelligence when compared to school children residing in areas with normal and low water fluoride levels. Thus, children's intelligence can be affected by high water fluoride levels.

  13. Fluoride estimation and its correlation with other physicochemical parameters in drinking water of some areas of Balochistan, Pakistan.

    Science.gov (United States)

    Chandio, Tasawar Ali; Khan, Muhammad Nasiruddin; Sarwar, Anila

    2015-08-01

    The fluoride level in drinking water is an important parameter and has to be controlled in order to prevent dental and skeletal fluorosis. The objective of this study is to assess fluoride content and other water quality parameters in the samples taken from open wells, tube wells, and karezes of Mastung, Mangochar, and Pringabad areas of Balochistan province. A total number of 96 drinking water samples out of 150 were found unfit for human consumption. Area-wise analysis show that the samples from 39 sites from Mastung, 12 from Mangochar, and 13 from Pringabad were found in the risk of dental fluorosis of mild to severe nature. However, 12 sampling sites from Mastung, 8 from Mangochar, and 2 from Pringabad were identified as the risks of mottling and skeletal fluorosis or other bone abnormalities. The highest concentration of F(-) has been observed as 14 mg L(-1) in Mastung. Correlation analysis show that fluoride solubility in drinking water is pH dependent; and the salts of Ca(2+), Na(+), K(+), Cl(-), and SO4(2-) contribute to attain the favorable pH for dissolution of fluoride compounds in drinking water. Principal component analysis shows that the geochemical composition of the rocks is only responsible for groundwater contamination. On the basis of the results, defloridation of the identified sampling sites and continuous monitoring of drinking water at regular basis is recommended at government level to avoid further fluorosis risks.

  14. [The influence of high fluoride exposure in drinking water on endocrine hormone in female].

    Science.gov (United States)

    Hou, Jia-xiang; Yang, Yue-jin; Gong, Biao; Li, Shi-hong; Ding, Zhong; Wen, Shi-bao; Li, Shi-qun; Cheng, Xue-min; Cui, Liu-xin; Ba, Yue

    2013-02-01

    To explore the influence of water fluoride exposure on reproductive hormones in female. Cross-sectional study was conducted in seven villages of a county in Henan province by using simple random sampling including high fluoride area, defluoridation project area and control area on April, 2011 based on the preliminary study results of fluoride concentration in drinking water. Women who were born and growth or lived in the village at least 5 years and aged 18-48 years old were recruited using cluster sampling. They were divided into high fluoride group (HFG, 116 subjects), defluoridation project group (DFPG, 132 subjects) and control group (CG, 227 subjects) in accordance with the above areas. All subjects accepted questionnaire and physical checkup. Fasting blood and morning urine samples were collected. The concentration of fluoride in urine was determined by fluoride ion selective electrode method. The serum level of GnRH was detected using enzyme linked immunosorbent assay (ELISA). The serum level of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), estradiol (E2) were determined by chemiluminesence immunoassay (CLIA). The average age was (39.44 ± 7.34), (38.84 ± 8.03), (37.45 ± 7.70) years old in female from DFPG, HFG and CG respectively, there were no significant differences among the three groups (F = 3.02, P = 0.05). The urine fluoride levels were (1.34 ± 1.07), (2.59 ± 1.57), (0.92 ± 0.46) mg/ml in female from DFPG, HFG and CG respectively, there was a significant difference among three groups (F = 105.38, P 0.05). The serum levels of E2 in Ovulatory period were 67.73, 58.09, 84.96 pg/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in CG (H = 4.00, P 0.05). The serum levels of GnRH in Luteal phase were 24.09, 20.16, 23.50 ng/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in DFPG (H = 14.14, P 0.05 respectively). The abnormal rates of E2 level were 22.73 (30

  15. Trend Analysis of Studies on Water Fluoridation Related to Dental Caries in PubMed.

    Science.gov (United States)

    Oh, Hyo-Jung; Choi, Hyeon-Mi; Kim, Chonghyuck; Jeon, Jae-Gyu

    2018-04-04

    Water fluoridation has been cited as one of the top 10 public health achievements of the 20th century. Herein, we analyzed water fluoridation articles related to dental caries published in PubMed between 1950 and 2016 using informetrics and linguistic methods to investigate trends in the studies. To this aim, queries such as "dental caries and (water fluoridation or fluoridated water)," "dental caries and (fluoride or fluoridation)," and "dental caries" were submitted to PubMed to retrieve information about articles on water fluoridation within the area of dental caries and fluoride - their titles, abstracts, publication dates, author affiliations, and publication journals. This article information was then collected by an automatic web crawler and examined through informetrics and linguistic analyses. It was found that the number of articles concerned with water fluoridation and dental caries was 3,381 and declined over time after 1970. The articles were published by 750 journals - most notably, Community Dentistry and Oral Epidemiology and Caries Research. With regard to the geographic distribution of the authors, Europe and North America, especially the USA and UK, accounted for 59.9% of the articles published during the years 1987 to 2015, though there was a sharp increase in the number of authors in Oceania and Asia in recent years. In the titles and abstracts of the articles, "community" and "fluorosis" were mentioned more frequently than the other key terms selected in this study, regardless of the period examined. Our findings may allow one to assess how the research on water fluoridation has evolved over the past several decades. © 2018 S. Karger AG, Basel.

  16. Determination of fluoride source in ground water using petrographic studies in Dashtestan area, south of Iran

    Science.gov (United States)

    Battaleb-Looie, Sedigheh; Moore, Farid, ,, Dr.

    2010-05-01

    The groundwater occurs in Dashtestan area, contains a high level of fluoride. Since groundwater is vastly used for drinking and irrigation purposes, the local residents are at high risk of fluoride toxicity, as already evidenced by the occurrence of dental Fluorosis in many residents. 35 surface and groundwater samples were collected in September, 2009. The results show that in 23 samples the fluoride concentration is above the permissible level (1.5ppm). Petrographic study of lithological units in the catchment area indicates that mica minerals are the most probable source of fluoride content in the study area.

  17. Geochemical studies of fluoride and other water quality parameters of ground water in Dhule region Maharashtra, India.

    Science.gov (United States)

    Patil, Dilip A; Deshmukh, Prashant K; Fursule, Ravindra A; Patil, Pravin O

    2010-07-01

    This study has been carried out to find out the water pollutants and to test the suitability of water for drinking and irrigation purposes in Dhule and surrounding areas in Maharashtra State in India. The analysis was carried out for the parameters pH, DO (dissolved oxygen), BOD (biological oxygen demand), Cl-, NO3-, F-, S(2)-, total alkalinity, total solid, total dissolved solids (TDS), total suspended solids (TSS), total hardness, calcium, magnesium, carbonate and noncarbonate hardness, and concentrations of calcium and magnesium. These parameters were compared against the standards laid down by World Health Organization (WHO) and Indian Council of Medical Research (ICMR) for drinking water quality. High levels of NO(3)-, Cl-, F-, S(2)-, total solid, TDS, TSS, total hardness, magnesium and calcium have been found in the collected samples. From these observations, it has been found that fluoride is present as per the permissible limit (WHO 2003) in some of the villages studied, but both fluoride and nitrate levels are unacceptable in drinking water samples taken from several villages in Dhule. This is a serious problem and, therefore, requires immediate attention. Excess of theses impurities in water causes many diseases in plants and animals. This study has been carried out to find out the water pollutants and to test the suitability of water for drinking and irrigation purposes in Dhule and surrounding areas in Maharashtra.

  18. Does the Presense of Water Fluoridation Alter the Use of Dental Preventive Services on United States Air Force Bases?

    National Research Council Canada - National Science Library

    Bober-Moken, Irene

    1999-01-01

    ... application of fluorides, oral hygiene counseling, diet planning and dental prophylaxis. Are these procedures employed at different rates relative to the presence or absence of fluoride in the community water supply...

  19. Physiologic Conditions Affect Toxicity of Ingested Industrial Fluoride

    Directory of Open Access Journals (Sweden)

    Richard Sauerheber

    2013-01-01

    Full Text Available The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity from ingestion is distinct from fully soluble toxic industrial fluorides. The toxicity of fluoride is determined by environmental conditions and the positive cations present. At a pH typical of gastric juice, fluoride is largely protonated as hydrofluoric acid HF. Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel. The widespread policy known as water fluoridation is discussed in light of these findings.

  20. Physiologic conditions affect toxicity of ingested industrial fluoride.

    Science.gov (United States)

    Sauerheber, Richard

    2013-01-01

    The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity from ingestion is distinct from fully soluble toxic industrial fluorides. The toxicity of fluoride is determined by environmental conditions and the positive cations present. At a pH typical of gastric juice, fluoride is largely protonated as hydrofluoric acid HF. Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel. The widespread policy known as water fluoridation is discussed in light of these findings.

  1. Treatability study of arsenic, fluoride and nitrate from drinking water by adsorption process

    International Nuclear Information System (INIS)

    Abbas, N.; Irfan, M.; Butt, M.T.

    2014-01-01

    Natural contamination of nitrate, fluoride, arsenic and dissolved salts in ground water sources is the main health menace at present in different parts of Pakistan. The metalloids especially arsenic, fluoride and nitrate pose severe health hazards to human being. The present research work investigated the removal techniques for arsenic, fluoride and nitrate from drinking water by adsorption process. Ion exchange resins, activated carbon and activated alumina were used for removal of selected contaminants. These adsorbents were evaluated by comparing their removal efficiency as well as requisite operator skills. The result of activated alumina was found good as compared to activated carbon, mix bed resins and ion exchange resins (IRA-400) for maximum removal of arsenic, nitrate and fluoride. The removal efficiency of arsenic, fluoride and nitrate were found 96%, 99%, 98% respectively in case of activated alumina. The advantage of adsorption process is easy to use and relatively cheaper as compared to other treatment methodologies. (author)

  2. Fluoride, boron and nitrate toxicity in ground water of northwest Rajasthan, India.

    Science.gov (United States)

    Chaudhary, Veena; Kumar, Mukesh; Sharma, Mukesh; Yadav, B S

    2010-02-01

    The study was carried out to access the fluoride, boron, and nitrate concentrations in ground water samples of different villages in Indira Gandhi, Bhakra, and Gang canal catchment area of northwest Rajasthan, India. Rural population, in the study site, is using groundwater for drinking and irrigation purposes, without any quality test of water. All water samples (including canal water) were contaminated with fluoride. Fluoride, boron, and nitrate were observed in the ranges of 0.50-8.50, 0.0-7.73, and 0.0-278.68 mg/l, respectively. Most of the water samples were in the categories of fluoride 1.50 mg/l, of boron 2.0-4.0 mg/l, and of nitrate availability of these compounds in groundwater was due to natural reasons and by the use of chemical fertilizers.

  3. Fluoride and Oral Health.

    Science.gov (United States)

    O'Mullane, D M; Baez, R J; Jones, S; Lennon, M A; Petersen, P E; Rugg-Gunn, A J; Whelton, H; Whitford, G M

    2016-06-01

    The discovery during the first half of the 20th century of the link between natural fluoride, adjusted fluoride levels in drinking water and reduced dental caries prevalence proved to be a stimulus for worldwide on-going research into the role of fluoride in improving oral health. Epidemiological studies of fluoridation programmes have confirmed their safety and their effectiveness in controlling dental caries. Major advances in our knowledge of how fluoride impacts the caries process have led to the development, assessment of effectiveness and promotion of other fluoride vehicles including salt, milk, tablets, toothpaste, gels and varnishes. In 1993, the World Health Organization convened an Expert Committee to provide authoritative information on the role of fluorides in the promotion of oral health throughout the world (WHO TRS 846, 1994). This present publication is a revision of the original 1994 document, again using the expertise of researchers from the extensive fields of knowledge required to successfully implement complex interventions such as the use of fluorides to improve dental and oral health. Financial support for research into the development of these new fluoride strategies has come from many sources including government health departments as well as international and national grant agencies. In addition, the unique role which industry has played in the development, formulation, assessment of effectiveness and promotion of the various fluoride vehicles and strategies is noteworthy. This updated version of 'Fluoride and Oral Health' has adopted an evidence-based approach to its commentary on the different fluoride vehicles and strategies and also to its recommendations. In this regard, full account is taken of the many recent systematic reviews published in peer reviewed literature.

  4. Determination of fluoride ions in water by condutometric titration with lanthanum nitrates

    International Nuclear Information System (INIS)

    Alves, J.C.

    1986-01-01

    An alternative method for determining fluoride ions in drinking water by condutometric titration using La(NO 3 ) 3 as titrant is presented. The method is based on previous separation of fluoride from sample by distillation at 135 0 C. The pH of the distillated is adjusted between 5,5 - 6,0; ethanol is adicioned in 50% titrating the resultant solution with La(NO 3 ) 3 . In these conditions, fluoride ions are determined with accuracy respectively, 5% and 4%. Natural samples of drinking water were analysed by this method and by the ion selective method, with agreement among the results. (author) [pt

  5. Defluoridation of drinking water using Al3+-modified bentonite clay: Optimization of fluoride adsorption conditions

    CSIR Research Space (South Africa)

    Vhahangwele, M

    2014-11-01

    Full Text Available , cation exchange capacity (CEC) by ammonium acetate method, and pH(subpzc) by solid addition method. Chemical constituents of water were determined by atomic absorption spectrometry (AAS), ion selective electrode (Crison 6955 Fluoride selective electrode...

  6. Oral fluoride levels 1 h after use of a sodium fluoride rinse: effect of sodium lauryl sulfate.

    Science.gov (United States)

    Vogel, Gerald L; Schumacher, Gary E; Chow, Laurence C; Tenuta, Livia M A

    2015-01-01

    Increasing the concentration of free fluoride in oral fluids is an important goal in the use of topical fluoride agents. Although sodium lauryl sulfate (SLS) is a common dentifrice ingredient, the influence of this ion on plaque fluid and salivary fluid fluoride has not been examined. The purpose of this study was to investigate the effect of SLS on these parameters and to examine the effect of this ion on total (or whole) plaque fluoride, an important source of plaque fluid fluoride after a sufficient interval following fluoride administration, and on total salivary fluoride, a parameter often used as a surrogate measure of salivary fluid fluoride. Ten subjects accumulated plaque for 48 h before rinsing with a 12 mmol/l NaF (228 µg/g F) rinse containing or not containing 0.5% (w/w) SLS. SLS had no statistically significant effect on total plaque and total saliva fluoride but significantly increased salivary fluid and plaque fluid fluoride (by 147 and 205%, respectively). These results suggest that the nonfluoride components of topical agents can be manipulated to improve the fluoride release characteristics from oral fluoride reservoirs and that statistically significant change may be observed in plaque fluid and salivary fluid fluoride concentrations that may not be observed in total plaque and total saliva fluoride concentrations.

  7. La3+-modified activated alumina for fluoride removal from water

    International Nuclear Information System (INIS)

    Cheng, Jiemin; Meng, Xiaoguang; Jing, Chuanyong; Hao, Jumin

    2014-01-01

    Graphical abstract: - Highlights: • A La 3+ -modified activated alumina adsorbent was prepared for effective removal F − . • SEM/EDS and EXAFS analyses determined the formation of La(OH) 3 coating on the AA. • The La-AA had much high adsorption rate and capacity than the AA. • The La-AA was promising adsorbent for effective removal of F − from water. - Abstract: A La 3+ -modified activated alumina (La-AA) adsorbent was prepared for effective removal of fluoride from water. The surface properties of adsorbent were characterized with zeta potential analysis, SEM-EDS and EXAFS. Batch and column experiments were conducted to evaluate improvement of F − removal by the La-AA. SEM/EDS and EXAFS analyses determined the formation of La(OH) 3 coating on the AA and strong bonding interactions between La 3+ and the Al atoms. The points of zero charge (pH PZC ) of AA and La-AA were at pH 8.94 and 9.57, respectively. Batch experimental results indicated that the La-AA had much higher adsorption rate and capacity than the AA. The F − adsorption processes on La-AA and AA followed the pseudo-second-order kinetics and the Langmuir isotherm. Column filtration results shows that the La-AA and AA treated 270 and 170 bed volumes of the F − -spiked tap water, respectively, before F − breakthrough occurred. The results demonstrated that the La-AA was a promising adsorbent for effective removal of F − from water

  8. Sustainable approach for recycling waste lamb and chicken bones for fluoride removal from water followed by reusing fluoride-bearing waste in concrete.

    Science.gov (United States)

    Ismail, Zainab Z; AbdelKareem, Hala N

    2015-11-01

    Sustainable management of waste materials is an attractive approach for modern societies. In this study, recycling of raw waste lamb and chicken bones for defluoridation of water has been estimated. The effects of several experimental parameters including contact time, pH, bone dose, fluoride initial concentration, bone grains size, agitation rate, and the effect of co-existing anions in actual samples of wastewater were studied for fluoride removal from aqueous solutions. Results indicated excellent fluoride removal efficiency up to 99.4% and 99.8% using lamb and chicken bones, respectively at fluoride initial concentration of 10 mg F/L and 120 min contact time. Maximum fluoride uptake was obtained at neutral pH range 6-7. Fluoride removal kinetic was well described by the pseudo-second order kinetic model. Both, Langmuir and Freundlich isotherm models could fit the experimental data well with correlation coefficient values >0.99 suggesting favorable conditions of the process. Furthermore, for complete sustainable management of waste bones, the resulted fluoride-bearing sludge was reused in concrete mixes to partially replace sand. Tests of the mechanical properties of fluoride sludge-modified concrete mixes indicated a potential environmentally friendly approach to dispose fluoride sludge in concrete and simultaneously enhance concrete properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Physiology and toxicity of fluoride

    Directory of Open Access Journals (Sweden)

    Dhar Vineet

    2009-01-01

    Full Text Available Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralization of bone and teeth. At high levels it has been known to cause dental and skeletal fluorosis. There are suggested effects of very high levels of fluoride on various body organs and genetic material. The purpose of this paper is to review the various aspects of fluoride and its importance in human life.

  10. Physiology and toxicity of fluoride.

    Science.gov (United States)

    Dhar, Vineet; Bhatnagar, Maheep

    2009-01-01

    Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralization of bone and teeth. At high levels it has been known to cause dental and skeletal fluorosis. There are suggested effects of very high levels of fluoride on various body organs and genetic material. The purpose of this paper is to review the various aspects of fluoride and its importance in human life.

  11. Removal of Fluoride from Drinking Water Using Modified Immobilized Activated Alumina

    Directory of Open Access Journals (Sweden)

    Aneeza Rafique

    2013-01-01

    Full Text Available The study describes the removal of fluoride from drinking water using modified immobilized activated alumina (MIAA prepared by sol-gel method. The modification was done by adding a specific amount of alum during the sol formation step. The fluoride removal efficiency of MIAA was 1.35 times higher as compared to normal immobilized activated alumina. A batch adsorption study was performed as a function of adsorbent dose, contact time, stirring rate, and initial fluoride concentration. More than 90% removal of fluoride was achieved within 60 minutes of contact time. The adsorption potential of MIAA was compared with activated charcoal which showed that the removal efficiency was about 10% more than the activated charcoal. Both the Langmuir and Freundlich adsorption isotherms fitted well for the fluoride adsorption on MIAA with the regression coefficient R2 of 0.99 and 0.98, respectively. MIAA can both be regenerated thermally and chemically. Adsorption experiments using MIAA were employed on real drinking water samples from a fluoride affected area. The study showed that modified immobilized activated alumina is an effective adsorbent for fluoride removal.

  12. The relationships between low levels of urine fluoride on children's intelligence, dental fluorosis in endemic fluorosis areas in Hulunbuir, Inner Mongolia, China.

    Science.gov (United States)

    Ding, Yunpeng; YanhuiGao; Sun, Huixin; Han, Hepeng; Wang, Wei; Ji, Xiaohong; Liu, Xuehui; Sun, Dianjun

    2011-02-28

    There has been public concern about children's intellectual performance at high levels of fluoride exposure, but few studies provide data directly to the question of whether low fluoride exposure levels less than 3.0 mg/L in drinking water adversely associated with children's intelligence. In this survey, we investigated the effects of low fluoride exposure on children's intelligence and dental fluorosis. 331 children aged from 7 to 14 were randomly recruited from four sites in Hulunbuir City, China. Intelligence was assessed using Combined Raven Test-The Rural in China while dental fluorosis was diagnosed with Dean's index. Mean value of fluoride in drinking water was 1.31±1.05 mg/L (range 0.24-2.84). Urine fluoride was inversely associated with IQ in the multiple linear regression model when children's age as a covariate variable was taken into account (Pintelligence and dental health and confirmed the dose-response relationships between urine fluoride and IQ scores as well as dental fluorosis. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. A Survey of Fluoride Dosage in Driniking Water and DMF Index in Damghan City

    Directory of Open Access Journals (Sweden)

    Hamid Reza Nasehi nia

    2004-05-01

    Full Text Available Fluoride is one of the important elements. There are so many controversial scientific points of view regarding fluoride and its presence in food chain. Water fluoridation is the best and most reliable method for the control of dental caries. In this research, the presence and concentration of fluoride in drinking water resources in the city of Damghan and DMF index (decayed, missed, filled between 560 school students (12-15 was investigated. The mean concentration of fluoride in water supplies of Damaghan city was measured in low rain seasons 0.37 mg/l and high rain seasons 0.6 mg/l the DMF index for 12 year sold student was equal 2.00 that comparing these data with the WHO classify cation for DMF index, showed them to be considered in the second surface (low classificatino. For conclusion, based on the mentioned data, a significant correlation may be found between the two parameters in different communities, and the most logic solution for the control of dental cavities in these communities, is the adjusment of fluoride concentration in drinking water.

  14. Uptake Fluoride from Water by Starch Stabilized Layered Double Hydroxides

    Directory of Open Access Journals (Sweden)

    Jiming Liu

    2018-06-01

    Full Text Available A novel starch stabilized Mg/Al layered Double hydroxides (S-LDHs was prepared in a facile approach and its fluoride ion removal performance was developed. Characterization of S-LDHs was employed by using X-ray diffraction (XRD, Fourier-transform infrared spectroscopy (FTIR, and particle size distribution. The adsorption property was studied through the assessment of the adsorption isotherms, kinetic models, thermal dynamics, and pH influence. The result shows that a low loading of starch of 10 mg onto layered double hydroxides (LDHs could obviously improve the fluoride removal rate. The S-LDHs had three times higher the adsorption capacity to fluoride than that of Mg/Al LDHs to fluoride. The particle size was smaller and the particle size distribution was narrower for S-LDHs than that for Mg/Al LDHs. The Langmuir adsorption isotherm model and pseudo-second-order kinetic model fitted well with the experimental data. In thermodynamic parameters, the enthalpy (ΔH0 value was 35.63 kJ·mol−1 and the entropy (ΔS0 value was 0.0806 kJ·mol−1K−1. The values of ΔG0 were negative, implying the adsorption process is spontaneous. S-LDHs reveals stable adsorption property in a wide pH range from 3 to 9. The mechanism for fluoride adsorption on S-LDHs included surface adsorption and interaction ion exchange.

  15. Focus on Fluoride and Fluorosis by Studying the Ground Water Quality in some Villages of Nalgonda, Nalgonda District, Andhra Pradesh

    OpenAIRE

    , Ishrath Aish; , B.L.P. Babu; , K. Sreenu

    2011-01-01

    The fluoride content of ground water was determined in eight villages of Shalsher vagu, Nalgonda district, Andhra Pradesh, where it is the only source for drinking water. Various water quality parameters such as Hydrogen potential, Electrical conductivity, Total dissolved solids, Total hardness, Total Alkalies and Fluoride were determined. The results indicated considerable variations among the analysed samples with respect to the above parameters the concentration of Fluoride in groundwater ...

  16. Fluoride removal performance of phosphoric acid treated lime ...

    African Journals Online (AJOL)

    Fluoride in drinking water above permissible levels is responsible for dental and skeletal fluorosis. In this study, removal of fluoride ions from water using phosphoric acid treated lime was investigated in continuous and point-of-use system operations. In the continuous column operations, fluoride removal performance was ...

  17. Physiology and toxicity of fluoride

    OpenAIRE

    Dhar Vineet; Bhatnagar Maheep

    2009-01-01

    Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralizat...

  18. Advantages of liquid fluoride thorium reactor in comparison with light water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bahri, Che Nor Aniza Che Zainul, E-mail: anizazainul@gmail.com; Majid, Amran Ab.; Al-Areqi, Wadeeah M. [Nuclear Science Program, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-04-29

    Liquid Fluoride Thorium Reactor (LFTR) is an innovative design for the thermal breeder reactor that has important potential benefits over the traditional reactor design. LFTR is fluoride based liquid fuel, that use the thorium dissolved in salt mixture of lithium fluoride and beryllium fluoride. Therefore, LFTR technology is fundamentally different from the solid fuel technology currently in use. Although the traditional nuclear reactor technology has been proven, it has perceptual problems with safety and nuclear waste products. The aim of this paper is to discuss the potential advantages of LFTR in three aspects such as safety, fuel efficiency and nuclear waste as an alternative energy generator in the future. Comparisons between LFTR and Light Water Reactor (LWR), on general principles of fuel cycle, resource availability, radiotoxicity and nuclear weapon proliferation shall be elaborated.

  19. Removal of lead and fluoride from contaminated water using exhausted coffee grounds based bio-sorbent.

    Science.gov (United States)

    Naga Babu, A; Reddy, D Srinivasa; Kumar, G Suresh; Ravindhranath, K; Krishna Mohan, G V

    2018-07-15

    Water pollution by industrial and anthropogenic actives has become a serious threat to the environment. World Health Organization (WHO) has identified that lead and fluoride amid the environmental pollutants are most poisonous water contaminants with devastating impact on the human race. The present work proposes a study on economical bio-adsorbent based technique using exhausted coffee grounds in the removal of lead and fluoride contaminants from water. The exhausted coffee grounds gathered from industrial wastes have been acid-activated and examined for their adsorption capacity. The surface morphology and elemental characterization of pre-and-post adsorption operations by FESEM, EDX and FTIR spectral analysis confirmed the potential of the exhausted coffee ground as successful bio-sorbent. However, thermodynamic analysis confirmed the adsorption to be spontaneous physisorption with Langmuir mode of homogenous monolayer deposition. The kinetics of adsorption is well defined by pseudo second order model for both lead and fluoride. A significant quantity of lead and fluoride is removed from the synthetic contaminated water by the proposed bio-sorbent with the respective sorption capabilities of 61.6 mg/g and 9.05 mg/g. However, the developed bio-sorbent is also recyclable and is capable of removing the lead and fluoride from the domestic and industrial waste-water sources with an overall removal efficiency of about 90%. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Fluoride level in public water supplies of cities from the northwest region of São Paulo State, Brazil Concentração de flúor nas águas de abastecimento público de municípios da região noroeste do estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Nemre Adas Saliba

    2006-10-01

    Full Text Available It may be difficult for small and medium cities to obtain information about the fluoride content of public water, because of the lack of equipments and technicians. This study aimed to analyze the fluoride levels of the water supplied by the public treatment stations of 40 cities situated in the northwest region of São Paulo State, during a period of 6 months, to verify if fluoridation occurs in a continuous manner and if the fluoride levels are within the recommended. Maps of the water distribution system were obtained from the water treatment companies and utilized to randomize the addresses of the collection sites, so that they included all regions with treated water sources. One water sample by month was collected and analyzed in duplicate using an ion-specific-electrode. Samples with 0.6 to 0.8 mgF/L were considered acceptable. In the 38 cities that regularly provided the samples in the 6 months of the study, water from 144 collection sites was collected and a total of 864 samples were analyzed, of which 61.81 percent were classified as unacceptable. It was observed that 33 cities performed fluoridation but in 78.79 percent of these cities there were variations in the fluoride level among the sites and in the same site during the period of study. One can conclude that most of these cities do not control the fluoride levels in the public water, since fluoridation occurs in a discontinuous manner and in most of the situations not within the recommended concentrations.Municípios de pequeno e médio porte podem ter dificuldades em realizar o controle da adição de flúor nas águas de abastecimento público em função da falta de infra-estrutura laboratorial e técnica. Este estudo realizou análises do teor de flúor das águas de abastecimento de 40 municípios situados na região noroeste do estado de São Paulo, durante 6 meses, para verificar se a adição ocorre de forma contínua e se os teores adicionados encontram-se dentro dos par

  1. Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures - Paper 2: The ability of fluorescence imaging to detect differences in fluorosis prevalence and severity for different fluoride intakes from water

    Science.gov (United States)

    2012-01-01

    Background To assess the ability of fluorescence imaging to detect a dose response relationship between fluorosis severity and different levels of fluoride in water supplies compared to remote photographic scoring in selected populations participating in an observational, epidemiological survey in Chiang Mai, Thailand. Methods Subjects were male and female lifetime residents aged 8-13 years. For each child the fluoride content of cooking water samples (CWS) was assessed to create categorical intervals of water fluoride concentration. Fluorescence images were taken of the maxillary central incisors and analyzed for dental fluorosis using two different software techniques. Output metrics for the fluorescence imaging techniques were compared to TF scores from blinded photographic scores obtained from the survey. Results Data from 553 subjects were available. Both software analysis techniques demonstrated significant correlations with the photographic scores. The metrics for area effected by fluorosis and the overall fluorescence loss had the strongest association with the photographic TF score (Spearman’s rho 0.664 and 0.652 respectively). Both software techniques performed well for comparison of repeat fluorescence images with ICC values of 0.95 and 0.85 respectively. Conclusions This study supports the potential use of fluorescence imaging for the objective quantification of dental fluorosis. Fluorescence imaging was able to discriminate between populations with different fluoride exposures on a comparable level to remote photographic scoring with acceptable levels of repeatability. PMID:22908997

  2. Estimated drinking water fluoride exposure and risk of hip fracture: a cohort study.

    Science.gov (United States)

    Näsman, P; Ekstrand, J; Granath, F; Ekbom, A; Fored, C M

    2013-11-01

    The cariostatic benefit from water fluoridation is indisputable, but the knowledge of possible adverse effects on bone and fracture risk due to fluoride exposure is ambiguous. The association between long-term (chronic) drinking water fluoride exposure and hip fracture (ICD-7-9: '820' and ICD-10: 'S72.0-S72.2') was assessed in Sweden using nationwide registers. All individuals born in Sweden between January 1, 1900 and December 31, 1919, alive and living in their municipality of birth at the time of start of follow-up, were eligible for this study. Information on the study population (n = 473,277) was linked among the Swedish National In-Patient Register (IPR), the Swedish Cause of Death Register, and the Register of Population and Population Changes. Estimated individual drinking water fluoride exposure was stratified into 4 categories: very low, hip fracture. The risk estimates did not change in analyses restricted to only low-trauma osteoporotic hip fractures. Chronic fluoride exposure from drinking water does not seem to have any important effects on the risk of hip fracture, in the investigated exposure range.

  3. SITUATION OF FLUORIDES RATE IN WATERS AND MAJOR CONSUMED FOOD IN WILAYA EL-OUED

    Directory of Open Access Journals (Sweden)

    A. Zobeidi

    2013-12-01

    Full Text Available The effects of mineral salts in the drinking water, beneficial or harmful depending on their concentration, are known for many years and thus the problem posed by fluoride ions in the waters of the region (Fluorosis Dental and skeletal. This study proposes, the estimated daily intake of fluoride from its water distribution and the main food consumed per capita in the region of El-Oued (dates, tea, couscous, lentils, carrots, potatoes, pumpkin ..., which has a significant content of fluoride in their composition. In addition to the arid climatic conditions, the air temperature is very high in summer, leads to a strong human perspiration. This preliminary result leads us to propose a standard fluoride-specific region of El-Oued. The results showed that the majority of water samples and analyzed the main foods of the region of El-Oued is charged fluoride ions and exceed the maximum dose recommended for adults from 0.05 to 0.07 mg / kg / day.

  4. SITUATION OF FLUORIDES RATE IN WATERS AND MAJOR CONSUMED FOOD IN WILAYA EL-OUED

    Directory of Open Access Journals (Sweden)

    A. Zobeidi

    2015-08-01

    Full Text Available The effects of mineral salts in the drinking water, beneficial or harmful depending on their concentration, are known for many years and thus the problem posed                     by fluoride ions in the waters of the region (Fluorosis Dental and skeletal. This                  study proposes, the estimated daily intake of fluoride from its water distribution and           the main food consumed per capita in the region of El-Oued (dates, tea,                          couscous, lentils, carrots, potatoes, pumpkin ..., which has a significant content of fluoride in their composition. In addition to the arid climatic conditions, the air temperature is very high in summer, leads to a strong human perspiration. This preliminary result leads us to propose a standard fluoride-specific region of El-Oued. The results showed that the majority of water samples and analyzed the main foods of the region of El-Oued is charged fluoride ions and exceed the maximum dose recommended for adults from 0.05 to 0.07 mg / kg / day.

  5. Fluoride analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C S

    1963-01-01

    The methods and procedures for the detection and estimation of fluoride are varied and numerous. The problems of sampling, contamination, and loss in sampling waters, plant and animal tissues and atmospheres are discussed, along with brief descriptors of methods most commonly used. Techniques for separating fluorides from matrixes are discussed, as well as gravimetric, calorimetric, and spectrophotometric analytical techniques.

  6. Original Article. Toxic effect of sodium fluoride on hydroxyproline level and expression of collagen-1 gene in rat bone and its amelioration by Tamrindus indica L. fruit pulp extract

    Directory of Open Access Journals (Sweden)

    Gupta Amit Raj

    2016-03-01

    Full Text Available Excessive fluoride intoxication plays an important role in the development of dental, skeletal and non-skeletal fluorosis. The aim of this study was to ascertain the toxic effect of excessive fluoride ingestion on the level of hydroxyproline and expression of type 1 collagen gene in rat bone and its amelioration by supplementation with Tamarindus indica fruit pulp extract. Forty albino rats were randomly assigned to four groups. The first group served as control and received only tap water. The second group received sodium fluoride (200 ppm through drinking water. The third group received T. indica fruit pulp extract (200 mg/kg body weight alone and the fourth group received the T. indica fruit pulp extract (200 mg/kg body weight along with fluorinated drinking water (200 ppm daily by gavage for a period of 90 days. The level of hydroxyproline and expression of type 1 collagen gene using quantitative real time PCR in the tibia bone decreased significantly with continuous exposure to sodium fluoride. Co-administration of T. indica fruit pulp extract during exposure to fluoride through drinking water restored the level of calcium, phosphorus and alkaline phosphatase in serum and the concentration of hydroxyproline in urine. It increased the level of hydroxyproline and expression of type 1 collagen gene in the tibia as compared to untreated fluoride-exposed rats. It is concluded that T. indica fruit pulp extract has an ameliorative potential to protect the bone from fluoride induced collagen damage.

  7. Combined electrocoagulation and electroflotation for removal of fluoride from drinking water.

    Science.gov (United States)

    Zuo, Qianhai; Chen, Xueming; Li, Wei; Chen, Guohua

    2008-11-30

    A combined electrocoagulation (EC) and electroflotation (EF) process was proposed to remove fluoride from drinking water. Its efficacy was investigated under different conditions. Experimental results showed that the combined process could remove fluoride effectively. The total hydraulic retention time required was only 30 min. After treatment, the fluoride concentration was reduced from initial 4.0-6.0mg/L to lower than 1.0mg/L. The influent pH value was found to be a very important variable that affected fluoride removal significantly. The optimal influent pH range is 6.0-7.0 at which not only can effective defluoridation be achieved, but also no pH readjustment is needed after treatment. In addition, it was found that SO(4)(2-) had negative effect; Ca(2+) had positive effect; while Cl(-) had little effect on the fluoride removal. The EC charge loading, EF charge loading and energy consumption were 3.0 Faradays/m(3), 1.5 Faradays/m(3), and 1.2 kWh/m(3), respectively, under typical conditions where fluoride was reduced from initial 4.0 to 0.87 mg/L.

  8. Dental fluorosis and urinary fluoride in 10-12 years old adolescents of Bushehr port

    OpenAIRE

    Giti Javan; Ehsan Mostaghni; Seyed Mojtaba Jafary; Batoul Amini; Bahram Hematinejad

    2006-01-01

    Background: Fluoride increases tooth resistance to dental caries, but mild toxicity due to excessive ingestion of fluoride can cause dental fluorosis. Drinking water naturally contains fluoride and is a major source of fluoride. In Bushehr port, drinking water is supplied from limestone springs with normal fluoride levels but dental fluorosis is observed. Methods: A total of 95 native school children (between the ages of 10-12 years old) were randomly selected from four Bushehr port regions. ...

  9. Preparation of fly ash based zeolite for removal of fluoride from drinking water

    Science.gov (United States)

    Panda, Laxmidhar; Kar, Biswabandita; Dash, Subhakanta

    2018-05-01

    Fluoride contamination of drinking water is a worldwide phenomenon and scientists are working relentlessly to find ways to remove fluoride from drinking water. Out of the different methods employed for removal fluoride from drinking water adsorption process is the most suitable because in this process the adsorbent is regenerated and the process is cost effective. In the present study fly ash is used as the raw material, which is treated with alkali (NaOH) to form NaP1 zeolite. This zeolite is then subjected to characterization by standard procedures. It is found that the synthesized zeolite has more crystalline character than the raw fly ash and has also more voids and channels on its surface. The surface of the synthesized zeolite is modified with calcium chloride and the same is employed for removal of fluoride under varying pH, contact time, initial concentration of fluoride, temperature and adsorbent dose etc so as to assess the suitably or otherwise of the synthesized product.

  10. The effect of fluoride on the serum level of calcium in the rat (Rattus norvegicus

    Directory of Open Access Journals (Sweden)

    Fočak M.

    2012-01-01

    Full Text Available The effect of fluoride on the calcium level in serum was analyzed in the laboratory rat Rattus norvegicus. The control group consisted of 10, and the experimental group of 15 animals. In the experimental group, fluoride at a concentration of 3 mg/100 g body weight of rats was intramuscularly injected into the musculus gluteus maximus. The concentration of calcium was measured by the CPC method. The average serum calcium concentration was 2.46 mmol/l, with female rats having higher values of serum calcium than male rats. Fluoride caused the reduction of calcium concentration in serum (p<0.05; the reduction was significantly expressed in female rats (p<0.000.

  11. Community water fluoridation online: an analysis of the digital media ecosystem.

    Science.gov (United States)

    Helmi, Mohammad; Spinella, Mary Kate; Seymour, Brittany

    2018-03-30

    Research demonstrates the safety and efficacy of community water fluoridation (CWF). Yet, the digitization of communication has triggered the spread of inaccurate information online. The purpose of this study was to analyze patterns of CWF information dissemination by a network of sources on the web. We used Media Cloud, a searchable big data platform of over 550 million stories from 50 thousand sources, along with tools to analyze that archive. We generated a network of fluoridation publishers using Media Cloud's keyword identification from August 1, 2015 to July 31, 2016. We defined the media type and sentiment toward CWF for each source and generated a network map of the most influential sources during our study period based on hyperlinking activity. Media Cloud detected a total of 980 stories from 325 different sources related to water fluoridation. We identified nine different media types participating in the dissemination of information: academic, government, scientific group, natural medicine, blogs, mainstream media, advocacy groups, user-generated (e.g., YouTube), and "other." We detected five sub-networks within the overall fluoridation network map, each with its own characteristics. Twenty-one percent of sources were pro-fluoridation, receiving 57 percent of all inlinks, 22 percent of sources were anti-fluoridation, and the rest were neutral (54 percent). The dominant neutral sentiment of the network may signify that anti- and pro-sides of the debate are viewed as balanced, not just in number but also in quality of information. Despite high inlinks to pro-sources, anti-fluoridation sentiment maintains influence online. © 2018 American Association of Public Health Dentistry.

  12. [The effect of fluoride-containing tooth paste on dental plaque and on fluoride level in the mouth].

    Science.gov (United States)

    Oomori, H

    1989-01-01

    Various kinds of fluoride have been used for a long time and there are many reports concerning fluorides and their effects. Recently, the caries-inhibiting action of fluoride-containing tooth paste has been given much attention. In this study, I tried to clarify the residual time and amount of fluoride derived from the fluoride-containing tooth paste in the mouth, as well as to assess possible variation in bacterial composition in the dental plaque bacteriologically and biochemically. In the study on the fluoride clearance from the mouth, both 1.0 g and 0.5 g of paste showed the same reduction rates; and about an 80% reduction was recognized between the value at 3 minutes and that at 30 minutes, and about a 40% reduction from the 30-minute to the 60-minute interval. Next, a study on the variation in plaque bacteria was carried out. The total number of the CFU on each plate was not different between samples obtained before and after the use of the tooth paste; moreover, no difference was noted between aerobic and anaerobic culture. However, when plaque before and after brushing with fluoride-containing tooth paste were cultured in 10% sucrose solution, the differences of acid production such as lactic acid, acetic acid, and formic acid were demonstrated. Namely, these acid productions were inhibited after the use of fluoride, especially lactic acid was strongly inhibited. On the other hand, when Str. mutans from the plaque obtained after the use of fluoride-containing tooth paste was cultured in fluoride-free BHI broth, the inhibition of acid from carbohydrates was not shown clearly.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. The fluoridation of drinking water and hip fracture hospitalization rates in two Canadian communities.

    Science.gov (United States)

    Suarez-Almazor, M E; Flowerdew, G; Saunders, L D; Soskolne, C L; Russell, A S

    1993-05-01

    The purpose of this study was to compare hip fracture hospitalization rates between a fluoridated and a non-fluoridated community in Alberta, Canada: Edmonton, which has had fluoridated drinking water since 1967, and Calgary, which considered fluoridation in 1991 but is currently revising this decision. Case subjects were all individuals aged 45 years or older residing in Edmonton or Calgary who were admitted to hospitals in Alberta between January 1, 1981, and December 31, 1987, and who had a discharge diagnosis of hip fracture. Edmonton rates were compared with Calgary rates, with adjustment for age and sex using the Edmonton population as a standard. The hip fracture hospitalization rate for Edmonton from 1981 through 1987 was 2.77 per 1000 person-years. The age-sex standardized rate for Calgary was 2.78 per 1000 person-years. No statistically significant difference was observed in the overall rate, and only minor differences were observed within age and sex subgroups, with the Edmonton rates being higher in males. These findings suggest that fluoridation of drinking water has no impact, neither beneficial nor deleterious, on the risk of hip fracture.

  14. Caries and fluoridated water in two Brazilian municipalities with low prevalence of the disease

    Directory of Open Access Journals (Sweden)

    Mariângela Guanaes Bortolo da Cruz

    2018-04-01

    Full Text Available ABSTRACT OBJECTIVE To analyze the association between exposure to fluoridated water and dental caries in a context of widespread use of fluoride toothpaste in Brazil, in a scenario of low prevalence of the disease. METHODS This is a cross-sectional observational study, of the census type, in the form of a double population-based epidemiological survey carried out in two municipalities of the state of São Paulo in 2014. The sample consisted of adolescents aged 11 and 12 years, exposed (n = 184 or not exposed (n = 128 to fluoridated water for at least five years. The populations studied lived in communities of the same geographic region and had small demographic size and similar socioeconomic classification, differing only in the exposure (Silveiras or not exposure (São José do Barreiro to fluoridated water. The experience, magnitude, and degree of polarization of dental caries in these populations were analyzed using the DMFT and SiC indexes, and the association was tested using Pearson’s chi-square statistics and prevalence ratio between those not exposed and those exposed to fluoridated water. RESULTS Although caries experience (DMFT ≥ 1 was not associated with exposure to fluoridated water (chi-square = 1.78; p = 0.18; α = 5%, a significant difference was observed in the magnitude with which the disease reached the population: the means of DMFT were 1.76 in those exposed and 2.60 in those not exposed and the means of SiC were 4.04 and 6.16, respectively. The degree of polarization, indicated by the percentage of subjects with DMFT = 0, was different, being it higher (41.8% in subjects exposed and lower (34.3% in subjects not exposed. The prevalence ratio between those not exposed and those exposed was 1.13, indicating little expressiveness in prevalence difference. CONCLUSIONS Exposure to fluoridated water implied lower mean values for the DMFT and SiC indexes, even in the presence of the concomitant exposure to fluoridated toothpaste

  15. Spectrophotometric determination of fluorides in water with Hach equipment; Determinacion espectrofotometrica de fluoruros en aguas con equipo Hach

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1994-11-15

    The spectrophotometric method for the determination of the fluoride ion in water, demineralized water, raw waters, laundry waters and waters treated with ion exchange resins , using the technique and the SPADNS coloring indicated in the operation manual of the Hach equipment is described. This method covers the determination of the fluoride ion in the range from 0 to 2 mg/l on 25 ml. of radioactive base sample. These limits can be variable if the size of the used aliquot one is changed for the final determination of the fluoride ion. (Author)

  16. Tritium in [18O]water containing [18F]fluoride for [18F]FDG synthesis

    International Nuclear Information System (INIS)

    Ito, Shigeki; Saze, Takuya; Sakane, Hitoshi; Ito, Satoshi; Ito, Shinichi; Nishizawa, Kunihide

    2004-01-01

    The presence of tritium in enriched [ 18 O]water irradiated with 9.6 MeV protons used to produce [ 18 F]fluoride by the 18 O(p, n) 18 F reaction was inferred from the cross sections and threshold energies of the 18 O(p, t) 16 O reaction, and the existence of tritium was confirmed experimentally. Tritium was also detected in both [ 18 O]water recovered for recycling and waste acetonitrile solutions. The purified [ 18 F]FDG was not contaminated with 3 H. The amount of 3 H discharged into the air was far less than the International Basic Safety Standard Level

  17. Fluoridation Basics

    Science.gov (United States)

    ... return on investment for community water fluoridation (including productivity losses) ranged from $4 in small communities of ... National Center for Chronic Disease Prevention and Health Promotion Email Recommend Tweet YouTube Instagram Listen Watch RSS ...

  18. A concurrent exposure to arsenic and fluoride from drinking water in Chihuahua, Mexico.

    Science.gov (United States)

    González-Horta, Carmen; Ballinas-Casarrubias, Lourdes; Sánchez-Ramírez, Blanca; Ishida, María C; Barrera-Hernández, Angel; Gutiérrez-Torres, Daniela; Zacarias, Olga L; Saunders, R Jesse; Drobná, Zuzana; Mendez, Michelle A; García-Vargas, Gonzalo; Loomis, Dana; Stýblo, Miroslav; Del Razo, Luz M

    2015-04-24

    Inorganic arsenic (iAs) and fluoride (F-) are naturally occurring drinking water contaminants. However, co-exposure to these contaminants and its effects on human health are understudied. The goal of this study was examined exposures to iAs and F- in Chihuahua, Mexico, where exposure to iAs in drinking water has been associated with adverse health effects. All 1119 eligible Chihuahua residents (>18 years) provided a sample of drinking water and spot urine samples. iAs and F- concentrations in water samples ranged from 0.1 to 419.8 µg As/L and from 0.05 to 11.8 mg F-/L. Urinary arsenic (U-tAs) and urinary F- (U-F-) levels ranged from 0.5 to 467.9 ng As/mL and from 0.1 to 14.4 µg F-/mL. A strong positive correlation was found between iAs and F- concentrations in drinking water (rs = 0.741). Similarly, U-tAs levels correlated positively with U-F- concentrations (rs = 0.633). These results show that Chihuahua residents exposed to high iAs concentrations in drinking water are also exposed to high levels of F-, raising questions about possible contribution of F- exposure to the adverse effects that have so far been attributed only to iAs exposure. Thus, investigation of possible interactions between iAs and F- exposures and its related health risks deserves immediate attention.

  19. Dental fluorosis and urinary fluoride concentration as a reflection of fluoride exposure and its impact on IQ level and BMI of children of Laxmisagar, Simlapal Block of Bankura District, W.B., India.

    Science.gov (United States)

    Das, Kousik; Mondal, Naba Kumar

    2016-04-01

    There has been growing public concern about intellectual performance of children at high levels of fluoride exposure. A cross-sectional study was conducted in Simlapal Block of Bankura District, West Bengal, to find out the relationship between fluoride (F) exposure as exposure dose (ED) with dental fluorosis (DF), urinary fluoride concentration (UF), intelligence quotient (IQ) and body mass index (BMI). Fifty groundwater samples were collected from the target area. One hundred forty-nine children belonging to age group 6 to 18 years were considered for this study. Experimental results reveal that mean F(-) concentration of that area is 2.11 mg/L (±SD 1.64). On the basis of F concentration in groundwater and water consumption pattern, ED was calculated to explore the impact of F(-) on DF, UF, IQ, and BMI. Paired t test results suggest that exposure rate of F does not show any significant differences ( severe > mild > very mild > questionable > normal conditions. The highest UF concentration was recorded as 17 mg/L, but the status of DF in the affected children was recorded as moderate. The results also reveal that ED has a positive correlation with DF (r = 0.299, P fluoride toxicity.

  20. Highly selective and efficient removal of fluoride from ground water by layered Al-Zr-La Tri-metal hydroxide

    Science.gov (United States)

    Zhou, Jian; Zhu, Wenkun; Yu, Jie; Zhang, Hongping; Zhang, Yongde; Lin, Xiaoyan; Luo, Xuegang

    2018-03-01

    A novel layered Zr-Al-La tri-metal composite (AZL) was fabricated via co-precipitation method for fluoride removal. The as-prepared adsorbent was characterized by various technologies, and its adsorption behaviors to fluoride were thoroughly carried out to investigate the fluoride removal performance. The results showed that the layered structure existed and the AZL exhibited the maximum adsorption capacity of 90.48 mg g-1 at 308 K and pH 3.0 from the Langmuir isotherm model. The adsorption kinetics was well fitted by the pseudo-second-order equation, and the adsorption isotherms were well described by the Langmuir equation. Adsorption thermodynamics result was indicative of endothermic reaction in the process of adsorption of AZL to fluoride. The as-prepared AZL composite has excellent fluoride removal performance for the practical ground water and satisfies the permissible limit of fluoride in drinking water recommended by Chinese Standard. In addition, based on the characterization, the adsorption mechanism of fluoride on AZL was proposed, including electrostatic interaction between the protonated surface of AZL and fluoride, as well as ion-exchange by hydroxyl group and fluoride.

  1. Fluoride ions sorption of the water using natural and modified hematite with aluminium hydroxide; Sorcion de iones fluoruro del agua utilizando hematita natural y hematita acondicionada con hidroxido de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Teutli S, E. A.

    2011-07-01

    Fluorine is a mineral known for its dental benefits, but fluoride ions can cause fluoro sis in excessive quantities. There are many epidemiological studies on possible adverse effects resulting from prolonged ingestion of fluoride through drinking water. These studies demonstrate that fluoride mainly affects the bone tissue (bones and teeth), may produce an adverse effect on tooth enamel and can cause mild dental fluoro sis at concentrations from 0.9 to 1.2 mg/L in drinking water. In several states of Mexico, water contaminated with fluoride ions can be found, such as Aguascalientes, Chihuahua, Coahuila, Durango, Guanajuato, Sonora, Zacatecas, San Luis Potosi and Jalisco, where the fluoride ions levels are higher than 1.5 mg/L, established by the Mexican Official Standard (NOM-127-Ssa-2000) which sets the permissible limits of water for human use and consumption. Currently, several technologies have been proposed to remove fluoride ions from water such as precipitation methods which are based on the addition of chemicals to water and sorption methods to removed fluoride ions by sorption or ion exchange reactions by some suitable substrate capable of regenerate and reuse. In this work, the sorption of fluoride ions using unmodified and modified hematite with aluminum hydroxide to remove fluoride ions from water by bath experiments was studied. The hematite was modified by treating it with aluminum hydroxide, NaOH and Al{sub 2}(SO{sub 4}){sub 3} solutions. The characterization of hematite before and after modification with aluminum hydroxide was studied by X-ray diffraction, scanning electron microscopy, EDS and Bet. The effect of ph, contact time, concentration of fluoride ions, and the dose of sorbent on the sorption of fluoride ions by the modified hematite were studied. Equilibrium was reached within 48 hours of contact time and the maximum sorption of fluoride ions were in the range pH{sub eq} between 2.3 and 6.2. Sorption capacities of fluoride ions as a

  2. Rapid detection of fluoride in potable water using a novel fluorogenic compound 7-O-tert-butyldiphenylsilyl-4-methylcoumarin

    Directory of Open Access Journals (Sweden)

    Ravi Chavali

    2015-12-01

    Full Text Available In the present work, we have synthesized a new water soluble colorless chemical compound 7-O-tert-butyldiphenylsilyl-4-methylcoumarin (TBDPSC that releases fluorescent molecules imparting blue fluorescence to the solution, upon interaction with fluoride ions in water. The blue fluorescence can be visualized using simple hand held ultraviolet (UV lamps. TBDPSC has excellent sensitivity and selectivity towards fluoride and our results indicate that fluoride concentrations as low as 0.2 mg/L can be accurately detected within a few seconds. Fluoride testing with TBDPSC is simple and rapid compared to the conventional methodologies without the requirement of trained personnel. Hence, the present fluoride detection method can be easily field deployable and particularly useful for monitoring water quality in limited resource communities.

  3. The differences in healthcare utilization for dental caries based on the implementation of water fluoridation in South Korea.

    Science.gov (United States)

    Cho, Myung-Soo; Han, Kyu-Tae; Park, Sohee; Moon, Ki Tae; Park, Eun-Cheol

    2016-11-08

    There were some debates about the water fluoridation program in South Korea, even if the program had generally substantial effectiveness. Because the out-of-pocket expenditures for dental care were higher in South Korea than in other countries, an efficient solution was needed. Therefore, we examined the relationship between the implementation of water fluoridation and the utilization of dental care. We used the National Health Insurance Service National Sample Cohort. In this study, data finally included 472,250 patients who were newly diagnosed with dental caries during 2003-2013. We performed survival analysis using cox proportional hazard model, negative binomial-regression, and regression analyses using generalized estimating equation models. There were 48.49 % outpatient dental care visit during study period. Individuals with water fluoridation had a lower risk of dental care visits (HR = 0.949, 95 % CI = 0.928-0.971). Among the individuals who experienced a dental care visit, those with water fluoridation program had a lower number of dental care visits (β = -0.029), and the period of water fluoridation had an inverse association with the dental care expenditures. The implementation of water fluoridation programs and these periods are associated with reducing the utilization of dental health care. Considering these positive impacts, healthcare professionals must consider preventive strategies for activating water fluoridation programs, such as changes in public perception and relations, for the effective management of dental care in South Korea.

  4. [The effect of alternating administration of aluminum chloride and sodium fluoride in drinking water on the concentration of fluoride in serum and its content in bones of rats].

    Science.gov (United States)

    Lubkowska, Anna; Chlubek, Dariusz; Machoy-Mokrzyniska, Anna

    2006-01-01

    Fluorine and aluminum remain a very interesting research topic due to equivocal and relatively unknown toxic action, role in the etiology of various diseases, and interactions of both elements. Fluorine and aluminum compounds are absorbed by organisms through the gastric and respiratory systems, although the latter route operates only at very high concentrations in air. Chronic exposure to fluorine and aluminum leads to accumulation of both elements, especially in bones and teeth, but also in lung, brain, kidney, and liver. Organisms excrete these elements with urine, faeces, and to a minor extent with sweat and bile. In the light of reports suggesting that aluminum has protective properties against fluorine toxicity during exposure to both elements, we decided to examine the effect of alternating doses of aluminum fluoride and sodium fluoride in drinking water on rats. Four female groups received: I--100 ppm fluorine ions during one month; II--100 ppm fluorine ions alternating every two days with 300 ppm aluminum ions during one month; III--100 ppm fluoride ions during four months; IV--100 ppm fluorine ions alternating every two days with 300 ppm aluminum ions during four months. The respective male groups called IA, IIA, IIIA, and IVA were treated identically. Subsequently, the animals were anesthetized and sacrificed. Blood was sampled from the heart and the right femur was removed for fluorine determination. Fluorine content in the femur and serum was determined with an ion-selective electrode (Orion). The results were analyzed statistically (Statistica 6). We observed higher fluoride concentrations in serum as compared with control values in all groups of female and male rats exposed to sodium fluoride only. Longer exposure time (4 months) did not result in further increase in serum fluoride concentration. However, longer exposure increased fluoride accumulation in the femur (p Fluorine content in the femur of rats exposed to NaF and AlCI3 for four months was

  5. WHO water quality standards Vs Synergic effect(s) of fluoride, heavy metals and hardness in drinking water on kidney tissues

    Science.gov (United States)

    Wasana, Hewa M. S.; Perera, Gamage D. R. K.; Gunawardena, Panduka De S.; Fernando, Palika S.; Bandara, Jayasundera

    2017-02-01

    Despite WHO standards, waterborne diseases among the human being are rising alarmingly. It is known that the prolong exposure to contaminated water has major impact on public health. The effect of chemical contaminations in drinking water on human being is found to be chronic rather than acute and hence can be defined “consumption of contaminated drinking water could be a silent killer”. As the WHO recommended water quality standards are only for individual element and synergic effects of trace metals and anions have not been considered, investigation of synergic effects of trace metals and anions and their effect on human being is of prime important research. By an animal trial, we investigated the synergic effect(s) of heavy metals, aluminium, arsenic, fluoride and hardness in drinking water on kidney tissues of mice. Our investigation strongly suggests existing of a synergic effect especially among Cd, F and hardness of water which could lead to severe kidney damage in mice, even at WHO maximum recommended levels. Hence, the synergic effect(s) of trace metals, fluoride and hardness present in drinking water should be investigated meticulously when stipulating the water quality at WHO maximum recommended levels.

  6. Fluoride distribution and contamination in the water, soil and plants continuum and its remedial technologies, an Indian perspective- a review.

    Science.gov (United States)

    Singh, Gayatri; Kumari, Babita; Sinam, Geetgovind; Kriti; Kumar, Navin; Mallick, Shekhar

    2018-04-09

    Fluorine is an essential element required in trace amounts but gets toxic for human beings at levels more than 1.5 mg F - L -1 primarily through drinking contaminated water. It is the 13th most abundant element and constitutes about 0.06-0.09% in the earth crust. It is electronegative in aqueous medium forming fluoride ion (F - ). Fluoride contamination in the environment occurs mostly due to anthropogenic and geogenic sources. Fluoride is widely distributed in all components of environment, air (0.1-0.6 μg L -1 ) soils (150-400 mg Kg -1 ) rocks (100-2000 mg Kg -1 ), plant (0.01-42 mg Kg -1 ) and water (1.0-38.5 mg L -1 ). Human beings and animals are being exposed to F - primarily from water (0.2-42.0 mg L -1 ) and plants (0.77-29.5 μg g -1 ). Fluorosis, a health hazard due to F - is a major problem in many countries across the world affecting about 200 million people globally. In India, > 62 million people in twenty states are facing problem due to F - . The most affected states are Rajasthan (7670 habitations), Telangana (1,174 habitations) and Karnataka (1122 habitations). To mitigate this problem, there is an urgent need to understand the current status and brief knowledge of F - geochemistry. The objective of this review is to highlight different sources of F - that contaminate different environmental matrices including plants, the extent of contamination level in India, uptake, translocation and toxicity mechanism in plants. The review also highlights currently available mitigation methods or technologies through physio-chemical and biological means. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Defluoridation of drinking water by combined electrocoagulation: effects of the molar ratio of alkalinity and fluoride to Al(III).

    Science.gov (United States)

    Zhao, Hua-Zhang; Yang, Wei; Zhu, Jun; Ni, Jin-Ren

    2009-03-01

    The defluoridation efficiency (epsilon(F)) of electrocoagulation (EC) is closely related to the pH level of the F(-)-containing solution. The pH level usually needs to be adjusted by adding acid in order to obtain the highest epsilon(F) for the F(-)-containing groundwater. The use of combined EC (CEC), which is the combination of chemical coagulation with EC, was proposed to remove fluoride from drinking water for the first time in this study. The optimal scheme for the design and operation of CEC were obtained through experiments on the treatment of F(-)-containing groundwater. It was found, with OH(-) being the only alkalinity of the raw water, that the highest efficiency would be obtained when the molar ratio of alkalinity and fluoride to Al(III) (gamma(Alkalinity+F)) was controlled at 3.0. However, when the raw water contained HCO(3)(-) alkalinity, a correction coefficient was needed to correct the concentration of HCO(3)(-) to obtain the optimal defluoridation condition of gamma(Alkalinity+F)=3.0 for CEC. The correction coefficient of HCO(3)(-) concentration was concluded as 0.60 from the experiment. For the practical F(-)-containing groundwater treatment, CEC can achieve similar epsilon(F) as an acid-adding EC process. The consumption of aluminum electrode was decreased in CEC. The energy consumption also declined greatly in CEC, which is less than one third of that in the acid-adding EC process.

  8. Removal of fluoride from drinking water using modified ultrafine tea powder processed using a ball-mill

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Huimei; Xu, Lingyun; Chen, Guijie; Peng, Chuanyi [School of Tea & Food Science and Technology, Anhui Agricultural University/State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, Anhui (China); Ke, Fei [School of Tea & Food Science and Technology, Anhui Agricultural University/State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, Anhui (China); School of Science, Anhui Agricultural University, Hefei 230036 (China); Liu, Zhengquan; Li, Daxiang; Zhang, Zhengzhu [School of Tea & Food Science and Technology, Anhui Agricultural University/State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, Anhui (China); Wan, Xiaochun, E-mail: xcwan@ahau.edu.cn [School of Tea & Food Science and Technology, Anhui Agricultural University/State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, Anhui (China)

    2016-07-01

    Highlights: • Ultrafine tea powder (UTP) was prepared by ball-milling. • A novel and high efficient biosorbent from ultrafine tea powder (UTP) for the removal of fluoride from drinking water was prepared. • Loaded ultrafine tea powder adsorbed more fluoride adsorption than loaded tea waste. • UTP-Zr performed well over a considerably wide pH range, from 3.0 to 10.0. • UTP-Zr retains Zr metal ion during defluoridation, limiting secondary pollution. - Abstract: A low-cost and highly efficient biosorbent was prepared by loading zirconium(IV) onto ball-milled, ultrafine tea powder (UTP-Zr) for removal of fluoride from drinking water. To evaluate the fluoride adsorption capacity of UTP-Zr over a wide range of conditions, the biosorbent dosage, contact time, initial pH, initial fluoride concentration and presence of other ions were varied. UTP-Zr performed well over the considerably wide pH range of 3–10. The residual concentration of Zr in the treated water was below the limit of detection (0.01 mg/L). Fluoride adsorption by the UTP-Zr biosorbent followed the Langmuir model, with a maximum adsorption capacity of 12.43 mgF/g at room temperature. The fluoride adsorption kinetics fit the pseudo-second-order kinetic model. The synthesized biosorbent was characterized by BET, SEM, EDS, XRD and XPS to reveal how UTP-Zr interacts with fluoride. Results from this study demonstrated that UTP-based biosorbents will be useful and safe for the removal of fluoride from drinking water.

  9. Removal of fluoride from drinking water using modified ultrafine tea powder processed using a ball-mill

    International Nuclear Information System (INIS)

    Cai, Huimei; Xu, Lingyun; Chen, Guijie; Peng, Chuanyi; Ke, Fei; Liu, Zhengquan; Li, Daxiang; Zhang, Zhengzhu; Wan, Xiaochun

    2016-01-01

    Highlights: • Ultrafine tea powder (UTP) was prepared by ball-milling. • A novel and high efficient biosorbent from ultrafine tea powder (UTP) for the removal of fluoride from drinking water was prepared. • Loaded ultrafine tea powder adsorbed more fluoride adsorption than loaded tea waste. • UTP-Zr performed well over a considerably wide pH range, from 3.0 to 10.0. • UTP-Zr retains Zr metal ion during defluoridation, limiting secondary pollution. - Abstract: A low-cost and highly efficient biosorbent was prepared by loading zirconium(IV) onto ball-milled, ultrafine tea powder (UTP-Zr) for removal of fluoride from drinking water. To evaluate the fluoride adsorption capacity of UTP-Zr over a wide range of conditions, the biosorbent dosage, contact time, initial pH, initial fluoride concentration and presence of other ions were varied. UTP-Zr performed well over the considerably wide pH range of 3–10. The residual concentration of Zr in the treated water was below the limit of detection (0.01 mg/L). Fluoride adsorption by the UTP-Zr biosorbent followed the Langmuir model, with a maximum adsorption capacity of 12.43 mgF/g at room temperature. The fluoride adsorption kinetics fit the pseudo-second-order kinetic model. The synthesized biosorbent was characterized by BET, SEM, EDS, XRD and XPS to reveal how UTP-Zr interacts with fluoride. Results from this study demonstrated that UTP-based biosorbents will be useful and safe for the removal of fluoride from drinking water.

  10. Removal of fluoride from drinking water using a modified fly ash adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Debasis Goswami; Arabinda K. Das

    2006-01-15

    Fly ash from a coal-fired power station was chemically modified and utilized for the removal of fluoride from drinking water. Two types of beds were used. Bed I was prepared by treatment with 12M HCl followed by neutralization with 5M NaOH solution. The reaction mass was filtered, washed, dried, and crushed to fine powder. Bed I material was mixed with alum and MgCl{sub 2} solutions and treated with 0.9M Na{sub 2}CO{sub 3} until pH reached to 4.5. Mass was again filtered, washed, dried at 120{sup o}C for 4 h and crushed to fine powder. This bed material is Bed II, which was used for defluoridation. Bed I was used to maintain pH (7.5-8.5) of the final effluent. Fluoride (100 ppm) present in both synthetic mixtures and drinking water samples was allowed to pass through Bed II (15 g) absorbent and effluents were found to contain no fluoride but pH of the effluent was 5.4-5.5. To maintain WHO guidelines for drinking water on pH, this effluent was again passed through Bed I. The effectiveness of the modified fly ash bed was satisfactory.

  11. Water Level Station History

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Images contain station history information for 175 stations in the National Water Level Observation Network (NWLON). The NWLON is a network of long-term,...

  12. Qualitative investigation of the reasons behind opposition to water fluoridation in regional NSW, Australia

    Directory of Open Access Journals (Sweden)

    Matthew C Knox

    2017-02-01

    Full Text Available Objectives: To investigate reasons behind strong opposition to water fluoridation in regional New South Wales, Australia, and to make recommendations to improve community engagement. Importance: Few studies have used qualitative methodologies to understand the reasons for strong antifluoridation views. An understanding of these reasons could be useful when designing public campaigns to combat the strong antifluoridation message. Methods: The qualitative study used semistructured interviewing and thematic analysis. Ten participants were recruited using purposive and snowball sampling methods until data saturation was reached. Thematic analysis and graphical representation of themes assisted in analysing the data for logical connections and relationships. Results: Six dominant themes and numerous subthemes were identified. Five of the major themes were reasons for opposition: scepticism, health effects, ethics, environmental impacts and economics. Each of these was inextricably linked to a sixth major theme: alternatives to fluoridation. Conclusions: All participants had strongly held antifluoridation views, and provided a unique insight into their perceptions and reasons for opposing water fluoridation. Concerns about ‘fraudulent research’ and the influence of industry on government bodies were novel themes. The concerns raised could be used to inform future population health campaigns, research, public education and resource-allocation decisions. Open community consultation may be able to address the issues raised in a nonjudgemental and collaborative manner.

  13. Comparative study of adsorbents for the removal of fluoride ions from water use and consumption in Mexico

    International Nuclear Information System (INIS)

    Teutli S, E. A.

    2014-01-01

    Although fluoride is essential for health many studies have shown it is associated with some health problems, such as fluoro sis, thyroid disorder, neurological disease, Alzheimer, pineal gland and cancer. One of the major routes of exposure is through drinking water. The World Health Organization (Who) allows only 1.5 mg/L as a safe limit for fluoride ions in drinking water and the EPA U. S. Environmental Protection Agency has recently proposed 0.7 mg/L. In some cases, the water extracted from deep wells has concentrations of fluoride ions above 1.5 mg/L (NOM-127-SSA1-2000) which is the permissible limit of water for human use and consumption (whuc). In several countries, there are high concentrations of fluoride ions due to the geological distribution of fluorine-rich rocks. In our country we can find several states that have concentrations higher than 1.5 mg/L of fluoride ions in water, such as Aguascalientes, Zacatecas, Chihuahua, Coahuila, Durango, Guanajuato, Sonora, Jalisco and San Luis Potosi. Various technologies have been proposed to remove fluoride ions from water, such as adsorption, ion exchange, reverse osmosis, nano filtration, electrodialysis, dialysis and electrocoagulation. Sorption is superior to other techniques in terms of initial cost, simplicity of design and ease of operation. In this work systematic studies were done considering the aspects mentioned above, in order to determine the adsorbents properties and most suitable conditions for the removal of fluoride ions from whuc. It is important to note that to date no adsorption treatments for the removal of fluoride ions from water for human use and consumption in our country is done, although there are established methodologies, they have not been implemented because of their high costs. In this work an integral study was done on the removal of fluoride ions from water for human use and consumption. A comparative study of hematite, calcite and zeolite as adsorbents was performed to develop a

  14. [Effects of long-term fluoride in drinking water on risks of hip fracture of the elderly: an ecologic study based on database of hospitalization episodes].

    Science.gov (United States)

    Park, Eun Young; Hwang, Seung Sik; Kim, Jai Yong; Cho, Soo Hun

    2008-05-01

    Fluoridation of drinking water is known to decrease dental caries, particularly in children. However, the effects of fluoridated water on bone over several decades are still in controversy. To assess the risk of hip fracture related to water fluoridation, we evaluated the hip fracture-related hospitalizations of the elderly between a fluoridated city and non-fluoridated cities in Korea. Cheongju as a fluoridated area and Chungju, Chuncheon, Suwon, Wonju as non-fluoridated areas were chosen for the study. We established a database of hip fracture hospitalization episode based on the claims data submitted to the Health Insurance Review Agency from January 1995 to December 2002. The hip fracture hospitalization episodes that satisfied the conditions were those that occurred in patients over 65 years old, the injuries had a hip fracture code (ICD-9 820, ICD-10 S72) and the patients were hospitalized for at least 7days. A total of 80,558 cases of hip fracture hospitalization episodes were analyzed. The admission rates for hip fracture increased with the age of the men and women in both a fluoridated city and the non-fluoridated cities (phip fracture increased significantly both for men and women as their age increased. However, any difference in the hip fracture admission rates was not consistently observed between the fluoridated city and the nonfluoridated cities. We cannot conclude that fluoridation of drinking water increases the risk of hip fracture in the elderly.

  15. Exposure to Fluoride in Drinking Water and Hip Fracture Risk: A Meta-Analysis of Observational Studies

    OpenAIRE

    Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

    2015-01-01

    Background Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. Methods PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies w...

  16. Fluoride Content of Bottled Waters in Hong Kong and Qatar.

    Science.gov (United States)

    Al-Mulla, Hessa I; Anthonappa, Robert P; King, Nigel M

    2016-01-01

    To determine the F concentration of bottled waters that was available in Hong Kong and Qatar. The F concentrations of bottled waters collected from Hong Kong (n=81) and Qatar (n=32) were analysed. The F ion selective electrode method was used to measure the F concentration in the samples. Three measurements were obtained for every sample to ensure reproducibility and appropriate statistical analyses were employed. Qatar group: F concentrations ranged from 0.06 ppm to 3.0 ppm with a mean value of 0.8 ppm. The F concentrations displayed on the labels of the samples (60%) were significantly lower than the measured F concentration (p Qatar. The F concentrations displayed on the labels were not consistent with the measured F concentrations.

  17. Diffusion of water and ethanol in silicalite crystals synthesized in fluoride media

    KAUST Repository

    Zhang, Ke

    2013-04-01

    Diffusion of water and ethanol in silicalite has been studied in large crystals (70 μm × 30 μm × 15 μm) synthesized via a fluoride mediated route. The near-perfect hydrophobic silicalite (F-) crystals have very few internal silanol defects and, as a result, display water and ethanol transport behavior that is uncontaminated by these defects. The transport diffusivity (Dt) of ethanol is higher than that of water at the same sorbate activity. However, this difference is due to the difference in the shape of the isotherms. The thermodynamically corrected diffusivity (D o) of water is almost an order of magnitude higher than that of ethanol reflecting the difference in molecular size. Estimates of the permeability/permselectivity/separation factors for ethanol/water separation based on the present kinetic and equilibrium data for the fluoride synthesized crystals are compared with the values observed for traditional silicalite membranes. The present diffusivity values for fluoride synthesized silicalite are similar to the values for regular silicalite (OH-) derived from uptake rate measurements but much smaller (by more than four orders of magnitude) than the self-diffusivities derived from PFG-NMR measurements. This result is consistent with the results of other measurements of the diffusion of small molecules in silicalite which suggest that, in macroscopic measurements, the rate of intra-crystalline transport is controlled by the sub-structure (extensive twinning), rather than by diffusion in the ideal MFI micropores. In this situation microscale measurements such as PFG-NMR will lead to erroneously high estimates of transport rates and therefore of permeability and permselectivity. © 2012 Elsevier Inc. All rights reserved.

  18. Diffusion of water and ethanol in silicalite crystals synthesized in fluoride media

    KAUST Repository

    Zhang, Ke; Lively, Ryan P.; Dose, Michelle E.; Li, Liwei; Koros, William J.; Ruthven, Douglas M.; McCool, Benjamin A.; Chance, Ronald R.

    2013-01-01

    Diffusion of water and ethanol in silicalite has been studied in large crystals (70 μm × 30 μm × 15 μm) synthesized via a fluoride mediated route. The near-perfect hydrophobic silicalite (F-) crystals have very few internal silanol defects and, as a result, display water and ethanol transport behavior that is uncontaminated by these defects. The transport diffusivity (Dt) of ethanol is higher than that of water at the same sorbate activity. However, this difference is due to the difference in the shape of the isotherms. The thermodynamically corrected diffusivity (D o) of water is almost an order of magnitude higher than that of ethanol reflecting the difference in molecular size. Estimates of the permeability/permselectivity/separation factors for ethanol/water separation based on the present kinetic and equilibrium data for the fluoride synthesized crystals are compared with the values observed for traditional silicalite membranes. The present diffusivity values for fluoride synthesized silicalite are similar to the values for regular silicalite (OH-) derived from uptake rate measurements but much smaller (by more than four orders of magnitude) than the self-diffusivities derived from PFG-NMR measurements. This result is consistent with the results of other measurements of the diffusion of small molecules in silicalite which suggest that, in macroscopic measurements, the rate of intra-crystalline transport is controlled by the sub-structure (extensive twinning), rather than by diffusion in the ideal MFI micropores. In this situation microscale measurements such as PFG-NMR will lead to erroneously high estimates of transport rates and therefore of permeability and permselectivity. © 2012 Elsevier Inc. All rights reserved.

  19. Evaluation and Assessment of Fluoride in Drinking Water Wells Damavand Villages Zoning in GIS According to DMF Index

    Directory of Open Access Journals (Sweden)

    Kave Kheirkhah Rahimabad

    2016-09-01

    Full Text Available Background:Fluoride is one the vital anions and the drinking water is the main source of preparing it for the human body. Nonetheless, the aim of this paper is to investigate the Fluoride rate in water supplying wells by using GIS environment according to decay, missing or filled (DMF index.  Methods: This research is an analytic and cross-sectional descriptive study with sampling approach of 12 water supplying wells of Damavand villages in summer and autumn the year 2013. The Fluoride concentration was measured by standard method SPADNS using MN-Nano color 400 Photometer in laboratory of Rural Water and Wastewater Company of Tehran. Then DMF was investigated for local students and finally the obtained data were modeled in GIS. Results: The average of Fluoride concentration was 0.094 to 0.212 mg/L in summer and 0.137 to 3.48 mg/L in autumn. The DMF index was estimated around 5.46 for all evaluated students that the mentioned index was 7.635 and 3.29 for male and female pupils respectively which are statistically significant difference. Conclusion: The amounts of fluorine in drinking water supplies in rural Damavand villages are lower than the international water standards. According to the results of experiments and lack of fluorine ion in the villages of this town, required fluorine should be done by drinkable water fluoridation and continuities of implementation plan for fluoride ion among the schools until reaching the fluoride concentration to the standard threshold, Supplying required fluorine of body by mouth-wash materials for people of this region

  20. Fluoride in drinking water and risk of hip fracture in the UK: a case-control study.

    Science.gov (United States)

    Hillier, S; Cooper, C; Kellingray, S; Russell, G; Hughes, H; Coggon, D

    2000-01-22

    Although the benefits of water fluoridation for dental health are widely accepted, concerns remain about possible adverse effects, particularly effects on bone. Several investigators have suggested increased rates of hip fracture in places with high concentrations of fluoride in drinking water, but this finding has not been consistent, possibly because of unrecognised confounding effects. We did a case-control study of men and women aged 50 years and older from the English county of Cleveland, and compared patients with hip fracture with community controls. Current addresses were ascertained for all participants; for those who agreed to an interview and who passed a mental test, more detailed information was obtained about lifetime residential history and exposure to other known and suspected risk factors for hip fracture. Exposures to fluoride in water were estimated from the residential histories and from information provided by water suppliers. Analysis was by logistic regression. 914 cases and 1196 controls were identified, of whom 514 and 527, respectively, were interviewed. Among those interviewed, hip fracture was strongly associated with low body-mass index (p for trend water ranged from 0.15 to 1.79 ppm. Current residence in Hartlepool was a good indicator for high lifetime exposure to fluoride. After adjustment for potential confounders, the odds ratio associated with an average lifetime exposure to fluoride > or =0.9 ppm was 1.0 [95% CI 0.7-1.5]. There is a low risk of hip fracture for people ingesting fluoride in drinking water at concentrations of about 1 ppm. This low risk should not be a reason for withholding fluoridation of water supplies.

  1. Evidence-based tailoring of behavior-change campaigns: increasing fluoride-free water consumption in rural Ethiopia with persuasion.

    Science.gov (United States)

    Huber, Alexandra C; Tobias, Robert; Mosler, Hans-Joachim

    2014-03-01

    Two hundred million people worldwide are at risk of developing dental and skeletal fluorosis due to excessive fluoride uptake from their water. Since medical treatment of the disease is difficult and mostly ineffective, preventing fluoride uptake is crucial. In the Ethiopian Rift Valley, a fluoride-removal community filter was installed. Despite having access to a fluoride filter, the community used the filter sparingly. During a baseline assessment, 173 face-to-face interviews were conducted to identify psychological factors that influence fluoride-free water consumption. Based on the results, two behavior-change campaigns were implemented: a traditional information intervention targeting perceived vulnerability, and an evidence-based persuasion intervention regarding perceived costs. The interventions were tailored to household characteristics. The campaigns were evaluated with a survey and analyzed in terms of their effectiveness in changing behavior and targeted psychological factors. While the intervention targeting perceived vulnerability showed no desirable effects, cost persuasion decreased the perceived costs and increased the consumption of fluoride-free water. This showed that altering subjective perceptions can change behavior even without changing objective circumstances. Moreover, interventions are more effective if they are based on evidence and tailored to specific households. © 2013 The International Association of Applied Psychology.

  2. Comparison of fluoride uptake level by enamel from Iranian school brand and standard NaF mouthrinses

    Directory of Open Access Journals (Sweden)

    Gasem Ansari

    2009-03-01

    Full Text Available Background and aims. The use of fluoride mouthrinses has been proved to be one of the most effective ways to prevent tooth decay. A community based program using F+ rinse at school has also proved to be well-controlled and efficient. The aim of this investigation was to evaluate fluoride uptake level of a locally prepared NaF rinse used in Iran’s school program during 2005. Materials and methods. A total of 30 freshly extracted sound human premolars were collected and divided into two groups of 15. Each tooth then underwent two steps of sectioning; first the root was amputated from CEJ and then a longitudinal section was performed in bucco-lingual direction to provide two similar samples of the same tooth. A specific hemi-circular area on either of the experimental halves was treated by NaF rinse from USA or a locally prepared NaF used in school programs. Two subsequent biopsies were taken from each half using acid etch enamel biopsy technique. Fluoride and calcium content of the specimens were measured in order to evaluate fluoride uptake level and biopsy depth effect, respectively. Collected data were recorded in the forms provided and statistical analysis, mostly descriptive, was performed for comparison. Results. Based on the data collected, it appears that the use of F+ rinse would clearly improve enamel quality by a rise in fluoride concentration. Statistical analysis using a paired t-test and repeated measure method revealed that with 95% confidence fluoride concentration increases at both levels of biopsy with no statistically significant differences between the samples treated with two rinses. Conclusion. There seem to be reasonable potential for the clinical use of Iranian brand fluoride mouthrinse. There was no significant difference between the level of uptake from NaF from USA and the Iranian product in 2 layers of enamel biopsy.

  3. Evaluation and Assessment of Fluoride in Drinking Water Wells Damavand Villages Zoning in GIS According to DMF Index

    OpenAIRE

    Kave Kheirkhah Rahimabad; Amir Hessam Hasani; Reza Saeedi; Mir Masoud Kheirkhah Zarkesh; Mojtaba Sayadi

    2016-01-01

    Background:Fluoride is one the vital anions and the drinking water is the main source of preparing it for the human body. Nonetheless, the aim of this paper is to investigate the Fluoride rate in water supplying wells by using GIS environment according to decay, missing or filled (DMF) index.  Methods: This research is an analytic and cross-sectional descriptive study with sampling approach of 12 water supplying wells of Damavand villages in summer and autumn the year 2013. The Fluor...

  4. Water level detection pipeline

    International Nuclear Information System (INIS)

    Koshikawa, Yukinobu; Imanishi, Masatoshi; Niizato, Masaru; Takagi, Masahiro

    1998-01-01

    In the present invention, water levels of a feedwater heater and a drain tank in a nuclear power plant are detected at high accuracy. Detection pipeline headers connected to the upper and lower portions of a feedwater heater or a drain tank are connected with each other. The connection line is branched at appropriate two positions and an upper detection pipeline and a lower detection pipeline are connected thereto, and a gauge entrance valve is disposed to each of the detection pipelines. A diaphragm of a pressure difference generator is connected to a flange formed to the end portion. When detecting the change of water level in the feedwater heater or the drain tank as a change of pressure difference, gauge entrance valves on the exit side of the upper and lower detection pipelines are connected by a connection pipe. The gauge entrance valve is closed, a tube is connected to the lower detection pipe to inject water to the diaphragm of the pressure difference generator passing through the connection pipe thereby enabling to calibrate the pressure difference generator. The accuracy of the calibration of instruments is improved and workability thereof upon flange maintenance is also improved. (I.S.)

  5. Grout formulation for disposal of low-level and hazardous waste streams containing fluoride

    Science.gov (United States)

    McDaniel, E.W.; Sams, T.L.; Tallent, O.K.

    1987-06-02

    A composition and related process for disposal of hazardous waste streams containing fluoride in cement-based materials is disclosed. the presence of fluoride in cement-based materials is disclosed. The presence of fluoride in waste materials acts as a set retarder and as a result, prevents cement-based grouts from setting. This problem is overcome by the present invention wherein calcium hydroxide is incorporated into the dry-solid portion of the grout mix. The calcium hydroxide renders the fluoride insoluble, allowing the grout to set up and immobilize all hazardous constituents of concern. 4 tabs.

  6. Arsenic, Boron, and Fluoride Concentrations in Ground Water in and Near Diabase Intrusions, Newark Basin, Southeastern Pennsylvania

    Science.gov (United States)

    Senior, Lisa A.; Sloto, Ronald A.

    2006-01-01

    During an investigation in 2000 by the U.S. Environmental Protection Agency (USEPA) of possible contaminant releases from an industrial facility on Congo Road near Gilbertsville in Berks and Montgomery Counties, southeastern Pennsylvania, concentrations of arsenic and fluoride above USEPA drinking-water standards of 10 ?g/L and 4 mg/L, respectively, and of boron above the USEPA health advisory level of 600 ?g/L were measured in ground water in an area along the northwestern edge of the Newark Basin. In 2003, the USEPA requested technical assistance from the U.S. Geological Survey (USGS) to help identify sources of arsenic, boron, and fluoride in the ground water in the Congo Road area, which included possible anthropogenic releases and naturally occurring mineralization in the local bedrock aquifer, and to identify other areas in the Newark Basin of southeastern Pennsylvania with similarly elevated concentrations of these constituents. The USGS reviewed available data and collected additional ground-water samples in the Congo Road area and four similar hydrogeologic settings. The Newark Basin is the largest of the 13 major exposed Mesozoic rift basins that stretch from Nova Scotia to South Carolina. Rocks in the Newark Basin include Triassic through Jurassic-age sedimentary sequences of sandstones and shales that were intruded by diabase. Mineral deposits of hydrothermal origin are associated with alteration zones bordering intrusions of diabase and also occur as strata-bound replacement deposits of copper and zinc in sedimentary rocks. The USGS review of data available in 2003 showed that water from about 10 percent of wells throughout the Newark Basin of southeastern Pennsylvania had concentrations of arsenic greater than the USEPA maximum contaminant level (MCL) of 10 ?g/L; the highest reported arsenic concentration was at about 70 ?g/L. Few data on boron were available, and the highest reported boron concentration in well-water samples was 60 ?g/L in contrast

  7. Water fluoridation in Brazilian cities at the first decade of the 21st century

    Directory of Open Access Journals (Sweden)

    Paulo Frazão

    Full Text Available ABSTRACT OBJECTIVE To assess the coverage of the fluoridation of the public water supply in Brazilian municipalities at the first decade of the 21st century, according to population size and municipal human development index (MHDI. METHODS We have used data produced by national information agencies and the United Nations Development Programme. Population size was separated into 50,000 inhabitants. The MHDI was classified into 0.799. Absolute and relative inequalities between categories were evaluated using indicators of effect and total impact. RESULTS We have obtained information for 5,558 municipalities. The coverage rate of water fluoridation increased from 67.7% to 76.3%. Approximately 884 (15.9% municipalities and 29,600,000 inhabitants started being benefited by the measure. We have observed a significant expansion in municipalities with < 10,000 inhabitants (increase of 21.0 percentage points and low or very low MHDI (17.7 percentage points. CONCLUSIONS Population coverage of the public policy has increased 8.6%, and we can also see significant reductions in absolute and relative inequality according to population size and MHDI. Regarding municipal coverage rate, there was also a reduction in inequality in all comparisons except for absolute inequality between the categories of MHDI. The public policy has operated as a factor of health protection in the context of the ongoing social protection policies in the country.

  8. Water level indicator

    International Nuclear Information System (INIS)

    Murase, Michio; Araki, Hidefumi.

    1996-01-01

    A difference of pressure between a standard pressure conduit in communication with a gas phase of a reactor pressure vessel and a water level pressure conduit in communication with a liquid phase of the pressure vessel is detected by a pressure difference gage. A communication pipe and a standard level vessel are disposed between the pressure vessel and the standard pressure conduit, and a standard liquid surface on the side of the standard pressure conduit is formed in the standard level vessel. A gas releaser is disposed to the gas phase portion of the standard level vessel. The gas releaser equipment is constituted by a porous material, a permeation membrane and a gas exhaustion hole. The gas phase of the standard level vessel is divided by a partition plate into a first gas phase being in contact with a connection portion with the communication pipe and a second gas phase in contact with the gas releaser. A gas flow channel hole and a condensate descending hole are disposed to the partition plate. Since incondensible gases accumulated to the standard level vessel are effectively exhausted, the incondensible gases are prevented from being dissolved into liquid. (I.N.)

  9. Assessment of arsenic, fluoride, bacteria, and other contaminants in drinking water sources for rural communities of Kasur and other districts in Punjab, Pakistan.

    Science.gov (United States)

    Arshad, Nasima; Imran, Saiqa

    2017-01-01

    High levels of arsenic contamination in drinking water of two villages, Badarpur and Ibrahimabad of district Kasur, central Punjab, Pakistan is reported first time in present studies. Groundwater quality situation was found to be impaired when samples of different rural areas of district Kasur were monitored according to Pakistan Standards and Quality Control Authority (PSQCA) for all significant water quality constituents and analyzed for trace elements, physico-chemical, and microbiological parameters. Out of 35water sources, 97 % were found unsafe and only 3 % of the sources were within safe limits. High concentrations of arsenic, fluoride, and bacteria were found in 91, 74, and 77 % sources of drinking water, respectively. Very high concentrations of arsenic ranging 58-3800 μg/L were found in the water samples obtained from Badarpur and Ibrahimabad. A decrease in water contamination was observed with increase in source depth. The health issues like arsenicosis and skeletal/dental flourosis were observed in the residents of the monitored areas. Drinking water quality conditions of some rural areas of northen and southern districts of Punjab was also analyzed and compared with Kasur district. High levels of nitrates were found in the samples of Islamabad and Rawalpindi, while high levels of arsenic, iron, fluoride, and TDS were found in Bahawalpur district. Graphical abstract ᅟ.

  10. Biomonitoring Equivalents for interpretation of urinary fluoride.

    Science.gov (United States)

    Aylward, L L; Hays, S M; Vezina, A; Deveau, M; St-Amand, A; Nong, A

    2015-06-01

    Exposure to fluoride is widespread due to its natural occurrence in the environment and addition to drinking water and dental products for the prevention of dental caries. The potential health risks of excess fluoride exposure include aesthetically unacceptable dental fluorosis (tooth mottling) and increased skeletal fragility. Numerous organizations have conducted risk assessments and set guidance values to represent maximum recommended exposure levels as well as recommended adequate intake levels based on potential public health benefits of fluoride exposure. Biomonitoring Equivalents (BEs) are estimates of the average biomarker concentrations corresponding to such exposure guidance values. The literature on daily urinary fluoride excretion rates as a function of daily fluoride exposure was reviewed and BE values corresponding to the available US and Canadian exposure guidance values were derived for fluoride in urine. The derived BE values range from 1.1 to 2.1mg/L (1.2-2.5μg/g creatinine). Concentrations of fluoride in single urinary spot samples from individuals, even under exposure conditions consistent with the exposure guidance values, may vary from the predicted average concentrations by several-fold due to within- and across-individual variation in urinary flow and creatinine excretion rates and due to the rapid elimination kinetics of fluoride. Thus, the BE values are most appropriately applied to screen population central tendency estimates for biomarker concentrations rather than interpretation of individual spot sample concentrations. Copyright © 2015. Published by Elsevier Inc.

  11. Fluoride Ion Regeneration of Cyclosarin (GF) From Rat Blood Following Whole-Body Exposure to Lethal Levels of GF Vapor

    National Research Council Canada - National Science Library

    Jakubowski, E. M; Anthony, J. S; Mioduszewski, R. J; Manthei, J. H; Burnett, D. C; Way, R. A; Gaviola, B. I; Scotto, J. A; Muse, W. T; Whalley, C. E

    2003-01-01

    .... Levels of exposure ranged from 2 mg/m3 for 240 min to 41.9 mg/m3 for 10 min. The GF biomarker found in rat plasma and red blood cell samples was regenerated GF, which is the product of adding fluoride ion at pH 4 to the post exposure samples...

  12. Water fluoridation and the association of sugar-sweetened beverage consumption and dental caries in Australian children.

    Science.gov (United States)

    Armfield, Jason M; Spencer, A John; Roberts-Thomson, Kaye F; Plastow, Katrina

    2013-03-01

    We examined demographic and socioeconomic differences in the consumption of sugar-sweetened beverages (SSBs), its association with dental caries in children, and whether exposure to water fluoridation modifies this association. In a cross-sectional study, we used a stratified, clustered sampling design to obtain information on 16 508 children aged 5 to 16 years enrolled in Australian school dental services in 2002 to 2005. Dental staff assessed dental caries, and parents completed a questionnaire about their child's residential history, sources of drinking water, toothbrushing frequency, socioeconomic status (SES), and SSB consumption. Children who brushed their teeth less often and were older, male, of low SES, from rural or remote areas consumed significantly more SSBs. Caries was significantly associated with greater SSB consumption after controlling for potential confounders. Finally, greater exposure to fluoridated water significantly reduced the association between children's SSB consumption and dental caries. Consumption of SSBs should be considered a major risk factor for dental caries. However, increased exposure to fluoridated public water helped ameliorate the association between SSB consumption and dental decay. These results reconfirm the benefits of community water fluoridation for oral health.

  13. Study on the removal of fluoride from drinking water and effluents

    International Nuclear Information System (INIS)

    Charbel, M.Y.

    1990-01-01

    A study for removal of excess fluoride from drinking water and aqueous effluents from nuclear power plants is presented. Inorganic and organic ion exchangers were used for this purpose: 1. Alumina microspheres form, granular alumina and zirconium oxide (powder or granular form with the aid of agglutinants) were experimented. 2. Strong cation exchange resins as Al-III, Fe-III, Zr-IV, RE-III, Ca-II and Mg-II salt form were examined. 3. Retention on hydrous oxide of Al-III, Fe-III, Zr-IV and RE-III supported on strong cation ion exchanger was performed. 4. Strong anion exchange resins in the form of OH sup(-), Cl sup(-), NO3 sup(-), CO3 sup(2-), SO4 sup(2-), ClO4 sup(-) and Zr(SO4)3 sup(2-) were examined. For the experiments pure fluoride solutions or dilute solutions containing the cations of Fe-III, Ca-II, Mn-II, Cu-II, Al-III, Cd-II and U-VI were used. Cation exchange resin loaded with zirconium, anion exchange resin as hydroxyl and zirconium sulfate complex form exhibited very good results, but the last performed best and we suggest it for industrial application. (author)

  14. Dental fluorosis and urinary fluoride in 10-12 years old adolescents of Bushehr port

    Directory of Open Access Journals (Sweden)

    Giti Javan

    2006-02-01

    Full Text Available Background: Fluoride increases tooth resistance to dental caries, but mild toxicity due to excessive ingestion of fluoride can cause dental fluorosis. Drinking water naturally contains fluoride and is a major source of fluoride. In Bushehr port, drinking water is supplied from limestone springs with normal fluoride levels but dental fluorosis is observed. Methods: A total of 95 native school children (between the ages of 10-12 years old were randomly selected from four Bushehr port regions. Dental fluorosis, height and weight were examined. Probable attributing factors of dental fluorosis were also questioned. A 16 to 18 hours urinary fluoride concentration was measured with a fluoride ion selective electrode. Results: Dental fluorosis in four upper incisors was apparent in 52.6 % of the subjects. The urinary fluoride concentration was 2.18 mg/lit. Fluoride concentration in drinking water of schools ranged from 0.41 to 0.58 mg/lit. Forty percent of subjects were caries free. Conclusion: In spite of the normal range of fluoride concentration in the drinking water of Bushehr, dental fluorosis and urinary fluoride concentration are higher than the recommended ranges. Therefore, it is necessary to further investigate the amount and effects of fluoride ingestion in residents of Bushehr province.

  15. Comparative studies on plasma mineral status of cattle in fluoride toxic brackish water zone of Punjab, India

    Directory of Open Access Journals (Sweden)

    Sushma Chhabra

    2012-05-01

    Full Text Available Objective: Chronic fluoride intoxication or fluorosis is a worldwide health problem in humans and animals. The present research work was aimed to assess the status of copper, zinc, cobalt, manganese, magnesium, calcium and phosphorus in blood of fluorotic cattle in brackish water zone of Punjab. Methods: The present study was conducted in villages of district Muktsar, a brackish water zone, of Punjab state. Cattle (n=103 showing signs of dental lesions or lameness, from the villages with water fluoride concentration more than 1 ppm, were selected for the study whereas cattle (n=98 from villages with water fluoride concentration less than 1 ppm and with no clinical signs served as control. Blood samples were collected from both the groups and were analysed for minerals.Results: Significantly (P<0.05 higher plasma F concentrations were observed in animals of fluorotic region in comparison to healthy control animals. Concentrations of plasma Ca, Mg, Cu and Zn were significantly lower in cattle of hydrofluorotic region. Plasma phosphorus, iron and iodine concentrations were higher in animals of hydrofluorotic region whereas Mo and Mn did not differ between the two groups. Conclusions: Present study indicated decrease in certain essential minerals in animals of fluorotic region and such changes may contribute to the toxic effects associated with exposure to excess fluoride and salinity

  16. On the distribution of fluoride, calcium and magnesium in the waters off the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.; Dias, C.F.M.

    The distribution of fluoride, calcium and magnesium was studied in the waters off the central west coast of India. The averages F/Cl, Ca/Cl and Mg/Cl ratios observed are (6.83 plus or minus 0.023) x 10@u-5@@, (0.02194 plus or minus 0.00068) and (0...

  17. [Territorial differences in the occurrence of caries in Karl Marx Stadt children and adolescent after 12 years of water fluoridation].

    Science.gov (United States)

    Künzel, W

    1976-01-01

    Cariostatistical comparisons made since the start of drinking-water fluoridation in Karl-Marx-Stadt suggested territorial differences in the prevalence of dental decay. In the present paper an attempt is made to analyse the problems involved, with due consideration being given to both demographic and ecological factors.

  18. The impact of geology on the migration of fluorides in mineral waters of the Bukulja and Brajkovac pluton area, Serbia

    Directory of Open Access Journals (Sweden)

    Papić Petar

    2012-01-01

    Full Text Available One of the hydrogeochemical parameters that classify groundwater as mineral water is the content of fluoride ions. Their concentration is both important and limited for bottled mineral waters. Hydrochemical research of mineral waters in the surrounding area of Bukulja and Brajkovac pluton, in central Serbia, was conducted in order to define the chemical composition and genesis of these waters. They are carbonated waters, with content of fluoride ranging from 0.2 up to 6.6 mg/L. Since hydrochemical analyses showed variations in the major water chemistry, it was obvious that, apart from hydrochemical research, some explorations of the structure of the regional terrain would be inevitable. For these purposes, some additional geological research was performed, creating an adequate basis for the interpretation of the genesis of these carbonated mineral waters. The results confirmed the significance of the application of hydrochemical methods in the research of mineral waters. The work tended to emphasize that “technological treatment” for decreasing the concentration of fluoride in mineral waters occurs in nature, indicating the existence of natural defluoridization. [Projekat Ministarstva nauke Republike Srbije, br. 43004

  19. Reactor water level control device

    International Nuclear Information System (INIS)

    Hiramatsu, Yohei.

    1980-01-01

    Purpose: To increase the rapid response of the waterlevel control converting a reactor water level signal into a non-linear type, when the water level is near to a set value, to stabilize the water level reducting correlatively the reactor water level variation signal to stabilize greatly from the set value, and increasing the variation signal. Constitution: A main vapor flow quality transmitter detects the vapor flow generated in a reactor and introduced into a turbine. A feed water flow transmitter detects the quantity of a feed water flow from the turbine to the reactor, this detected value is sent to an addition operating apparatus. On the other hand, the power signal of the reactor water level transmitter is sent to the addition operating apparatus through a non-linear water level signal converter. The addition operation apparatus generates a signal for requesting the feed water flow quantity from both signals. Upon this occasion, the reactor water level signal converter makes small the reactor water level variation when the reactor level is close the set value, and when the water level deviates greatly from the set value, the reactor water level variation is made large thereby to improve the rapid response of the reactor coater level control. (Yoshino, Y.)

  20. Effectiveness of water fluoridation in the prevention of dental caries across adult age groups.

    Science.gov (United States)

    Do, Loc; Ha, Diep; Peres, Marco A; Skinner, John; Byun, Roy; Spencer, A John

    2017-06-01

    Lifetime access to fluoridated water (FW) is associated with lower caries experience. However, assessing this association in adults is likely affected by age. Cohort stratification and categorization of per cent lifetime access to fluoridated water (% LAFW) within cohorts are current approaches to this assessment. These approaches require an examination of the % LAFW and caries experience variation within and across age groups and their association to inform future analyses. This secondary analysis aimed to examine the age group variation in % LAFW and caries experience; and the association of % LAFW with caries within and across age groups of adults. A secondary analysis was undertaken using the Australian National Survey of Adult Oral Health 2004-2006 data on 4090 persons aged 15-91 years randomly sampled by a stratified, multistage probability method. Study participants underwent an interview, an oral examination by trained and standardized dentists to determine decayed, missing or filled tooth surfaces (DMFS) and a mailed self-complete questionnaire which collected residential history to calculate % LAFW. Variations in % LAFW and DMFS across age groups (15-34; 35-44; 45-54; 55+) were examined. Multivariable regression log-link models were generated for DMFS score within each age group. The age groups varied in values and distribution of % LAFW. Caries experience was strongly associated with age. % LAFW was significantly associated with DMFS score in the two younger age groups, but not in the others. Multivariable regression models showed that the highest % LAFW quartile had significantly lower DMFS count than the lowest quartile in the two younger age groups (mean ratios: 0.67 and 0.78, respectively), controlling for other covariates. Access to FW was associated with caries experience in Australian adults. The magnitude of associations varied between age groups, dependent on the natural history of caries and its measurement by DMFS. © 2017 John Wiley & Sons A

  1. Dental caries prevalence in children up to 36 months of age attending daycare centers in municipalities with different water fluoride content

    Directory of Open Access Journals (Sweden)

    Ana Valéria Pagliari Tiano

    2009-02-01

    Full Text Available This study determined the prevalence of cavitated caries lesions (CCL and early childhood caries (ECC, and the contribution of some variables in children up to 36 months of age attending daycare centers in municipalities with different fluoride levels in the water supply: AFC (adequate fluoride content and LFC (low fluoride content. After approval of the Ethics Committee, the parents were interviewed. The children were clinically examined using the same codes and criteria established by the WHO (World Health Organization and the ADA (American Dental Association. Fisher's exact test (p<0.05 was applied for statistical analysis of data. The dmft indices calculated in the LFC and AFC municipalities were 0.57 and 0.68, respectively. Considering all children examined, 17.6% presented CCL and 33.8% ECC. The economic classification, mother's education level and duration of breastfeeding were considered statistically significant with regards to CCL prevalence. The age group, duration of the habit of drinking milk before bedtime and age at which oral hygiene started were considered statistically significant with regards to ECC prevalence.

  2. Polyvinylidene Fluoride Micropore Membranes as Solid-Phase Extraction Disk for Preconcentration of Nanoparticulate Silver in Environmental Waters.

    Science.gov (United States)

    Zhou, Xiao-Xia; Lai, Yu-Jian; Liu, Rui; Li, Sha-Sha; Xu, Jing-Wen; Liu, Jing-Fu

    2017-12-05

    Efficient separation and preconcentration of trace nanoparticulate silver (NAg) from large-volume environmental waters is a prerequisite for reliable analysis and therefore understanding the environmental processes of silver nanoparticles (AgNPs). Herein, we report the novel use of polyvinylidene fluoride (PVDF) filter membrane for disk-based solid phase extraction (SPE) of NAg in 1 L of water samples with the disk-based SPE system, which consists of a syringe pump and a syringe filter holder to embed the filter membrane. While the PVDF membrane can selectively adsorb NAg in the presence of Ag + , aqueous solution of 2% (m/v) FL-70 is found to efficiently elute NAg. Analysis of NAg is performed following optimization of filter membrane and elution conditions with an enrichment factor of 1000. Additionally, transmission electron microscopy (TEM), UV-vis spectroscopy, and size-exclusion chromatography coupled with ICP-MS (SEC-ICP-MS) analysis showed that the extraction gives rise to no change in NAg size or shape, making this method attractive for practical applications. Furthermore, feasibility of the protocol is verified by applying it to extract NAg in four real waters with recoveries of 62.2-80.2% at 0.056-0.58 μg/L spiked levels. This work will facilitate robust studies of trace NAg transformation and their hazard assessments in the environment.

  3. Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

    Science.gov (United States)

    Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

    2015-01-01

    Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

  4. Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

    Directory of Open Access Journals (Sweden)

    Xin-Hai Yin

    Full Text Available Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk.PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs with corresponding 95% confidence intervals (CIs were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed.Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15. Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed.The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

  5. Comparison of Fluoride Content in Drinking Water and Prevalence of Dental Fluorosis in 6 - 12-Year-Old Students in Mariwan (a Cold Region and Behbahan (a Warm Region during the 2013 - 2014 Educational Year

    Directory of Open Access Journals (Sweden)

    Rezvan Rafatjou

    2016-07-01

    .6% very mild, 2.3% mild, and 0.8% moderate. In Mariwan, the prevalence in areas related to reservoir 1 was 96.7% healthy and 3.3% questionable; in areas related to reservoir 2 it was 94.4% healthy and 5.6% questionable. Conclusions The fluoride content of drinking water in reservoirs and at homes was below the optimal level in Mariwan. No differences were observed from the standard levels in Behbahan. There were no differences in fluoride content of water in reservoirs and in home pipelines, indicating no tangible changes in fluoride content from the reservoirs to the homes. In neither of the towns was severe fluorosis observed. There was no significant difference in the prevalence and severity of fluorosis between genders.

  6. Toxicity levels to humans during acute exposure to hydrogen fluoride - An update

    Energy Technology Data Exchange (ETDEWEB)

    Halton, D M

    1995-09-01

    In March 1993, the Atomic Energy Control Board (AECB) commissioned and update of a 1984 review on the acute toxicity of hydrogen fluoride (HF). The study places particular emphasis on the effects of inhalation of gaseous HF and is divided into two main parts: a literature review and a lethal concentration (LC) estimation. The literature review summarizes data under four categories: animal studies, controlled human studies, community exposure, and industrial exposure. Data in these areas were critically reviewed for their relevance to lethal concentrations at LC{sub LO}, LC{sub 10} and LC{sub 50} levels that were derived in the 1984 report. In the last ten years, only one relevant animal study has been published. No new controlled human studies were found but a community exposure incident was reported. There were three new industrial/accidental exposures reported since 1984. Evaluation of new data does not change the lethal concentration estimates made in the 1984 report, but does indicate the absence of appropriate models to estimate the lethality of irritant and corrosive gases. In the last 10 years, much literature on the evaluation of major hazards has been published and suggests that such assessments are of growing political, economic and social importance. Numerous articles have been published on the acute toxicity of HF from skin contact and chronic toxicity from repeated airborne exposure. These publications offer important insights into the nature of HF toxicity. Several avenues of investigative research are suggested. (author). 55 refs., 4 tabs.

  7. Toxicity levels to humans during acute exposure to hydrogen fluoride - An update

    International Nuclear Information System (INIS)

    Halton, D.M.

    1995-09-01

    In March 1993, the Atomic Energy Control Board (AECB) commissioned and update of a 1984 review on the acute toxicity of hydrogen fluoride (HF). The study places particular emphasis on the effects of inhalation of gaseous HF and is divided into two main parts: a literature review and a lethal concentration (LC) estimation. The literature review summarizes data under four categories: animal studies, controlled human studies, community exposure, and industrial exposure. Data in these areas were critically reviewed for their relevance to lethal concentrations at LC LO , LC 10 and LC 50 levels that were derived in the 1984 report. In the last ten years, only one relevant animal study has been published. No new controlled human studies were found but a community exposure incident was reported. There were three new industrial/accidental exposures reported since 1984. Evaluation of new data does not change the lethal concentration estimates made in the 1984 report, but does indicate the absence of appropriate models to estimate the lethality of irritant and corrosive gases. In the last 10 years, much literature on the evaluation of major hazards has been published and suggests that such assessments are of growing political, economic and social importance. Numerous articles have been published on the acute toxicity of HF from skin contact and chronic toxicity from repeated airborne exposure. These publications offer important insights into the nature of HF toxicity. Several avenues of investigative research are suggested. (author). 55 refs., 4 tabs

  8. Measurement of the deuterium concentration in water samples using a CW chemical deuterium fluoride laser

    International Nuclear Information System (INIS)

    Trautmann, M.

    1979-10-01

    In this study a new method for the determination of the deuterium content in water samples is described. The absorption of the radiation of a CW deuterium fluoride laser by the isotope HDO in the water vapor of the sample is measured by means of an optoacoustic detector (spectrophone). Thereby advantage is taken of the fact that H 2 O hardly absorbs the laser radiation and that D 2 O only exists in negligible concentrations. The isotope ratio of hydrogen can be calculated from the measured relative concentration of HDO. In the course of this investigation the relative absorption cross sections of HDO for the different laser lines were determined. It was thereby established that there exists a very good coincidence of an HDO absorption line with the 2P2 laser line. Using a very sensitive nonresonant spectrophone the relative concentration of HDO in natural water samples could be determined with an accuracy of about 10%. The experiments also demonstrated that with appropriate improvements made to the apparatus and using a second spectrophone as a reference it should be possible to increase this accuracy to 0,1%. (orig.)

  9. Kinetics and equilibrium studies for removal of fluoride from underground water using cryptocrystalline magnesite

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2015-09-01

    Full Text Available of competing ions. Optimum defluoridation conditions were observed to be 20 g/L magnesite, 2:100 solid:liquid ratio, 20 min of agitation and 60 mg/L fluoride concentration. Adsorption of fluoride by magnesite was observed to be independent of p...

  10. Demons versus level-set motion registration for coronary 18F-sodium fluoride PET

    Science.gov (United States)

    Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R.; Fletcher, Alison; Motwani, Manish; Thomson, Louise E.; Germano, Guido; Dey, Damini; Berman, Daniel S.; Newby, David E.; Slomka, Piotr J.

    2016-03-01

    Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated 18F-sodium fluoride (18F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated 18F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary 18F-NaF PET. To this end, fifteen patients underwent 18F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between 18F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically

  11. Synthesis and properties of a high-capacity iron oxide adsorbent for fluoride removal from drinking water

    Science.gov (United States)

    Zhang, Chang; Li, Yingzhen; Wang, Ting-Jie; Jiang, Yanping; Fok, Jason

    2017-12-01

    A novel iron oxide adsorbent with a high fluoride adsorption capacity was prepared by a facile wet-chemical precipitation method and ethanol treatment. The ethanol-treated adsorbent was amorphous and had a high specific surface area. The adsorption capacity of the treated adsorbent was much higher than that of untreated adsorbent. The Langmuir maximum adsorption capacity of the adsorbent prepared at a low final precipitation pH (≤9.0) and treated with ethanol reached 60.8 mg/g. A fast adsorption rate was obtained, and 80% of the adsorption equilibrium capacity was achieved within 2 min. The adsorbent had high fluoride-removal efficiency for water in a wide initial pH range of 3.5-10.3 and had a high affinity for fluoride in the presence of common co-anions. The ethanol treatment resulted in structure transformation of the adsorbent by inhibiting the crystallization of the nano-precipitates. The adsorption was confirmed to be ion exchange between fluoride ions and the hydroxyl groups on the adsorbent surface.

  12. CORRELATION AMONG FLUORIDE AND METALS IN IRRIGATION ...

    African Journals Online (AJOL)

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    The levels of fluoride and selected metals in Ethiopian Rift Valley soils and irrigation water in the nearby sources were ... exhaust fumes, process waters and waste from various industrial processes [1]. The uses of ... into four sub-systems: Lake Rudolf, Chew Bahir, the Main Ethiopian Rift (MER) and the Afar. The seismically ...

  13. Dentinal hypersensitivity following scaling and root planing: comparison of low-level laser and topical fluoride treatment.

    Science.gov (United States)

    Pesevska, Snezana; Nakova, Marija; Ivanovski, Kiro; Angelov, Nikola; Kesic, Ljiljana; Obradovic, Radmila; Mindova, Sonja; Nares, Salvador

    2010-09-01

    The aim of this study is to compare the effectiveness of low-level laser irradiation to traditional topical fluoride treatment for treatment choices of dentinal hypersensitivity following scaling and root planing. The experimental group (15 patients) was treated with low-energy-level diode laser at each site of dentinal hypersensitivity following scaling and root planning. The control group (15 patients) received topical fluoride treatment (protective varnish for desensitization). All the patients were treated at baseline visit, and then at day 2 and 4 after the initial treatment; the pain was subjectively assessed by the patients as strong, medium, medium low, low, or no pain. Total absence of the dental hypersensitivity was reported in 26.66% of the examined group even after the second visit, compared to the control group where complete resolution of the hypersensitivity was not present after the second visit in any of the treated cases. Complete absence of pain was achieved in 86.6% of patients treated with laser and only in 26.6% in the fluoride treated group, after the third visit. Based on our findings, we conclude that low-energy biostimulative laser treatment can be successfully used for treatment of dental hypersensitivity following scaling and root planing.

  14. FLUORIDE TOXICITY – A HARSH REALITY

    OpenAIRE

    Bandlapalli Pavani; Mandava Ragini; David Banji; Otilia J F Banji; N Gouri Pratusha

    2011-01-01

    There are many incidents of fluoride toxicity whether it is acute or chronic. Fluoride toxicity is an environmental hazard which arises from the upper layers of geological crust and is dissolved in water. Prolonged drinking of such water causes chronic fluoride toxicity. Use of fluoride containing compounds for various purposes such as dental products, metal, glass, refrigerator and chemical industries act as a source of fluoride poisoning and increase the risk of toxicity. This review reflec...

  15. Drinking water quality and chronic kidney disease of unknown etiology (CKDu): synergic effects of fluoride, cadmium and hardness of water.

    Science.gov (United States)

    Wasana, Hewa M S; Aluthpatabendi, Dharshani; Kularatne, W M T D; Wijekoon, Pushpa; Weerasooriya, Rohan; Bandara, Jayasundera

    2016-02-01

    High prevalence of chronic kidney disease of unknown etiology (CKDu) in some regions of the world is suspected mainly due to a toxin-mediated renal failure. We examined the incidence of CKDu and potable chemical water quality in a CKDu-affected region. This region has been identified as a high-risk zone for CKDu (location: latitude: 8.3500°-9.0000°, longitude: 80.3833°-81.3000°, North Central Province, NCP, Sri Lanka) by the World Health Organization (WHO). However, within this macro-region, small pockets of CKDu non-prevalence zones do exist; notably, the residents in those pockets consume spring water. Therefore, the drinking water quality of four areas, namely high-CKDu-prevalence areas (zone I), low-CKDu-prevalence area (zone II), the CKDu-free isolated pockets (zone III) and control areas (controls) were examined for F, Al, Cd, and As, and hardness and the statistical analysis were carried out to probe possible correlations among these parameters. The fluoride and hardness concentrations of water in zone III and control areas are much lower compared to zones I and II, and the water hardness is ~61 mg/L CaCO3. In zones I and II, the harness of drinking water is ~121-180 mg/L CaCO3; however, Al, Cd and As concentrations are almost comparable and below WHO recommendations. In most of the locations in zones I and II, the F concentration in drinking water is higher than the WHO recommendations. The peculiar distribution patterns of CKDu point to a synergic effect of trace elements in water for etiology of the disease.

  16. Fluoride removal from diluted solutions by Donnan dialysis using full factorial design

    Energy Technology Data Exchange (ETDEWEB)

    Boubakri, Ali; Helali, Nawel; Tlili, Mohamed; Amor, Mohamed Ben [Center of Researches and Water Technologies, Soliman (Turkey)

    2014-03-15

    Excessive fluoride concentration in potable water can lead to fluorosis of teeth and bones. In the present study, Donnan dialysis (DD) is applied for the removal of fluoride ions from diluted sodium fluoride solutions. A four factor two level (2{sup 4}) full factorial design was used to investigate the influence of different physico-chemical parameters on fluoride removal efficiency (Y{sub F}) and fluoride flux (J{sub F}) through anion exchange membrane. The statistical design determines factors which have the important effects on Donnan dialysis performance and studies all interactions among the considered parameters. The four significant factors were initial fluoride concentration, feed flow rate, temperature and agitation speed. The experimental results and statistical analysis show that the temperature and agitation speed have positive effects on fluoride removal efficiency and the initial fluoride concentration has a negative effect. In the case of fluoride flux, feed flow rate and initial concentration are the main effect and all factors have a positive effect. The interaction between studied parameters was not negligible on two responses. A maximum fluoride removal of 75.52% was obtained under optimum conditions and the highest value of fluoride flux obtained was 2.4 mg/cm{sup 2}·h. Empirical regression models were also obtained and used to predict the flux and the fluoride removal profiles with satisfactory results.

  17. Effects of combined oleic acid and fluoride at sub-MIC levels on EPS formation and viability of Streptococcus mutans UA159 biofilms.

    Science.gov (United States)

    Cai, Jian-Na; Kim, Mi-A; Jung, Ji-Eun; Pandit, Santosh; Song, Kwang-Yeob; Jeon, Jae-Gyu

    2015-01-01

    Despite the widespread use of fluoride, dental caries, a biofilm-related disease, remains an important health problem. This study investigated whether oleic acid, a monounsaturated fatty acid, can enhance the effect of fluoride on extracellular polysaccharide (EPS) formation by Streptococcus mutans UA159 biofilms at sub-minimum inhibitory concentration levels, via microbiological and biochemical methods, confocal fluorescence microscopy, and real-time PCR. The combination of oleic acid with fluoride inhibited EPS formation more strongly than did fluoride or oleic acid alone. The superior inhibition of EPS formation was due to the combination of the inhibitory effects of oleic acid and fluoride against glucosyltransferases (GTFs) and GTF-related gene (gtfB, gtfC, and gtfD) expression, respectively. In addition, the combination of oleic acid with fluoride altered the bacterial biovolume of the biofilms without bactericidal activity. These results suggest that oleic acid may be useful for enhancing fluoride inhibition of EPS formation by S. mutans biofilms, without killing the bacterium.

  18. Poisoning by coal smoke containing arsenic and fluoride

    Energy Technology Data Exchange (ETDEWEB)

    An, D.; He, Y.G.; Hu, Q.X. [Guizhou Sanitary and Epidemiological Station, Guiyang (China)

    1997-02-01

    An investigation was made into a disease involving skin pigmentation, keratosis of the hands and feet, dental discoloration, and generalized bone and joint pain, stiffness and rigidity, in the village of Bazhi, Zhijin County, Ghizhou Province, People`s Republic of China. Measurements were made of the arsenic and fluoride levels of coal, water, air, food, urine and hair in Bazhi and a control village, Xinzhai, in which coal with a low arsenic content was used. Up to 188 people, including children, in Bazhi and 752 in Xinzhai, were examined for the presence of chronic arsenium, skeletal fluorosis, dental fluorosis and electrocardiogram abnormalities. The coal in Bazhi was found to contain high levels of arsenic and fluoride resulting, after burning in homes without an adequate chimney systems, in pollution of air and food with arsenic and fluoride. The coal in Xinzhai did not cause arsenic pollution but did produce a higher level of fluoride pollution. It was concluded that the endemic disease in Bazhi was caused by pollution by coal smoke containing arsenic and fluoride. It is suggested that arsenic may act synergistically with fluoride so that a lower level of fluoride may produce fluoride toxicity with dental and skeletal fluorosis.

  19. The Effects of Remineralization via Fluoride Versus Low-Level Laser IR810 and Fluoride Agents on the Mineralization and Microhardness of Bovine Dental Enamel

    Directory of Open Access Journals (Sweden)

    Edith Lara-Carrillo

    2018-01-01

    Full Text Available The objective of this study was to assess the mineralization and microhardness of bovine dental enamel surfaces treated with fluoride, tri-calcium phosphate, and infrared (IR 810 laser irradiation. The study used 210 bovine incisors, which were divided into six groups (n = 35 in each: Group A: Untreated (control, Group B: Fluoride (Durapath-Colgate, Group C: Fluoride+Tri-calcium phosphate (Clin-Pro White-3 M, Group D: Laser IR 810 (Quantum, Group E: Fluoride+laser, and Group F: Fluoride+tri-calcium phosphate+laser. Mineralization was measured via UV-Vis spectroscopy for phosphorus and via atomic absorption spectroscopy for calcium upon demineralization and remineralization with proven agents. Microhardness (SMH was measured after enamel remineralization. Mineral loss data showed differences between the groups before and after the mineralizing agents were placed (p < 0.05. Fluoride presented the highest remineralization tendency for both calcium and phosphate, with a Vickers microhardness of 329.8 HV0.1/11 (p < 0.05. It was observed that, if remineralization solution contained fewer minerals, the microhardness surface values were higher (r = −0.268 and −0.208; p < 0.05. This study shows that fluoride has a remineralizing effect compared with calcium triphosphate and laser IR810. This in vitro study imitated the application of different remineralizing agents and showed which one was the most efficient for treating non-cavitated injuries. This can prevent the progression of lesions in patients with white spot lesions.

  20. Exposure to Fluoride in Smelter Workers in a Primary Aluminum Industry in India

    Directory of Open Access Journals (Sweden)

    AK Susheela

    2013-04-01

    Full Text Available Background: Fluoride is used increasingly in a variety of industries in India. Emission of fluoride dust and fumes from the smelters of primary aluminum producing industries is dissipated in the work environment and poses occupational health hazards. Objective: To study the prevalence of health complaints and its association with fluoride level in body fluids of smelter workers in a primary aluminum producing industry. Methods: In an aluminum industry, health status of 462 smelter workers, 60 supervisors working in the smelter unit, 62 non-smelter workers (control group 1 and 30 administration staff (control group 2 were assessed between 2007 and 2009. Their health complaints were recorded and categorized into 4 groups: 1 gastro-intestinal complaints; 2 non-skeletal manifestations; 3 skeletal symptoms; and (4 respiratory problems. Fluoride level in body fluids, nails, and drinking water was tested by an ion selective electrode; hemoglobin level was tested using HemoCue. Results: The total complaints reported by study groups were significantly higher than the control groups. Smelter workers had a significantly (p<0.001 higher urinary and serum fluoride level than non-smelter workers; the nail fluoride content was also higher in smelter workers than non-smelter workers (p<0.001. The smelter workers with higher hemoglobin level had a significantly (p<0.001 lower urinary fluoride concentration and complained less frequently of health problems. Only 1.4% of the smelter workers were consuming water with high fluoride concentrations. A high percentage of participants was using substances with high fluoride contents. Conclusions: Industrial emission of fluoride is not the only important sources of fluoride exposure—consumption of substance with high levels of fluoride is another important route of entry of fluoride into the body. Measurement of hemoglobin provides a reliable indicator for monitoring the health status of employees at risk of fluorosis.

  1. The cariostatic mechanisms of fluoride

    Directory of Open Access Journals (Sweden)

    Kata Rošin-Grget

    2013-11-01

    Full Text Available This article discusses the possible cariostatic mechanisms of the action of fluoride. In the past, fluoride inhibition of caries was ascribed to reduced solubility of enamel due to incorporation of fluoride (F– into the enamel minerals. The present evidence from clinical and laboratory studies suggests that the caries-preventive mode of action of fluoride is mainly topical. There is convincing evidence that fluoride has a major effect on demineralisation and remineralisation of dental hard tissue. The source of this fluoride could either be fluorapatite (formed due to the incorporation of fluoride into enamel or calcium fluoride (CaF2-like precipitates, which are formed on the enamel and in the plaque after application of topical fluoride. Calcium fluoride deposits are protected from rapid dissolution by a phosphate –protein coating of salivary origin. At lower pH, the coating is lost and an increased dissolution rate of calcium fluoride occurs. The CaF2, therefore, act as an efficient source of free fluoride ions during the cariogenic challenge. The current evidence indicates that fluoride has a direct and indirect effect on bacterial cells, although the in vivo implications of this are still not clear. Conclusion. A better understanding of the mechanisms of the action of fluoride is very important for caries prevention and control. The effectiveness of fluoride as a cariostatic agent depends on the availability of free fluoride in plaque during cariogenic challenge, i.e. during acid production. Thus, a constant supply of low levels of fluoride in biofilm/saliva/dental interference is considered the most beneficial in preventing dental caries.

  2. The cariostatic mechanisms of fluoride.

    Science.gov (United States)

    Rošin-Grget, Kata; Peroš, Kristina; Sutej, Ivana; Bašić, Krešimir

    2013-11-01

    This article discusses the possible cariostatic mechanisms of the action of fluoride. In the past, fluoride inhibition of caries was ascribed to reduced solubility of enamel due to incorporation of fluoride (F-) into the enamel minerals. The present evidence from clinical and laboratory studies suggests that the caries-preventive mode of action of fluoride is mainly topical. There is convincing evidence that fluoride has a major effect on demineralisation and remineralisation of dental hard tissue. The source of this fluoride could either be fluorapatite (formed due to the incorporation of fluoride into enamel) or calcium fluoride (CaF2)-like precipitates, which are formed on the enamel and in the plaque after application of topical fluoride. Calcium fluoride deposits are protected from rapid dissolution by a phosphate -protein coating of salivary origin. At lower pH, the coating is lost and an increased dissolution rate of calcium fluoride occurs. The CaF2, therefore, act as an efficient source of free fluoride ions during the cariogenic challenge. The current evidence indicates that fluoride has a direct and indirect effect on bacterial cells, although the in vivo implications of this are still not clear. A better understanding of the mechanisms of the action of fluoride is very important for caries prevention and control. The effectiveness of fluoride as a cariostatic agent depends on the availability of free fluoride in plaque during cariogenic challenge, i.e. during acid production. Thus, a constant supply of low levels of fluoride in biofilm/saliva/dental interference is considered the most beneficial in preventing dental caries. Copyright © 2013 by Academy of Sciences and Arts of Bosnia and Herzegovina.

  3. 4-phenylbutyrate Mitigates Fluoride-Induced Cytotoxicity in ALC Cells

    Directory of Open Access Journals (Sweden)

    Maiko Suzuki

    2017-05-01

    Full Text Available Chronic fluoride over-exposure during pre-eruptive enamel development can cause dental fluorosis. Severe dental fluorosis is characterized by porous, soft enamel that is vulnerable to erosion and decay. The prevalence of dental fluorosis among the population in the USA, India and China is increasing. Other than avoiding excessive intake, treatments to prevent dental fluorosis remain unknown. We previously reported that high-dose fluoride induces endoplasmic reticulum (ER stress and oxidative stress in ameloblasts. Cell stress induces gene repression, mitochondrial damage and apoptosis. An aromatic fatty acid, 4-phenylbutyrate (4PBA is a chemical chaperone that interacts with misfolded proteins to prevent ER stress. We hypothesized that 4PBA ameliorates fluoride-induced ER stress in ameloblasts. To determine whether 4PBA protects ameloblasts from fluoride toxicity, we analyzed gene expression of Tgf-β1, Bcl2/Bax ratio and cytochrome-c release in vitro. In vivo, we measured fluorosis levels, enamel hardness and fluoride concentration. Fluoride treated Ameloblast-lineage cells (ALC had decreased Tgf-β1 expression and this was reversed by 4PBA treatment. The anti-apoptotic Blc2/Bax ratio was significantly increased in ALC cells treated with fluoride/4PBA compared to fluoride treatment alone. Fluoride treatment induced cytochrome-c release from mitochondria into the cytosol and this was inhibited by 4PBA treatment. These results suggest that 4PBA mitigates fluoride-induced gene suppression, apoptosis and mitochondrial damage in vitro. In vivo, C57BL/6J mice were provided fluoridated water for six weeks with either fluoride free control-chow or 4PBA-containing chow (7 g/kg 4PBA. With few exceptions, enamel microhardness, fluorosis levels, and fluoride concentrations of bone and urine did not differ significantly between fluoride treated animals fed with control-chow or 4PBA-chow. Although 4PBA mitigated high-dose fluoride toxicity in vitro, a diet

  4. 4-phenylbutyrate Mitigates Fluoride-Induced Cytotoxicity in ALC Cells.

    Science.gov (United States)

    Suzuki, Maiko; Everett, Eric T; Whitford, Gary M; Bartlett, John D

    2017-01-01

    Chronic fluoride over-exposure during pre-eruptive enamel development can cause dental fluorosis. Severe dental fluorosis is characterized by porous, soft enamel that is vulnerable to erosion and decay. The prevalence of dental fluorosis among the population in the USA, India and China is increasing. Other than avoiding excessive intake, treatments to prevent dental fluorosis remain unknown. We previously reported that high-dose fluoride induces endoplasmic reticulum (ER) stress and oxidative stress in ameloblasts. Cell stress induces gene repression, mitochondrial damage and apoptosis. An aromatic fatty acid, 4-phenylbutyrate (4PBA) is a chemical chaperone that interacts with misfolded proteins to prevent ER stress. We hypothesized that 4PBA ameliorates fluoride-induced ER stress in ameloblasts. To determine whether 4PBA protects ameloblasts from fluoride toxicity, we analyzed gene expression of Tgf -β 1, Bcl2 / Bax ratio and cytochrome-c release in vitro . In vivo , we measured fluorosis levels, enamel hardness and fluoride concentration. Fluoride treated Ameloblast-lineage cells (ALC) had decreased Tgf -β 1 expression and this was reversed by 4PBA treatment. The anti-apoptotic Blc2 / Bax ratio was significantly increased in ALC cells treated with fluoride/4PBA compared to fluoride treatment alone. Fluoride treatment induced cytochrome-c release from mitochondria into the cytosol and this was inhibited by 4PBA treatment. These results suggest that 4PBA mitigates fluoride-induced gene suppression, apoptosis and mitochondrial damage in vitro . In vivo , C57BL/6J mice were provided fluoridated water for six weeks with either fluoride free control-chow or 4PBA-containing chow (7 g/kg 4PBA). With few exceptions, enamel microhardness, fluorosis levels, and fluoride concentrations of bone and urine did not differ significantly between fluoride treated animals fed with control-chow or 4PBA-chow. Although 4PBA mitigated high-dose fluoride toxicity in vitro , a diet rich

  5. Influência de diferentes concentrações de flúor na água em indicadores epidemiológicos de saúde/doença bucal Influence of different concentrations of fluoride in the water on epidemiologic indicators of oral health/disease

    Directory of Open Access Journals (Sweden)

    Raquel Baroni de Carvalho

    2011-08-01

    Full Text Available O objetivo deste estudo foi avaliar o acesso a fontes de fluoreto e as condições de saúde bucal de 237 escolares de nove a dezesseis anos, de três localidades com diferentes concentrações de fluoreto na água. O teor de flúor na água de cada região foi analisado pela técnica do eletrodo seletivo para o íon flúor e a foi avaliada prevalência de cárie e fluorose, respectivamente, pelo índice CPOD e TSIF, apresentando diferença estatisticamente significante (ANOVA; p The scope of this study was to evaluate access to fluoride sources and oral health hygiene of 237 schoolchildren aged nine to sixteen, from three locations with different fluoride concentrations in the water. The fluoride level in the water of each area was analyzed by the selective electrode technique for the fluoride ion and the prevalence of dental caries and fluorosis were evaluated, respectively, by the DMFT and TSIF index, revealing a statistically significant difference (ANOVA; p <0,05 in the three locations: area without artificial fluoridation (DMTF 5.32 ± 3.49 and 16% of dental fluorosis; area with artificial fluoridation of 0.8 ppmF (DMTF 1.88 ± 2.22 and 94% of dental fluorosis; area with natural fluoridation of 2.54 ppmF (DMTF 3.96 ± 2.38 and 100% of dental fluorosis. The findings suggest that the epidemiologic indicators of oral health/disease are influenced by the presence of fluoride in the water supply and that supervision and orientation are fundamental in the correct use of fluoridated compositions, taking advantage of the maximum benefit in the control of dental caries with minimum risk of the occurrence of dental fluorosis.

  6. LLL2: an international global level questionnaire on toothbrushing and use of fluoride toothpaste.

    Science.gov (United States)

    Llodra, Juan Carlos; Phantumvanit, Prathip; Bourgeois, Denis M; Horn, Virginie

    2014-10-01

    To determine the evolution of toothbrushing frequency and use of fluoridetoothpaste in the FDI-Unilever partnership Live.Learn.Laugh. phase 2 programme using a self-reported questionnaire. The study was conducted in 23 countries. The key focus of this partnership was to educate people about the benefits of twice-daily brushing with fluoride toothpaste and to support people in adopting this important oral health behaviour. The partnership offers a choice of four project options to the local partnership team of the National Dental Association and local Unilever-operating companies. A self-report questionnaire was used in all participating subjects in local projects to evaluate the brushing frequency, the brushing timing and the use of fluoride toothpaste. After implementation of the project interventions, a clear improvement in the reported frequency of brushing twice a day, regardless of the type of project, was observed. Subjects also increased day and night brushing and the use of fluoride toothpaste. The strategy of using mothers to increase healthy behaviours in oral health achieved the greatest increase in twice-daily toothbrushing, followed by the intervention in schools. © 2014 FDI World Dental Federation.

  7. Fluoride in groundwater: toxicological exposure and remedies.

    Science.gov (United States)

    Jha, S K; Singh, R K; Damodaran, T; Mishra, V K; Sharma, D K; Rai, Deepak

    2013-01-01

    Fluoride is a chemical element that is found most frequently in groundwater and has become one of the most important toxicological environmental hazards globally. The occurrence of fluoride in groundwater is due to weathering and leaching of fluoride-bearing minerals from rocks and sediments. Fluoride when ingested in small quantities (dental health by reducing dental caries, whereas higher concentrations (>1.5 mg/L) may cause fluorosis. It is estimated that about 200 million people, from among 25 nations the world over, may suffer from fluorosis and the causes have been ascribed to fluoride contamination in groundwater including India. High fluoride occurrence in groundwaters is expected from sodium bicarbonate-type water, which is calcium deficient. The alkalinity of water also helps in mobilizing fluoride from fluorite (CaF2). Fluoride exposure in humans is related to (1) fluoride concentration in drinking water, (2) duration of consumption, and (3) climate of the area. In hotter climates where water consumption is greater, exposure doses of fluoride need to be modified based on mean fluoride intake. Various cost-effective and simple procedures for water defluoridation techniques are already known, but the benefits of such techniques have not reached the rural affected population due to limitations. Therefore, there is a need to develop workable strategies to provide fluoride-safe drinking water to rural communities. The study investigated the geochemistry and occurrence of fluoride and its contamination in groundwater, human exposure, various adverse health effects, and possible remedial measures from fluoride toxicity effects.

  8. Urinary fluoride excretion after application of fluoride varnish and use of fluoride toothpaste in young children

    DEFF Research Database (Denmark)

    Lockner, Frida; Twetman, Svante; Stecksén-Blicks, Christina

    2017-01-01

    BACKGROUND: The efficacy and safety of combined use of topical fluoride products are essential issues that must be monitored. AIM: To assess urinary excretion of fluoride after application of two different dental varnishes containing 2.26% fluoride in 3- to 4-year-old children and to compare...... the levels with and without parallel use of fluoride toothpaste. DESIGN: Fifteen healthy children were enrolled to a randomized crossover trial that was performed in two parts: Part I with twice-daily tooth brushing with fluoride toothpaste and Part II with twice-daily brushing with a non-fluoride toothpaste....... After a 1-week run-in period, 0.1 mL of the two fluoride varnishes (Duraphat and Profluorid Varnish) was topically applied in a randomized order. Baseline and experimental urine was collected during 6-h periods. The fluoride content was determined with an ion-sensitive electrode. RESULTS...

  9. Reactor water level control device

    International Nuclear Information System (INIS)

    Utagawa, Kazuyuki.

    1993-01-01

    A device of the present invention can effectively control fluctuation of a reactor water level upon power change by reactor core flow rate control operation. That is, (1) a feedback control section calculates a feedwater flow rate control amount based on a deviation between a set value of a reactor water level and a reactor water level signal. (2) a feed forward control section forecasts steam flow rate change based on a reactor core flow rate signal or a signal determining the reactor core flow rate, to calculate a feedwater flow rate control amount which off sets the steam flow rate change. Then, the sum of the output signal from the process (1) and the output signal from the process (2) is determined as a final feedwater flow rate control signal. With such procedures, it is possible to forecast the steam flow rate change accompanying the reactor core flow rate control operation, thereby enabling to conduct preceding feedwater flow rate control operation which off sets the reactor water level fluctuation based on the steam flow rate change. Further, a reactor water level deviated from the forecast can be controlled by feedback control. Accordingly, reactor water level fluctuation upon power exchange due to the reactor core flow rate control operation can rapidly be suppressed. (I.S.)

  10. Purifying fluoride-contaminated water by a novel forward osmosis design with enhanced flux under reduced concentration polarization.

    Science.gov (United States)

    Pal, Madhubonti; Chakrabortty, Sankha; Pal, Parimal; Linnanen, Lassi

    2015-08-01

    For purifying fluoride-contaminated water, a new forward osmosis scheme in horizontal flat-sheet cross flow module was designed and investigated. Effects of pressure, cross flow rate, draw solution and alignment of membrane module on separation and flux were studied. Concentration polarization and reverse salt diffusion got significantly reduced in the new hydrodynamic regime. This resulted in less membrane fouling, better solute separation and higher pure water flux than in a conventional module. The entire scheme was completed in two stages-an upstream forward osmosis for separating pure water from contaminated water and a downstream nanofiltration operation for continuous recovery and recycle of draw solute. Synchronization of these two stages of operation resulted in a continuous, steady-state process. From a set of commercial membranes, two polyamide composite membranes were screened out for the upstream and downstream filtrations. A 0.3-M NaCl solution was found to be the best one for forward osmosis draw solution. Potable water with less than 1% residual fluoride could be produced at a high flux of 60-62 L m(-2) h(-1) whereas more than 99% draw solute could be recovered and recycled in the downstream nanofiltration stage from where flux was 62-65 L m(-2) h(-1).

  11. Fluoride removal from aqueous solution by pumice: case study on ...

    African Journals Online (AJOL)

    EJIRO

    conditions, the fluoride removal efficiency from Kuhbonan water by 2.8 mg/L fluoride was 74.64%. Eventually ... industrial wastewater containing fluoride is a key ..... solution using silica ceramic: Adsorption kinetics and equilibrium studies.

  12. Ammonium boranes for the selective complexation of cyanide or fluoride ions in water.

    Science.gov (United States)

    Hudnall, Todd W; Gabbaï, François P

    2007-10-03

    With the recognition of aqueous fluoride and cyanide ions as an objective, we have investigated the anion binding properties of two isomeric ammonium boranes, namely [p-(Mes2B)C6H4(NMe3)]+ ([1]+) and [o-(Mes2B)C6H4(NMe3)]+ ([2]+). These cationic boranes, which could be obtained by reaction of the known 4- and 2-dimesitylboryl-N,N-dimethylaniline with MeOTf, have been investigated both experimentally and computationally. They both react with fluoride and cyanide ions in organic solvents to afford the corresponding fluoroborate/ or cyanoborate/ammonium zwitterions 1F, 1CN, 2F, and 2CN. In aqueous solution, however, these cationic boranes behave as remarkably selective receptors. Indeed, [1]+ only complexes cyanide ions while [2]+ only complexes fluoride ions. In H2O/DMSO 60:40 vol (HEPES 6 mM, pH 7), the cyanide binding constant of [1]+ and the fluoride binding constant of [2]+ are respectively equal to 3.9 (+/-0.1) x 108 and 910 (+/-50) M-1. Structural and computational studies indicate that both steric and electronic effects contribute to the unusual selectivity displayed by these cationic boranes. Owing to favorable Coulombic effects, the para-derivative [1]+ has a very high affinity for cyanide; yet these effects are not sufficiently intense to allow complexation of the more efficiently hydrated and less basic fluoride anion. In the case of the ortho-derivative [2]+, the proximity of the ammonium moiety leads to an increase in the Lewis acidity of the boron center thus making fluoride binding possible. However, steric effects prevent cyanide coordination to the boron center of [2]+. Finally, cation [1]+ and [2]+ bind their dedicated anions reversibly and show a negligible response in the presence of other common anions including Cl-, Br-, I-, NO3-, OAc-, H2PO4-, and HSO4-.

  13. Levels of Antioxidant Activity and Fluoride Content in Coffee Infusions of Arabica, Robusta and Green Coffee Beans in According to their Brewing Methods.

    Science.gov (United States)

    Wolska, J; Janda, Katarzyna; Jakubczyk, K; Szymkowiak, M; Chlubek, D; Gutowska, I

    2017-10-01

    Coffee is a rich source of dietary antioxidants, and this property links with the fact that coffee is one of the world's most popular beverages. Moreover, it is a source of macro- and microelements, including fluoride. The aim of this work was to determine antioxidant activity of coffee beverages and fluoride content depending on different coffee species and conditions of brewing. Three species of coffee, arabica, robusta and green coffee beans obtained from retail stores in Szczecin (Poland) were analyzed. Five different techniques of preparing drink were used: simple infusion, french press, espresso maker, overflow espresso and Turkish coffee. Antioxidant potential of coffee beverages was investigated spectrophotometrically by DPPH method. Fluoride concentrations were measured by potentiometric method with a fluoride ion-selective electrode. Statistical analysis was performed using Stat Soft Statistica 12.5. Antioxidant activity of infusions was high (71.97-83.21% inhibition of DPPH) depending on coffee species and beverage preparing method. It has been shown that the method of brewing arabica coffee and green coffee significantly affects the antioxidant potential of infusions. The fluoride concentration in the coffee infusions changed depending, both, on the species and conditions of brewing, too (0.013-0.502 mg/L). Methods of brewing didn't make a difference to the antioxidant potential of robusta coffee, which had also the lowest level of fluoride among studied species. Except overflow espresso, the fluoride content was the highest in beverages from green coffee. The highest fluoride content was found in Turkish coffee from green coffee beans.

  14. Fluoride caused thyroid endocrine disruption in male zebrafish (Danio rerio).

    Science.gov (United States)

    Jianjie, Chen; Wenjuan, Xue; Jinling, Cao; Jie, Song; Ruhui, Jia; Meiyan, Li

    2016-02-01

    Excessive fluoride in natural water ecosystem has the potential to detrimentally affect thyroid endocrine system, but little is known of such effects or underlying mechanisms in fish. In the present study, we evaluated the effects of fluoride on growth performance, thyroid histopathology, thyroid hormone levels, and gene expressions in the HPT axis in male zebrafish (Danio rerio) exposed to different determined concentrations of 0.1, 0.9, 2.0 and 4.1 M of fluoride to investigate the effects of fluoride on thyroid endocrine system and the potential toxic mechanisms caused by fluoride. The results indicated that the growth of the male zebrafish used in the experiments was significantly inhibited, the thyroid microtrastructure was changed, and the levels of T3 and T4 were disturbed in fluoride-exposed male fish. In addition, the expressional profiles of genes in HPT axis displayed alteration. The expressions of all studied genes were significantly increased in all fluoride-exposed male fish after exposure for 45 days. The transcriptional levels of corticotrophin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroglobulin (TG), sodium iodide symporter (NIS), iodothyronine I (DIO1), and thyroid hormone receptor alpha (TRα) were also elevated in all fluoride-exposed male fish after 90 days of exposure, while the inconsistent expressions were found in the mRNA of iodothyronineⅡ (DIO2), UDP glucuronosyltransferase 1 family a, b (UGT1ab), transthyretin (TTR), and thyroid hormone receptor beta (TRβ). These results demonstrated that fluoride could notably inhibit the growth of zebrafish, and significantly affect thyroid endocrine system by changing the microtrastructure of thyroid, altering thyroid hormone levels and endocrine-related gene expressions in male zebrafish. All above indicated that fluoride could pose a great threat to thyroid endocrine system, thus detrimentally affected the normal function of thyroid of male zebrafish. Copyright © 2015

  15. Salivary Fluoride level in preschool children after toothbrushing with standard and low fluoride content dentifrice, using the transversal dentifrice application technique: pilot study

    Directory of Open Access Journals (Sweden)

    Fabiana Jandre Melo

    2008-01-01

    Full Text Available Objective: To investigate the salivary fluoride concentration in pre-school children after toothbrushing with dentifrice containing standard (1100ppmF/NaF and low (500ppmF/NaF fluoride concentration, using the transversal technique of placing the product on the toothbrush. Methods: Eight children of both sexes, ranging from 4 to 9 years, and 5 years and 6 months of age, participated in the study. The experiment was divided into two phases with a weekly interval. In the first stage, the children used the standard concentration dentifrice for one week, and in the second, the low concentration product. Samples were collected at the end of each experimental stage, at the following times: Before brushing, immediately afterwards, and after 15, 30 and 45 minutes. The fluoride contents were analyzed by the microdiffusion technique. Statistical analysis was done by the analysis of variance ANOVA and Student’s-t test (p<0.05. Results: The salivary fluoride concentration was significantly higher at all times, when the standard concentration product was used. The comparison between the Halogen concentration found before bushing and immediately afterwards, showed that there was a 6.8 times increase in the standard dentifrice (0.19 x 1.29μgF/ml and in the low concentration product, an increase of 20.5 times (0.02 x 0.41μgF/ml. Conclusion: Toothbrushing with both products promoted relevant increases in the salivary fluoride concentration; however, longitudinal studies are necessary to verify the clinical result of this measurement.

  16. Tissue distributions of fluoride and its toxicity in the gills of a freshwater teleost, Cyprinus carpio.

    Science.gov (United States)

    Cao, Jinling; Chen, Jianjie; Wang, Jundong; Wu, Xiangtian; Li, Yundong; Xie, Lingtian

    2013-04-15

    Fish take up fluoride directly from water and are susceptible to fluoride contamination of their environment. In this study, we examined the tissue distributions of fluoride and its toxicity in the gills of the common carp (Cyprinus carpio) chronically exposed to fluoride. Carp were exposed to a range of aqueous fluoride (35-124 mg/L) and sampled at 30, 60 and 90 days. The accumulation of fluoride in the tissues increased with the level and duration of exposure. Steady state was not achieved under the experimental conditions. The gills accumulated the highest levels of fluoride followed by the liver>brain>kidney>muscle>intestine. A dose-dependent inhibition was observed for the enzyme activities of Na(+)-K(+)-ATPase and Ca(2+)-ATPase in the gills after the fish were exposed for 90 days. Also, accumulation of fluoride was associated with the inhibition of superoxide dismutase (SOD) activities and a dose-dependent stimulation of malondialdehyde (MDA) levels in the gill tissues, suggesting that fluoride promoted oxidative stress in the fish. Microscopic examinations revealed injuries to gill tissues and chloride cells, with the severity of injury increasing with exposure concentration. These results suggest that chronic exposure to elevated concentrations of fluoride may induce toxicity in the common carp. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Small molecule fluoride toxicity agonists.

    Science.gov (United States)

    Nelson, James W; Plummer, Mark S; Blount, Kenneth F; Ames, Tyler D; Breaker, Ronald R

    2015-04-23

    Fluoride is a ubiquitous anion that inhibits a wide variety of metabolic processes. Here, we report the identification of a series of compounds that enhance fluoride toxicity in Escherichia coli and Streptococcus mutans. These molecules were isolated by using a high-throughput screen (HTS) for compounds that increase intracellular fluoride levels as determined via a fluoride riboswitch reporter fusion construct. A series of derivatives were synthesized to examine structure-activity relationships, leading to the identification of compounds with improved activity. Thus, we demonstrate that small molecule fluoride toxicity agonists can be identified by HTS from existing chemical libraries by exploiting a natural fluoride riboswitch. In addition, our findings suggest that some molecules might be further optimized to function as binary antibacterial agents when combined with fluoride. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Nutritional status and dental fluorosis among schoolchildren in communities with different drinking water fluoride concentrations in a central region in Mexico.

    Science.gov (United States)

    Irigoyen-Camacho, M E; García Pérez, A; Mejía González, A; Huizar Alvarez, R

    2016-01-15

    Poor water quality and under nutrition are important factors affecting the health of many communities in developing countries. The aims of this study were: i) to describe the fluoride water concentration and the hydrogeological conditions in a region of a state located in the central in Mexico ii) to measure the association between undernutrition and dental fluorosis in children living in communities with different drinking water fluoride concentrations in a state located in the central region of Mexico. Field work was performed in the region to identify the prevailing groundwater flow characteristics and water wells were sampled to analyze water fluoride concentration. Children were selected from three communities that had different drinking water fluoride concentrations (i.e., 0.56, 0.70 and 1.60 mg/l). Fluoridated salt was available in these communities. The Thylstrup-Fejerskov Index (TFI) was used to assess dental fluorosis. Categories four or higher of this index involve changes in the entire tooth surface (ITF ≥ 4). The weight and height of the children were measured. The assessment of undernutrition was based on the World Health Organization criteria: children were classified as being at risk of low-height (Height-for-Age Z score water captured by the wells is the result of a reaction with volcanic materials. The water fluoride concentration in the region ranged from 0.2 to 1.6 mg/l. A total of 734 schoolchildren participated in the study. The percentage of children in fluorosis categories (ITF ≥ 4) was 15.9%, 21.1% of the children were at risk of low height-for-age, and 8.0% had low height-for-age. The percentage of children with fluorosis (ITF ≥ 4) was 6.3%, 9.1% and 31.9% (p ˂ 0.001) and low high-for-age was 2.9%, 2.5% and 8.4% (p ˂ 0.001), for the communities with F concentrations of 0.56 mg/l, 0.70 mg/l and 1.6 mg/l, respectively. The logistic regression model showed an association between dental fluorosis (TFI ≥ 4) and low height-for-age (OR

  19. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers

    DEFF Research Database (Denmark)

    Kirkeskov, Lilli; Kristiansen, Eva; Bøggild, Henrik

    2010-01-01

    Kirkeskov L, Kristiansen E, Bøggild H, von Platen-Hallermund F, Sckerl H, Carlsen A, Larsen MJ, Poulsen S. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers. Community...... Dent Oral Epidemiol 2010. (c) 2010 John Wiley & Sons A/S Abstract - Objectives: To study the association between fluoride concentration in drinking water and dental caries in Danish children. Methods: The study linked registry data on fluoride concentration in drinking water over a 10-year period...... with data on dental caries from the Danish National Board of Health database on child dental health for 5-year-old children born in 1989 and 1999, and for 15-year-old children born in 1979 and 1989. The number of children included in the cohorts varied between 41.000 and 48.000. Logistic regression was used...

  20. Preparation of novel alginate based anion exchanger from Ulva japonica and its application for the removal of trace concentrations of fluoride from water.

    Science.gov (United States)

    Paudyal, Hari; Pangeni, Bimala; Inoue, Katsutoshi; Kawakita, Hidetaka; Ohto, Keisuke; Ghimire, Kedar Nath; Alam, Shafiq

    2013-11-01

    A green seaweed, Ulva japonica, was modified by loading multivalent metal ions such as Zr(IV) and La(III) after CaCl2 cross-linking to produce metal loaded cross-linked seaweed (M-CSW) adsorbents, which were characterized by elemental analysis, functional groups identification, and metal content determination. Maximum sorption potential for fluoride was drastically increased after La(III) and Zr(IV) loading, which were evaluated as 0.58 and 0.95 mmol/g, respectively. Loaded fluoride was quantitatively desorbed by using dilute alkaline solution for its regeneration. Mechanism of fluoride adsorption was inferred in terms of ligand exchange reaction between hydroxyl ion on co-ordination sphere of the loaded metal ions of M-CSW and fluoride ion in aqueous solution. Application of M-CSW for the treatment of actual waste plating solution exhibited successful removal of fluoride to clear the effluent and environmental standards in Japan, suggesting high possibility of its application for the treatment of fluoride rich waste water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Cooperative effects in the structuring of fluoride water clusters: Ab initio hybrid quantum mechanical/molecular mechanical model incorporating polarizable fluctuating charge solvent

    Science.gov (United States)

    Bryce, Richard A.; Vincent, Mark A.; Malcolm, Nathaniel O. J.; Hillier, Ian H.; Burton, Neil A.

    1998-08-01

    A new hybrid quantum mechanical/molecular mechanical model of solvation is developed and used to describe the structure and dynamics of small fluoride/water clusters, using an ab initio wave function to model the ion and a fluctuating charge potential to model the waters. Appropriate parameters for the water-water and fluoride-water interactions are derived, with the fluoride anion being described by density functional theory and a large Gaussian basis. The role of solvent polarization in determining the structure and energetics of F(H2O)4- clusters is investigated, predicting a slightly greater stability of the interior compared to the surface structure, in agreement with ab initio studies. An extended Lagrangian treatment of the polarizable water, in which the water atomic charges fluctuate dynamically, is used to study the dynamics of F(H2O)4- cluster. A simulation using a fixed solvent charge distribution indicates principally interior, solvated states for the cluster. However, a preponderance of trisolvated configurations is observed using the polarizable model at 300 K, which involves only three direct fluoride-water hydrogen bonds. Ab initio calculations confirm this trisolvated species as a thermally accessible state at room temperature, in addition to the tetrasolvated interior and surface structures. Extension of this polarizable water model to fluoride clusters with five and six waters gave less satisfactory agreement with experimental energies and with ab initio geometries. However, our results do suggest that a quantitative model of solvent polarization is fundamental for an accurate understanding of the properties of anionic water clusters.

  2. The prevalence of molar incisor hypomineralisation in Northern England and its relationship to socioeconomic status and water fluoridation.

    Science.gov (United States)

    Balmer, Richard; Toumba, Jack; Godson, Jenny; Duggal, Monty

    2012-07-01

    Molar incisor hypomineralisation (MIH) is a condition which has significant implications for patients and service provision. The aim of this survey was to determine the prevalence of MIH in 12-year olds in Northern England and to consider the relationship with socioeconomic status and background water fluoridation. Twelve-year-old children were examined for the presence of MIH. Participating dentists were trained and calibrated in the use of the modified Developmental Defects of Enamel index. Children were examined at school under direct vision with the aid of a dental mirror. A diagnosis of MIH was attributed to a child if they had a demarcated defect in one or more of their first permanent molars. Of 4795 children that were selected, 3233 (67.4%) were examined. Overall prevalence of MIH was 15.9% (14.5-17.1%). There was an association between prevalence of MIH and deprivation quintiles with a positive correlation in the first 4 quintiles (P water fluoridation. © 2011 The Authors. International Journal of Paediatric Dentistry © 2011 BSPD, IAPD and Blackwell Publishing Ltd.

  3. Estado de salud bucodental de escolares residentes en localidades abastecidas con agua de consumo humano de muy alto y muy bajo contenido de fluoruros State of oral health among schoolchildren living in towns supplied with drinking water containing very high and very low levels of fluoride

    Directory of Open Access Journals (Sweden)

    Ana Isabel Azcurra

    1995-10-01

    ña a concentração é de 0,19mg/l. A proporção de escolares (6-7 e 12-13 anos que não apresentaram cárie foi significativamente maior em Sampacho do que em Porteña, enquanto, que os índices ceo-d, ceo-s, CPO-D e CPO-S resultaram consideravelmente mais altos nesta última localidade. A severidade da doença de cárie nas crianças de 12-13 anos de Sampacho esteve compreendida entre as categorias baixa e moderada (CPO-D = 2,53, enquanto que em suas similares em Porteña atingiu o grau de moderada e alta (CPO-D=4,41. Não se registrou nenhum caso de fluorose dental em Porteña enquanto que em Sampacho houve uma alta proporção de crianças que apresentou fluoroses leve (6-7 anos e leve ou intensa (12-13 anos. Os níveis salivares de cálcio, fosfatos, tiocianato, proteínas totais e lg A secretora foram muito similares nos escolares de ambas localidades, e também entre crianças com diferentes tipos de cárie e diferentes graus de gravidade de fluorose. Conclui-se ser necessária a aplicação de medidas sanitárias urgentes (preventivas ou curativas para reduzir ou controlar as doenças de cárie em Porteña e a fluorose dental em Sampacho.The results of a cross sectional epidemiological survey for the purpose of evaluating the state of dental health of schoolchildren (aged 6-7 and 12-13 living in Sampacho and Porteña, two towns in the Province of Córdoba (Argentina, supplied with drinking water containing quite different levels of fluoride, are described and analized. In Sampacho, F- level is 9.05 mg/l. while in Porteña the concentration is of 0.19 mg/l. The proportion of scholchildren (aged 6-7 and 12-13 without caries was significaticantly higher in Sampacho than in Porteña, while the dmf-t, dmf-s, DMF-Tand DMF-S indexes were considerably higher in the latter place. The severity of caries in children (age 12-13 living in Sampacho ranged from low to moderate (DMF-T=2.53, whilst in Porteña the range went from moderate to high (DMF-T=4.41. No cases of

  4. Adsorption process of fluoride from drinking water with magnetic core-shell Ce-Ti@Fe3O4 and Ce-Ti oxide nanoparticles.

    Science.gov (United States)

    Abo Markeb, Ahmad; Alonso, Amanda; Sánchez, Antoni; Font, Xavier

    2017-11-15

    Synthesized magnetic core-shell Ce-Ti@Fe 3 O 4 nanoparticles were tested, as an adsorbent, for fluoride removal and the adsorption studies were optimized. Adsorption capacity was compared with the synthesized Ce-Ti oxide nanoparticles. The adsorption equilibrium for the Ce-Ti@Fe 3 O 4 adsorbent was found to occur in cycles of adsorption-desorption. Although the nanoparticles suffer slight structure modifications after their reusability, they keep their adsorption capacity. Likewise, the efficiency of the Ce-Ti@Fe 3 O 4 was demonstrated when applied to real water to obtain a residual concentration of F - below the maximum contaminated level, 1.5mg/L (WHO, 2006). Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Application of Electrocoagulation Process Using Iron and Aluminum Electrodes for Fluoride Removal from Aqueous Environment

    Directory of Open Access Journals (Sweden)

    Edris Bazrafshan

    2012-01-01

    Full Text Available Fluoride in drinking water above permissible level is responsible for human being affected by skeletal fluorosis. The present study was carried out to assess the ability of electrocoagulation process with iron and aluminum electrodes in order to removal of fluoride from aqueous solutions. Several working parameters, such as fluoride concentration, pH, applied voltage and reaction time were studied to achieve a higher removal capacity. Variable concentrations (1, 5 and 10 mg L-1 of fluoride solutions were prepared by mixing proper amount of sodium fluoride with deionized water. The varying pH of the initial solution (3, 7 and 10 was also studied to measure their effects on the fluoride removal efficiency. Results obtained with synthetic solution revealed that the most effective removal capacities of fluoride could be achieved at 40 V electrical potential. In addition, the increase of electrical potential, in the range of 10-40 V, enhanced the treatment rate. Also comparison of fluoride removal efficiency showed that removal efficiency is similar with iron and aluminum electrodes. Finally it can be concluded that the electrocoagulation process has the potential to be utilized for the cost-effective removal of fluoride from water and wastewater.

  6. The relationship between dental caries and dental fluorosis in areas with moderate- and high-fluoride drinking water in Ethiopia.

    Science.gov (United States)

    Wondwossen, Fantaye; Astrøm, Anne Nordrehaug; Bjorvatn, Kjell; Bårdsen, Asgeir

    2004-10-01

    The aim of the study is to assess the relationship between caries and dental fluorosis in Ethiopian children living in Rift Valley areas known for endemic fluorosis. A total of 306 children (12-15 years old), selected from areas with moderate (0.3-2.2 mg/l), or high (10-14 mg/l) fluoride concentration in the drinking water were interviewed and examined for caries and dental fluorosis. Scorings were recorded according to the DMF system, and the Thylstrup-Fejerskov (TF) Index. Prevalence of dental fluorosis (TF-score > or = 1) was 91.8% (moderate area) and 100% (high-fluoride area). The corresponding caries prevalence and mean DMFT in the areas were 45.3% versus 61.6%, and 1.2 versus 1.8, respectively. Age and severity of dental fluorosis were found to be independent predictors for DMFT > or = 1. When compared with 12-year olds with TF-scores 0-4, odds ratios were 3.0 (95% CI 1.6-5.7) and 2.0 (95% CI 1.2-3.2) if TF-scores were > or = 5 and age 13-15 years, respectively. A positive relationship between caries and fluorosis was observed across tooth types in both areas. The percentage of children with DMFT > or = 1 was highest in groups with TF-score > or = 5 in the second molar, followed by the first molar. The present findings indicate that the second molar is the tooth most severely affected by dental fluorosis and dental caries. Dental caries increased with increasing severity of dental fluorosis, both in moderate- and high-fluoride areas. Thus, a positive relationship between dental caries and dental fluorosis was observed across various tooth types, in both areas. Copyright Blackwell Munksgaard, 2004

  7. Exploring the short-term impact of community water fluoridation cessation on children's dental caries: a natural experiment in Alberta, Canada.

    Science.gov (United States)

    McLaren, L; Patterson, S; Thawer, S; Faris, P; McNeil, D; Potestio, M L; Shwart, L

    2017-05-01

    Dental caries (tooth decay) is common and can be serious. Dental caries is preventable, and community water fluoridation is one means of prevention. There is limited current research on the implications of fluoridation cessation for children's dental caries. Our objective was to explore the short-term impact of community water fluoridation cessation on children's dental caries, by examining change in caries experience in population-based samples of schoolchildren in two Canadian cities, one that discontinued community water fluoridation and one that retained it. We used a pre-post cross-sectional design. We examined dental caries indices (deft [number of decayed, extracted, or filled primary teeth] and DMFT [number of decayed, missing, or filled permanent teeth]) among grade 2 schoolchildren in 2004/05 and 2013/14 in two similar cities in the province of Alberta, Canada: Calgary (cessation of community water fluoridation in 2011) and Edmonton (still fluoridated). We compared change over time in the two cities. For Calgary only, we had a third data point from 2009/10, and we considered trends across the three points. We observed a worsening in primary tooth caries (deft) in Calgary and Edmonton, but changes in Edmonton were less consistent and smaller. This effect was robust to adjustment for covariates available in 2013/14 and was consistent with estimates of total fluoride intake from biomarkers from a subsample. This finding occurred despite indication that treatment activities appeared better in Calgary. The worsening was not observed for permanent teeth. For prevalence estimates only (% with >0 deft or DMFT), the three data points in Calgary suggest a trend that, though small, appears consistent with an adverse effect of fluoridation cessation. Our results suggest an increase in dental caries in primary teeth during a time period when community fluoridation was ceased. That we did not observe a worsening for permanent teeth in the comparative analysis could

  8. Fluoride Exposure Aggravates the Testicular Damage and Sperm Quality in Diabetic Mice: Protective Role of Ginseng and Banaba.

    Science.gov (United States)

    Sm, Saumya; Mahaboob Basha, P

    2017-06-01

    Fluoride toxicity is known to pose infertility in fluoride-intoxicated animals as well as in people residing in fluoride endemic zones. The present study addresses the degree of impairments caused due to co-exposure of high fluoride toxicity in diabetic mice. Swiss mice, Mus musculus, were subjected to fluoride toxicity by providing fluoride-supplemented drinking water (600 ppm NaF) for a period of 30 days after the confirmation of streptozotocin-induced diabetes(STZ, 50 mg/kgbw). Consequently, aggravated hyperglycemia and tissue fluoride accumulation were witnessed in fluoride-intoxicated diabetic mice; later, these toxicated mice were treated with ginseng extract (GE) and banaba leaf extract, (BLE) at dose of 150 mg/kgbw/day alone and in combination for 15 and 30-day duration to check the efficacy of phytoextracts in reversing the toxicity. The spermatological indices studied, such as sperm density, motility, viability and morphology as well as the testicular biochemical parameters showed enhanced impairment in reproductive status of fluoride-intoxicated diabetic mice. Further, 15-days administration of GE and BLE in combination at a dose of 150 mg/kgbw/day was found to be beneficial in normalizing the alterations observed upon fluoride intoxication to diabetic mice. However, the correlates showed moderate association between blood glucose levels and the spermatological as well as biochemical indices wherein the tissue fluoride levels correlate least.

  9. Geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples, and its possible relationship with the prevalence of enamel fluorosis in children in four municipalities of the department of Huila (Colombia).

    Science.gov (United States)

    Martignon, Stefania; Opazo-Gutiérrez, Mario Omar; Velásquez-Riaño, Möritz; Orjuela-Osorio, Iván Rodrigo; Avila, Viviana; Martinez-Mier, Esperanza Angeles; González-Carrera, María Clara; Ruiz-Carrizosa, Jaime Alberto; Silva-Hermida, Blanca Cecilia

    2017-06-01

    Fluoride is an element that affects teeth and bone formation in animals and humans. Though the use of systemic fluoride is an evidence-based caries preventive measure, excessive ingestion can impair tooth development, mainly the mineralization of tooth enamel, leading to a condition known as enamel fluorosis. In this study, we investigated the geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples in four endemic enamel fluorosis sentinel municipalities of the department of Huila, Colombia (Pitalito, Altamira, El Agrado and Rivera), and its possible relationship with the prevalence of enamel fluorosis in children. The concentration of fluoride in drinking water, table salt, active sediment, rock, and soil was evaluated by means of an ion selective electrode and the geochemical analyses were performed using X-ray fluorescence. Geochemical analysis revealed fluoride concentrations under 15 mg/kg in active sediment, rock and soil samples, not indicative of a significant delivery to the watersheds studied. The concentration of fluoride in table salt was found to be under the inferior limit (less than 180 μg/g) established by the Colombian regulations. Likewise, exposure doses for fluoride water intake did not exceed the recommended total dose for all ages from 6 months. Although the evidence does not point out at rocks, soils, fluoride-bearing minerals, fluoridated salt and water, the hypothesis of these elements as responsible of the current prevalence of enamel fluorosis cannot be discarded since, aqueducts might have undergone significant changes overtime.

  10. Pollution level and inhalation exposure of ambient aerosol fluoride as affected by polymetallic rare earth mining and smelting in Baotou, north China

    Science.gov (United States)

    Zhong, Buqing; Wang, Lingqing; Liang, Tao; Xing, Baoshan

    2017-10-01

    Airborne fluoride associated with total suspended particles (TSP) and respirable particulate (PM10) in the rare earth mining and smelting areas were analyzed during August 2012 and March 2013. In March, average concentrations of fluoride bound to TSP in the mining and smelting areas were 0.598 ± 0.626 μg/m3 and 3.615 ± 4.267 μg/m3, respectively, whereas that in August were 0.699 ± 0.801 μg/m3 and 1.917 ± 2.233 μg/m3, respectively. TSP samples were classified into four categories by different sampling periods and locations using Kohonen's self-organizing map, which demonstrates that high airborne fluoride concentrations in March in the smelting area were probably attributed to industrial emissions from smelting activities and wind-blown dust from tailings pond, influenced by meteorologic parameters such as temperature, relative humidity, precipitation and wind speed. The mean daily amount of fluoride inhaled in the mining and smelting areas were estimated to be in the range of 2.77-57.61 μg/day and 3.39-64.32 μg/day, respectively. These results indicate the high potential exposure level of fluoride inhaled for local residents in the polymetallic mining and smelting areas.

  11. Industrial fluoride pollution: chronic fluoride poisoning in Cornwall Island cattle

    Energy Technology Data Exchange (ETDEWEB)

    Krook, L.; Maylin, G.A.

    1979-04-01

    An aluminum plant on the south bank of the St. Lawrence River, southwest of Cornwall Island, Ontario, Canada, has emitted 0.816 metric tons of fluoride daily since 1973. Considerably higher amounts were emitted from 1959 to 1973. The plant was designated as the major source of fluoride emissions impacting on Cornwall Island. Cattle located on this island showed signs of chronic fluoride poisoning. This poisoning was manifested clinically by stunted growth and dental fluorosis to a degree of severe interference with drinking and mastication. This Cornwall Island herds study indicates that the established tolerance level of fluoride for performance of dairy and beef cattle is not valid since the tolerance level was set based on experiments with healthy calves which were exposed to dietary fluoride from 3 to 4 months of age and not on cattle which were chronically exposed to fluoride from conception to death. 56 references.

  12. Reactor water level measuring device

    International Nuclear Information System (INIS)

    Kuroki, Reiji; Asano, Tamotsu.

    1996-01-01

    A condensation vessel is connected to the upper portion of a reactor pressure vessel by way of a pipeline. The lower portion of the condensation vessel is connected to a low pressure side of a differential pressure transmission device by way of a reference leg pipeline. The high pressure side of the differential pressure transmission device is connected to the lower portion of the pressure vessel by way of a pipeline. The condensation vessel is equipped with a temperature sensor. When a temperature of a gas phase portion in the condensation vessel is lowered below a predetermined level, and incondensible gases in the condensation vessel starts to be dissolved in water, signals are sent from the temperature sensor to a control device and a control valve is opened. With such a constitution, CRD driving water flows into the condensation vessel, and water in which gases at the upper portion of the condensation vessel is dissolved flows into the pressure vessel by way of a pipeline. Then, gases dissolved in a reference water column in the reference leg pipeline are eliminated and the value of a reference water pressure does not change even upon abrupt lowering of pressure. (I.N.)

  13. HOUSEHOLD PURIFICATION OF FLUORIDE CONTAMINATED MAGADI (TRONA)

    DEFF Research Database (Denmark)

    Nielsen, Joan Maj; Dahi, Elian

    1997-01-01

    Purification of fluoride contaminated magadi is studied using bone char sorption and calcium precipitation. The bone char treatment is found to be workable both in columns and in batches where the magadi is dissolved in water prior to treatment. The concentrations in the solutions were 89 g magadi....../L and 95 and 400 mg F/L respectively in natural and synthetic solutions. The fluoride removal capacities observed were 4.6 mg F/g bone char for the column system and 2.7 mg F/g bone char for the batch system in case of synthetic magadi solution. It is however concluded that the batch system is the best...... treatment method. A procedure for purification of fluoride contaminated magadi at household level is described....

  14. Gene-environment interaction: Does fluoride influence the reproductive hormones in male farmers modified by ERα gene polymorphisms?

    Science.gov (United States)

    Ma, Qiang; Huang, Hui; Sun, Long; Zhou, Tong; Zhu, Jingyuan; Cheng, Xuemin; Duan, Lijv; Li, Zhiyuan; Cui, Liuxin; Ba, Yue

    2017-12-01

    The occurrence of endemic fluorosis is derived from high fluoride levels in drinking water and industrial fumes or dust. Reproductive disruption is also a major harm caused by fluoride exposure besides dental and skeletal lesions. However, few studies focus on the mechanism of fluoride exposure on male reproductive function, especially the possible interaction of fluoride exposure and gene polymorphism on male reproductive hormones. Therefore, we conducted a cross-sectional study in rural areas of Henan province in China to explore the interaction between the estrogen receptor alpha (ERα) gene and fluoride exposure on reproductive hormone levels in male farmers living in the endemic fluorosis villages. The results showed that fluoride exposure significantly increased the serum level of estradiol in the hypothalamic-pituitary-testicular (HPT) axis in male farmers. Moreover, the observations indicated that fluoride exposure and genetic markers had an interaction on serum concentration of follicle-stimulating hormone and estradiol, and the interaction among different loci of the ERα gene could impact the serum testosterone level. Findings in the present work suggest that chronic fluoride exposure in drinking water could modulate the levels of reproductive hormones in males living in endemic fluorosis areas, and the interaction between fluoride exposure and ERα polymorphisms might affect the serum levels of hormones in the HPT axis in male farmers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Exposure to fluoride in smelter workers in a primary aluminum industry in India.

    Science.gov (United States)

    Susheela, A K; Mondal, N K; Singh, A

    2013-04-01

    Fluoride is used increasingly in a variety of industries in India. Emission of fluoride dust and fumes from the smelters of primary aluminum producing industries is dissipated in the work environment and poses occupational health hazards. To study the prevalence of health complaints and its association with fluoride level in body fluids of smelter workers in a primary aluminum producing industry. In an aluminum industry, health status of 462 smelter workers, 60 supervisors working in the smelter unit, 62 non-smelter workers (control group 1) and 30 administration staff (control group 2) were assessed between 2007 and 2009. Their health complaints were recorded and categorized into 4 groups: 1) gastro-intestinal complaints; 2) non-skeletal manifestations; 3) skeletal symptoms; and (4) respiratory problems. Fluoride level in body fluids, nails, and drinking water was tested by an ion selective electrode; hemoglobin level was tested using HemoCue. The total complaints reported by study groups were significantly higher than the control groups. Smelter workers had a significantly (pworkers; the nail fluoride content was also higher in smelter workers than non-smelter workers (pworkers with higher hemoglobin level had a significantly (pworkers were consuming water with high fluoride concentrations. A high percentage of participants was using substances with high fluoride contents. Industrial emission of fluoride is not the only important sources of fluoride exposure--consumption of substance with high levels of fluoride is another important route of entry of fluoride into the body. Measurement of hemoglobin provides a reliable indicator for monitoring the health status of employees at risk of fluorosis.

  16. Emissions of fluorides from welding processes.

    Science.gov (United States)

    Szewczyńska, Małgorzata; Pągowska, Emilia; Pyrzyńska, Krystyna

    2015-11-01

    The levels of fluoride airborne particulates emitted from welding processes were investigated. They were sampled with the patented IOM Sampler, developed by J. H. Vincent and D. Mark at the Institute of Occupational Medicine (IOM), personal inhalable sampler for simultaneous collection of the inhalable and respirable size fractions. Ion chromatography with conductometric detection was used for quantitative analysis. The efficiency of fluoride extraction from the cellulose filter of the IOM sampler was examined using the standard sample of urban air particle matter SRM-1648a. The best results for extraction were obtained when water and the anionic surfactant N-Cetyl-N-N-N-trimethylammonium bromide (CTAB) were used in an ultrasonic bath. The limits of detection and quantification for the whole procedure were 8μg/L and 24μg/L, respectively. The linear range of calibration was 0.01-10mg/L, which corresponds to 0.0001-0.1mg of fluorides per m(3) in collection of a 20L air sample. The concentration of fluorides in the respirable fraction of collected air samples was in the range of 0.20-1.82mg/m(3), while the inhalable fraction contained 0.23-1.96mg/m(3) of fluorides during an eight-hour working day in the welding room. Copyright © 2015. Published by Elsevier B.V.

  17. Development of an empirical model for fluoride removal from photovoltaic wastewater by electrocoagulation process

    KAUST Repository

    Drouiche, Nadjib

    2011-05-01

    Electrocoagulation experiments were conducted with bipolar aluminium electrodes to determine the optimum conditions for the fluoride removal from synthetic photovoltaic wastewater. A high fluoride concentration in community water supplies can cause fluorosis which has a detrimental effect on human health in particular on teeth and bones. A full 23 factorial design of experiments was used to obtain the best conditions of fluoride removal from water solutions. The three factors considered were initial fluoride concentration, applied potential, and supporting electrolyte dosage. Two levels for each factor were used; supporting electrolyte (0 and 100), applied potential (10 and 30 V), and initial fluoride concentration (20 and 25 mg/L). Results showed that the optimum conditions for fluoride removal from photovoltaic wastewater containing an initial fluoride concentration of 20 mg/L were a supporting electrolyte dose of 100 mg/L and an applied potential of 30 V. These gave a residual fluoride concentration of 8.6 mg/L which was below the standard discharge limit. A mathematical equation showing the relation between residual fluoride concentration and the effective variables was also developed. © 2011 Desalination Publications. All rights reserved.

  18. Development of an empirical model for fluoride removal from photovoltaic wastewater by electrocoagulation process

    KAUST Repository

    Drouiche, Nadjib; Aoudj, Salaheddine; Lounici, Hakim; Mahmoudi, Hacè ne; Ghaffour, NorEddine; Goosen, Mattheus F A

    2011-01-01

    Electrocoagulation experiments were conducted with bipolar aluminium electrodes to determine the optimum conditions for the fluoride removal from synthetic photovoltaic wastewater. A high fluoride concentration in community water supplies can cause fluorosis which has a detrimental effect on human health in particular on teeth and bones. A full 23 factorial design of experiments was used to obtain the best conditions of fluoride removal from water solutions. The three factors considered were initial fluoride concentration, applied potential, and supporting electrolyte dosage. Two levels for each factor were used; supporting electrolyte (0 and 100), applied potential (10 and 30 V), and initial fluoride concentration (20 and 25 mg/L). Results showed that the optimum conditions for fluoride removal from photovoltaic wastewater containing an initial fluoride concentration of 20 mg/L were a supporting electrolyte dose of 100 mg/L and an applied potential of 30 V. These gave a residual fluoride concentration of 8.6 mg/L which was below the standard discharge limit. A mathematical equation showing the relation between residual fluoride concentration and the effective variables was also developed. © 2011 Desalination Publications. All rights reserved.

  19. Sirtuin1 and autophagy protect cells from fluoride-induced cell stress

    Science.gov (United States)

    Suzuki, Maiko; Bartlett, John D.

    2014-01-01

    Sirtuin1 (SIRT1) is an (NAD+)-dependent deacetylase functioning in the regulation of metabolism, cell survival and organismal lifespan. Active SIRT1 regulates autophagy during cell stress, including calorie restriction, endoplasmic reticulum stress and oxidative stress. Previously, we reported that fluoride induces endoplasmic reticulum (ER) stress in ameloblasts responsible for enamel formation, suggesting that ER-stress plays a role in dental fluorosis. However, the molecular mechanism of how cells respond to fluoride-induced cell stress is unclear. Here, we demonstrate that fluoride activates SIRT1 and initiates autophagy to protect cells from fluoride exposure. Fluoride treatment of ameloblast-derived cells (LS8) significantly increased Sirt1 expression and induced SIRT1 phosphorylation resulting in the augmentation of SIRT1 deacetylase activity. To demonstrate that fluoride exposure initiates autophagy, we characterized the expression of autophagy related genes (Atg); Atg5, Atg7 and Atg8/LC3 and showed that both their transcript and protein levels were significantly increased following fluoride treatment. To confirm that SIRT1 plays a protective role in fluoride toxicity, we used resveratrol (RES) to augmented SIRT1 activity in fluoride treated LS8 cells. RES increased autophagy, inhibited apoptosis, and decreased fluoride cytotoxicity. Rats treated with fluoride (0, 50 and 100 ppm) in drinking water for 6 weeks had significantly elevated expression levels of Sirt1, Atg5, Atg7 and Atg8/LC3 in their maturation stage enamel organs. Increased protein levels of p-SIRT1, ATG5 and ATG8/LC3 were present in fluoride-treated rat maturation stage ameloblasts. Therefore, the SIRT1/autophagy pathway may play a critical role as a protective response to help prevent dental fluorosis. PMID:24296261

  20. Sirtuin1 and autophagy protect cells from fluoride-induced cell stress.

    Science.gov (United States)

    Suzuki, Maiko; Bartlett, John D

    2014-02-01

    Sirtuin1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase functioning in the regulation of metabolism, cell survival and organismal lifespan. Active SIRT1 regulates autophagy during cell stress, including calorie restriction, endoplasmic reticulum (ER) stress and oxidative stress. Previously, we reported that fluoride induces ER-stress in ameloblasts responsible for enamel formation, suggesting that ER-stress plays a role in dental fluorosis. However, the molecular mechanism of how cells respond to fluoride-induced cell stress is unclear. Here, we demonstrate that fluoride activates SIRT1 and initiates autophagy to protect cells from fluoride exposure. Fluoride treatment of ameloblast-derived cells (LS8) significantly increased Sirt1 expression and induced SIRT1 phosphorylation resulting in the augmentation of SIRT1 deacetylase activity. To demonstrate that fluoride exposure initiates autophagy, we characterized the expression of autophagy related genes (Atg); Atg5, Atg7 and Atg8/LC3 and showed that both their transcript and protein levels were significantly increased following fluoride treatment. To confirm that SIRT1 plays a protective role in fluoride toxicity, we used resveratrol (RES) to augment SIRT1 activity in fluoride treated LS8 cells. RES increased autophagy, inhibited apoptosis, and decreased fluoride cytotoxicity. Rats treated with fluoride (0, 50, 100 and 125ppm) in drinking water for 6weeks had significantly elevated expression levels of Sirt1, Atg5, Atg7 and Atg8/LC3 in their maturation stage enamel organs. Increased protein levels of p-SIRT1, ATG5 and ATG8/LC3 were present in fluoride-treated rat maturation stage ameloblasts. Therefore, the SIRT1/autophagy pathway may play a critical role as a protective response to help prevent dental fluorosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. [The effect of daily controlled oral hygiene on the oral health of children in a town with drinking water fluoridation (Karl Marx Stadt)].

    Science.gov (United States)

    Georgi, J; Künzel, W

    1976-03-01

    Under the conditions of an optimized (with regard to caries prevention) fluoride content of the drinking uater, the authors studied (in the framework of an oral hygiene measure covering 32 months) in 149 children 6.5-8 years of age the effects of supervised daily dental and oral care on dental health. The improvement in oral hygiene (OHI) by 33% is in harmony with an additional caries reduction by 33.3% (DMF/S index) and a decrease of the PM index by 47%. A wider use of oral hygiene actions as secondary preventive measures is, therefore, recommended also for towns with fluoridated drinking water.

  2. Annotated bibliography on the effects of water containing fluorides on container-grown crops

    Energy Technology Data Exchange (ETDEWEB)

    1962-01-01

    Most of the literature on fluorine and plants relates to damage caused by atmospheric pollution, for example HF from aluminium works etc, which causes much greater damage than is possible with uptake through the roots. However a few papers do deal with uptake via the roots as follows: reviews of a general nature; uptake of fluorine and its effect on oxygen consumption; and fluoride induced chlorosis. The remainder deal with the effects of various concentrations of fluoride on container grown crops. One suggests that fluorine may be an essential trace element although its growth promoting action is not confirmed elsewhere. For the rest, the limits of fluorine tolerance are shown to be variable, related perhaps to the normal F content of the plant. No plant species however is recorded to have been damaged by concentrations of F below 10 ppM. The influence of nutrition on the appearance of symptoms of F toxicity, especially Ca nutrition but also N supply, is emphasized in two papers.

  3. Risk Assessment Study of Fluoride Salts: Probability-Impact Matrix of Renal and Hepatic Toxicity Markers.

    Science.gov (United States)

    Usuda, Kan; Ueno, Takaaki; Ito, Yuichi; Dote, Tomotaro; Yokoyama, Hirotaka; Kono, Koichi; Tamaki, Junko

    2016-09-01

    The present risk assessment study of fluoride salts was conducted by oral administration of three different doses of sodium and potassium fluorides (NaF, KF) and zinc fluoride tetrahydrate (ZnF2 •4H2O) to male Wistar rats. The rats were divided into control and nine experimental groups, to which oral injections of 0.5 mL distilled water and 0.5 mL of fluoride solutions, respectively, were given. The dosage of fluoride compounds was adjusted to contain 2.1 mg (low-dose group, LG), 4.3 mg (mid-dose group, MG), and 5.4 mg fluoride per 200 g rat body weight (high-dose group, HG) corresponding to 5, 10, and 12.5 % of LD50 values for NaF. The 24-h urine volume, N-acetyl-β-D-glucosaminidase (NAG) and creatinine clearance (Ccr) were measured as markers of possible acute renal impact. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined in serum samples as markers of acute hepatic impact. The levels of serum and urinary fluoride were determined to evaluate fluoride bioavailability. The results reveal that higher doses of NaF, KF, and ZnF2 induced renal damage as indicated by higher urinary NAG (p fluoride is a potential, dose-dependent risk factor of renal tubular damage.

  4. Purifying arsenic and fluoride-contaminated water by a novel graphene-based nanocomposite membrane of enhanced selectivity and sustained flux.

    Science.gov (United States)

    Pal, Madhubonti; Mondal, Mrinal Kanti; Paine, Tapan Kanti; Pal, Parimal

    2018-06-01

    A novel graphene-based nanocomposite membrane was synthesized by interfacial polymerization (IP) through chemical bonding of the graphene oxide (GO) layer to polyethersulfone surface. Detailed characterization of the composite membrane through AFM, SEM, ATR-FTIR, XRD analysis, and Raman spectroscopy indicates strong potential of the membrane in highly selective removal of the toxic contaminants like arsenic and fluoride while permeating the essential minerals like calcium and magnesium. This makes the membrane suitable for production of safe drinking water from contaminated water. The membrane applied in a flat-sheet cross-flow module succeeded in removal of more than 98% arsenic and around 80% fluoride from contaminated water while selectively retaining the useful calcium and magnesium minerals in drinking water. A sustained pure water flux of around 150 LMH (liter per square meter per hour) during operation over long hours (> 150 h) with only 3-5% drop in flux indicates antifouling character of the membrane module.

  5. Vegetation and overburden cover on phosphogypsum: Effects on radon emission, runoff water quality, and plant uptake of fluoride and radium

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, S.G. [Florida Institute of Phosphate Research, Bartow, FL (United States)

    1997-12-31

    Phosphogypsum is a byproduct of phosphate fertilizer production, and more than 700 million metric tons have accumulated on 2,500 ha in Florida. Field research was conducted to compare the benefits of capping phosphogypsum with overburden (up to 15 cm in depth) from mined sites versus treatment of the phosphogypsum with minimal amendments. After four growing seasons, vegetation cover was excellent (no bare ground) on plots amended with dolomitic limestone or capped with overburden. However, more species became established with an overburden cap. Fluoride uptake by bermudagrass (Cynodon dactylon) was high when grown directly on phosphogypsum (895 mg kg{sup -1} in leaf tissue) and was reduced slightly by a 15 cm overburden cap (670 mg kg{sup -1}). Unexpectedly, radium ({sup 226}Ra) uptake in bermudagrass grown directly on phosphogypsum (0.6 pCi g{sup -1}) was less than when grown on the overburden cap (1.8 pCi g{sup -1}). The presence of grass cut the radon ({sup 222}Rn) efflux from phosphogypsum in half (from 24 pCi m{sup -2} s{sup -1} to 11 pCi m{sup -2} s{sup -1}), while 15 cm of overburden, in addition to grass cover, halved it again (down to 5 pCi m{sup -2} s{sup -1}). Vegetation cover on phosphogypsum resulted in a 30-fold decrease in electrical conductivity and a 5-fold decrease in the fluoride concentration of surface runoff water. Runoff water quality from vegetated plots was equally good with or without a 15 cm overburden cap on top of the phosphogypsum.

  6. Optimizing School-Based Health-Promotion Programmes: Lessons from a Qualitative Study of Fluoridated Milk Schemes in the UK

    Science.gov (United States)

    Foster, Geraldine R. K.; Tickle, Martin

    2013-01-01

    Background and objective: Some districts in the United Kingdom (UK), where the level of child dental caries is high and water fluoridation has not been possible, implement school-based fluoridated milk (FM) schemes. However, process variables, such as consent to drink FM and loss of children as they mature, impede the effectiveness of these…

  7. Soil fluoride spiking effects on olive trees (Olea europaea L. cv. Chemlali).

    Science.gov (United States)

    Zouari, M; Ben Ahmed, C; Fourati, R; Delmail, D; Ben Rouina, B; Labrousse, P; Ben Abdallah, F

    2014-10-01

    A pot experiment under open air conditions was carried out to investigate the uptake, accumulation and toxicity effects of fluoride in olive trees (Olea europaea L.) grown in a soil spiked with inorganic sodium fluoride (NaF). Six different levels (0, 20, 40, 60, 80 and 100mM NaF) of soil spiking were applied through NaF to irrigation water. At the end of the experiment, total fluoride content in soil was 20 and 1770mgFkg(-1) soil in control and 100mM NaF treatments, respectively. The comparative distribution of fluoride partitioning among the different olive tree parts showed that the roots accumulated the most fluoride and olive fruits were minimally affected by soil NaF spiking as they had the lowest fluoride content. In fact, total fluoride concentration varied between 12 and 1070µgFg(-1) in roots, between 9 and 570µgFg(-1) in shoots, between 12 and 290µgFg(-1) in leaves, and between 10 and 29µgFg(-1) in fruits, respectively for control and 100mM NaF treatments. Indeed, the fluoride accumulation pattern showed the following distribution: roots>shoots>leaves>fruits. On the other hand, fluoride toxicity symptoms such as leaf necrosis and leaf drop appeared only in highly spiked soils (60, 80 and 100mM NaF). Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Adsorbent synthesis of polypyrrole/TiO(2) for effective fluoride removal from aqueous solution for drinking water purification: Adsorbent characterization and adsorption mechanism.

    Science.gov (United States)

    Chen, Jie; Shu, Chiajung; Wang, Ning; Feng, Jiangtao; Ma, Hongyu; Yan, Wei

    2017-06-01

    More than 20 countries are still suffering problems of excessive fluoride containing water, and greater than 8mg/L fluoride groundwater has been reported in some villages in China. In order to meet the challenge in the drinking water defluoridation engineering, a high efficiency and affinity defluoridation adsorbent PPy/TiO 2 composite was designed and synthetized by in-situ chemical oxidative polymerization. Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction Investigator (XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric analysis (TG), N 2 isotherm analysis, Scanning Electron Microscopy (SEM) and Zeta potential analysis were conducted to characterize surface and textural properties of the as-prepared PPy/TiO 2 , and the possibility of fluoride adsorption was carefully estimated by adsorption isotherm and kinetic studies. Characterization investigations demonstrate the uniqueness of surface and textural properties, such as suitable specific surface area and abundant positively charged nitrogen atoms (N + ), which indicate the composite is a suitable material for the fluoride adsorption. Adsorption isotherms and kinetics follow better with Langmuir and pseudo-second-order model, respectively. The maximum adsorption capacity reaches 33.178mg/g at 25°C according to Langmuir model, and particular interest was the ability to reduce the concentration of fluoride from 11.678mg/L to 1.5mg/L for drinking water at pH of 7 within 30min. Moreover, the adsorbent can be easily recycled without the loss of adsorption capacity after six cycles, greatly highlighting its outstanding affinity to fluoride, low-cost and novel to be used in the purification of fluoride containing water for drinking. Furthermore, the adsorption mechanism was extensively investigated and discussed by FTIR investigation and batch adsorption studies including effect of pH, surface potential and thermodynamics. The adsorption is confirmed to be a spontaneous and exothermic

  9. The Role of Calcium in Ameliorating the Oxidative Stress of Fluoride in Rats.

    Science.gov (United States)

    Mohamed, N E

    2016-03-01

    The present study was carried out to investigate the effects of fluoride toxicity on some biochemical, hormonal, and histological parameters of female rats and the protective role of calcium against such effects. Adult female albino rats were divided into five groups; control group received distilled water for 60 days, calcium group received calcium carbonate with dose of 50 mg/kg three times per week for 60 days, fluoride group received sodium fluoride with dose of 20 mg/kg three times per week for 60 days, calcium + fluoride group received calcium carbonate (50 mg/kg) then after 2 h received sodium fluoride (20 mg/kg) three times per week for 60 days, and fluoride + calcium group received sodium fluoride (20 mg/kg) three times per week for 30 days then received calcium carbonate (50 mg/kg) three times per week for another 30 days. The results showed that the levels of thiobarbituric acid reactive substances, urea, creatinine, alkaline phosphatase, triiodothyronine, thyroxine, parathormone, phosphorous, magnesium, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma glutamyl transferase were significantly increased in rats treated with fluoride while serum estradiol, calcium, and organ glutathione were significantly decreased. The histological examination of the femur bone revealed that fluoride treatment induced thinning of bone trabeculae with wilding of marrow space, demineralization, and loss of trabeculae interconnections. Also, the histological examination of hepatic and renal tissues of fluoride-treated rats showed some damages in these tissues while administration of calcium carbonate for 30 or 60 days during fluoride treatment minimized such damages. It could be concluded that administration of calcium to female rats can ameliorate the hazardous effects of fluoride observed in the biochemical, hormonal, and histological parameters.

  10. Fabrication and characterization of functionally graded poly(vinylidine fluoride)-silver nanocomposite hollow fibers for sustainable water recovery

    KAUST Repository

    Francis, Lijo

    2014-12-01

    Poly(vinylidine fluoride) (PVDF) asymmetric hydrophobic hollow fibers were fabricated successfully using dryjet wet spinning. Hydrophobic silver nanoparticles were synthesized and impregnated into the PVDF polymer matrix and functionally graded PVDF-silver nanocomposite hollow fibers are fabricated and tested in the direct contact membrane distillation (DCMD) process. The as-synthesized silver nanoparticles were characterized for Transmission Electron Microscopy (TEM), particle size distribution (PSD) and Ultra Violet (UV) visible spectroscopy. Both the PVDF and PVDF-silver nanocomposite asymmetric hollow fibers were characterized for their morphology, water contact angle and mechanical strength. Addition of hydrophobic silver nanoparticles was found to enhance the hydrophobicity and ~ 2.5 fold increase the mechanical strength of the hollow fibers. A water vapor flux of 31.9kg m-2 h-1 was observed at a feed inlet temperature of 80 °C and at a permeate temperature of 20 °C in the case of hollow fiber membrane modules fabricated using PVDF hollow fibers; the water vapor flux was found to be increased by about 8% and to reach 34.6kg m-2 h-1 for the hollow fiber membrane modules fabricated from the PVDF-silver nanocomposite hollow fibers at the same operating conditions with 99.99% salt rejection.

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

    Science.gov (United States)

    Theerawasttanasiri, Nonthaphat; Taneepanichskul, Surasak; Pingchai, Wichain; Nimchareon, Yuwaree; Sriwichai, Sangworn

    2018-01-01

    Many 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. A 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. We 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. These 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

  12. Accumulation of fluoride by plants and vegetables

    International Nuclear Information System (INIS)

    Njenga, L.W.; Kariuki, D.N.

    1994-01-01

    Fluoride in plant and vegetable samples has been determined using ion selective electrode. The analysis was carried out after ashing the sample on an open flame, adding perchloric acid and allowing the hydrogen fluoride to diffuse into sodium hydroxide layer.The results obtained show that kale and pumpkins can accumulate more than ten times their normal values of fluoride while plants were found to accumulate upto 100μg/g fluoride when exposed to highlevels of fluoride in water or soil. (author)

  13. Water level monitoring device in nuclear reactor

    International Nuclear Information System (INIS)

    Miura, Kiyohide; Otake, Tomohiro.

    1988-01-01

    Purpose: To monitor the water level in a pressure vessel of BWR type nuclear reactors at high accuracy by improving the compensation functions. Constitution: In the conventional water level monitor in a nuclear reactor, if the pressure vessel is displaced by the change of the pressure in the reactor or the temperature of the reactor water, the relative level of the reference water head in a condensation vessel is changed to cause deviation between the actual water level and the indicated water level to reduce the monitoring accuracy. According to the invention, means for detecting the position of the reference water head and means for detection the position in the condensation vessel are disposed to the pressure vessel. Then, relative positional change between the condensation vessel and the reference water head is calculated based on detection sinals from both of the means. The water level is compensated and calculated by water level calculation means based on the relative positional change, water level signals from the level gage and the pressure signals from the pressure gage. As a result, if the pressure vessel is displaced due to the change of the temperature or pressure, it is possible to measure the reactor water level accurately thereby remakably improve the reliability for the water level control in the nuclear reactor. (Horiuchi, T.)

  14. Effect of fluoride exposure on the intelligence of school children in Madhya Pradesh, India

    Directory of Open Access Journals (Sweden)

    Sudhanshu Saxena

    2012-01-01

    Full Text Available Objective: To assess the relationship between exposure to different drinking water fluoride levels and children′s intelligence in Madhya Pradesh state, India. Materials and Methods: This cross-sectional study was conducted among 12-year-old school children of Madhya Pradesh state, India. The children were selected from low (0.05. However, a statistically significant difference was observed in the urinary fluoride levels (P 0.000. Reduction in intelligence was observed with an increased water fluoride level (P 0.000. The urinary fluoride level was a significant predictor for intelligence (P 0.000. Conclusion: Children in endemic areas of fluorosis are at risk for impaired development of intelligence.

  15. IUPAC-NIST Solubility Data Series. 100. Rare Earth Metal Fluorides in Water and Aqueous Systems. Part 3. Heavy Lanthanides (Gd–Lu)

    Energy Technology Data Exchange (ETDEWEB)

    Mioduski, Tomasz [Institute of Nuclear Chemistry and Technology, 03195 Warszawa (Poland); Gumiński, Cezary, E-mail: cegie@chem.uw.edu.pl [Department of Chemistry, University of Warsaw, 02093 Warszawa (Poland); Zeng, Dewen, E-mail: dewen-zeng@hotmail.com [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2015-06-15

    This is the third part of the volume devoted to solubility data for the rare earth metal (REM) fluorides in water and in aqueous ternary and multicomponent systems. It covers experimental results of trivalent fluorides of Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu (so-called heavy lanthanides), since no quantitative data on solubilities of TbF{sub 4} and YbF{sub 2} (the most stable compounds at these valencies) are available. The related literature has been covered through the end of 2014. Compilations of all available papers with the solubility data are introduced for each REM fluoride with a corresponding critical evaluation. Every such assessment contains a collection of all solubility results in aqueous solution, a selection of suggested solubility data, a solubility equation, and a brief discussion of the multicomponent systems. Only simple fluorides (no complexes or double salts) are treated as the input substances in this report. General features of the systems, such as nature of the equilibrium solid phases, solubility as a function of temperature, influence of ionic strength, solution pH, mixed solvent medium on the solubility, quality of the solubility results, and the solubility as a function of REM atomic number, have already been presented in Part 1 of the volume.

  16. Studies on the comparative effect of sodium fluoride on collagen ...

    African Journals Online (AJOL)

    Fluoride is an essential element for the normal development and growth of human beings. The main source of fluoride for humans is the intake of groundwater. At high levels, fluoride causes dental and skeletal fluorosis. In this study, control and sodium fluoride (NaF) treated groups of rats had significant (p < 0.05) higher ...

  17. Scandium fluorides

    International Nuclear Information System (INIS)

    Melnikov, P.; Nalin, M.; Messaddeq, Y.

    1997-01-01

    A new modification of scandium fluoride has been synthesised. The compound is deficient in fluorine, with the composition ScF 2.76 . It belongs to the tetragonal system, lattice parameters being a=3.792 and c=6.740 A and may be obtained at low temperatures by the decomposition of the precursor NH 4 ScF 4 . The reaction is topotactic, tetragonal parameters of the precursor are a=4.021 and c=6.744 A. Structural relationships with various fluorides and ammonium aminofluorides are discussed. This synthesis route with IR-assisted decomposition should be considered as a soft-chemistry approach. (orig.)

  18. Effects of fluoride on growth, body composition, and serum biochemical profile in a freshwater teleost, Cyprinus carpio.

    Science.gov (United States)

    Chen, Jianjie; Cao, Jinling; Wang, Jundong; Jia, Ruhui; Xue, Wenjuan; Li, Yundong; Luo, Yongju; Xie, Lingtian

    2013-10-01

    Fluoride is ubiquitously distributed in natural waters. Elevated fluoride may cause histopathological changes and induce oxidative stress in the gills of the common carp (Cyprinus carpio). The present study further evaluates the effects of fluoride on growth performance, body composition, and biochemical measurements of C. carpio. The results showed that food intake, growth, serum osmolality, body composition, and biochemical measures in the blood were affected by fluoride. Weight gain rate and specific growth rate in the exposed fish decreased compared with those of the control fish. Levels of crude protein and crude lipids were reduced in the fluoride-exposed fish. The major ion levels in the sera of fluoride-exposed fish were severely disturbed, resulting in a lower osmolality. All the biochemical parameters measured in the blood were affected by the exposure to fluoride. Total protein, albumin, globulin, and glucose in fish exposed to 63.6 mg/L, 77.7 mg/L, and 124.4 mg/L were lower than those in the control fish. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were markedly increased in exposed fish compared with control. Taken together, the data showed that exposure to fluoride caused a suite of detrimental effects in C. carpio, which might lead to a decrease in growth and food utilization efficiency. The results of the present study indicated that high levels of fluoride could pose a threat to carp in the field. © 2013 SETAC.

  19. [Influence of dental caries prophylaxis using fluor-vigantoletten 1000 on plasma fluoride levels in infants (author's transl)].

    Science.gov (United States)

    Fuchs, C; Pohlandt, F; Abigt, J; Töllner, U; Heimann, G

    1979-04-01

    A group of 57 newborns was divided into two: group I (27 subjects) received solely 1,000 I.U. vitamin D3 per day for 6 months, whereas group II (30 subjects) were given a combination of 1,000 I.U. vitamin D3 and 0.25 mg fluoride. At the end of the time of observation there was a significant difference between the plasma concentrations in the two groups. The median value was 13.06 microgram/l (range: 8:18-39.4 microgram/l) in group I and 16.54 microgram/l (range: 9.9--41.2 microgram/l) in group II. Fluoride is obviously available to infants when administered in combination with Vitamin D3. In addition, it could be proven, that after 6 month administration of fluoride there are no signs of cumulation, overdosage or even intoxication.

  20. Potentiometric chip-based multipumping flow system for the simultaneous determination of fluoride, chloride, pH, and redox potential in water samples.

    Science.gov (United States)

    Chango, Gabriela; Palacio, Edwin; Cerdà, Víctor

    2018-08-15

    A simple potentiometric chip-based multipumping flow system (MPFS) has been developed for the simultaneous determination of fluoride, chloride, pH, and redox potential in water samples. The proposed system was developed by using a poly(methyl methacrylate) chip microfluidic-conductor using the advantages of flow techniques with potentiometric detection. For this purpose, an automatic system has been designed and built by optimizing the variables involved in the process, such as: pH, ionic strength, stirring and sample volume. This system was applied successfully to water samples getting a versatile system with an analysis frequency of 12 samples per hour. Good correlation between chloride and fluoride concentration measured with ISE and ionic chromatography technique suggests satisfactory reliability of the system. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Fluoride ions vs removal technologies: A study

    OpenAIRE

    Singh, Jagvir; Singh, Prashant; Singh, Anuradha

    2016-01-01

    Literature reported that drinking water is a precious and scarce resource and it has to be protected and kept free from any kind of contamination. Further, it has to be used carefully without wasting. Literature also reported that fluoride bearing rocks are abundant in India, as a result, fluoride leaches out and contaminates the adjacent water and soil resources. A high concentration of fluoride ions in ground water increases up to more than 30 mg/L. This high concentration of fluoride ions ...

  2. Quaternary ammonium promoted ultra selective and sensitive fluorescence detection of fluoride ion in water and living cells.

    Science.gov (United States)

    Li, Long; Ji, Yuzhuo; Tang, Xinjing

    2014-10-21

    Highly selective and sensitive fluorescent probes with a quaternary ammonium moiety have been rationally designed and developed for fast and sensitive fluorescence detection of fluoride ion (F(-) from NaF, not TBAF) in aqueous solution and living cells. With the sequestration effect of quaternary ammonium, the detection time was less than 2 min and the detection limit of fluoride ion was as low as 0.57 ppm that is among the lowest detection limits in aqueous solutions of many fluoride fluorescence probes in the literature.

  3. Eukaryotic resistance to fluoride toxicity mediated by a widespread family of fluoride export proteins.

    Science.gov (United States)

    Li, Sanshu; Smith, Kathryn D; Davis, Jared H; Gordon, Patricia B; Breaker, Ronald R; Strobel, Scott A

    2013-11-19

    Fluorine is an abundant element and is toxic to organisms from bacteria to humans, but the mechanisms by which eukaryotes resist fluoride toxicity are unknown. The Escherichia coli gene crcB was recently shown to be regulated by a fluoride-responsive riboswitch, implicating it in fluoride response. There are >8,000 crcB homologs across all domains of life, indicating that it has an important role in biology. Here we demonstrate that eukaryotic homologs [renamed FEX (fluoride exporter)] function in fluoride export. FEX KOs in three eukaryotic model organisms, Neurospora crassa, Saccharomyces cerevisiae, and Candida albicans, are highly sensitized to fluoride (>200-fold) but not to other halides. Some of these KO strains are unable to grow in fluoride concentrations found in tap water. Using the radioactive isotope of fluoride, (18)F, we developed an assay to measure the intracellular fluoride concentration and show that the FEX deletion strains accumulate fluoride in excess of the external concentration, providing direct evidence of FEX function in fluoride efflux. In addition, they are more sensitive to lower pH in the presence of fluoride. These results demonstrate that eukaryotic FEX genes encode a previously unrecognized class of fluoride exporter necessary for survival in standard environmental conditions.

  4. Water level measurement uncertainty during BWR instability

    International Nuclear Information System (INIS)

    Torok, R.C.; Derbidge, T.C.; Healzer, J.M.

    1994-01-01

    This paper addresses the performance of the water-level measurement system in a boiling water reactor (BWR) during severe instability oscillations which, under some circumstances, can occur during an anticipated transient without SCRAM (ATWS). Test data from a prototypical mock-up of the water-level measurement system was used to refine and calibrate a water-level measurement system model. The model was then used to predict level measurement system response, using as boundary conditions vessel pressures calculated by ppercase RETRAN for an ATWS/instability event.The results of the study indicate that rapid pressure changes in the reactor pressure vessel which cause oscillations in downcomer water level, coupled with differences in instrument line lengths, can produce errors in the sensed water level. Using nominal parameters for the measurement system components, a severe instability transient which produced a 0.2 m peak-to-minimum water-level oscillation in the vessel downcomer was predicted to produce pressure difference equivalent to a 0.7 m level oscillation at the input to the differential pressure transmitter, 0.5 m oscillation at the output of the transmitter, and an oscillation of 0.3 m on the water-level indicator in the control room. The level measurement system error, caused by downcomer water-level oscillations and instrument line length differential, is mitigated by damping both in the differential pressure transmitter used to infer level and in the control room display instrument. ((orig.))

  5. Matrix supported tailored polymer for solid phase extraction of fluoride from variety of aqueous streams

    International Nuclear Information System (INIS)

    Thakur, Neha; Kumar, Sanjukta A.; Wagh, D.N.; Das, Sadananda; Pandey, Ashok K.; Kumar, Sangita D.; Reddy, A.V.R.

    2012-01-01

    Highlights: ► Th complexed with poly (bis[2-(methacryloyloxy)-ethyl]phosphate) as tailored polymer membranes. ► Membranes offered high capacity and selectivity for fluoride in aqueous media. ► Quantitative uptake (80 ± 5%) of fluoride. ► Fast sorption kinetics. ► Reusability of polymer membranes. - Abstract: Fluoride related health hazards (fluorosis) are a major environmental problem in many regions of the world. It affects teeth; skeleton and its accumulation over a long period can lead to changes in the DNA structure. It is thus absolutely essential to bring down the fluoride levels to acceptable limits. Here, we present a new inorganic–organic hybrid polymer sorbent having tailored fixed-sites for fluoride sorption. The matrix supported poly (bis[2-(methacryloyloxy)-ethyl]phosphate) was prepared by photo-initiator induced graft-polymerization in fibrous and microporous (sheet) host poly(propylene) substrates. These substrates were conditioned for selective fluoride sorption by forming thorium complex with phosphate groups on bis[2-methacryloyloxy)-ethyl] phosphate (MEP). These tailored sorbents were studied for their selectivity towards fluoride in aqueous media having different chemical conditions. The fibrous sorbent was found to take up fluoride with a faster rate (15 min for ≈76% sorption) than the sheet sorbent. But, the fluoride loading capacity of sheet sorbent (4320 mg kg −1 ), was higher than fibrous and any other sorbent reported in the literature so far. The sorbent developed in the present work was found to be reusable after desorption of fluoride using NaOH solution. It was tested for solid phase extraction of fluoride from natural water samples.

  6. The Effects of Water Spray Cooling in Conjunction with Halogenated Extinguishants on Hydrogen Fluoride Generation and Decay

    National Research Council Canada - National Science Library

    Burch, Ian

    2007-01-01

    The halogenated extinguishants Halon 1301, HFC-227ea (FM200) and NAF-S-III used within Royal Australian Navy vessels for total flooding fire suppression applications have hydrogen fluoride (HF) toxicity concerns...

  7. Groundwater fluoride enrichment in an active rift setting: Central Kenya Rift case study

    Energy Technology Data Exchange (ETDEWEB)

    Olaka, Lydia A., E-mail: lydiaolaka@gmail.com [Department of Geology, University of Nairobi, P.O Box 30197, Nairobi (Kenya); Wilke, Franziska D.H. [Geoforschungs Zentrum, Telegrafenberg, 14473 Potsdam (Germany); Olago, Daniel O.; Odada, Eric O. [Department of Geology, University of Nairobi, P.O Box 30197, Nairobi (Kenya); Mulch, Andreas [Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt (Germany); Institut für Geowissenschaften, Goethe Universität Frankfurt, Altenhöferallee 1, 60438 Frankfurt (Germany); Musolff, Andreas [UFZ-Helmholtz-Centre for Environmental Research, Department of Hydrogeology, Permoserstr. 15, 04318 Leipzig (Germany)

    2016-03-01

    Groundwater is used extensively in the Central Kenya Rift for domestic and agricultural demands. In these active rift settings groundwater can exhibit high fluoride levels. In order to address water security and reduce human exposure to high fluoride in drinking water, knowledge of the source and geochemical processes of enrichment are required. A study was therefore carried out within the Naivasha catchment (Kenya) to understand the genesis, enrichment and seasonal variations of fluoride in the groundwater. Rocks, rain, surface and groundwater sources were sampled for hydrogeochemical and isotopic investigations, the data was statistically and geospatially analyzed. Water sources have variable fluoride concentrations between 0.02–75 mg/L. 73% exceed the health limit (1.5 mg/L) in both dry and wet seasons. F{sup −} concentrations in rivers are lower (0.2–9.2 mg/L) than groundwater (0.09 to 43.6 mg/L) while saline lake waters have the highest concentrations (0.27–75 mg/L). The higher values are confined to elevations below 2000 masl. Oxygen (δ{sup 18}O) and hydrogen (δD) isotopic values range from − 6.2 to + 5.8‰ and − 31.3 to + 33.3‰, respectively, they are also highly variable in the rift floor where they attain maximum values. Fluoride base levels in the precursor vitreous volcanic rocks are higher (between 3750–6000 ppm) in minerals such as cordierite and muscovite while secondary minerals like illite and kaolinite have lower remnant fluoride (< 1000 ppm). Thus, geochemical F{sup −} enrichment in regional groundwater is mainly due to a) rock alteration, i.e. through long residence times and natural discharge and/or enhanced leakages of deep seated geothermal water reservoirs, b) secondary concentration fortification of natural reservoirs through evaporation, through reduced recharge and/or enhanced abstraction and c) through additional enrichment of fluoride after volcanic emissions. The findings are useful to help improve water management

  8. Dose-dependent effect of fluoride on clinical and subclinical indices of fluorosis in school going children and its mitigation by supply of safe drinking water for 5 years: an Indian study.

    Science.gov (United States)

    Khandare, Arjun L; Validandi, Vakdevi; Gourineni, Shankar Rao; Gopalan, Viswanathan; Nagalla, Balakrishna

    2018-02-02

    Fluorosis is a public health problem in India; to know its prevalence and severity along with its mitigation measures is very important. The present study has been undertaken with the aim to assess the F dose-dependent clinical and subclinical symptoms of fluorosis and reversal of the disease by providing safe drinking water. For this purpose, a cross-sectional study was undertaken in 1934 schoolgoing children, Nalgonda district. Study villages were categorized into control (category I, F = 0.87 mg/L), affected (category II, F = 2.53 mg/L, and category III, F = 3.77 mg/L), and intervention categories (category IV, F = water and urinary fluoride (UF) in different categories. However, there was a significant decrease in the UF levels in the intervention category IV compared to affected group (category III). Fluoride altered the clinical (dental fluorosis and stunting) and subclinical indices (urine and blood) of fluorosis in a dose-dependent manner. In conclusion, the biochemical indices were altered in a dose-dependent manner and intervention with safe drinking water for 5 years in intervention group-mitigated clinical and subclinical symptoms of fluorosis.

  9. Evaluation of exposure to fluoride in child population of North Argentina.

    Science.gov (United States)

    Rocha, René Antonio; Calatayud, Marta; Devesa, Vicenta; Vélez, Dinoraz

    2017-09-01

    Fluoride is an important element for humans. It inhibits initiation and progression of dental caries and stimulates bone formation. However, excessive intake may lead to the appearance of dental and/or skeletal fluorosis and a decrease in intellectual coefficient in child populations. This study evaluates exposure to fluoride in the child population of Chaco province (Argentina) by analysis of drinking water, food and its bioaccessible fraction (quantity of fluoride solubilised by gastrointestinal digestion and available for intestinal absorption) and urine as a biomarker of internal dose. The concentration of fluoride in drinking water varied between 0.050 and 4.6 mg L -1 , and 80% of the samples exceeded the WHO drinking-water guideline value (1.5 mg L -1 ). Fluoride concentrations in food ranged between 0.80 and 3.0 mg kg -1 fresh weight (fw), being lower in bioaccessible fraction (0.43-1.9 mg kg -1 , fw). On the basis of the consumption data declared for the young child population, fluoride intake varies between 4.1 and 6.5 mg day -1 , greater than the level recommended for this age group. Moreover, in some cases, concentrations of fluoride found in urine (0.62-8.9 mg L -1 ) exceeded those reported in areas with declared fluorosis. All data obtained show the worrying situation of child population in this area of Argentina.

  10. Evaluation of toxic action of fluorides on agricultural plants

    Directory of Open Access Journals (Sweden)

    V. N. Grishko

    2007-03-01

    Full Text Available The toxicity of potassium fluoride, sodium fluoride and ammonium fluoride for pea, maize, oat and onion was studied. It was found that the level of the toxic influence had grown with increase of fluoride concentration in the media of growth (from 5 to 100 mg of F–/l. By increase of the toxic influence the agricultural crops are disposed in the following row: oat < onion < maize < pea. Ammonium fluoride demonstrates lesser toxicity, than potassium and sodium fluorides. Under low concentrations of fluoride compounds (5 and 10 mg of F–/l stimulation of roots growth is noted only for the oat.

  11. Assessment of fluoride contaminations in groundwater of hard rock aquifers in Madurai district, Tamil Nadu (India)

    Science.gov (United States)

    Thivya, C.; Chidambaram, S.; Rao, M. S.; Thilagavathi, R.; Prasanna, M. V.; Manikandan, S.

    2017-05-01

    The fluoride contamination in drinking water is already gone to the alarming level and it needs the immediate involvement and attention of all people to solve this problem. Fluoride problem is higher in hard rock terrains in worldwide and Madurai is such type of hard rock region. Totally 54 samples were collected from the Madurai district of Tamilnadu with respect to lithology. The samples collected were analysed for major cations and anions using standard procedures. The higher concentration of fluoride is noted in the Charnockite rock types of northern part of the study area. 20 % of samples are below 0.5 ppm and 6 % of samples are above 1.5 ppm exceeding the permissible limit. The affinity between the pH and fluoride ions in groundwater suggests that dissolution of fluoride bearing minerals in groundwater. The higher concentration of fluoride ions are observed in the lower EC concentration. The isotopic study suggests that fluoride is geogenic in nature. In factor scores, fluoride is noted in association with pH which indicates the dissolution process.

  12. Water: Local-Level Management

    International Development Research Centre (IDRC) Digital Library (Canada)

    Each publication distills IDRC's research experience with an eye to drawing out ..... in an arid area can drip as much water into the dry soil as might ever arrive ..... disintegrate without careful maintenance into smelly sources of disease and ...

  13. Physiologic Conditions Affect Toxicity of Ingested Industrial Fluoride

    OpenAIRE

    Richard Sauerheber

    2013-01-01

    The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity ...

  14. Influence of resin-modified glass ionomer and topical fluoride on levels of Streptococcus mutans in saliva and biofilm adjacent to metallic brackets

    Directory of Open Access Journals (Sweden)

    Marcela Cristina Damião ANDRUCIOLI

    Full Text Available Abstract Decalcification of enamel during fixed orthodontic appliance treatment remains a problem. White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. The use of fluoride-containing orthodontic materials has shown inconclusive results on their ability to reduce decalcification. The aims of this investigation were to compare the levels of Streptococcus mutans (SM in saliva and biofilm adjacent to orthodontic brackets retained with a resin-modified glass ionomer cement (RMGIC (Fuji ORTHO LC and a light cured composite resin (Transbond XT, and to analyze the influence of topical application of the 1.23% acidulated phosphate fluoride (APF on SM counts. In a parallel study design, two groups (n=14/15 were used with random allocation and high salivary SM counts before treatment. Biofilm was collected from areas adjacent to the brackets on teeth 13, 22, 33, and 41. Both saliva and biofilm were collected on the 7th, 21st, 35th, and 49th days after appliance placement. Topical fluoride application was carried out on the 35th day. Bonding with RMGIC did not alter SM counts in saliva or biofilm adjacent to the brackets. On the other hand, the biofilm adjacent to brackets retained with composite resin showed a significant increase in SM counts along the trial period. Topical application of 1.23% APF did not reduce salivary or biofilm SM counts regardless of the bonding material. In conclusion, fluoride topical application did not show efficacy in reducing SM. The use of RMGIC as bonding materials allowed a better control of SM cfu counts in dental biofilm hindering the significant increase of these microorganisms along the trial period, which was observed in the biofilm adjacent to the composite material.

  15. 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.

    Science.gov (United States)

    Jin, Xiaoyan; Qian, Zhaosheng; Lu, Bangmei; Yang, Wenjing; Bi, Shuping

    2011-01-01

    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.

  16. Method of measuring reactor water level

    International Nuclear Information System (INIS)

    Shinohara, Kaoru.

    1979-01-01

    Purpose: To provide a water level measuring system so that a reactor water level detecting signal can be corrected in correspondence to a recirculation flow, thereby to carry out a correct water level detection in a wide range of the reactor. Method: According to the operation record of a precursor reactor, the ratio Δh of the lowering of the water level due to the recirculation flow is lowered in proportion to the ratiowith respect to the rated differential pressure of the recirculation flow. Accordingly, the flow of recirculation pump is measured by an elbow differential pressure generator utilizing an elbow of a pipe, and the measured value is multiplied by a gain by a ratio setter, and therefter, an addition computation is carried out by an adder for correcting the signal from a water level detector. When the signal from the water level detector is corrected in this manner, the influence of the lowering of the water level due to the recirculation flow can be removed, and an interlocker predetermined in the defined water level can be actuated, thus the influence of the dynamic pressure due to the recirculation flow acting on the instrumental pipe line detecting the reactor water level can be removed effectively. (Yoshino, Y.)

  17. Fluoride removal from aqueous solution by pumice: case study on ...

    African Journals Online (AJOL)

    The fluoride removal from synthetic water by pumice was studied at batch experiments in this study. The effect of pH, contact time, fluoride concentration and adsorbent dose on the fluoride sequestration was investigated. The optimum conditions were studied on Kuhbonan water as a case study. The results showed that ...

  18. An In-vitro Study of the Load Deflection Characteristics of the Thermal Wires Immersed in Different Fluoride Prophylactic Agents

    Directory of Open Access Journals (Sweden)

    Sami K. Al-Joubori

    2018-04-01

    Full Text Available Background: Fluoridated prophylactic agents have been reported to cause corrosion and discoloration of titanium alloys. Degradation in the mechanical properties lead to a decrease in a suitable orthodontic force, thereby causing delayed leveling of crooked teeth. This study was designed to evaluate the load deflection characteristics of thermal nickel titanium arch wires during unloading phase after ninety minutes immersion in three different fluoride agents. Material and methods: Forty specimens of thermal wires were obtained from Ortho Technology Company, which had 0.019” × 0.025” rectangular in cross section. Ten specimens from the wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or Phos-Flur® mouth rinse or in the controlled medium of normal saline and incubated at 37°C for ninety minutes. A Wp 300 universal material testing machine was modified and used to perform a three-point bending test in a water path at 37 ± 1°C. The statistical difference between the different agents was analyzed using ANOVA and least significant difference tests. Results: The unloading forces at 0.5 mm, 1.0 mm, and 1.5 mm where significantly reduced especially in acidulated phosphate fluoride treated specimens followed by neutral fluoride treated specimens. Conclusion: Based on the results found in this study it can be preferred to use fluoride prophylactic agents with the least acidity and fluoride ions concentration.

  19. Comparative study of adsorbents for the removal of fluoride ions from water use and consumption in Mexico; Estudio comparativo de adsorbentes para la remocion de iones fluoruro del agua de uso y consumo en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Teutli S, E. A.

    2014-07-01

    Although fluoride is essential for health many studies have shown it is associated with some health problems, such as fluoro sis, thyroid disorder, neurological disease, Alzheimer, pineal gland and cancer. One of the major routes of exposure is through drinking water. The World Health Organization (Who) allows only 1.5 mg/L as a safe limit for fluoride ions in drinking water and the EPA U. S. Environmental Protection Agency has recently proposed 0.7 mg/L. In some cases, the water extracted from deep wells has concentrations of fluoride ions above 1.5 mg/L (NOM-127-SSA1-2000) which is the permissible limit of water for human use and consumption (whuc). In several countries, there are high concentrations of fluoride ions due to the geological distribution of fluorine-rich rocks. In our country we can find several states that have concentrations higher than 1.5 mg/L of fluoride ions in water, such as Aguascalientes, Zacatecas, Chihuahua, Coahuila, Durango, Guanajuato, Sonora, Jalisco and San Luis Potosi. Various technologies have been proposed to remove fluoride ions from water, such as adsorption, ion exchange, reverse osmosis, nano filtration, electrodialysis, dialysis and electrocoagulation. Sorption is superior to other techniques in terms of initial cost, simplicity of design and ease of operation. In this work systematic studies were done considering the aspects mentioned above, in order to determine the adsorbents properties and most suitable conditions for the removal of fluoride ions from whuc. It is important to note that to date no adsorption treatments for the removal of fluoride ions from water for human use and consumption in our country is done, although there are established methodologies, they have not been implemented because of their high costs. In this work an integral study was done on the removal of fluoride ions from water for human use and consumption. A comparative study of hematite, calcite and zeolite as adsorbents was performed to develop a

  20. Taurine Ameliorates Renal Oxidative Damage and Thyroid Dysfunction in Rats Chronically Exposed to Fluoride.

    Science.gov (United States)

    Adedara, Isaac A; Ojuade, Temini Jesu D; Olabiyi, Bolanle F; Idris, Umar F; Onibiyo, Esther M; Ajeigbe, Olufunke F; Farombi, Ebenezer O

    2017-02-01

    Excessive exposure to fluoride poses several detrimental effects to human health particularly the kidney which is a major organ involved in its elimination from the body. The influence of taurine on fluoride-induced renal toxicity was investigated in a co-exposure paradigm for 45 days using five groups of eight rats each. Group I rats received normal drinking water alone, group II rats were exposed to sodium fluoride (NaF) in drinking water at 15 mg/L alone, group III received taurine alone at a dose of 200 mg/kg group IV rats were co-administered with NaF and taurine (100 mg/kg), while group V rats were co-administered with NaF and taurine (200 mg/kg). Administration of taurine significantly reversed the fluoride-mediated decrease in absolute weight and organo-somatic index of the kidney in the exposed rats. Taurine significantly prevented fluoride-induced elevation in plasma urea and creatinine levels in the exposed rats. Moreover, taurine restored fluoride-mediated decrease in the circulatory concentrations of triiodothyronine, thyroxine, and the ratio of triiodothyronine to thyroxine. Taurine ameliorated fluoride-mediated decrease in renal antioxidant status by significantly enhancing the antioxidant enzyme activities as well as glutathione level in the exposed rats. Additionally, taurine inhibited fluoride-induced renal oxidative damage by markedly decreasing the hydrogen peroxide and malondialdehyde levels as well as improved the kidney architecture in the treated rats. Collectively, taurine protected against fluoride-induced renal toxicity via enhancement of thyroid gland function, renal antioxidant status, and histology in rats.

  1. Fluoride concentrations in soils, vegetation samples and soil fauna in the direct vicinity of a pollution source

    International Nuclear Information System (INIS)

    Vogel, J.; Ottow, J.C.G.; Breimer, R.F.

    1989-01-01

    Fluoride analyses CF t = total F; F w = water soluble F and F HCI HCI-extractable F) of different soils, vegetation samples and soil fauna (Helix pomatia, Lumbricus spp., arthropodes) in a locally polluted area (for nearly 65 years) clearly revealed an F-accumulation in top soil, vegetation and animals. Based on 1N HCI-extractable fluoride, two contamination zones around the emitting industry could be identified. In the calcareous soils, leaching of fluoride seems to be insignificant because of a strong immobilization as CaF 2 . A highly significant correlation between the F HCI content of soils and Lumbricus spp. (with and without gut content) or Helix pomatia shells was found. Fluoride concentrations in washed leaves of Hedera helix and in decaying grass reached levels of 306 and 997 μgF/g respectively. Saprophagous soil arthropods contained high fluoride levels, up to 732 μgF/g in Armadillidium vulgare. (orig.)

  2. Virus Disinfection in Water by Biogenic Silver Immobilized in Polyvinylidene Fluoride Membranes

    Energy Technology Data Exchange (ETDEWEB)

    B De Gusseme; T Hennebel; E Christiaens; H Saveyn; K Verbeken; J Fitts; N Boon; W Vertraete

    2011-12-31

    The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag{sup 0}) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag{sup 0} particles, preventing aggregation during encapsulation. In this study, bio-Ag{sup 0} was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag{sup 0} and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag{sup +} from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag{sup 0}{sub powder} m{sup -2} in a submerged plate membrane reactor operated at a flux of 3.1 L m{sup -2} h{sup -1}. Upon startup, the silver concentration in the effluent initially increased to 271 {mu}g L{sub -1} but after filtration of 31 L m{sup -2}, the concentration approached the drinking water limit (= 100 {mu}g L{sup -1}). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m{sup -2} h{sup -1}, showing the potential of this membrane technology for water disinfection on small scale.

  3. Virus disinfection in water by biogenic silver immobilized in polyvinylidene fluoride membranes

    Energy Technology Data Exchange (ETDEWEB)

    Gusseme, B.D.; Fitts, J.; Hennebel, T.; Christiaens, E.; Saveyn, H.; Verbeken, K.; Boon, N.; Verstraete, W.

    2011-03-01

    The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag{sup 0}) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag{sup 0} particles, preventing aggregation during encapsulation. In this study, bio-Ag{sup 0} was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag{sup 0} and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag{sup +} from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag{sub powder}{sup 0} m{sup -2} in a submerged plate membrane reactor operated at a flux of 3.1 L m{sup -2} h{sup -1}. Upon startup, the silver concentration in the effluent initially increased to 271 {micro}g L{sup -1} but after filtration of 31 L m{sup -2}, the concentration approached the drinking water limit (= 100 {micro}g L{sup -1}). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m{sup -2} h{sup -1}, showing the potential of this membrane technology for water disinfection on small scale. In biogenic silver, silver nanoparticles are attached to a bacterial carrier matrix. Bio-Ag{sup 0} was successfully immobilized in PVDF membranes using immersion-precipitation. The antiviral activity of this material was demonstrated in a plate membrane reactor. The antimicrobial mechanism was most probably related to the slow release of Ag{sup +} ions. The membranes can be applied for treatment of limited volumes of contaminated water.

  4. Fluoridation and tooth wear in Irish adults.

    LENUS (Irish Health Repository)

    Burke, F M

    2010-10-01

    The aim of this study was to determine the prevalence of tooth wear in adults in Ireland and its relationship with water fluoridation. The National Survey of Adult Oral Health was conducted in 2000\\/2001. Tooth wear was determined using a partial mouth examination assessing the upper and lower anterior teeth. A total of 2456 subjects were examined. In this survey, increasing levels and severity of tooth wear were associated with ageing. Men were more affected by tooth wear and were more likely to be affected by severe tooth wear than women. It was found that age, and gender were significant predictors of tooth wear (P < 0.01). Overall, there was no significant relationship between fluoridation and tooth wear in this study.

  5. Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures - paper 1: assessing fluorosis risk, predictors of fluorosis and the potential role of food preparation.

    Science.gov (United States)

    McGrady, Michael G; Ellwood, Roger P; Srisilapanan, Patcharawan; Korwanich, Narumanas; Worthington, Helen V; Pretty, Iain A

    2012-06-21

    To determine the severity of dental fluorosis in selected populations in Chiang Mai, Thailand with different exposures to fluoride and to explore possible risk indicators for dental fluorosis. Subjects were male and female lifetime residents aged 8-13 years. For each child the fluoride content of drinking and cooking water samples were assessed. Digital images were taken of the maxillary central incisors for later blind scoring for TF index (10% repeat scores). Interview data explored previous cooking and drinking water use, exposure to fluoride, infant feeding patterns and oral hygiene practices. Data from 560 subjects were available for analysis (298 M, 262 F). A weighted kappa of 0.80 was obtained for repeat photographic scores. The prevalence of fluorosis (TF 3+) for subjects consuming drinking and cooking water with a fluoride concentration of cooking water >0.9 ppm F the prevalence of fluorosis (TF 3+) rose to 37.3%. Drinking and cooking water at age 3, water used for infant formula and water used for preparing infant food all demonstrated an increase in fluorosis severity with increase in water fluoride level (p cooking water (≥1.6 ppm). The consumption of drinking water with fluoride content >0.9 ppm and use of cooking water with fluoride content >1.6 ppm were associated with an increased risk of aesthetically significant dental fluorosis. Fluoride levels in the current drinking and cooking water sources were strongly correlated with fluorosis severity. Further work is needed to explore fluorosis risk in relation to total fluoride intake from all sources including food preparation.

  6. Urinary fluoride excretion by children 4-6 years old in a south Texas community

    Directory of Open Access Journals (Sweden)

    Ramon J. Baez

    2000-04-01

    Full Text Available This study evaluated urinary fluoride excretion by school children 4-6 years old who were living in a south Texas rural community that had concentrations of fluoride in drinking water supplies generally around the optimal level. We took supervised collections of urine samples in the morning and afternoon at school, and parents of the participating students collected nocturnal samples. We recorded the beginning and end times of the three collection periods and then determined the urinary volume and urinary flow for each of the periods. We measured urinary fluoride concentrations and calculated the urinary excretion rate per hour. The children had breakfast and lunch provided at the school, where the drinking water contained 1.0-1.3 milligrams/liter (mg/L fluoride. Fluoride concentrations in the tested household water supplies, from wells, ranged from 0.1 to 3.2 mg/L fluoride. The children's average urinary fluoride concentrations found for the day were similar to those for the night, with means ranging from 1.26 mg/L to 1.42 mg/L. Average excretion was 36.4 µg/h in the morning, 45.6 µg/h in the afternoon, and 17.5 µg/h at night. The lower nocturnal excretion rates are easily explained by low urinary flow at night. Based on the 15 hours of urine collected, the extrapolated 24-hour fluoride excretion was 749 µg. In conjunction with similar studies, the data from this study will help in developing upper limits for urinary fluoride excretion that are appropriate for avoiding unsightly fluorosis while providing optimal protection against dental decay.

  7. A review of global outlook on fluoride contamination in groundwater with prominence on the Pakistan current situation.

    Science.gov (United States)

    Rasool, Atta; Farooqi, Abida; Xiao, Tangfu; Ali, Waqar; Noor, Sifat; Abiola, Oyebamiji; Ali, Salar; Nasim, Wajid

    2017-12-19

    Several million people are exposed to fluoride (F - ) via drinking water in the world. Current review emphasized the elevated level of fluoride concentrations in the groundwater and associated potential health risk globally with a special focus on Pakistan. Millions of people are deeply dependent on groundwater from different countries of the world encompassing with an elevated level of fluoride. The latest estimates suggest that around 200 million people, from among 25 nations the world over, are under the dreadful fate of fluorosis. India and China, the two most populous countries of the world, are the worst affected. In Pakistan, fluoride data of 29 major cities are reviewed and 34% of the cities show fluoride levels with a mean value greater than 1.5 mg/L where Lahore, Quetta and Tehsil Mailsi are having the maximum values of 23.60, 24.48, > 5.5 mg/L, respectively. In recent years, however, other countries have minimized, even eliminated its use due to health issues. High concentration of fluoride for extended time period causes adverse effects of health such as skin lesions, discoloration, cardiovascular disorders, dental fluorosis and crippling skeletal fluorosis. This review deliberates comprehensive strategy of drinking water quality in the global scenario of fluoride contamination, especially in Pakistan with prominence on major pollutants, mitigation technologies, sources of pollution and ensuing health problems. Considering these verities, health authorities urgently need to establish alternative means of water decontamination in order to prevent associated health problems.

  8. Method for steam generator water level measurement

    International Nuclear Information System (INIS)

    Srinivasan, J.S.

    1991-01-01

    This paper describes a nuclear power plant, a method of controlling the steam generator water level, wherein the steam generator has an upper level tap corresponding to an upper level, a lower level, a riser positioned between the lower and upper taps, and level sensor means for indicating water level between a first range limit and a second range limit, the sensor means being connected to at least the lower tap. It comprises: calculating a measure of velocity head at about the lower level tap; calculating a measure of full water level as the upper level less the measure of velocity head; calibrating the level sensor means to provide an output at the first limit corresponding to an input thereto representative of the measure of full level; calculating a high level setpoint equal to the level of the riser less a bias amount which is a function of the position of the riser relative to the span between the taps; and controlling the water level when the sensor means indicates that the high level setpoint has been reached

  9. THE USE OF FLUORIDE AND ITS EFFECT ON HEALTH

    Directory of Open Access Journals (Sweden)

    Domen Kanduti

    2016-07-01

    Full Text Available Appropriate oral health care is fundamental for any individual’s health. Dental caries is still one of the major public health problems. The most effective way of caries prevention is the use of fluoride. Fluoride occurs naturally in our environment and is always present in our lives. However, the concentration differs from area to area. Exposure can occur through diet, respiration and fluoride supplements. During pregnancy, the placenta acts as a barrier. The fluoride, therefore, crosses the placenta in low concentrations. Drinking water in Slovenia is not fluoridated; the amount of naturally present fluoride is very low. Fluoride can be toxic in extremely high concentrations. The most important effect of fluoride on caries incidence is through its role in the process of remineralisation and demineralisation of tooth enamel. The European Academy of Paediatric Dentistry (EAPD recommends a preventive topical use of fluoride supplements because of their cariostatic effect. 

  10. Radon levels in a water distribution network

    International Nuclear Information System (INIS)

    Alabdula'aly, A.I.

    1997-01-01

    The capital city of Saudi Arabia, Riyadh, relies on both desalinated sea water as well as treated groundwater to meet all its water requirements. About 66% of the water demand is met by desalinated sea water, and the remaining is supplied by six groundwater treatment plants located in the vicinity of the city and supplied with water from 161 wells. The desalinated sea water is blended with only one plant product water and pumped to the distribution network, whereas the other five plants product water is pumped directly to the network. A study of 222 Rn levels in the city distribution network was carried out in which 89 samples were collected from different locations representing the city districts. All samples have shown low radon levels with an average concentration of 0.2 Bq l -1 and a range values of 0.1-1.0 Bq l -1 . The level of radon in different parts of the network was found to be influenced by the water sources to which they are supplied. The lowest radon levels were observed in districts supplied mostly by desalinated sea water. (Author)

  11. Fluoride ions vs removal technologies: A study

    Directory of Open Access Journals (Sweden)

    Jagvir Singh

    2016-11-01

    Full Text Available Literature reported that drinking water is a precious and scarce resource and it has to be protected and kept free from any kind of contamination. Further, it has to be used carefully without wasting. Literature also reported that fluoride bearing rocks are abundant in India, as a result, fluoride leaches out and contaminates the adjacent water and soil resources. A high concentration of fluoride ions in ground water increases up to more than 30 mg/L. This high concentration of fluoride ions causes many harmful and dangerous effects on our datum. Fluoride ions in larger quantities i.e. 20–80 mg/day taken over a period of 10–20 years result in crippling and skeletal fluorosis, severely damaging the bone. In the present scenario, there is a continuously increasing worldwide concern for the development of fluoride treatment technologies. Possibilities of reducing the high fluorine content in groundwater are by defluorination process/dilution with the surface water which is a very simple technique but the addition of Ca2+ ions to a solution in contact with fluorite when experimented in distilled water caused an appreciable decrease in fluoride concentration. In this review article, we emphasized the relationship between high concentrations of fluoride ions and their compounds and their health impact.

  12. Effects of hydrogen fluoride on plants

    Energy Technology Data Exchange (ETDEWEB)

    Yamazoe, F

    1970-07-15

    Symptoms of fluorosis in plants are chlorotic markings around the tip or edges of young leaves. Examples of damage to plants and livestock by fluorides are listed, including the retarded growth of silkworms fed on mulberry leaves polluted by more than 30 ppm fluorides. Plants can be classified into six groups according to their resistance to hydrogen fluoride. Threshold values of the fluoride concentration range from 5-10 ppb for the plants. Gladiolus is normally employed as a plant indicator for hydrogen fluoride and silkworms as indicator insects. The relationship between plant damage by fluorides and exposure time, density, soil, fertilizer, meteorology and location are examined. Several preventive measures are listed, including the spraying of water or lime on plant leaves. It is concluded that the establishment of an environmental standard is difficult because of the extremely high sensitivity of the plants to the gas. 8 references.

  13. Urinary fluoride output in children following the use of a dual-fluoride varnish formulation

    Directory of Open Access Journals (Sweden)

    Kelly Polido Kaneshiro Olympio

    2009-06-01

    Full Text Available OBJECTIVE: This study evaluated the bioavailability of fluoride after topical application of a dual-fluoride varnish commercially available in Brazil, when compared to DuraphatTM. MATERIAL AND METHODS: The urinary fluoride output was evaluated in seven 5-year-old children after application of the fluoride varnishes, in two different phases. In the first phase (I, children received topical application of the fluoride varnish Duofluorid XII (2.92% fluorine, calcium fluoride + 2.71% fluorine, sodium fluoride, FGM TM. After 1-month interval (phase II, the same amount (0.2 mL of the fluoride varnish Duraphat (2.26% fluorine, sodium fluoride, ColgateTM was applied. Before each application all the volunteers brushed their teeth with placebo dentifrice for 7 days. Urinary collections were carried out 24 h prior up to 48 h after the applications. Fluoride intake from the diet was also estimated. Fluoride concentration in diet samples and urine was analyzed with the fluoride ion-specific electrode and a miniature calomel reference electrode coupled to a potentiometer. Data were tested by ANOVA and Tukey's post hoc test (p<0.05. RESULTS: There were significant differences in the urinary fluoride output between phases I and II. The use of Duofluorid XII did not significantly increase the urinary fluoride output, when compared to baseline levels. The application of Duraphat caused a transitory increase in the urinary fluoride output, returning to baseline levels 48 h after its use. CONCLUSIONS: The tested varnish formulation, which has been shown to be effective in in vitro studies, also can be considered safe.

  14. Forecasting Water Levels Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Shreenivas N. Londhe

    2011-06-01

    Full Text Available For all Ocean related activities it is necessary to predict the actual water levels as accurate as possible. The present work aims at predicting the water levels with a lead time of few hours to a day using the technique of artificial neural networks. Instead of using the previous and current values of observed water level time series directly as input and output the water level anomaly (difference between the observed water level and harmonically predicted tidal level is calculated for each hour and the ANN model is developed using this time series. The network predicted anomaly is then added to harmonic tidal level to predict the water levels. The exercise is carried out at six locations, two in The Gulf of Mexico, two in The Gulf of Maine and two in The Gulf of Alaska along the USA coastline. The ANN models performed reasonably well for all forecasting intervals at all the locations. The ANN models were also run in real time mode for a period of eight months. Considering the hurricane season in Gulf of Mexico the models were also tested particularly during hurricanes.

  15. Proximal renal tubular injury in rats sub-chronically exposed to low fluoride concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Cárdenas-González, Mariana C.; Del Razo, Luz M. [Departmento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D. F., México (Mexico); Barrera-Chimal, Jonatan [Unidad de Fisiología Molecular, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México and Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México, D. F., México (Mexico); Jacobo-Estrada, Tania [Departmento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D. F., México (Mexico); López-Bayghen, Esther [Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D. F., México (Mexico); and others

    2013-11-01

    Fluoride is usually found in groundwater at a very wide range of concentration between 0.5 and 25 ppm. At present, few studies have assessed the renal effects of fluoride at environmentally relevant concentrations. Furthermore, most of these studies have used insensitive and nonspecific biomarkers of kidney injury. The aim of this study was to use early and sensitive biomarkers to evaluate kidney injury after fluoride exposure to environmentally relevant concentrations. Recently weaned male Wistar rats were exposed to low (15 ppm) and high (50 ppm) fluoride concentrations in drinking water for a period of 40 days. At the end of the exposure period, kidney injury biomarkers were measured in urine and renal mRNA expression levels were assessed by real time RT-PCR. Our results showed that the urinary kidney injury molecule (Kim-1), clusterin (Clu), osteopontin (OPN) and heat shock protein 72 excretion rate significantly increased in the group exposed to the high fluoride concentration. Accordingly, fluoride exposure increased renal Kim-1, Clu and OPN mRNA expression levels. Moreover, there was a significant dose-dependent increase in urinary β-2-microglobulin and cystatin-C excretion rate. Additionally, a tendency towards a dose dependent increase of tubular damage in the histopathological light microscopy findings confirmed the preferential impact of fluoride on the tubular structure. All of these changes occurred at early stages in which, the renal function was not altered. In conclusion using early and sensitive biomarkers of kidney injury, we were able to found proximal tubular alterations in rats sub-chronically exposed to fluoride. - Highlights: • Exposure to low concentrations of fluoride induced proximal tubular injury • Increase in urinary Kim-1, Clu, OPN and Hsp72 in 50 ppm fluoride-exposed group • Increase in urinary B2M and CysC in 15 and 50 ppm fluoride-exposed groups • Fluoride exposure increased renal Kim, Clu and OPN mRNA expression levels.

  16. Prevalence and extent of dental caries, dental fluorosis, and developmental enamel defects in Lithuanian teenage populations with different fluoride exposures

    DEFF Research Database (Denmark)

    Machiulskiene, Vita; Bælum, Vibeke; Fejerskov, Ole

    2009-01-01

    The aim of this study was to describe the pattern of dental caries, dental fluorosis, and developmental defects of non-fluoride origin in Lithuanian children born and raised in regions with 1.1 ppm (1.1 mg/l F) and 0.3 ppm (0.3 mg/l F) water fluoride levels, respectively. All permanent surfaces/t...... difference, 3.43). The results lend support to the hypothesis that the presence of fluoride in the oral environment promotes lesion arrest rather than inhibiting the initiation of new lesions......./teeth of 300 teenagers were examined for dental caries, dental fluorosis, and non-fluoride developmental defects. The caries prevalence of the study population was 100%. The mean number of decayed surfaces (DS) differed only slightly and statistically insignificantly between the '1.1 ppm fluoride' and '0.3 ppm...

  17. Parents' Attitude towards the Use of Fluorides and Fissure Sealants and its Effect on their Children's Oral Health.

    Science.gov (United States)

    Blumer, Sigalit; Ratson, Tal; Peretz, Benjamin; Dagon, Nurit

    To characterize the attitudes of Israeli parents towards caries preventive measures. participating parents completed a 21-item questionnaire on their demographics, dental history, attitudes and satisfaction from fluorides and fissure sealants. One hundred parents (average age 41.62±4.9 years, 85 females) participated. Most of the parents (88% of the mothers and 84% of the fathers) had an academic education. Most of the parents (54%) had a favorable attitude towards the use of fluoridated gels, while only 37% of them had a positive opinion regarding fluoridated water. The satisfaction levels were very high regarding fissure sealants, fluoridated mouth rinses and fluoridated gels (78.1%, 73.6% and 72.5% respectively). The satisfaction from fluoridated water was split almost equally (50.8% were 'pleased' and 49.2% 'not pleased'). The main source for parental oral health knowledge was the dentist (83%). Parents' attitude towards caries preventive measures was significantly correlated to their gender, dental experience, level of education and the number of children in the family. positive attitude towards caries preventive measures was found among parents with higher awareness for preventive oral health measures and among bigger families. Mothers were more positive about fissure sealants than fathers. Mothers with up to 12 years of education tended to have a positive opinion regarding water fluoridation.

  18. Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures – Paper 1: assessing fluorosis risk, predictors of fluorosis and the potential role of food preparation

    Directory of Open Access Journals (Sweden)

    McGrady Michael G

    2012-06-01

    Full Text Available Abstract Background To determine the severity of dental fluorosis in selected populations in Chiang Mai, Thailand with different exposures to fluoride and to explore possible risk indicators for dental fluorosis. Methods Subjects were male and female lifetime residents aged 8–13 years. For each child the fluoride content of drinking and cooking water samples were assessed. Digital images were taken of the maxillary central incisors for later blind scoring for TF index (10% repeat scores. Interview data explored previous cooking and drinking water use, exposure to fluoride, infant feeding patterns and oral hygiene practices. Results Data from 560 subjects were available for analysis (298 M, 262 F. A weighted kappa of 0.80 was obtained for repeat photographic scores. The prevalence of fluorosis (TF 3+ for subjects consuming drinking and cooking water with a fluoride concentration of 0.9 ppm F the prevalence of fluorosis (TF 3+ rose to 37.3%. Drinking and cooking water at age 3, water used for infant formula and water used for preparing infant food all demonstrated an increase in fluorosis severity with increase in water fluoride level (p  Conclusions The consumption of drinking water with fluoride content >0.9 ppm and use of cooking water with fluoride content >1.6 ppm were associated with an increased risk of aesthetically significant dental fluorosis. Fluoride levels in the current drinking and cooking water sources were strongly correlated with fluorosis severity. Further work is needed to explore fluorosis risk in relation to total fluoride intake from all sources including food preparation.

  19. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers

    DEFF Research Database (Denmark)

    Kirkeskov, Lilli; Kristiansen, Eva; Bøggild, Henrik

    2010-01-01

    with data on dental caries from the Danish National Board of Health database on child dental health for 5-year-old children born in 1989 and 1999, and for 15-year-old children born in 1979 and 1989. The number of children included in the cohorts varied between 41.000 and 48.000. Logistic regression was used...... if analysis was limited to children residing in the same place during the entire study period. Conclusions: The study confirmed previous findings of an inverse relation between fluoride concentration in the drinking water and dental caries in children. This correlation was found in spite of the extensive use...

  20. Electrochemical removal of fluoride from water by PAOA-modified carbon felt electrodes in a continuous flow reactor.

    Science.gov (United States)

    Cui, Hao; Qian, Yan; An, Hao; Sun, Chencheng; Zhai, Jianping; Li, Qin

    2012-08-01

    A novel poly(aniline-co-o-aminophenol) (PAOA) modified carbon felt electrode reactor was designed and investigated for fluoride removal from aqueous solutions. This reactor design is innovative because it operates under a wider pH range because of coating with a copolymer PAOA ion exchange film. In addition, contaminant mass transfer from bulk solution to the electrode surface is enhanced by the porous carbon felt as an electron-conducting carrier material compared to other reactors. The electrically controlled anion exchange mechanism was investigated by X-ray photoelectron spectroscopy and cyclic voltammetry. The applicability of the reactor in the field was tested through a series of continuous flow experiments. When the flow rate and initial fluoride concentration were increased, the breakthrough curve became sharper, which lead to a decrease in the breakthrough time and the defluoridation capacity of the reactor. The terminal potential values largely influenced fluoride removal by the reactor and the optimal defluoridation efficiency was observed at around 1.2V. The breakthrough capacities were all >10mg/g over a wide pH range (pH 5-9) with an initial fluoride concentration of 10mg/L. Consecutive treatment-regeneration studies over a week (once each day) revealed that the PAOA-modified carbon felt electrode could be effectively regenerated for reuse. The PAOA-modified carbon felt electrode reactor is a promising system that could be made commercially available for fluoride removal from aqueous solutions in field applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. 杭锦后旗饮水氟砷暴露对儿童智力的影响%Effects of fluoride and arsenic in drinking water on children's intelligence

    Institute of Scientific and Technical Information of China (English)

    康家琦; 程义斌; 武克恭; 林少彬; 何公理; 金银龙

    2011-01-01

    目的 了解饮水氟、砷暴露对儿童智力的影响,为保护饮水型地方性氟砷中毒病区儿童健康提供科学依据.方法 选择内蒙古杭锦后旗农村地区268名小学生作为研究对象,采集家庭饮用水样,测定氟、砷含量;采用联合型瑞文测试对研究对象进行智力测验,并针对家庭一般情况、饮水水源情况、儿童健康状况及其他智力影响因素等情况进行问卷调查.结果 杭锦后旗儿童家庭饮用水氟含量为(1.24±0.74)mg/L,砷含量为(0.13±0.16)mg/L,均超过国家饮用水卫生标准限值.饮水砷含量≥0.05mg/L的女生智商(95.9±14.2)显著低于饮水砷含量<0.05 mg/L的女生(101.3±13.2),而不同水砷浓度男生智商差异无统计学意义.饮水砷浓度≥0.05mg/L对女生智商影响的调整OR值为2.81,而不同水氟浓度儿童智商差异无统计学意义.结论 饮水氟、砷暴露不利于儿童的智力发育,对女生智力的影响较明显.%Objective To study the effect of fluoride and arsenic exposure in drinking water on children's intelligence, and to provide scientific basis for children's health protection. Methods Two hundred and sixty-eight pupils in Hangjinhou Qi, Inner Mongolia were selected as subjects.Fluoride and arsenic in drinking water were determined. The Chinese combined Raven's Test was applied to evaluate the intelligence of children. In addition, the questionnaire survey was conducted to find out information including general information of households, source of drinking water, health of subjects and intelligence-related factors. Results The average concentrations of fluoride and arsenic in drinking water were ( 1.24 ± 0.74 ) mg/L and (0.13 ± 0.16) mg/L, which were higher than limits of national standard. The intelligence quotient (95.9 ± 14.2) of girls exposed to arsenic ≥0. 05 mg/L in drinking water was lower than IQ of girls ( 101.3 ± 13.2 ) exposed to low level arsenic ( < 0.05 mg/L). IQ of boys had not

  2. The effective use of fluorides in public health

    DEFF Research Database (Denmark)

    Jones, Sheila; Burt, Brian A; Petersen, Poul Erik

    2005-01-01

    , systematic reviews summarizing these extensive databases have indicated that water fluoridation and fluoride toothpastes both substantially reduce the prevalence and incidence of dental caries. We present four case studies that illustrate the use of fluoride in modern public health practice, focusing on......Dental caries remain a public health problem for many developing countries and for underprivileged populations in developed countries. This paper outlines the historical development of public health approaches to the use of fluoride and comments on their effectiveness. Early research...

  3. Equity in children's dental caries before and after cessation of community water fluoridation: differential impact by dental insurance status and geographic material deprivation.

    Science.gov (United States)

    McLaren, Lindsay; McNeil, Deborah A; Potestio, Melissa; Patterson, Steve; Thawer, Salima; Faris, Peter; Shi, Congshi; Shwart, Luke

    2016-02-11

    One of the main arguments made in favor of community water fluoridation is that it is equitable in its impact on dental caries (i.e., helps to offset inequities in dental caries). Although an equitable effect of fluoridation has been demonstrated in cross-sectional studies, it has not been studied in the context of cessation of community water fluoridation (CWF). The objective of this study was to compare the socio-economic patterns of children's dental caries (tooth decay) in Calgary, Canada, in 2009/10 when CWF was in place, and in 2013/14, after it had been discontinued. We analyzed data from population-based samples of schoolchildren (grade 2) in 2009/10 and 2013/14. Data on dental caries (decayed, missing, and filled primary and permanent teeth) were gathered via open mouth exams conducted in schools by registered dental hygienists. We examined the association between dental caries and 1) presence/absence of dental insurance and 2) small area index of material deprivation, using Poisson (zero-inflated) and logistic regression, for both time points separately. For small-area material deprivation at each time point, we also computed the concentration index of inequality for each outcome variable. Statistically significant inequities by dental insurance status and by small area material deprivation were more apparent in 2013/14 than in 2009/10. Results are consistent with increasing inequities in dental caries following cessation of CWF. However, further research is needed to 1) confirm the effects in a study that includes a comparison community, and 2) explore possible alternative reasons for the findings, including changes in treatment and preventive programming.

  4. Magnesium fluoride recovery method

    International Nuclear Information System (INIS)

    Gay, R.L.; McKenzie, D.E.

    1989-01-01

    A method of obtaining magnesium fluoride substantially free from radioactive uranium from a slag formed in the production of metallic uranium by the reduction of depleted uranium tetrafluoride with metallic magnesium in a retort wherein the slag contains the free metals magnesium and uranium and also oxides and fluorides of the metals. The slag having a radioactivity level of at least about 7,000 rhoCi/gm. The method comprises the steps of: grinding the slag to a median particle size of about 200 microns; contacting the ground slag in a reaction zone with an acid having a strength of from about 0.5 to 1.5 N for a time of from about 4 to about 20 hours in the presence of a catalytic amount of iron; removing the liquid product; treating the particulate solid product; repeating the last two steps at least one more time to produce a solid residue consisting essentially of magnesium fluoride substantially free of uranium and having a residual radioactivity level of less than about 1000 rhoCi/gm

  5. Widespread genetic switches and toxicity resistance proteins for fluoride.

    Science.gov (United States)

    Baker, Jenny L; Sudarsan, Narasimhan; Weinberg, Zasha; Roth, Adam; Stockbridge, Randy B; Breaker, Ronald R

    2012-01-13

    Most riboswitches are metabolite-binding RNA structures located in bacterial messenger RNAs where they control gene expression. We have discovered a riboswitch class in many bacterial and archaeal species whose members are selectively triggered by fluoride but reject other small anions, including chloride. These fluoride riboswitches activate expression of genes that encode putative fluoride transporters, enzymes that are known to be inhibited by fluoride, and additional proteins of unknown function. Our findings indicate that most organisms are naturally exposed to toxic levels of fluoride and that many species use fluoride-sensing RNAs to control the expression of proteins that alleviate the deleterious effects of this anion.

  6. An Overview of Liquid Fluoride Salt Heat Transport Systems

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David Eugene [ORNL; Cetiner, Sacit M [ORNL

    2010-09-01

    Heat transport is central to all thermal-based forms of electricity generation. The ever increasing demand for higher thermal efficiency necessitates power generation cycles transitioning to progressively higher temperatures. Similarly, the desire to provide direct thermal coupling between heat sources and higher temperature chemical processes provides the underlying incentive to move toward higher temperature heat transfer loops. As the system temperature rises, the available materials and technology choices become progressively more limited. Superficially, fluoride salts at {approx}700 C resemble water at room temperature being optically transparent and having similar heat capacity, roughly three times the viscosity, and about twice the density. Fluoride salts are a leading candidate heat-transport material at high temperatures. Fluoride salts have been extensively used in specialized industrial processes for decades, yet they have not entered widespread deployment for general heat transport purposes. This report does not provide an exhaustive screening of potential heat transfer media and other high temperature liquids such as alkali metal carbonate eutectics or chloride salts may have economic or technological advantages. A particular advantage of fluoride salts is that the technology for their use is relatively mature as they were extensively studied during the 1940s-1970s as part of the U.S. Atomic Energy Commission's program to develop molten salt reactors (MSRs). However, the instrumentation, components, and practices for use of fluoride salts are not yet developed sufficiently for commercial implementation. This report provides an overview of the current understanding of the technologies involved in liquid salt heat transport (LSHT) along with providing references to the more detailed primary information resources. Much of the information presented here derives from the earlier MSR program. However, technology has evolved over the intervening years

  7. Fluoride concentration in water at the area supplied by the Water Treatment Station of Bauru, SP Concentração de fluoreto na água do setor abastecido pela Estação de Tratamento de Água de Bauru, SP

    Directory of Open Access Journals (Sweden)

    Carolina Simonetti Lodi

    2006-10-01

    Full Text Available OBJECTIVE: to analyze the fluoride concentration in the public water supply at the area supplied by the Water Treatment Station of Bauru and classify the samples as acceptable or unacceptable according to the fluoride concentration. MATERIAL AND METHODS: samples were collected from 30 areas at two periods, October 2002 and March 2003. The fluoride concentration in the samples was determined in duplicate, using an ion sensitive electrode (Orion 9609 connected to a potentiometer (Procyon, model 720. Samples with fluoride concentration ranging from 0.55 to 0.84 mg F/L were considered acceptable, and those whose concentration was outside this range as unacceptable. Data were analyzed by descriptive statistics. RESULTS: the fluoride concentration of the water samples varied between 0.31 and 2.01 mg F/L. Nearly 56% of the samples were classified as acceptable. CONCLUSION: the variations in fluoride concentration at the area supplied by the Water Treatment Station reinforce the need of constant monitoring for maintenance of adequate fluoride levels in the public water supply.OBJETIVO: Analisar a concentração de fluoreto da água de abastecimento público do setor abastecido pela Estação de Tratamento de Água de Bauru e classificar as amostras em aceitáveis ou inaceitáveis de acordo com a concentração de flúor. MATERIAL E MÉTODOS: Foram coletadas 238 amostras de 30 bairros em duas etapas, Outubro de 2002 e Março de 2003. A concentração de fluoreto presente nas amostras foi determinada em duplicata, utilizando-se o eletrodo íon sensível (Orion 9609, acoplado ao potenciômetro (Procyon, modelo 720. As amostras com concentração de flúor variando entre 0,55 e 0,84 mg F/L foram consideradas como aceitáveis e aquelas cuja concentração estava fora do intervalo, como inaceitáveis. Os dados foram analisados por meio de estatística descritiva. RESULTADOS: A concentração de fluoreto das amostras de água variou entre 0,31 e 2,01 mg F

  8. Water-level fluctuations influence sediment porewater ...

    Science.gov (United States)

    Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluctuations impact Hg cycling, particularly the formation of the more toxic and bioaccumulative methylmercury (MeHg). Total-Hg (THg), MeHg, stable isotope methylation rates and several ancillary parameters were measured in reservoir sediments (including some in porewater and overlying water) that are seasonally and permanently inundated. The results showed that sediment and porewater MeHg concentrations were over 3-times higher in areas experiencing water-level fluctuations compared to permanently inundated sediments. Analysis of the data suggest that the enhanced breakdown of organic matter in sediments experiencing water-level fluctuations has a two-fold effect on stimulating Hg methylation: 1) it increases the partitioning of inorganic Hg from the solid phase into the porewater phase (lower log Kd values) where it is more bioavailable for methylation; and 2) it increases dissolved organic carbon (DOC) in the porewater which can stimulate the microbial community that can methylate Hg. Sulfate concentrations and cycling were enhanced in the seasonally inundated sediments and may have also contributed to increased MeHg production. Overall, our results suggest that reservoir management a

  9. Comparison of the Amount of Fluoride Release from Nanofilled Resin Modified Glass Ionomer Conventional and Resin Modified Glass Ionomer Cements

    Directory of Open Access Journals (Sweden)

    Sumitha Upadhyay

    2013-01-01

    Full Text Available Objective: To investigate and compare the amount of fluoride release of conventional, resin modified and nanofilled resin modified glass ionomer cements.Materials and Methods: Tablets of glass-ionomer cements were immersed in deionized water and incubated at 37◦C. After 1, 2, 7, 15 and 30 days, fluoride ion was measured under normal atmospheric conditions by fluoride ion selective electrode. Buffer (TISAB II was used to decomplex the fluoride ion and to provide a constant background ionic strength and to maintain the pH of water between 5.0 and 5.5 as the fluoride electrode is sensitive to changes in pH. Statistical evaluation was carried out by one way ANOVA (Analysis of Variance using SPSS 11.0. The significance level was set at p< 0.05.Results: The release of fluoride was highest on day 1 and there was a sudden fall on day 2 in all three groups. Initially fluoride release from conven-tional glass-ionomer cement was highest compared to the other two glass-ionomer cements, but the amount drastically reduced over the period. Although the amount of fluoride release was less than both the resin modified and nanofilled resin modified glass-ionomer cement, the release was sustained consistently for 30 daysConclusion: The cumulative fluoride release of nanofilled resin modified glass ionomer cement was very less compared to the conventional and resin modified glass ionomer cements and Nanofilled resin modified glass ionomer cement released less but steady fluoride as compared to other resin modified glass ionomer cements.

  10. Análise da fluoretação da água de abastecimento público da zona urbana do município de Campo Grande (MS Water fluoridation analysis of Campo Grande (MS urban zone public supply

    Directory of Open Access Journals (Sweden)

    Bruno Luiz Lessa Bellé

    2009-08-01

    Full Text Available O presente estudo teve por objetivo analisar a concentração de fluoreto na água que flui das torneiras da zona urbana do município de Campo Grande (MS. Para tanto, foram coletadas amostras de água de 21 escolas situadas nos sete subdistritos da cidade, em três oportunidades diferentes para análise do teor de fluoreto, determinada pelo método do eletrodo específico (medidor de fluoreto combinado Orion 9609 BN, acoplado a um potenciômetro digital EA-940 da Orion. Os resultados mostraram que 63,5% das amostras coletadas apresentaram níveis aceitáveis (entre 0,6 a 0,8 ppm de fluoreto e 36,5%, níveis inaceitáveis. Em relação à condição dos locais de coleta, 76,2% foram consideradas adequadas e 23,8%, inadequadas.The objective of this study was to analyze the fluoride concentration on the water that flows of the tap in the urban area of the city of Campo Grande (MS. For the fluoride concentration analysis, it was collected water samples of 21 schools placed in the 7 sub districts of the city, in 3 different opportunities, was made by the specific electrode method (using an Orion 9609 BN combined fluoride measuring electrode, coupled with an Orion EA-940 digital potentiometer. The results showed that 63.5% of the water samples presented acceptable fluoride levels (between 0.60 and 0.80 ppm and 36.5%, unacceptable levels. In relation to the condition of the collect places, 76.2% were considered appropriate and 23.8% were inappropriate.

  11. FLUORIDE: A REVIEW OF USE AND EFFECTS ON HEALTH.

    Science.gov (United States)

    Kanduti, Domen; Sterbenk, Petra; Artnik, Barbara

    2016-04-01

    Appropriate oral health care is fundamental for any individual's health. Dental caries is still one of the major public health problems. The most effective way of caries prevention is the use of fluoride. The aim of our research was to review the literature about fluoride toxicity and to inform physicians, dentists and public health specialists whether fluoride use is expedient and safe. Data we used in our review were systematically searched and collected from web pages and documents published from different international institutions. Fluoride occurs naturally in our environment but we consume it in small amounts. Exposure can occur through dietary intake, respiration and fluoride supplements. The most important factor for fluoride presence in alimentation is fluoridated water. Methods, which led to greater fluoride exposure and lowered caries prevalence, are considered to be one of the greatest accomplishments in the 20th century`s public dental health. During pregnancy, the placenta acts as a barrier. The fluoride, therefore, crosses the placenta in low concentrations. Fluoride can be transmitted through the plasma into the mother's milk; however, the concentration is low. The most important action of fluoride is topical, when it is present in the saliva in the appropriate concentration. The most important effect of fluoride on caries incidence is through its role in the process of remineralization and demineralization of tooth enamel. Acute toxicity can occur after ingesting one or more doses of fluoride over a short time period which then leads to poisoning. Today, poisoning is mainly due to unsupervised ingestion of products for dental and oral hygiene and over-fluoridated water. Even though fluoride can be toxic in extremely high concentrations, it`s topical use is safe. The European Academy of Paediatric Dentistry (EAPD) recommends a preventive topical use of fluoride supplements because of their cariostatic effect.

  12. Fluoride varnish or fluoride mouth rinse?

    DEFF Research Database (Denmark)

    Keller, M K; Klausen, BJ; Twetman, S

    2016-01-01

    OBJECTIVE: In many Danish communities, school-based fluoride programs are offered to children with high caries risk in adjunct to tooth brushing. The purpose of this field trial was to compare the caries-preventive effectiveness of two different fluoride programs in 6-12 year olds. BASIC RESEARCH...... different schools were enrolled after informed consent and their class unit was randomly allocated to one of two fluoride programs. INTERVENTIONS: One group received a semi-annual fluoride varnish applications (FV) and the other group continued with an existing program with fluoride mouth rinses once per...... in caries development over two years among children participating in a school-based fluoride varnish or mouth rinse program....

  13. Dietary Fluoride Intake and Associated Skeletal and Dental Fluorosis in School Age Children in Rural Ethiopian Rift Valley

    Directory of Open Access Journals (Sweden)

    Aweke Kebede

    2016-07-01

    Full Text Available An observational study was conducted to determine dietary fluoride intake, diet, and prevalence of dental and skeletal fluorosis of school age children in three fluorosis endemic districts of the Ethiopian Rift Valley having similar concentrations of fluoride (F in drinking water (~5 mg F/L. The duplicate plate method was used to collect foods consumed by children over 24 h from 20 households in each community (n = 60 and the foods, along with water and beverages, were analyzed for fluoride (F content. Prevalence of dental and skeletal fluorosis was determined using presence of clinical symptoms in children (n = 220. Daily dietary fluoride intake was at or above tolerable upper intake level (UL of 10 mg F/day and the dietary sources (water, prepared food and beverages all contributed to the daily fluoride burden. Urinary fluoride in children from Fentale and Adamitulu was almost twice (>5 mg/L the concentration found in urine from children from Alaba, where rain water harvesting was most common. Severe and moderate dental fluorosis was found in Alaba and Adamitulu, the highest severity and prevalence being in the latter district where staple foods were lowest in calcium. Children in all three areas showed evidence of both skeletal and non-skeletal fluorosis. Our data support the hypothesis that intake of calcium rich foods in addition to using rain water for household consumption and preparation of food, may help in reducing risk of fluorosis in Ethiopia, but prospective studies are needed.

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

    Directory of Open Access Journals (Sweden)

    Theerawasttanasiri N

    2018-01-01

    Full Text Available Nonthaphat Theerawasttanasiri,1,2 Surasak Taneepanichskul,1 Wichain Pingchai,3 Yuwaree Nimchareon,4 Sangworn Sriwichai5 1College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand; 2Department of Health, Health Promotion Center Region 1, Chiang Mai, Thailand; 3Mueang Lamphun District Public Health Office, 4Pasang District Public Health Office, 5Ban Thi District Public Health Office, Lamphun, Thailand Introduction: Many 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.Methods: A 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.Results: We 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

  15. Reading Ground Water Levels with a Smartphone

    Science.gov (United States)

    van Overloop, Peter-Jules

    2015-04-01

    Most ground water levels in the world are measured manually. It requires employees of water management organizations to visit sites in the field and execute a measurement procedure that requires special tools and training. Once the measurement is done, the value is jotted down in a notebook and later, at the office, entered in a computer system. This procedure is slow and prone to human errors. A new development is the introduction of modern Information and Communication Technology to support this task and make it more efficient. Two innovations are introduced to measure and immediately store ground water levels. The first method is a measuring tape that gives a sound and light when it just touches the water in combination with an app on a smartphone with which a picture needs to be taken from the measuring tape. Using dedicated pattern recognition algorithms, the depth is read on the tape and it is verified if the light is on. The second method estimates the depth using a sound from the smartphone that is sent into the borehole and records the reflecting waves in the pipe. Both methods use gps-localization of the smartphone to store the depths in the right location in the central database, making the monitoring of ground water levels a real-time process that eliminates human errors.

  16. El fluoruro en aguas de consumo y su asociación con variables geológicas y geográficas de Cuba Fluoride in drinking water in Cuba and its association with geological and geographical variables

    Directory of Open Access Journals (Sweden)

    Liliam Cuéllar Luna

    2003-11-01

    Full Text Available OBJETIVO: Determinar la asociación entre las diferentes concentraciones del ión fluoruro en aguas de consumo y algunas variables geológicas y geográficas de Cuba, mediante el empleo de un sistema de información geográfica. MÉTODOS: De noviembre de 1998 a octubre de 1999 se estudiaron las concentraciones de fluoruro en fuentes de abastecimiento de agua de consumo de 753 localidades cubanas de 1 000 habitantes o más. Para el análisis de la información se utilizó el sistema de información geográfica MapInfo Professional (v. 5.5 con el método de superposición. Las variables de estudio fueron la concentración del ión fluoruro en fuentes de abastecimiento de agua, las características geológicas del territorio, los alineamientos, los tipos de fuente y las categorías de relieve (llanura o montaña. Los resultados se agruparon por localidad y municipio. RESULTADOS: En 83,1% de las localidades, las muestras de agua fueron recolectadas en pozos y manantiales y en el 16,9% restante, en presas y ríos. De las 753 localidades estudiadas, 675 (89,6% presentaron concentraciones de fluoruro bajas o medias (OBJECTIVE: To determine the association between different concentrations of the fluoride ion in drinking water and some geological and geographical variables in Cuba, by using a geographic information system. METHODS: From November 1998 to October 1999 we studied the fluoride concentration in the sources of drinking water for 753 Cuban localities that had at least 1 000 inhabitants. For the information analysis we utilized the MapInfo Professional version 5.5 geographic information system, using the overlaying method. The study variables were the concentration of the fluoride ion in the water sources, the geological characteristics of the area, the alignments (geological characteristics that were found together, the types of water sources, and whether an area was a plain or mountainous. The results were grouped by locality and municipality

  17. Calcium fluoride

    International Nuclear Information System (INIS)

    King, C.W.; Nestor, O.H.

    1989-01-01

    A new process for producing large, single, oriented crystals of calcium fluoride (CaF 2 ) has been developed which overcomes the limitations of current growing methods. This process has been reduced to practice and has yielded oriented crystals 17.5 x 17.5 x 5 cm 3 . Currently nearing completion is a system for producing 35 x 35 x 7.5 cm 3 single crystals. A scale up to one-meter-square is considered feasible. This crystal growing process makes possible the fabrication of very large CaF 2 windows. Suitability for very high power lasers, however, requires attention to properties beyond mere size. A process to generate higher purity growth stock (starting material) was also developed. The additional purification of the growth stock contributes to lower bulk absorption, the absence of color centers and increased radiation hardness. Also identified were several specific impurities which correlate with radiation hardness. A correlation was found between color centers induced by laser radiation and ionizing radiation. Other CaF 2 crystal properties such as tensile strength, absorption and laser damage thresholds were studied and are discussed

  18. Fluoride Levels of Major Sources of Drinking Water in Edo State of ...

    African Journals Online (AJOL)

    ... also strengthens the enamel thereby making the teeth generally more resistant to dental caries. The incidence of dental caries has increased in Nigeria today due to dietary changes and so it becomes important that means of enhancing resistance to tooth decay are put in place to check this down ward trend in oral health.

  19. A improved tidal method without water level

    Science.gov (United States)

    Luo, xiaowen

    2017-04-01

    Now most tide are obtained use water Level and pressure type water gage, but it is difficult to install them and reading is in low accuracy in this method . In view of above-mentioned facts, In order to improve tide accuracy, A improved method is introduced.sea level is obtained in given time using high-precision GNSS buoy combined instantaneous position from pressure gage. two steps are as following, (1) the GNSS time service is used as the source of synchronization reference in tidal measurement; (2) centimeter-level sea surface positions are obtained in real time using difference GNSS The improved method used in seafloor topography survey,in 145 cross points, 95% meet the requirements of the Hydrographic survey specification. It is effective method to obtain higher accuracy tide.

  20. Climate-driven changes in water level

    DEFF Research Database (Denmark)

    Hansen, Rikke Bjerring; Olsen, Jesper; Jeppesen, Erik

    2013-01-01

    level rose. Moreover, Nymphaeaceae trichosclereids were abundant during the period of algal enrichment. Cladoceran taxa associated with floating leaved plants or benthic habitats responded in a complex way to changes in water level, but the cladoceran assemblages generally reflected deep lake conditions...... hydrology driven by precipitation. The isotopic, sedimentary and plant macrofossil records suggested that the lake level started to decrease around 8400 cal. yr BP, the decrease accelerating during 8350-8260 before an abrupt increase during 8260-8210. This pattern shows that the climate anomaly started...... rates of cladoceran subfossils and algal pigments, possibly due to increased turbidity and reduced nutrient input during this drier period. Pigment analysis also showed added importance of diatoms and cryptophytes during this climate anomaly, while cyanobacteria became more important when the water...

  1. Story of Fluoridation

    Science.gov (United States)

    ... Home Health Info Health Topics Fluoride Share The Story of Fluoridation It started as an observation, that ... this time using photospectrographic analysis, a more sophisticated technology than that used by McKay. Churchill asked an ...

  2. Fluoride in diet

    Science.gov (United States)

    Diet - fluoride ... bones and teeth. Too much fluoride in the diet is very rare. Rarely, infants who get too ... of essential vitamins is to eat a balanced diet that contains a variety of foods from the ...

  3. Concentração de flúor em águas engarrafadas comercializadas no município de São Paulo Fluoride concentration in bottled water on the market in the municipality of São Paulo

    Directory of Open Access Journals (Sweden)

    Roberto Henrique da Costa Grec

    2008-02-01

    Full Text Available O objetivo do estudo foi avaliar a concentração de flúor na água engarrafada comercializada, comparando-a aos valores impressos no rótulo da embalagem. Foram coletadas 229 amostras de água das 35 marcas disponíveis em diversos supermercados, mercearias e lanchonetes de grande circulação nas diferentes regiões do município de São Paulo, em 2006. A concentração de flúor foi determinada por análise em duplicata, utilizando o eletrodo íon-específico. A concentração de flúor variou entre 0,01 e 2,04 mg/l, com diferenças significantes entre os valores estipulados nos rótulos e os encontrados com a análise. Esses resultados reforçam a importância do controle dos níveis de flúor na água engarrafada por parte da vigilância sanitária.The objective of the study was to evaluate the fluoride concentration in bottled water available on the market, in comparison with the values printed on the bottle label. Two hundred and twenty-nine water samples were collected from 35 brands available in several supermarkets, grocery stores and snack bars with high turnover in different regions of the municipality of São Paulo, Southeastern Brazil, in 2006. Fluoride concentrations were determined by duplicate analysis using an ion-specific electrode. The fluoride concentrations ranged from 0.01 to 2.04 mg/l, with significant differences between the values stipulated on labels and those found in the analyses. These results emphasize the importance of controls over fluoride levels in bottled water enforced by the sanitary surveillance agency.

  4. Fluoride toxicity and status of serum thyroid hormones, brain histopathology, and learning memory in rats: a multigenerational assessment.

    Science.gov (United States)

    Basha, Piler Mahaboob; Rai, Puja; Begum, Shabana

    2011-12-01

    High-fluoride (100 and 200 ppm) water was administered to rats orally to study the fluoride-induced changes on the thyroid hormone status, the histopathology of discrete brain regions, the acetylcholine esterase activity, and the learning and memory abilities in multigeneration rats. Significant decrease in the serum-free thyroxine (FT4) and free triiodothyronine (FT3) levels and decrease in acetylcholine esterase activity in fluoride-treated group were observed. Presence of eosinophilic Purkinje cells, degenerating neurons, decreased granular cells, and vacuolations were noted in discrete brain regions of the fluoride-treated group. In the T-maze experiments, the fluoride-treated group showed poor acquisition and retention and higher latency when compared with the control. The alterations were more profound in the third generation when compared with the first- and second-generation fluoride-treated group. Changes in the thyroid hormone levels in the present study might have imbalanced the oxidant/antioxidant system, which further led to a reduction in learning memory ability. Hence, presence of generational or cumulative effects of fluoride on the development of the offspring when it is ingested continuously through multiple generations is evident from the present study.

  5. Fluoride Alteration of [3H]Glucose Uptake in Wistar Rat Brain and Peripheral Tissues.

    Science.gov (United States)

    Rogalska, Anna; Kuter, Katarzyna; Żelazko, Aleksandra; Głogowska-Gruszka, Anna; Świętochowska, Elżbieta; Nowak, Przemysław

    2017-04-01

    The present study was designed to investigate the role of postnatal fluoride intake on [3H]glucose uptake and transport in rat brain and peripheral tissues. Sodium fluoride (NaF) in a concentration of 10 or 50 ppm was added to the drinking water of adult Wistar rats. The control group received distilled water. After 4 weeks, respective plasma fluoride levels were 0.0541 ± 0.0135 μg/ml (control), 0.0596 ± 0.0202 μg/ml (10 ppm), and 0.0823 ± 0.0199 μg/ml (50 ppm). Although plasma glucose levels were not altered in any group, the plasma insulin level in the fluoride (50 ppm) group was elevated (0.72 ± 0.13 μg/ml) versus the control group (0.48 ± 0.24 μg/ml) and fluoride (10 ppm) group. In rats receiving fluoride for 4 weeks at 10 ppm in drinking water, [3H]glucose uptake was unaltered in all tested parts of the brain. However, in rats receiving fluoride at 50 ppm, [3H]glucose uptake in cerebral cortex, hippocampus, and thalamus with hypothalamus was elevated, versus the saline group. Fluoride intake had a negligible effect on [3H]glucose uptake by peripheral tissues (liver, pancreas, stomach, small intestine, atrium, aorta, kidney, visceral tissue, lung, skin, oral mucosa, tongue, salivary gland, incisor, molars, and jawbone). In neither fluoride group was glucose transporter proteins 1 (GLUT 1) or 3 (GLUT 3) altered in frontal cortex and striatum versus control. On the assumption that increased glucose uptake (by neural tissue) reasonably reflects neuronal activity, it appears that fluoride damage to the brain results in a compensatory increase in glucose uptake and utilization without changes in GLUT 1 and GLUT 3 expression.

  6. [Analysis on the exposure level and geographic distribution trend of toxicological indicators in rural drinking water, Shandong Province, in 2015].

    Science.gov (United States)

    Shi, F; Lyu, S P; Kong, F L; Yang, X T; Zhou, J Y

    2017-09-06

    Objective: To analyze the exposure level and the geographical distribution trend of toxicological indicators of rural drinking water in Shandong Province. Methods: The drawing method was used to randomly select no less than 60% villages and towns from 137 counties (cities, districts) of 17 cities in Shandong Province in 2015, and then 1-3 rural centralized water supply units were selected according to the circumstance of rural centralized water supply units in each village and town. In total, 735 villages and towns, 1 473 rural centralized water supply units were selected, and 1 473 water samples were collected. The water treatment process, water supply population and other circumstances of the rural centralized water supply units were investigated, the water quality was monitored, the content of toxicological indicators of drinking water in different areas was compared, and the trend surface isogram of excessive toxicological indicators was drawn. Results: The qualified rate of toxicological indicators in 1 473 water samples was 83.64% ( n =1 232). The main toxicological indicators that affected the qualified rate of toxicological indicators of drinking water in rural areas in Shandong Province were nitrate and fluoride. The excessive rate of fluoride was 5.70% ( n =84) and the exposed population was 1 736 709 (4.22%). The excessive rate of nitrate (as nitrogen) was 12.29% ( n =181) and the exposed population was 1 393 612 (3.39%). The P (5)0 content of fluoride in the eastern, middle and western regions was 0.24, 0.29 and 0.59 mg/L, respective;which was higher in the western region than in the east and the middle regions ( P 0.05). The P (50) content of nitrate (as nitrogen) in the eastern, middle and western regions was 8.00, 7.48, and 2.00 mg/L, which was higher in the eastern and middle regions than in the west region ( P 0.05). The trend surface isogram of nitrate and fluoride content showed that the content of nitrate (as nitrogen) in rural drinking water in

  7. Fluoride metabolism in plants

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R; Shorthouse, M

    1964-04-04

    Grass seedlings exposed to inorganic fluoride solutions do not take up appreciable amounts of fluoride until concentrations of more than 1.0 mM (19 p.p.m.) are used. No formation of organic fluoride has been found, even with exposure to 15.75 mM fluoride, indicating that there is no formation of fluoroacetate or similar compounds. 8 references, 2 tables.

  8. Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures – Paper 1: assessing fluorosis risk, predictors of fluorosis and the potential role of food preparation

    Science.gov (United States)

    2012-01-01

    Background To determine the severity of dental fluorosis in selected populations in Chiang Mai, Thailand with different exposures to fluoride and to explore possible risk indicators for dental fluorosis. Methods Subjects were male and female lifetime residents aged 8–13 years. For each child the fluoride content of drinking and cooking water samples were assessed. Digital images were taken of the maxillary central incisors for later blind scoring for TF index (10% repeat scores). Interview data explored previous cooking and drinking water use, exposure to fluoride, infant feeding patterns and oral hygiene practices. Results Data from 560 subjects were available for analysis (298 M, 262 F). A weighted kappa of 0.80 was obtained for repeat photographic scores. The prevalence of fluorosis (TF 3+) for subjects consuming drinking and cooking water with a fluoride concentration of 0.9 ppm F the prevalence of fluorosis (TF 3+) rose to 37.3%. Drinking and cooking water at age 3, water used for infant formula and water used for preparing infant food all demonstrated an increase in fluorosis severity with increase in water fluoride level (p 0.9 ppm and use of cooking water with fluoride content >1.6 ppm were associated with an increased risk of aesthetically significant dental fluorosis. Fluoride levels in the current drinking and cooking water sources were strongly correlated with fluorosis severity. Further work is needed to explore fluorosis risk in relation to total fluoride intake from all sources including food preparation. PMID:22720834

  9. Spatial and temporal variability of fluoride concentrations in groundwater resources of Larestan and Gerash regions in Iran from 2003 to 2010.

    Science.gov (United States)

    Amini, Hassan; Haghighat, Gholam Ali; Yunesian, Masud; Nabizadeh, Ramin; Mahvi, Amir Hossein; Dehghani, Mohammad Hadi; Davani, Rahim; Aminian, Abd-Rasool; Shamsipour, Mansour; Hassanzadeh, Naser; Faramarzi, Hossein; Mesdaghinia, Alireza

    2016-02-01

    There is discrepancy about intervals of fluoride monitoring in groundwater resources by Iranian authorities. Spatial and temporal variability of fluoride in groundwater resources of Larestan and Gerash regions in Iran were analyzed from 2003 to 2010 using a geospatial information system and the Mann-Kendall trend test. The mean concentrations of fluoride for the 8-year period in the eight cities and 31 villages were 1.6 and 2.0 mg/l, respectively; the maximum values were 2.4 and 3.8 mg/l, respectively. Spatial, temporal, and spatiotemporal variability of fluoride in overall groundwater resources were relatively constant over the years. However, results of the Mann-Kendall trend test revealed a monotonic trend in the time series of one city and 11 villages for the 8-year period. Specifically, one city and three villages showed positive significant Kendall's Tau values, suggesting an upward trend in fluoride concentrations over the 8-year period. In contrast, seven villages displayed negative significant Kendall's Tau values, arguing for a downward trend in fluoride concentrations over the years. From 2003 to 2010, approximately 52 % of the Larestan and Gerash areas have had fluoride concentrations above the maximum permissible Iranian drinking water standard fluoride level (1.4 mg/l), and about 116,000 people were exposed to such excess amounts. Therefore, our study supports for a close monitoring of fluoride concentrations from health authorities in monthly intervals, especially in villages and cities that showed positive trend in fluoride concentrations. Moreover, we recommend simultaneous implementation of cost-effective protective measures or interventions until a standard fluoride level is achieved.

  10. Effects of fluorides on plants

    Energy Technology Data Exchange (ETDEWEB)

    Yamazoe, F

    1975-11-01

    Fluorine compounds known to be air pollutants, such as hydrogen fluoride and silicon tetrachloride, are highly poisonous to plants even at ppm - ppb levels. As solid microparticles, acidic sodium fluoride and cryolite cause problems by adhering to plant leaves and absorbing into plant bodies. Plants are classified by their susceptibility to hydrogen fluoride: gladiolus, apricot, buckwheat, turnip and Vaccinium vitis-idaea are most susceptible showing slight injury at less than 5 ppb for 7-9 days; maize, pepper, and dahlia are fairly susceptible, followed by azalea, rose, lilac, and alfalfa, then by oak and tomato. Gladiolus is used as an indicator plant. The exposure factor for one species was known. The symptoms of plants exposed to gaseous fluorine compounds are described in detail at various concentrations. The causal mechanism of the injuries due to fluorine compounds is described in detail, with the method of determining the fluorine content of plant parts. 7 references.

  11. Determination of Fluoride in Different Toothpaste Formulations

    International Nuclear Information System (INIS)

    Kamau, N.G.; Njoroge, M.; Njau, M.

    1998-01-01

    Fluoride ion selective electrode was used to determine fluoride ion concentrations in seven brands of toothpaste. These were the only available formulations found in Kenya. The brands were classified into three groups-fluoridated, non fluoridated or not indicated. However, there was no independent indication of their quantitative composition. The analysed brands had fluoride content between 0.0033% and 0.096%. These values compared favourably with those obtained elsewhere. The calculated lowest limit of detection (LLD) was 0.01 ppmF- . The mean calibration curve gave a slope of of -50.0mV. which was not significantly different from the theoretical value of 5.88mV at 23 degrees celsius at 95% confidence level

  12. Mitigation of non-point source of fluoride on groundwater by dug well recharge

    Science.gov (United States)

    Ganesan, G.; Lakshmanan, E.

    2017-12-01

    Groundwater used for drinking purpose is affected in many regions due to the presence of excess fluoride. The excess intake of fluoride through drinking water causes fluorosis to human in many states of India, including Tamil Nadu. The present study was carried out with the objective of assessing hydrogeochemistry of groundwater and the feasibility of dug well recharge to reduce the fluoride concentration in Vaniyar river basin, Tamil Nadu, India. The major source for fluoride in groundwater of this area is the epidote hornblende gneissic and charnockite which are the major rocks occurring in this region. As a pilot study a cost effective induced recharge structure was constructed at Papichettipatty village in the study region. The study shows that the groundwater level around the recharge site raised up to 2 m from 14.5 m (bgl) and fluoride concentration has decreased from 3.8 mg/l to 0.9 mg/l due to dilution. The advantage of this induced recharge structure is of its low cost, the ease of implementation, improved groundwater recharge and dilution of fluoride in groundwater. An area of about 1.5 km2 has benefited due to this dug well recharge system.

  13. GNSS-Reflectometry based water level monitoring

    Science.gov (United States)

    Beckheinrich, Jamila; Schön, Steffen; Beyerle, Georg; Apel, Heiko; Semmling, Maximilian; Wickert, Jens

    2013-04-01

    Due to climate changing conditions severe changes in the Mekong delta in Vietnam have been recorded in the last years. The goal of the German Vietnamese WISDOM (Water-related Information system for the Sustainable Development Of the Mekong Delta) project is to build an information system to support and assist the decision makers, planners and authorities for an optimized water and land management. One of WISDOM's tasks is the flood monitoring of the Mekong delta. Earth reflected L-band signals from the Global Navigation Satellite System show a high reflectivity on water and ice surfaces or on wet soil so that GNSS-Reflectometry (GNSS-R) could contribute to monitor the water level in the main streams of the Mekong delta complementary to already existing monitoring networks. In principle, two different GNSS-R methods exist: the code- and the phase-based one. As the latter being more accurate, a new generation of GORS (GNSS Occultation, Reflectometry and Scatterometry) JAVAD DELTA GNSS receiver has been developed with the aim to extract precise phase observations. In a two week lasting measurement campaign, the receiver has been tested and several reflection events at the 150-200 m wide Can Tho river in Vietnam have been recorded. To analyze the geometrical impact on the quantity and quality of the reflection traces two different antennas height were tested. To track separately the direct and the reflected signal, two antennas were used. To derive an average height of the water level, for a 15 min observation interval, a phase model has been developed. Combined with the coherent observations, the minimum slope has been calculated based on the Least- Squares method. As cycle slips and outliers will impair the results, a preprocessing of the data has been performed. A cycle slip detection strategy that allows for automatic detection, identification and correction is proposed. To identify outliers, the data snooping method developed by Baarda 1968 is used. In this

  14. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  15. Determination of boron, silica, fluoride, MBAS, phenols, cyanide and sulphide

    International Nuclear Information System (INIS)

    Smith, R.

    1982-01-01

    This study forms part of the NIWR's series of interlaboratory comparison studies involving southern African laboratories engaged in water and wastewater analysis, and is concerned with the analysis of synthetic water samples by 31 laboratories for boron, silica, fluoride, methylene blue active substances (MBAS), phenols, cyanide and sulphide. The results obtained are evaluated and discussed. Recognised standard methods, or modifications of these methods, were used for most of the determinations. Results from the boron, silica and fluoride determinations showed, in general, acceptable accuracy and precision. Results from the MBAS, phenols, cyanide and sulphide determinations were, however, somewhat widespread, and illustrated the difficulty in obtaining reliable results from the measurement of relatively low levels of these determinands

  16. Sources of carrier F-19 in F-18 fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Link, J. M.; Shoner, S. C.; Krohn, K. A. [University of Washington, Department of Radiology, Molecular Imaging Center, 1959 NE Pacific St., Box 356004, Seattle, WA 98195-6004 (United States)

    2012-12-19

    Fluorine-18 is used for many PET radiopharmaceuticals. Theoretically {sup 18}F should be carrier free and a good candidate for nanochemistry. However, {sup 18}F has 10 to 1000 times more stable fluorine atoms than radioactive atoms. In order to understand the source of carrier fluoride and other ions associated with {sup 18}F radiosynthesis, anion concentrations of different components of {sup 18}F target systems as well as solvents and chemicals used in radiosynthesis were measured. Results: The enriched water used for production of {sup 18}F had low levels of anions. In general, the sources of anions, particularly of fluoride, were the chemical reagents used for synthesis and trace contaminants in tubing, valves and fittings. A major component of contamination was nitrate from irradiation of dissolved nitrogen gas in the target water.

  17. Fluoride release, recharge and flexural properties of polymethylmethacrylate containing fluoridated glass fillers.

    Science.gov (United States)

    Al-Bakri, I A; Swain, M V; Naoum, S J; Al-Omari, W M; Martin, E; Ellakwa, A

    2014-06-01

    The purpose of this study was to investigate the effect of fluoridated glass fillers on fluoride release, recharge and the flexural properties of modified polymethylmethacrylate (PMMA). Specimens of PMMA denture base material with various loading of fluoridated glass fillers (0%, 1%, 2.5%, 5% and 10% by weight) were prepared. Flexural properties were evaluated on rectangular specimens (n = 10) aged in deionized water after 24 hours, 1 and 3 months. Disc specimens (n = 10) were aged for 43 days in deionized water and lactic acid (pH 4.0) and fluoride release was measured at numerous intervals. After ageing, specimens were recharged and fluoride re-release was recorded at 1, 3 and 7 days after recharge. Samples containing 2.5%, 5% and 10% glass fillers showed significantly (p glass fillers specimens. All experimental specimens exhibited fluoride release in both media. The flexural strength of specimens decreased in proportion to the percentage filler inclusion with the modulus of elasticity values remaining within ISO Standard 1567. The modified PMMA with fluoridated glass fillers has the ability to release and re-release fluoride ion. Flexural strength decreased as glass filler uploading increased. © 2014 Australian Dental Association.

  18. Fluoride-elicited developmental testicular toxicity in rats: roles of endoplasmic reticulum stress and inflammatory response.

    Science.gov (United States)

    Zhang, Shun; Jiang, Chunyang; Liu, Hongliang; Guan, Zhizhong; Zeng, Qiang; Zhang, Cheng; Lei, Rongrong; Xia, Tao; Gao, Hui; Yang, Lu; Chen, Yihu; Wu, Xue; Zhang, Xiaofei; Cui, Yushan; Yu, Linyu; Wang, Zhenglun; Wang, Aiguo

    2013-09-01

    Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. Sprague-Dawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of male offspring were studied at 8weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), and C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by gene up-regulation of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-κB (NF-κB)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. A dual-reservoir remote loading water target system for 18F and 13N production with direct in-target liquid level sensing

    International Nuclear Information System (INIS)

    Ferrieri, R.A.; Alexoff, D.L.; Schlyer, D.J.; Wolf, A.P.

    1991-01-01

    This report describes our universal water target loading system that serves both [ 18 F] and [ 13 N] production targets, and a radionuclide delivery system that is specific for [ 18 F] fluoride. The system was designed and fabricated around the operation of a single pneumatic syringe dispenser that accesses one of two reservoirs filled with [ 18 O] enriched water for [ 18 F] fluoride production from the 18 O(p,n) 18 F reaction and natural abundance water for [ 13 N] nitrate/nitrite production from the 16 O(p,α) 13 N reaction and loads one of two targets depending on the radionuclide desired. The system offers several novel features for reliable radionuclide production. First, there exists an in-target probe for direct liquid level sensing using the conductivity response of water. In addition, transfer of [ 18 F] fluoride to the Hot Lab is completely decoupled from the irradiated water through the actions of a resin/recovery system which is located in the cyclotron vault, thus maintaining transfer line integrity. This feature also provides a mechanism for vault-containment of long-lived contaminants generated through target activation and leaching into the water

  20. Dug Well Recharge Method for Insitu Mitigation of Fluoride Contamination in Groundwater

    Science.gov (United States)

    Ganesan, G.; Lakshmanan, E.; Gunalan, J.

    2016-12-01

    Groundwater with fluoride concentration exceeding 1.5 mg/l is not suitable for drinking water supply as it may cause health issues such as dental and skeletal fluorosis to humans. Several million people around the world has been affected by fluorosis. The objective of the study is to mitigate the problem of fluoride contamination in groundwater by increasing groundwater recharge through a dug well recharge system. The study was carried out in a part of Vaniyar river basin, northwest Tamil Nadu, India where fluorosis is prevalent. A cylindrical pit of 1m diameter and 1.5 m height was constructed during May 2014 at a distance of about 4 m from a dug well existing in this area. This cylindrical pit was divided into 3 compartments and one of them was filled with gravel and one with sand. The third compartment was kept empty for inspection and maintenance. The rainfall collected in a funnel shaped depression was allowed to pass through these compartments to discharge in the nearby dug well through a pipe. The concentration of the fluoride in groundwater from this well was had been monitoring on bi-monthly basis from the year 2012 to 2014. After construction of dug well recharge system, the groundwater level has raised by about 5 m and the fluoride concentration has decreased from 3.1 mg/l to 1.44 mg/l due to recharge. The concentration of fluoride and groundwater level is being monitored on daily basis from June 2014. It is evident that the recharge system constructed is working well and the concentration of fluoride in groundwater is within the permissible limit. The advantage of this dug well recharge system is its low cost and the ease of implementation. Thus this pilot study on dug well recharge system demonstrated it's potential in reducing the concentration of fluoride in groundwater which is more beneficial to the society as they cannot afford the well proven water treatment methods.

  1. Hydrostatic Water Level Systems At Homestake DUSEL

    Science.gov (United States)

    Stetler, L. D.; Volk, J. T.

    2009-12-01

    Two arrays of Fermilab-style hydrostatic water level sensors have been installed in the former Homestake gold mine in Lead, SD, the site of the new Deep Underground Science and Engineering Laboratory (DUSEL). Sensors were constructed at Fermilab from 8.5 cm diameter PVC pipe (housing) that was sealed on the ends and fit with a proximity sensor. The instrument have a height of 10 cm. Two ports in each sensor housing provide for connectivity, the upper port for air and the bottom port for water. Multiple instruments connected in series provide a precise water level and differences in readings between successive sensors provide for ground tilt to be resolved. Sensor resolution is 5 μm per count and has a range of approximately 1.25 cm. Data output from each sensor is relayed to a Fermilab-constructed readout card that also has temperature/relative humidity and barometric pressure sensors connected. All data are relayed out of the mine by fiber optic cable and can be recorded by Ethernet at remote locations. The current arrays have been installed on the 2000-ft level (610 m) and consist of six instruments in each array. Three sensors were placed in a N-S oriented drift and three in an E-W oriented drift. Using this orientation, it is anticipated that tilt direction may be resolved in addition to overall tilt magnitude. To date the data show passage of earth tides and frequency analysis has revealed five components to this signal, three associated with the semi-diurnal (~12.4 hr) and two with the diurnal (~24.9 hr) tides. Currently, installation methods are being analyzed between concrete pillar and rib-mounting using the existing setup on the 2000-ft level. Using these results, two additional arrays of Fermilab instruments will be installed on the 4550-ft and 4850-ft levels (1387 and 1478 m, respectively). In addition to Fermilab instruments, several high resolution Budker tiltmeters (1 μm resolution) will be installed in the mine workings in the near future, some

  2. Fluoride method for silicon determination i silicovadium

    International Nuclear Information System (INIS)

    Komarnitskaya, N.N.; Sergeev, K.I.; Shamraj, Z.Ya.

    1977-01-01

    The method used was based on formation of a silicon-potassium fluoride-sodium sediment in strongly acid medium in the presence of excess potassium chloride which decreased the sediment solubility. The sediment was dissolved in hot water to titrate the resultant hydrofluoric acid with a caustic potash solution in the presence of phenolphthalein. Gravity hydrochloric and volumetric fluoride methods were used to compare the results of silicon estimation

  3. Association between Urine Fluoride and Dental Fluorosis as a Toxicity Factor in a Rural Community in the State of San Luis Potosi

    Directory of Open Access Journals (Sweden)

    Lizet Jarquín-Yañez

    2015-01-01

    Full Text Available Objective. The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico. Materials and Methods. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13 mg/L was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinical examination, and the severity of damage was determined using Dean’s index and the Thylstrup-Fejerskov (TF index. Results. The range of exposure in the study population, evaluated through the fluoride content in urine, was 1.1 to 5.9 mg/L, with a mean of 3.14 ± 1.09 mg/L. Dental fluorosis was present in all subjects, of which 95% had severe cases. Higher urine fluoride levels and greater degrees of severity occurred in older children. Conclusions. The results show that dental fluorosis was determined by the presence of fluoride exposure finding a high positive correlation between the severity of fluorosis and urine fluoride concentration and the years of exposure suggested a cumulative effect.

  4. Association between urine fluoride and dental fluorosis as a toxicity factor in a rural community in the state of San Luis Potosi.

    Science.gov (United States)

    Jarquín-Yañez, Lizet; de Jesús Mejía-Saavedra, José; Molina-Frechero, Nelly; Gaona, Enrique; Rocha-Amador, Diana Olivia; López-Guzmán, Olga Dania; Bologna-Molina, Ronell

    2015-01-01

    The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13 mg/L) was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinical examination, and the severity of damage was determined using Dean's index and the Thylstrup-Fejerskov (TF) index. The range of exposure in the study population, evaluated through the fluoride content in urine, was 1.1 to 5.9 mg/L, with a mean of 3.14±1.09 mg/L. Dental fluorosis was present in all subjects, of which 95% had severe cases. Higher urine fluoride levels and greater degrees of severity occurred in older children. The results show that dental fluorosis was determined by the presence of fluoride exposure finding a high positive correlation between the severity of fluorosis and urine fluoride concentration and the years of exposure suggested a cumulative effect.

  5. Caries With Dental Fluorosis and Oral Health Behaviour Among 12-year School Children In Moderate-fluoride Drinking Water Community in Quetta, Pakistan

    International Nuclear Information System (INIS)

    Sami, E.; Vichayanrat, T.; Satitvipawee, P.

    2016-01-01

    Objective: To determine the prevalence of dental caries and its relationship with dental fluorosis, oral health behaviour and dietary behaviour among 12-year school children in moderate-fluoride drinking water community in Quetta, Pakistan. Study Design: Cross-sectional study. Place and Duration of Study: Government and private schools of Quetta, from November 2012 to February 2013. Methodology: A total of 349 children aged 12-year from 14 randomly selected schools were included. The data collection was done on questionnaire designed for children. Dental caries status was examined by using WHO criteria. Result: Dental caries was found in 81 children (23.2 percent) with mean DMFT 0.61. Boys had 1.6 times more chance to have dental caries than girls. Dental fluorosis was found in 63.6 percent of children with majority of moderate degree (50.5 percent). Dental fluorosis status was found significantly associated with dental caries status in children. The children who had mild, moderate and severe fluorosis, had 4 times more chances to develop caries than those who did not have fluorosis. There was no significant association between children's caries status and use of paste, brushing habit, miswak, and visit to the dentist. The use of pastries and juices had a direct relation with the children's dental caries status. Conclusion: Dental caries in children of Quetta is not so much frequent as compared to the fluoride deficient countries. However, the high prevalence of moderate dental fluorosis and consumption of pastries and juices resulted in dental caries. (author)

  6. Water levels shape fishing participation in flood-control reservoirs

    Science.gov (United States)

    Miranda, Leandro E.; Meals, K. O.

    2013-01-01

    We examined the relationship between fishing effort (hours fished) and average March–May water level in 3 flood control reservoirs in Mississippi. Fishing effort increased as water level rose, peaked at intermediate water levels, and decreased at high water levels. We suggest that the observed arched-shaped relationship is driven by the shifting influence of fishability (adequacy of the fishing circumstances from an angler's perspective) and catch rate along a water level continuum. Fishability reduces fishing effort during low water, despite the potential for higher catch rates. Conversely, reduced catch rates and fishability at high water also curtail effort. Thus, both high and low water levels seem to discourage fishing effort, whereas anglers seem to favor intermediate water levels. Our results have implications for water level management in reservoirs with large water level fluctuations.

  7. Qualidade da água para consumo humano e concentração de fluoreto Calidad del agua para consumo humano y concentración de fluoruro Drinking water quality and fluoride concentration

    Directory of Open Access Journals (Sweden)

    Paulo Frazão

    2011-10-01

    clima típicamente tropical se debe revisar el Documento Público 635/75, relacionado con el fluoruro adicionado a las aguas de abastecimiento público.This paper aimed to analyze the fluoride concentration in drinking water, taking into account the balance between the benefits and risks to health, in order to produce scientific backing for the updating of the Brazilian legislation. Systematic reviews studies, official documents and meteorological data were examined. The temperatures in Brazilian state capitals indicate that fluoride levels should be between 0.6 and 0.9 mg F/l in order to prevent dental caries. Natural fluoride concentration of 1.5 mg F/l is tolerated for consumption in Brazil if there is no technology with an acceptable cost-benefit ratio for adjusting/removing the excess. Daily intake of water with a fluoride concentration > 0.9 mg F/l presents a risk to the dentition among children under the age of eight years, and consumers should be explicitly informed of this risk. In view of the expansion of the Brazilian water fluoridation program to regions with a typically tropical climate, Ordinance 635/75 relating to fluoride added to the public water supply should be revised.

  8. Effect of fluoride addition on the properties of dental alginate impression materials.

    Science.gov (United States)

    Lee, Yong-Keun; Lim, Bum-Soon; Kim, Cheol-We

    2004-03-01

    Fluoride-containing dental alginate impression materials can exert a considerable reduction in enamel solubility. The objective was to evaluate the effects of fluoride addition in the alginate impression materials on the properties and subsequent release of fluoride. Four experimental alginate impression materials were studied. Materials were mixed with distilled water (control) or 100-ppm fluoride solution. One or two percent NaF, or 1% SnF2 was added to the materials, which were mixed with distilled water. Fluoride release, flexibility, recovery from deformation, setting time, compressive strength and elastic modulus were determined in accordance with the ISO 1563 and ANSI/ADA Spec. 18. Fluoride release increased after addition of fluoride, and the released amount was 0.762-14.761 ppm. Addition of NaF or SnF2 resulted in higher fluoride release than the control group (p alginate impression material may result in effective release of fluoride without deteriorating the properties of material itself.

  9. Equilibrium Studies of Fluoride Adsorption onto a Ferric Poly ...

    African Journals Online (AJOL)

    African countries along the Great Rift Valley are among areas of the world where excess fluoride in water sources is a major public health problem. In this work, the removal of fluoride (F) from water solutions using a ferric poly-mineral (FPM) from Kenya was therefore studied using batch adsorption experiments. The effect of ...

  10. Silver diamine fluoride: a caries "silver-fluoride bullet".

    Science.gov (United States)

    Rosenblatt, A; Stamford, T C M; Niederman, R

    2009-02-01

    The antimicrobial use of silver compounds pivots on the 100-year-old application of silver nitrate, silver foil, and silver sutures for the prevention and treatment of ocular, surgical, and dental infections. Ag(+) kills pathogenic organisms at concentrations of linings, water purification systems, hospital gowns, and caries prevention. To distill the current best evidence relative to caries, this systematic review asked: Will silver diamine fluoride (SDF) more effectively prevent caries than fluoride varnish? A five-database search, reference review, and hand search identified 99 human clinical trials in three languages published between 1966 and 2006. Dual review for controlled clinical trials with the patient as the unit of observation, and excluding cross-sectional, animal, in vitro studies, and opinions, identified 2 studies meeting the inclusion criteria. The trials indicated that SDF's lowest prevented fractions for caries arrest and caries prevention were 96.1% and 70.3%, respectively. In contrast, fluoride varnish's highest prevented fractions for caries arrest and caries prevention were 21.3% and 55.7%, respectively. Similarly, SDF's highest numbers needed to treat for caries arrest and caries prevention were 0.8 (95% CI=0.5-1.0) and 0.9 (95% CI=0.4-1.1), respectively. For fluoride varnish, the lowest numbers needed to treat for caries arrest and prevention were 3.7 (95% CI=3.4-3.9) and 1.1 (95% CI=0.7-1.4), respectively. Adverse events were monitored, with no significant differences between control and experimental groups. These promising results suggest that SDF is more effective than fluoride varnish, and may be a valuable caries-preventive intervention. As well, the availability of a safe, effective, efficient, and equitable caries-preventive agent appears to meet the criteria of both the WHO Millennium Goals and the US Institute of Medicine's criteria for 21st century medical care.

  11. Simultaneous arsenic and fluoride removal from synthetic and real groundwater by electrocoagulation process: Parametric and cost evaluation.

    Science.gov (United States)

    Thakur, Lokendra Singh; Mondal, Prasenjit

    2017-04-01

    Co-existence of arsenic and fluoride in groundwater has raised severe health issues to living being. Thus, the present research has been conducted for simultaneous removal of arsenic and fluoride from synthetic groundwater by using electrocoagulation process with aluminum electrode. Effects of initial pH, current density, run time, inter electrode distance and NaCl concentration over percentage removal of arsenic and fluoride as well as operating cost have been studied. The optimum experimental conditions are found to be initial pH: 7, current density: 10 A/m 2 , run time: 95 min, inter electrode distance: 1 cm, NaCl concentration: 0.71 g/l for removal of 98.51% arsenic (initial concentration: 550 μg/l) and 88.33% fluoride (initial concentration: 12 mg/l). The concentration of arsenic and fluoride in treated water are found to be 8.19 μg/l and 1.4 mg/l, respectively, with an operating cost of 0.357 USD/m 3 treated water. Pseudo first and second order kinetic model of individual and simultaneous arsenic and fluoride removal in electrocoagulation have also been studied. Produced sludge characterization studies also confirm the presence of arsenic in As(III) form, and fluoride in sludge. The present electrocoagulation process is able to reduce the arsenic and fluoride concentration of synthetic as well as real groundwater to below 10 μg/l and 1.5 mg/l, respectively, which are maximum contaminant level of these elements in drinking water according to WHO guidelines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Nuclide, metal and non metal levels in percolated water from soils fertilized with phosphogypsum

    International Nuclear Information System (INIS)

    Silva, Camilla Bof; Knupp, Eliana Aparecida Nonato; Palmieri, Helena E.L.; Jacomino, Vanusa Maria Feliciano; Taddei, Maria Helena; Ciqueira, Maria Celia

    2009-01-01

    Systematic generation of residues is more and more worrying in today.s world; adequate storage and reutilization are of great importance. Since generation of residues has become impossible to avoid, the possibility of reuse must be studied and researched. An example of these residues is phosphogypsum, which is generated in phosphoric acid production at the rate of around 4.8 tons for each ton of phosphoric acid produced. Many studies seek to reuse phosphogypsum in agriculture as a source of calcium and sulfur, potassium or aluminum, especially in soils from Brazil's cerrado regions. Though phosphogypsum is mainly composed of dehydrated calcium sulfate, it can have high levels of heavy metals, non metals (As and Se), fluorides and natural radionuclides. Thus, its uncontrolled use as a soil conditioner can lead to contamination of underground water. (author)

  13. Prospecting for safe (low fluoride groundwater in the Eastern African Rift: the Arumeru District (Northern Tanzania

    Directory of Open Access Journals (Sweden)

    G. Ghiglieri

    2010-06-01

    Full Text Available A multidisciplinary research effort, including geological, hydrogeological, hydro-chemical, geophysical and hydrological investigations, was aimed at locating a source of safe groundwater for a district of northern Tanzania, within the western branch of the East Africa Rift Valley, where water shortage is common and much of the surface water carries unacceptable levels of dissolved fluoride. The 440 km2 study area lies in the northern part of Arumeru district and is dominated by Mt. Meru (4565 m a.s.l.. The local climate is semi-arid, with distinct wet and dry seasons. Four hydrogeological complexes were identified, occurring within different volcanic formations, either alone or superimposed upon one another. The groundwater flow system was interpreted from the spatial distribution of the springs, combined with a lithology- and geometry-based reconstruction of the aquifers. The dominant pattern consists of a multi-directional flow from the higher elevations in the south towards the lower areas in the north, but this is complicated by structures such as grabens, faults, lava domes and tholoids. After the identification of the major fluoride source, an interference pattern between groundwater and high fluoride surface water was drawn. Finally, vertical electrical soundings were performed to define the location of aquifers in regions where release of fluoride was prevented. The methodological approach for the prospecting of safe water in a semi-arid, fluoride polluted region was validated by the drilling of a 60 m deep well capable of supplying at least 3.8 l/s of low fluoride, drinkable water.

  14. Estimation of atmospheric fluoride by limed filter papers

    International Nuclear Information System (INIS)

    Smith, D.R.

    1988-09-01

    The limed filter paper method of static sampling of atmospheric fluoride is reviewed in this report. Use of the technique, in conjunction with precise measurement of the absorbed fluoride and calibration with dynamic air sampling techniques, to estimate atmospheric fluoride levels, is considered to give only qualitative data (± 50%). The limed filter paper method is site specific due to variations in meteorological conditions. Its main value is to indicate seasonal and annual trends in fluoride exposure of vegetation. Subject to these considerations, the lower and upper limits of atmospheric fluoride exposure and the applicability to atmospheric fluoride estimation under routine or emergency fluoride release conditions are discussed, with special emphasis on the limiting factors

  15. Unsustainability of water resources in the Upper Laja River Basin, Mexico: Social-hydrology interactions in a regional overexploited aquifer with increasing concentrations of fluoride, arsenic and sodium

    Science.gov (United States)

    Ortega, A.

    2013-05-01

    The Upper Laja River Basin, also known as the Independence Basin (IB), with an area of 7,000 km2 and a population near to 500,000 inhabitants is part of the regional Lerma-Chapala Basin in Central Mexico. Groundwater is the main source for drinking water supply, agriculture and industrial uses. Total groundwater extraction is in the order of 1,000 million of m3/a, through near to 3,000 wells in the basin, from which about 85% is for agriculture production, mainly for exportation. Historical hydrologic information in the basin showed the existence of numerous streams, rivers and lakes within the catchments in addition to thousands of springs in the discharge area. At present there is not permanent runoff in the main river and most of the springs and associated ecosystems have disappeared. Water table in the aquifer is between 100 and 200 m depth with decreasing rates between 2 m/a and 10 m/a, while 60 years ago water tables was near ground surface. Dissolved concentration of arsenic and fluoride in groundwater is increasing with time, causing severe health effects in rural villages and more recently in the main urban centers. Increasing concentration of sodium is affecting soil productivity and plant grow, where several hectares of land are been abandoned. There are several pieces of evidence that show the unsustainability of water resources in the IB creating complex social-hydrology interactions: Human actions are impairing the long-term renewability of freshwater stocks and flows. Basic water requirement are not been guaranteed to all inhabitants to maintain human health, neither to restore nor to maintain the remaining ecosystems. Water quality does not meet certain minimum standards in most of the basin. Water-planning and decision making are not democratic, the COTAS, a representation of water users is controlled by farmers with political power; therefore, limiting the participation of other parties and fostering direct participation of affected interests

  16. Review on fluoride-releasing restorative materials--fluoride release and uptake characteristics, antibacterial activity and influence on caries formation.

    Science.gov (United States)

    Wiegand, Annette; Buchalla, Wolfgang; Attin, Thomas

    2007-03-01

    The purpose of this article was to review the fluoride release and recharge capabilities, and antibacterial properties, of fluoride-releasing dental restoratives, and discuss the current status concerning the prevention or inhibition of caries development and progression. Information from original scientific full papers or reviews listed in PubMed (search term: fluoride release AND (restorative OR glass-ionomer OR compomer OR polyacid-modified composite resin OR composite OR amalgam)), published from 1980 to 2004, was included in the review. Papers dealing with endodontic or orthodontic topics were not taken into consideration. Clinical studies concerning secondary caries development were only included when performed in split-mouth design with an observation period of at least three years. Fluoride-containing dental materials show clear differences in the fluoride release and uptake characteristics. Short- and long-term fluoride releases from restoratives are related to their matrices, setting mechanisms and fluoride content and depend on several environmental conditions. Fluoride-releasing materials may act as a fluoride reservoir and may increase the fluoride level in saliva, plaque and dental hard tissues. However, clinical studies exhibited conflicting data as to whether or not these materials significantly prevent or inhibit secondary caries and affect the growth of caries-associated bacteria compared to non-fluoridated restoratives. Fluoride release and uptake characteristics depend on the matrices, fillers and fluoride content as well as on the setting mechanisms and environmental conditions of the restoratives. Fluoride-releasing materials, predominantly glass-ionomers and compomers, did show cariostatic properties and may affect bacterial metabolism under simulated cariogenic conditions in vitro. However, it is not proven by prospective clinical studies whether the incidence of secondary caries can be significantly reduced by the fluoride release of

  17. Fluoride mouthrinses for preventing dental caries in children and adolescents.

    Science.gov (United States)

    Marinho, Valeria C C; Chong, Lee Yee; Worthington, Helen V; Walsh, Tanya

    2016-07-29

    Fluoride mouthrinses have been used extensively as a caries-preventive intervention in school-based programmes and by individuals at home. This is an update of the Cochrane review of fluoride mouthrinses for preventing dental caries in children and adolescents that was first published in 2003. The primary objective is to determine the effectiveness and safety of fluoride mouthrinses in preventing dental caries in the child and adolescent population.The secondary objective is to examine whether the effect of fluoride rinses is influenced by:• initial level of caries severity;• background exposure to fluoride in water (or salt), toothpastes or reported fluoride sources other than the study option(s); or• fluoride concentration (ppm F) or frequency of use (times per year). We searched the following electronic databases: Cochrane Oral Health's Trials Register (whole database, to 22 April 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 3), MEDLINE Ovid (1946 to 22 April 2016), Embase Ovid (1980 to 22 April 2016), CINAHL EBSCO (the Cumulative Index to Nursing and Allied Health Literature, 1937 to 22 April 2016), LILACS BIREME (Latin American and Caribbean Health Science Information Database, 1982 to 22 April 2016), BBO BIREME (Bibliografia Brasileira de Odontologia; from 1986 to 22 April 2016), Proquest Dissertations and Theses (1861 to 22 April 2016) and Web of Science Conference Proceedings (1990 to 22 April 2016). We undertook a search for ongoing trials on the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the World Health Organization International Clinical Trials Registry Platform. We placed no restrictions on language or date of publication when searching electronic databases. We also searched reference lists of articles and contacted selected authors and manufacturers. Randomised or quasi-randomised controlled trials where blind outcome assessment was stated or

  18. A health risk assessment for fluoride in Central Europe.

    Science.gov (United States)

    Fordyce, F M; Vrana, K; Zhovinsky, E; Povoroznuk, V; Toth, G; Hope, B C; Iljinsky, U; Baker, J

    2007-04-01

    Like many elements, fluorine (which generally occurs in nature as fluoride) is beneficial to human health in trace amounts, but can be toxic in excess. The links between low intakes of fluoride and dental protection are well known; however, fluoride is a powerful calcium-seeking element and can interfere with the calcified structure of bones and teeth in the human body at higher concentrations causing dental or skeletal fluorosis. One of the main exposure routes is via drinking water and the World Health Organisation currently sets water quality guidelines for the element. In Central Europe, groundwater resources that exceed the guideline value of 1.5 mg l-1 are widespread and effects on health of high fluoride in water have been reported. The aim of the current project was to develop a geographic information system (GIS) to aid the identification of areas where high-fluoride waters and fluorosis may be a problem; hence, where water treatment technologies should be targeted. The development of the GIS was based upon the collation and digitisation of existing information relevant to fluoride risk in Ukraine, Moldova, Hungary and Slovakia assembled for the first time in a readily accessible form. In addition, geochemistry and health studies to examine in more detail the relationships between high-fluoride drinking waters and health effects in the population were carried out in Moldova and Ukraine demonstrating dental fluorosis prevalence rates of 60-90% in adolescents consuming water containing 2-7 mg l-1 fluoride.

  19. Multi-criteria assessment of community-based fluoride-removal technologies for rural Ethiopia.

    Science.gov (United States)

    Osterwalder, Lars; Johnson, C Annette; Yang, Hong; Johnston, Richard B

    2014-08-01

    Elevated concentrations of naturally-occurring fluoride in groundwater pose a serious health risk to millions of people living in the Ethiopian Rift Valley. In the absence of low-fluoride water resources of sufficient capacity, fluoride removal from drinking water is the accepted mitigation option. To date, five different community-level fluoride-removal technologies have been implemented in Ethiopia, although only a few units have been found in a functional state in the field. Which technology should be promoted and up-scaled is the subject of controversial debate amongst key stakeholders. This paper describes a multi-criteria decision analysis exercise, which was conducted with the participation of stakeholders in Ethiopia during a one-day workshop, to assess in an objective and transparent manner the available technology options. Criteria for technology comparison were selected and weighted, thus enabling the participants to assess the advantages and disadvantages of the different technologies and hear the views of other stakeholders. It was shown that there is no single most-preferable, technical solution for fluoride removal in Ethiopia. Selection of the most suitable solution depends on location-specific parameters and on the relative importance given to different criteria by the stakeholders involved. The data presented in this paper can be used as reference values for Ethiopia. © 2013. Published by Elsevier B.V. All rights reserved.

  20. Technologies for Decentralized Fluoride Removal: Testing Metallic Iron-based Filters

    Directory of Open Access Journals (Sweden)

    Arnaud Igor Ndé-Tchoupé

    2015-11-01

    Full Text Available Since the realization in the 1930s that elevated fluoride concentrations in drinking water can have detrimental effects on human health, new methods have been progressively developed in order to reduce fluoride to acceptable levels. In the developing world the necessity for filtration media that are both low-cost and sourced from locally available materials has resulted in the widespread use of bone char. Since the early 1990s metallic iron (Fe0 has received widespread use as both an adsorbent and a reducing agent for the removal of a wide range of contaminant species from water. The ion-selectivity of Fe0 is dictated by the positively charged surface of iron (hydroxides at circumneutral pH. This suggests that Fe0 could potentially be applied as suitable filter media for the negatively charged fluoride ion. This communication seeks to demonstrate from a theoretical basis and using empirical data from the literature the suitability of Fe0 filters for fluoride removal. The work concludes that Fe0-bearing materials, such as steel wool, hold good promise as low-cost, readily available and highly effective decentralized fluoride treatment materials.

  1. Fluoride-releasing restorative materials and secondary caries.

    Science.gov (United States)

    Hicks, John; Garcia-Godoy, Franklin; Donly, Kevin; Flaitz, Catherine

    2003-03-01

    Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. Risk factors for secondary caries are similar to those for primary caries development. Unfortunately, it is not possible to accurately predict which patients are at risk for restoration failure. During the past several decades, fluoride-releasing dental materials have become a part of the dentist's armamentarium. Considerable fluoride is released during the setting reaction and for periods up to eight years following restoration placement. This released fluoride is readily taken up by the cavosurface tooth structure, as well as the enamel and root surfaces adjacent to the restoration. Resistance against caries along the cavosurface and the adjacent smooth surface has been shown in both in vitro and in vivo studies. Fluoride-releasing dental materials provide for improved resistance against primary and secondary caries in coronal and root surfaces. Plaque and salivary fluoride levels are elevated to a level that facilitates remineralization. In addition, the fluoride released to dental plaque adversely affects the growth of lactobacilli and mutans streptococci by interference with bacterial enzyme systems. Fluoride recharging of these dental materials is readily achieved with fluoridated toothpastes, fluoride mouthrinses, and other sources of topical fluoride. This allows fluoride-releasing dental materials to act as intraoral fluoride reservoirs. The improvement in the properties of dental materials with the ability to release fluoride has improved dramatically in the past decade, and it is anticipated that in the near future the vast majority of restorative procedures will employ fluoride-releasing dental materials as bonding agents, cavity liners, luting agents, adhesives for orthodontic brackets, and definitive restoratives.

  2. Role of endoplasmic reticulum stress-induced apoptosis in rat thyroid toxicity caused by excess fluoride and/or iodide.

    Science.gov (United States)

    Liu, Hongliang; Hou, Changchun; Zeng, Qiang; Zhao, Liang; Cui, Yushan; Yu, Linyu; Wang, Lingzhi; Zhao, Yang; Nie, Junyan; Zhang, Bin; Wang, Aiguo

    2016-09-01

    Excess fluoride and iodide coexist in drinking water in many regions, but few studies have investigated the single or interactive effects on thyroid in vivo. In our study, Wistar rats were exposed to excess fluoride and/or iodide through drinking water for 2 or 8 months. The structure and function of the thyroid, cells apoptosis and the expression of inositol-requiring enzyme 1 (IRE1) pathway-related factors were analyzed. Results demonstrated that excess fluoride and/or iodide could change thyroid follicular morphology and alter thyroid hormone levels in rats. After 8 months treatment, both single and co-exposure of the two microelements could raise the thyroid cells apoptosis. However, the expressions of IRE1-related factors were only increased in fluoride-alone and the combined groups. In conclusion, thyroid structure and thyroid function were both affected by excess fluoride and/or iodide. IRE1-induced apoptosis were involved in this cytotoxic process caused by fluoride or the combination of two microelements. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Fluoride remediation using floating macrophytes

    Directory of Open Access Journals (Sweden)

    Naba Kumar Mondal

    2014-04-01

    Full Text Available Six aquatic macrophytes, such as Pistia stratiotes, Ceratophyllum demersum, Nymphoides indica, Lemna major, Azolla pinnata,and Eichhornia crassipes were considered for remove fluoride from aqueous solution. Five different concentrations (10, 30, 50, and 100 ppm of fluoride solution were taken in 1 L plastic container. Fixed weight (20 g of macrophytes along with 500 ml fluoride solution was taken in each plastic container for 72 hours observation. Results demonstrated all the macrophytes show highest fluoride removal during 24 h to 48 h, but after 72 h their efficiency reduced drastically. The species N. indica showed better removal efficiency than other experimental macrophytes. In general, pigment measurement data indicated higher concentration at 72 h. However, Pistia sp. showed higher concentration of pigmentation at intermediate time interval (48 h. Higher level of dry weight to fresh weight ratio was recorded for L. major and A. pinnata at all concentrations, excepting at 10 ppm. In addition, all macrophytes showed lower RGR at higher concentration. Isotherm study indicated that macrophyte C. demersum is a good fitted with Freundlich and Langmuir isotherm whereas L. major with Langmuir isotherm during 24 hours.

  4. Spectrophotometric determination of fluoride with alizarin complexone

    Energy Technology Data Exchange (ETDEWEB)

    Marczenko, Z; Lenarczyk, L [Politechnika Warszawska (Poland)

    1976-01-01

    The modification of direct spectrophotometric method of fluoride determination by alizarin complexone has been developed. It was shown that the lanthanum alizarin complexone chelate is more convenient than that of cerium (3). The influence of acetone, dioxane and dimethyl sulphoxide in water solution on the increase of sensitivity of the method and the rate of colour reaction has been determined. The optimal pH ranges for the reaction with lanthanum and cerium (3) have been estimated. Some amines having a large molecule are useful for extraction of blue fluoride complex with isobutanol. Dioctylamine was applied in a new extraction spectrophotometric procedure of fluoride determination. Conditions in reagent have been established. Both variants of the method have been applied to the fluoride determination in several chemicals. The obtained results show a good precision and accuracy.

  5. Drinking Water Maximum Contaminant Levels (MCLs)

    Data.gov (United States)

    U.S. Environmental Protection Agency — National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards...

  6. The influence of the unsaturated zone on the high fluoride contents in groundwater in the middle voltaian aquifers-the Gusghegu District, Northern Region

    International Nuclear Information System (INIS)

    Salifu, M.

    2012-01-01

    Elevated levels of fluoride have been reported to occur in some groundwater in the Gushegu district of the Northern region of Ghana leading to the closure of some boreholes in the area. Hydrochemical data from 21 water, soil and some rock samples were used to evaluate water quality, water types and to identify whether the unsaturated zone has influence on the elevated fluoride levels in groundwater as well as the processes that control fluoride level in the groundwater. Water samples were extracted from soil sample for flouride analysis using the cryogenic vacuum extraction set-up. Results of the water quality analysis showed that the groundwater in the study area were generally potable. A plot of Gibbs diagram revealed that rock weathering and rainfall were the major hydrogeochemical processes regulating the water chemistry of the study area. Two different water types were identified in the study area, namely: Na-HCO 3 - , which happened to be the major water type in the study area and Na-Ca-Mg-HCO 3 - water type. The fluoride concentration in the groundwater varied from 0.0 to 1.97 mg/L while that of the unsaturated zone ranged from 0.0 to 2.08 mg/L. The elevated fluoride levels in the groundwater strongly correlated with that of fluoride levels in the unsaturated zone (r 2 =0.76). Petrographic analysis of rock samples (siltstones) identified the minerals present to be muscovite, plagioclase feldspars, quartz, sericite and iron oxide. Other clay minerals such as montmorillonite, illite and chloride were identified. The elevated fluoride levels recorded in the groundwater may be due to leaching, as a result of the weathering and dissolution of muscovite, sericite as well as the presence of other clay minerals in the unsaturated zone. Application of phosphate fertilizers may also account for the the elevated fluoride concentrations recorded in the study area. Stable isotopic composition of the waters revealed that most of the groundwater were of meteoric origin

  7. Influence of the method of fluoride administration on toxicity and fluoride concentrations in Japanese quail

    Science.gov (United States)

    Fleming, W.J.; Schuler, C.A.

    1988-01-01

    Young Japanese quail (Coturnix japonica) were administered NaF for 16 d either in their diet or by esophageal intubation. Based on the total fluoride ion (Emg F-) intake over the l6-d experimental period, fluoride administered by intubation was at least six times more toxic than that fed in the diet. Dietary concentrations of 1,000 ppm F- (Emg F- for 16 d = approx. 144) produced no mortality, whereas intubated doses produced 73% or greater mortality in all groups administered 54 mg F- /kg/d or more (Emg F- for 16 d _ approx. 23 mg). GraphIc companson of the regression of log F- ppm in femurs/mg F- intake showed that fluoride levels in the femurs of quail administered fluoride by intubation were higher than in those administered fluoride in the diet.

  8. Operational Principle of Water Level Detector for Agricultural and ...

    African Journals Online (AJOL)

    This paper proposes a design to automatically detect the level of water in a reservoir (storage tank) at a preset level and initializes an information to the users in case of low water level. The functionality of this sensor depends basically on the electrical conductivity of water (probes) which varies, depending on the level of its ...

  9. Effects of fluoridated milk on root dentin remineralization.

    Directory of Open Access Journals (Sweden)

    Wolfgang H Arnold

    Full Text Available The prevalence of root caries is increasing with greater life expectancy and number of retained teeth. Therefore, new preventive strategies should be developed to reduce the prevalence of root caries. The aim of this study was to investigate the effects of fluoridated milk on the remineralization of root dentin and to compare these effects to those of sodium fluoride (NaF application without milk.Thirty extracted human molars were divided into 6 groups, and the root cementum was removed from each tooth. The dentin surface was demineralized and then incubated with one of the following six solutions: Sodium chloride NaCl, artificial saliva, milk, milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Serial sections were cut through the lesions and investigated with polarized light microscopy and quantitative morphometry, scanning electron microscopy (SEM and energy-dispersive X-ray spectroscopy (EDS. The data were statistically evaluated using a one-way ANOVA for multiple comparisons.The depth of the lesion decreased with increasing fluoride concentration and was the smallest after incubation with artificial saliva+10 ppm fluoride. SEM analysis revealed a clearly demarcated superficial remineralized zone after incubation with milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Ca content in this zone increased with increasing fluoride content and was highest after artificial saliva+10 ppm fluoride incubation. In the artificial saliva+10 ppm fluoride group, an additional crystalline layer was present on top of the lesion that contained elevated levels of F and Ca.Incubation of root dentin with fluoridated milk showed a clear effect on root dentin remineralization, and incubation with NaF dissolved in artificial saliva demonstrated a stronger effect.

  10. Toxicity of fluoride to microorganisms in biological wastewater treatment systems.

    Science.gov (United States)

    Ochoa-Herrera, Valeria; Banihani, Qais; León, Glendy; Khatri, Chandra; Field, James A; Sierra-Alvarez, Reyes

    2009-07-01

    Fluoride is a common contaminant in a variety of industrial wastewaters. Available information on the potential toxicity of fluoride to microorganisms implicated in biological wastewater treatment is very limited. The objective of this study was to evaluate the inhibitory effect of fluoride towards the main microbial populations responsible for the removal of organic constituents and nutrients in wastewater treatment processes. The results of short-term batch bioassays indicated that the toxicity of sodium fluoride varied widely depending on the microbial population. Anaerobic microorganisms involved in various metabolic steps of anaerobic digestion processes were found to be very sensitive to the presence of fluoride. The concentrations of fluoride causing 50% metabolic inhibition (IC(50)) of propionate- and butyrate-degrading microorganisms as well as mesophilic and thermophilic acetate-utilizing methanogens ranged from 18 to 43 mg/L. Fluoride was also inhibitory to nitrification, albeit at relatively high levels (IC(50)=149 mg/L). Nitrifying bacteria appeared to adapt rapidly to fluoride, and a near complete recovery of their metabolic activity was observed after only 4d of exposure to high fluoride levels (up to 500 mg/L). All other microbial populations evaluated in this study, i.e., glucose fermenters, aerobic glucose-degrading heterotrophs, denitrifying bacteria, and H(2)-utilizing methanogens, tolerated fluoride at very high concentrations (>500 mg/L).

  11. Groundwater fluoride contamination: A reappraisal

    Directory of Open Access Journals (Sweden)

    Amlan Banerjee

    2015-03-01

    Full Text Available Dissolution of fluorite (CaF2 and/or fluorapatite (FAP [Ca5(PO43F], pulled by calcite precipitation, is thought to be the dominant mechanism responsible for groundwater fluoride (F− contamination. Here, one dimensional reactive–transport models are developed to test this mechanism using the published dissolution and precipitation rate kinetics for the mineral pair FAP and calcite. Simulation results correctly show positive correlation between the aqueous concentrations of F− and CO32− and negative correlation between F− and Ca2+. Results also show that precipitation of calcite, contrary to the present understanding, slows down the FAP dissolution by 106 orders of magnitude compared to the FAP dissolution by hydrolysis. For appreciable amount of fluoride contamination rock–water interaction time must be long and of order 106 years.

  12. Geogenic fluoride and arsenic contamination in the groundwater environments in Tanzania

    Science.gov (United States)

    Bhattacharya, Prosun; Lesafi, Fina; Filemon, Regina; Ligate, Fanuel; Ijumulana, Julian; Mtalo, Felix

    2016-04-01

    Adequate, safe and accessible drinking water is an important aspect to human health worldwide. Understanding this importance, the Tanzanian Government has initiated a number of programmes to ensure access to high quality water by the citizens. However, elevated concentration of geochemical pollutants in many drinking water sources pose a serious challenge to water suppliers and users in the country. Fluoride is a widespread drinking water contaminant of geogenic origin occuring in both surface- and groundwater around volcanic mountains and many parts within the East African Rift Valley in regions including Arusha (10 mg/L), Shinyanga (2.9 mg/L) and Singida (1.8 mg/L). An estimated 90% of the population living along the Rift Valley region are affected by dental or skeletal fluorosis and bone crippling because of long term exposure to very high levels of fluoride in drinking water sources. In the mining areas within Lake Victoria basin, groundwater wit elevated concentrations of arsenic has been discovered over an extended area. Most of these geochemical and naturally occurring drinking water pollutants are patchy with uncertainities in their spatial and temporal distribution patterns. The adverse health effects of skin disorder and cancer due to an elevated As concentration are reported from the North Mara gold and Geita mining areas in the Lake Victoria basin. About 30% of the water sources used for drinking in Tanzania exceed the WHO guideline values of fluoride (1.5 mg/L) and arsenic (10 μg/L). There is a scarcity of baseline information on the water quality data especially on geogenic contaminants in the groundwater and surface water as potable sources. This information is crucial in exploring sources of safe drinking water aquifers, associated human health risks of fluoride and arsenic pollution. using Laboratory based studies during the past two decades have shown promising results on the removal of fluoride and arsenic using locally available adsorbent

  13. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse......, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam...

  14. Sulfochlorphenol S as reagent for direct photometric determination of fluorides

    International Nuclear Information System (INIS)

    Dzhashi, D.O.; Dedkova, V.P.; Savvin, S.B.

    1978-01-01

    The system of zirconium-sulfochlorphenol S-fluoride was studied by the spectrophotometry method. The effect of pH, temperature and time on the formation of zirconium complexes with sulfochlorphenol S was investigated. A comparison of the above method of determining fluorides with other methods (using alizarinecomplexonate, quinalizarincomplexonate, cerium chelates, lanthanum, arsenazo 3) is presented. The sensitivity of determining fluorides with arsenazo 3 is lower than that with sulfochlorphenol S. The molar absorption coefficient is 3x10 4 , the reaction of determining fluorides with the aid of sulfochlorphenol S is highly selective. The method was used to determine fluorides in the supply water, zirconium solutions and electrolyzer cell. The range of concentration determination for fluorides is 0-3 μg/25 ml

  15. Portable Water Level Monitoring System via SMS

    Directory of Open Access Journals (Sweden)

    Jomar S. Vitales

    2015-11-01

    Full Text Available Damages and lives taken by the typhoon Ondoy and other super typhoons brought the researchers to think and develop a device that warns people an hour or more than an hour before the devastating phenomena. In this project the researchers have thought of using text messaging in which the country’s leading means of communication. The development of the project was guided by the Engineering Design Cycle of Dr. Allan Cheville in his book entitled “Rocket Engineering”. The researchers have identified and used the needed materials which are suited in the intended function of the project. The project was already evaluated and had gathered a favorable response from the knowledgeable respondents in the field where the design project is intended to use. The project has a high acceptability level in the respondents’ point of view. The researchers are highly recommending the implementation of the project for a better testing in the incoming rainy season and also recommending to be placed in the Pantalan Bridge in Pantalan, Nasugbu, Batangas, Philippines. The researchers are also suggesting another study for a better water proof casing of the project.

  16. Fluoride loaded polymeric nanoparticles for dental delivery.

    Science.gov (United States)

    Nguyen, Sanko; Escudero, Carlos; Sediqi, Nadia; Smistad, Gro; Hiorth, Marianne

    2017-06-15

    The overall aim of the present paper was to develop fluoride loaded nanoparticles based on the biopolymers chitosan, pectin, and alginate, for use in dental delivery. First, the preparation of nanoparticles in the presence of sodium fluoride (NaF) as the active ingredient by ionic gelation was investigated followed by an evaluation of their drug entrapment and release properties. Chitosan formed stable, spherical, and monodisperse nanoparticles in the presence of NaF and tripolyphoshate as the crosslinker, whereas alginate and pectin were not able to form any definite nanostructures in similar conditions. The fluoride loading capacity was found to be 33-113ppm, and the entrapment efficiency 3.6-6.2% for chitosan nanoparticles prepared in 0.2-0.4% (w/w) NaF, respectively. A steady increase in the fluoride release was observed for chitosan nanoparticles prepared in 0.2% NaF both in pH5 and 7 until it reached a maximum at time point 4h and maintained at this level for at least 24h. Similar profiles were observed for formulations prepared in 0.4% NaF; however the fluoride was released at a higher level at pH5. The low concentration, but continuous delivery of fluoride from the chitosan nanoparticles, with possible expedited release in acidic environment, makes these formulations highly promising as dental delivery systems in the protection against caries development. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Effects of different amine fluoride concentrations on enamel remineralization.

    Science.gov (United States)

    Naumova, E A; Niemann, N; Aretz, L; Arnold, W H

    2012-09-01

    The aim of this study was to investigate the effects of decreasing fluoride concentrations on repeated demineralizing challenges on human enamel. In 24 teeth, 3mm×3mm windows were prepared on the buccal and lingual sides and treated in a cycling demineralization-remineralization model. Remineralization was achieved with 100, 10 and 0.1 ppm fluoride from anime fluoride. Coronal sections were cut through the artificial lesions, and three sections per tooth were investigated using polarized light microscopy and scanning electron microscopy with quantitative element analysis. The morphology of the lesions was studied, and the extensions of the superficial layer and the body of the lesion were measured. Using element analysis, the Ca, P and F content were determined. The body of the lesion appeared remineralized after application of 100 ppm fluoride, while remineralization of the lesion was less successful after application of 10 and 0.1 ppm fluoride. The thickness of the superficial layer increased with decreasing fluoride concentrations, and also the extension of the body of the lesion increased. Ca and P content increased with increasing fluoride concentrations. The effectiveness of fluoride in enamel remineralization increased with increasing fluoride concentration. A consistently higher level of fluoride in saliva should be a goal in caries prevention. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Fluoride varnishes and enamel caries

    NARCIS (Netherlands)

    Bruyn, Hugo de

    1987-01-01

    Topical fluoride applications have the aim of increasing the fluoride uptake in enamel and consequently reducing caries. In the early ‘60s fluoride varnishes were introduced because they had a long contact period with the enamel which resulted in a higher fluoride uptake than from other topical

  19. Oral fluoride retention after professional topical application in children with caries activity: comparison between 1.23% fluoride foam and fluoride gel

    Directory of Open Access Journals (Sweden)

    Cecília Claudia Costa Ribeiro

    2008-01-01

    Full Text Available Objective: This study evaluated fluoride retention in the saliva of children with caries activity after topical fluoride application in the form of gel and foam. Methods: A cross-sectional, blind and randomized study, conducted with ten caries-active children aged between 8 and 10 years, in two stage, with a washout interval of two weeks between them. The treatments consisted of: a application of 2mL acidulated phosphate fluoride of the gel type in a mold and b application of 2mL acidulated phosphate fluoride of the foam type in a mold. After the washout, the treatments were inverted. Non-stimulated saliva was collected from the children at the times of 5, 15, 30 and 60 minutes after topical fluoride application. For statistical analysis the Student’s-t test was used, with a level of significance of 5%. Results: Saliva analysis was performed using a fluoride-specific electrode (ISE25F/ Radiometer, Copenhagen, Denmark at the Aquatic Science Center of the Federal University of Marana, which revealed differences after 5 minutes (p=0.0055 and 15 minutes (p=0.0208. The topical application of fluoride in the gel form revealed a higher concentration of fluoride in the saliva. Conclusion: There were differences in the retention of fluoride in the saliva of children with caries activity after the topical application of fluoride gel and the topical application of fluoride foam after 5 and 15 minutes of their application. The topical application of fluoride foam is recommended, on the basis of the lower probability of toxicity during its use.

  20. Analysis of water-level fluctuations in Wisconsin wells

    Science.gov (United States)

    Patterson, G.L.; Zaporozec, A.

    1987-01-01

    More than 60 percent of the residents of Wisconsin use ground water as their primary water source. Water supplies presently are abundant, but ground-water levels continually fluctuate in response to natural factors and human-related stresses. A better understanding of the magnitude, duration, and frequency of past fluctuations, and the factors controlling these fluctuations may help anticipate future changes in ground-water levels.

  1. Evaluation of yield and water-level relations

    International Nuclear Information System (INIS)

    Cushman, R.L.; Purtymun, W.D.

    1975-10-01

    Yield and water relations in the Los Alamos supply wells were evaluated because of the increasing demand for water. Water-level declines were extrapolated for 10 yr, to 1983, on the basis of past records. On the basis of current pumpage, the extrapolations indicate that nonpumping water levels in individual wells will decline from 10 to 30 ft. Well characteristics were compiled to provide an individual history of each well, and recommendations for improving water production are presented

  2. The Effect of Calcium Pre-Rinse on Salivary Fluoride After 900 ppm Fluoride Mouthwash: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Nahid Ramazani

    2013-01-01

    Full Text Available Objective: Calcium fluoride deposit during fluoride application. Uptake and retention of fluoride by saliva depends generally on the concentration of calcium. In this study, the ef-fect of calcium pre-rinse on salivary fluoride concentration after a 900 ppm fluoride mouthwash was investigated.Materials and Methods: This cross-over double-blind randomized clinical trial was con-ducted in a girls' dormitory in Zahedan University of Medical Sciences, southeast Iran. In this study, 42 female dental students were chosen using simple randomization. During the first phase, 21 subjects (group A used fluoride rinse (F regimen and the remaining (group B used calcium pre-rinse followed immediately by fluoride rinse (Ca + F regi-men. In the second phase, participants rinsed using the mouthwashes not previously used. Prior to each phase prophylaxis was performed and no fluoridated product was used dur-ing a two-week interval between the phases. Salivary samples were taken immediately be-fore (baseline, 1 and 12 hours after rinsing. The salivary fluoride concentration was de-termined using fluoride sensitive electrode. Repeated measures ANOVA was used for sta-tistical analysis and the significance level was set at P<0.05.Results: There was significant difference between fluoride concentrations at different time points (P< 0.001. Significant differences were observed when the different time points of two regimens were examined. In contrast to this, the baseline before using F regimen and the baseline before using Ca + F regimen did not show any significance (P= 0.070.Conclusion: Pre-rinsing with calcium before fluoride is recommended because of signifi-cant increases in salivary fluoride concentration.

  3. The cariostatic mechanisms of fluoride

    OpenAIRE

    Kata Rošin-Grget; Kristina Peroš; Ivana Šutej; Krešimir Bašić

    2013-01-01

    This article discusses the possible cariostatic mechanisms of the action of fluoride. In the past, fluoride inhibition of caries was ascribed to reduced solubility of enamel due to incorporation of fluoride (F–) into the enamel minerals. The present evidence from clinical and laboratory studies suggests that the caries-preventive mode of action of fluoride is mainly topical. There is convincing evidence that fluoride has a major effect on demineralisation and remineralisation of dental hard t...

  4. Magnetic interactions through fluoride

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen; Sigrist, Marc; Weihe, Høgni

    2014-01-01

    support the parameter values and resolve |E| ≈ 0.04 cm(-1). The exchange coupling constant (J) is 1 order of magnitude smaller than that found in comparable systems with linear oxide bridging but comparable to typical magnitudes through cyanide, thus underlining the potential of fluoride complexes......The nature of the magnetic interaction through fluoride in a simple, dinuclear manganese(III) complex (1), bridged by a single fluoride ion in a perfectly linear fashion, is established by experiment and density functional theory. The magnitude of the antiferromagnetic exchange interaction...

  5. Fabrication and characterization of functionally graded poly(vinylidine fluoride)-silver nanocomposite hollow fibers for sustainable water recovery

    KAUST Repository

    Francis, Lijo; Ghaffour, NorEddine; Amy, Gary L.

    2014-01-01

    the hydrophobicity and ~ 2.5 fold increase the mechanical strength of the hollow fibers. A water vapor flux of 31.9kg m-2 h-1 was observed at a feed inlet temperature of 80 °C and at a permeate temperature of 20 °C in the case of hollow fiber membrane modules

  6. Fluorides in groundwater and its impact on health.

    Science.gov (United States)

    Shailaja, K; Johnson, Mary Esther Cynthia

    2007-04-01

    Fluoride is a naturally occurring toxic mineral present in drinking water and causes yellowing of teeth, tooth problems etc. Fluorspar, Cryolite and Fluorapatite are the naturally occurring minerals, from which fluoride finds its path to groundwater through infiltration. In the present study two groundwater samples, Station I and Station II at Hyderabad megacity, the capital of Andhra Pradesh were investigated for one year from January 2001 to December 2001. The average fluoride values were 1.37 mg/l at Station I and 0.91 mg/l at Station II. The permissible limit given by BIS (1983) 0.6-1.2 mg/l and WHO (1984) 1.5 mg/l for fluoride in drinking water. The groundwaters at Station I exceeded the limit while at Station II it was within the limits. The study indicated that fluoride content of 0.5 mg/l is sufficient to cause yellowing of teeth and dental problems.

  7. Development of reactor water level sensor for extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Miura, K; Ogasawara, T [Sukegawa Electric Co., Ltd., Hitachi, Ibaraki (Japan); Shibata, Akira; Nakamura, Jinichi; Saito, Takashi; Tsuchiya, Kunihiko [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

    2012-03-15

    In the Fukushima accident, measurement failure of water level was one of the most important factors which caused serious situation. The differential pressure type water level indicators are widely used in various place of nuclear power plant but after the accident of TMI-2, the need of other reliable method has been required. The BICOTH type and the TRICOTH type water level indicator for light water power reactors had been developed for in-pile water level indicator but currently those are not adopted to nuclear power plant. In this study, the development of new type water level indicator composed of thermocouple and heater is described. Demonstration test and characteristic evaluation of the water level indicator were performed and we had obtained satisfactory results. (author)

  8. Water levels in the Yucca Mountain area, Nevada, 1993

    International Nuclear Information System (INIS)

    Tucci, P.; Goemaat, R.L.; Burkhardt, D.J.

    1996-01-01

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1993. Seventeen wells were monitored periodically, generally on a monthly basis, and 11 wells representing 18 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes and pressure transducers; steel-tape measurements were corrected for mechanical stretch, thermal expansion, and borehole deviation to obtain precise water-level altitudes. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 meters above sea level east of Yucca Mountain to about 1,034 meters above sea level north of Yucca Mountain. Water-level altitudes in the well monitoring the Paleozoic carbonate rocks varied between 752 and 753 meters above sea level during 1993. Water levels were an average of about 0.04 meter lower than 1992 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  9. Zirconium-carbon hybrid sorbent for removal of fluoride from water: oxalic acid mediated Zr(IV) assembly and adsorption mechanism

    Science.gov (United States)

    Halla, Velazquez-Jimenez Litza; Hurt Robert, H; Juan, Matos; Rene, Rangel-Mendez Jose

    2014-01-01

    When activated carbon (AC) is modified with zirconium(IV) by impregnation or precipitation, the fluoride adsorption capacity is typically improved. There is significant potential to improve these hybrid sorbent by controlling the impregnation conditions, which determine the assembly and dispersion of the Zr phases on carbon surfaces. Here, commercial activated carbon was modified with Zr(IV) together with oxalic acid (OA) used to maximize the zirconium dispersion and enhance fluoride adsorption. Adsorption experiments were carried out at pH 7 and 25 °C with a fluoride concentration of 40 mg L−1. The OA/Zr ratio was varied to determine the optimal conditions for subsequent fluoride adsorption. The data was analyzed using the Langmuir and Freundlich isotherm models. FTIR, XPS and the surface charge distribution were performed to elucidate the adsorption mechanism. Potentiometric titrations showed that the modified activated carbon (ZrOx-AC) possesses positive charge at pH lower than 7, and FTIR analysis demonstrated that zirconium ions interact mainly with carboxylic groups on the activated carbon surfaces. Moreover, XPS analysis demonstrated that Zr(IV) interacts with oxalate ions, and the fluoride adsorption mechanism is likely to involve –OH− exchange from zirconyl oxalate complexes. PMID:24359079

  10. Suppression device for the reactor water level lowering

    International Nuclear Information System (INIS)

    Kasuga, Hajime; Kasuga, Hiroshi.

    1984-01-01

    Purpose: To suppress the lowering in the reactor water level so as to avoid unnecessary actuation of ECCS upon generation of transient changes which forecasts the lowering of the reactor water level in a BWR type reactor. Constitution: There are provided a water level suppression signal generator for generating a water level suppression signal upon generation of a transient change signal which forecasts the water level lowering in a nuclear reactor and a recycling flow rate controller that applies a recycling flow rate control signal to a recycling pump drive motor by the water level lowering suppression signal. The velocity of the recycling pump is controlled by a reactor scram signal by way of the water level lowering suppresion signal generator and a recycling flow rate controller. Then, the recycling reactor core flow rate is decreased and the void amount in the reactor is transiently increased where the water level tends to increase. Accordingly, the water level lowering by the scram is moderated by the increasing tendency of the water level. (Ikeda, J.)

  11. Preparation of bromine fluoride

    International Nuclear Information System (INIS)

    Domange, Pr; Duflo, J.

    1958-05-01

    This note addresses the preparation of bromine fluoride. It indicates the implemented process for the reaction, used products (fluorine and bromine), and column characteristics. It describes the operating mode. Apparatus drawing is provided

  12. Excessive apoptosis and defective autophagy contribute to developmental testicular toxicity induced by fluoride.

    Science.gov (United States)

    Zhang, Shun; Niu, Qiang; Gao, Hui; Ma, Rulin; Lei, Rongrong; Zhang, Cheng; Xia, Tao; Li, Pei; Xu, Chunyan; Wang, Chao; Chen, Jingwen; Dong, Lixing; Zhao, Qian; Wang, Aiguo

    2016-05-01

    Fluoride, a ubiquitous environmental contaminant, is known to impair testicular functions and fertility; however the underlying mechanisms remain obscure. In this study, we used a rat model to mimic human exposure and sought to investigate the roles of apoptosis and autophagy in testicular toxicity of fluoride. Sprague-Dawley rats were developmentally exposed to 25, 50, or 100 mg/L sodium fluoride (NaF) via drinking water from pre-pregnancy to post-puberty, and then the testes of offspring were excised on postnatal day 56. Our results demonstrated that developmental NaF exposure induced an enhanced testicular apoptosis, as manifested by a series of hallmarks such as caspase-3 activation, chromatin condensation and DNA fragmentation. Further study revealed that fluoride exposure elicited significant elevations in the levels of cell surface death receptor Fas with a parallel increase in cytoplasmic cytochrome c, indicating the involvement of both extrinsic and intrinsic apoptotic pathways. Intriguingly, fluoride treatment also simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II but not Beclin1. Unexpectedly, the expression of p62, a substrate that is degraded by autophagy, was also significantly elevated, suggesting that the accumulated autophagosomes resulted from impaired autophagy degradation rather than increased formation. Importantly, these were associated with marked histopathological lesions including spermatogenic failure and germ cell loss, along with severe ultrastructural abnormalities in testes. Taken together, our findings provide deeper insights into roles of excessive apoptosis and defective autophagy in the aggravation of testicular damage, which could contribute to a better understanding of fluoride-induced male reproductive toxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Fluoride-elicited developmental testicular toxicity in rats: Roles of endoplasmic reticulum stress and inflammatory response

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shun [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Jiang, Chunyang [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Department of Thoracic Surgery, Tianjin Union Medicine Centre, 190 Jieyuan Road, Hongqiao District, Tianjin 300121, Tianjin (China); Liu, Hongliang [Tianjin Center for Disease Control and Prevention, Huayue Road 6, Hedong Region, Tianjin 300011, Tianjin (China); Guan, Zhizhong [Department of Pathology, Guiyang Medical College, Guiyang 550004, Guizhou (China); Zeng, Qiang [Tianjin Center for Disease Control and Prevention, Huayue Road 6, Hedong Region, Tianjin 300011, Tianjin (China); Zhang, Cheng; Lei, Rongrong; Xia, Tao; Gao, Hui; Yang, Lu; Chen, Yihu; Wu, Xue; Zhang, Xiaofei [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Cui, Yushan; Yu, Linyu [Tianjin Center for Disease Control and Prevention, Huayue Road 6, Hedong Region, Tianjin 300011, Tianjin (China); Wang, Zhenglun [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Wang, Aiguo, E-mail: wangaiguo@mails.tjmu.edu.cn [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China)

    2013-09-01

    Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. Sprague–Dawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100 mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of male offspring were studied at 8 weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), and C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by gene up-regulation of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-κB (NF-κB)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress. - Highlights: • We used a rat model to simulate the situations of human fluoride (F) exposure. • Developmental F exposure induces testicular damage related with oxidative stress.

  14. Fluoride-elicited developmental testicular toxicity in rats: Roles of endoplasmic reticulum stress and inflammatory response

    International Nuclear Information System (INIS)

    Zhang, Shun; Jiang, Chunyang; Liu, Hongliang; Guan, Zhizhong; Zeng, Qiang; Zhang, Cheng; Lei, Rongrong; Xia, Tao; Gao, Hui; Yang, Lu; Chen, Yihu; Wu, Xue; Zhang, Xiaofei; Cui, Yushan; Yu, Linyu; Wang, Zhenglun; Wang, Aiguo

    2013-01-01

    Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. Sprague–Dawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100 mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of male offspring were studied at 8 weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), and C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by gene up-regulation of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-κB (NF-κB)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress. - Highlights: • We used a rat model to simulate the situations of human fluoride (F) exposure. • Developmental F exposure induces testicular damage related with oxidative stress.

  15. Effect of a stannous fluoride dentifrice on the sulcular microbiota: a prospective cohort study in subjects with various levels of periodontal inflammation.

    Science.gov (United States)

    Benjasupattananan, Supranee; Lai, Caroline S Y; Persson, G Rutger; Pjetursson, Bjarni E; Lang, Niklaus P

    2005-01-01

    To assess the effects of an experimental 0.454% stannous fluoride (SnF2) dentifrice on the oral sulcular microbiota in patients with various stages of oral diseases using checkerboard DNA-DNA hybridization. In the present one-month, single center, single product, prospective cohort trial, 37 adults (mean age 37.6) were assigned to one of four oral health condition cohorts with seven to 10 subjects each: 1. mild gingivitis, 2. marked generalized gingivitis to moderate periodontitis, 3. caries-prone and 4. treated moderate to advanced chronic periodontitis in supportive periodontal care. All four groups were asked to use the test dentifrice and a power toothbrush twice a day for one minute during a four-week test period. Before and after the trial period, Plaque Indices (PII, Silness and Löe, 1964) and Gingival Indices (GI, Löe and Silness, 1963) were recorded. Subgingival plaque samples were collected from all patients at Baseline, as well as after two and four weeks. These samples were analyzed for content of 40 bacterial species using checkerboard DNA-DNA hybridization. As a result of the only one minute brushing with the stannous fluoride dentifrice, the mean PII at Baseline was significantly lower (p bacterial loads of bacteria than groups 1, and 3 (i.e. A. actinomyctemcomitans P. gingivalis, T. forsythia, and T. denticola. Over the study period, the total bacterial load did not change in groups 2, 3 and 4. In groups 1 and 3, however, an increase in the loads of Streptococci spp. were noticed (p fluoride dentifrice did--after four weeks--not affect the subgingival microbial profiles in patients with moderate periodontitis and treated moderate to advanced periodontitis. However, the sulcular microbial profiles of mild gingivitis and caries-prone patients were affected, indicating a shift towards a gingival health associated microbiota in the sulcular region of patients not affected by attachment loss. RUNNING HEAD: Effect of stannous fluoride on sulcular

  16. Controlling the fluoride dosage in a patient with compromised salivary function.

    Science.gov (United States)

    Eichmiller, Frederick C; Eidelman, Naomi; Carey, Clifton M

    2005-01-01

    High-concentration topical fluorides are used commonly to with compromised salivary function due to irradiation and chemotherapy. The authors describe a 50-year-old man with previously treated cancer who was using tray-applied topical fluoride gel. He complained of gastric symptoms, difficulty in swallowing, leg muscle soreness and knee joint soreness. A computed tomographic scan revealed thickening of the esophageal walls. An upper endoscopy revealed abnormal motility. The motility test indicated high-amplitude peristalsis and hypertensive lower esophageal sphincter, and urine testing indicated high levels of systemic fluoride. The patient's fluoride regimen was altered, and within a short period his urinary fluoride levels returned to normal and his symptoms resolved. Clinicians prescribing home-applied high-concentration fluorides need to be cognizant of the symptoms of fluoride toxicity, carefully monitor the patient's compliance with the treatment regimen, and adjust the dosage or mode of application to control the total ingested dose of fluoride.

  17. Waterborne fluoride exposure changed the structure and the expressions of steroidogenic-related genes in gonads of adult zebrafish (Danio rerio).

    Science.gov (United States)

    Li, MeiYan; Cao, Jinling; Chen, Jianjie; Song, Jie; Zhou, Bingrui; Feng, Cuiping; Wang, Jundong

    2016-02-01

    Excessive fluoride in natural water ecosystem has been demonstrated to have adverse effects on reproductive system in humans and mammals, while the most vulnerable aquatic organisms were ignored. In this study, the effects of waterborne fluoride on growth performance, sex steroid hormone, histological structure, and the transcriptional profiles of sex steroid related genes were examined in both female and male zebrafish exposed to different concentrations of 0.79, 18.60, 36.83 mg L(-1) of fluoride for 30 and 60 d to investigate the effects of fluoride on reproductive system and the underlying toxic mechanisms caused by fluoride. The results showed that the body weight was remarkably decreased, the structure of ovary and testis were serious injured, and the T and E2 levels were significantly reduced in male zebrafish. The transcriptional profiles of steroidogenic related genes displayed phenomenal alterations, the expressions of pgr and cyp19a1a were significantly up-regulated, while the transcriptional levels of er, ar and hsd3β were decreased both in the ovary and testis, and hsd17β8 were down-regulated just in males. Taken together, these results demonstrated that fluoride could significantly inhibit the growth of zebrafish, and notably affect the reproductive system in both sex zebrafish by impairing the structure of ovary and testis, altering steroid hormone levels and steroidogenic genes expression related to the synthesis of sex hormones in zebrafish. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Fluoride Alters Serum Elemental (Calcium, Magnesium, Copper, and Zinc) Homeostasis Along with Erythrocyte Carbonic Anhydrase Activity in Fluorosis Endemic Villages and Restores on Supply of Safe Drinking Water in School-Going Children of Nalgonda District, India.

    Science.gov (United States)

    Khandare, Arjun L; Validandi, Vakdevi; Boiroju, Naveen

    2018-02-17

    The present study aimed to determine the serum trace elements (copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg)) along with erythrocyte carbonic anhydrase (CA) activity and effect of intervention with safe drinking water for 5 years in the school children of fluorosis endemic area. For this purpose, three categories of villages were selected based on drinking water fluoride (F): Category I (control, F = 1.68 mg/L), category II (affected F = 3.77 mg/L), and category III (intervention village) where initial drinking water F was 4.51 mg/L, and since the last 5 years, they were drinking water containing water for 5 years in school-going children.

  19. some factors influencing the free fluoride content in black tea

    African Journals Online (AJOL)

    ACSS

    Fluoride is an essential micro-nutrient owing to its role in the prevention of dental caries. Chronic exposure to high levels of the ion (F-) results in both dental and skeletal fluorosis. A study was carried out to determine free fluoride content in tea (Camellia sinensis) infusions of different grades of black Cut, Tear and Curl ...

  20. Water levels in the Yucca Mountain Area, Nevada, 1996

    International Nuclear Information System (INIS)

    Graves, R.P.

    1998-01-01

    Water levels were monitored in 24 wells in the Yucca Mountain area, Nevada, during 1996. Twenty-two wells representing 28 depth intervals were monitored periodically, generally on a monthly basis, and 2 wells representing 3 depth intervals were monitored both hourly and periodically. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in paleozoic carbonate rocks. Water levels were measured using either calibrated steel tapes or a pressure sensor. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 727.86 to about 1,034.58 meters above sea level during 1996. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 752.57 meters above sea level during 1996. Mean water-level altitudes for 1996 were an average of about 0.06 meter lower than 1995 mean water-level altitudes and 0.03 meter lower than 1985--95 mean water-level altitudes. During 1996, water levels in the Yucca Mountain area could have been affected by long-term pumping at the C-hole complex that began on May 8, 1996. Through December 31, 1996, approximately 196 million liters were pumped from well UE-25 c number-sign 3 at the C-hole complex. Other ground-water pumpage in the Yucca Mountain area includes annual pumpage from water-supply wells UE-25 J-12 and UE-25 J-13 of approximately 163 and 105 million liters, respectively, and pumpage from well USW G-2 for hydraulic testing during February and April 1996 of approximately 6 million liters

  1. Arsenic and fluoride removal from contaminated drinking water with Haix-Fe-Zr and Haix-Zr resin beads.

    Science.gov (United States)

    Phillips, Debra H; Sen Gupta, Bhaskar; Mukhopadhyay, Soumyadeep; Sen Gupta, Arup K

    2018-06-01

    The objective of the study was to carry-out batch tests to examine the effectiveness of Haix-Fe-Zr and Haix-Zr resin beads in the removal of As(III), As(V) and F - from groundwater with a similar geochemistry to a site where a community-based drinking water plant has been installed in West Bengal, India. The groundwater was spiked separately with ∼200 μg/L As(III) and As(V) and 5 mg/L F - . Haix-Zr resin beads were more effective than Haix-Fe-Zr resin beads in removing As(III) and As(V). Haix-Zr resin beads showed higher removal of As(V) compared to As(III). Haix-Zr resin beads removed As(V) below the WHO (10 μg/L) drinking water standards at 8.79 μg/L after 4 h of shaking, while As(III) was reduced to 7.72 μg/L after 8 h of shaking. Haix-Fe-Zr resin beads were more effective in removing F - from the spiked groundwater compared to Haix-Zr resin beads. Concentrations of F - decreased from 6.27 mg/L to 1.26 mg/L, which is below the WHO drinking water standards (1.5 mg/L) for F - , after 15 min of shaking with Haix-Fe-Zr resin beads. After 20 min of shaking in groundwater treated with Haix-Zr resin beads, F - concentrations decreased from 6.27 mg/L to 1.43 mg/L. In the removal of As(III), As(V), and F - from the groundwater, Haix-Fe-Zr and Haix-Zr resin beads fit the parabolic diffusion equation (PDE) suggesting that adsorption of these contaminants was consistent with inter-particle diffusion. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Controlling taste and odour levels in water

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, A J

    1980-12-01

    Taste and odor of drinking water supplies act as indicator mechanisms, indicating increased degrees of biological activity, possible contamination of the supply, treatment inadequacies, or contamination of the distribution systems. Disinfection and coagulation are effective preventive measures. Taste and odor problems may arise even with the application of preventive measures, so protective and treatment techniques must be implemented. These include chlorination and activated carbon absorption. (1 photo, 3 references, 1 table)

  3. Lake Erie Water Level Study. Main Report.

    Science.gov (United States)

    1981-07-01

    indirectly through excessive turbidity, current or depth would impact the higher life forms. Phytoplankton , periphyton and aquatic macrophyte comprise...System. The hydro-electric interest relates to the facilities at the St. Marys River, Welland Canal, Niagara River, St. Lawrence River at Cornwall... relates to three components: water quality, fish, and wildlife. The economic evaluations of regulation plans were also made to determine effects on

  4. Automatic photometric titration of fluoride with thorium nitrate and alizarin S as indicator

    International Nuclear Information System (INIS)

    Bliefert, C.; Sobek, M.

    1978-01-01

    The photometric titration of fluoride with thorium nitrate and Alizarin S as indicator has been automated and optimized for fluoride levels between 1 and 20mg/85ml solution. The interference of several ions has been investigated. This procedure is particularly useful for the determination of fluoride after fusion with peroxides as fluxing agents. (orig.) [de

  5. Sources of fluoride pollution in Kasur district, Pakistan

    International Nuclear Information System (INIS)

    Khan, I.H.; Haq, M.M.I.

    2005-01-01

    Serious bone problems were reported in certain localities in Pakistan due to contamination of drinking water by fluoride pollution. Against WHO recommended threshold limit of 0.7 mg/L, about 40 mg/L of fluoride is determined by ion chromatographic technique of HPLC. The compositions of pollutants were investigated in the present study by examination the chemical and mineralogical studies of water and soil samples. It is found that main problem in Manga Mandi area of District Kasur, was caused due to the decomposition of phosphorus containing minerals in soil under acidic conditions. The other sources of fluoride contamination in different areas of Pakistan is being investigated. (author)

  6. Modelling the Effects of Competing Anions on Fluoride Removal by ...

    African Journals Online (AJOL)

    NICOLAAS

    in drinking waters.5 Various technologies are currently available to remove fluoride from ... Materials and Methods. 2.1. Materials ... Characterization of the Adsorbent. The functional group and iron oxide nanoparticles on PAN were detected by ...

  7. Water levels in the Yucca Mountain area, Nevada, 1995

    International Nuclear Information System (INIS)

    Graves, R.P.; Goemaat, R.L.

    1998-01-01

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1995. Seventeen wells representing 18 depth intervals were monitored periodically, generally on a monthly basis, 2 wells representing 3 depth intervals were monitored hourly, and 9 wells representing 15 depth intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and/or pressure transducers. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1995. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1995. Mean water level altitudes were only an average of about 0.01 meters higher than 1994 mean water level altitudes. A single-well aquifer test was conducted on well UE-25 WT number-sign 12 during August and September 1995. Well USW 0-2 was also pumped during October and November 1995, in preparation for single-well aquifer test at that well. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  8. Fluoride contamination sensor based on optical fiber grating technology

    Science.gov (United States)

    Jadhav, Mangesh S.; Laxmeshwar, Lata S.; Akki, Jyoti F.; Raikar, P. U.; Kumar, Jitendra; Prakash, Om; Raikar, U. S.

    2017-11-01

    A number of distinct advantages of the optical fiber technology in the field of sensors and communications which leads to enormous applications. Fiber Bragg grating (FBG) developed from the fabrication of photosensitive fiber through phase mask technique is used in the present report. The designed fiber sensor used for the detection and determination of contaminants in drinking water at ppm & ppb level and it is considered as a special type of concentration sensor. The test samples of drinking water have been collected from different regions. In this paper we have calibrated the FBG sensor to detect Flouride concentration in drinking water in the range of 0.05-8 ppm. According to WHO, the normal range of fluoride content in drinking water is about 0.7 ppm to 1.5 ppm. The results for resultant spectral shifts for test samples are closely agree with standard values.

  9. Antibacterial Effect of Silver Diamine Fluoride on Cariogenic Organisms.

    Science.gov (United States)

    Lou, Yali; Darvell, Brain W; Botelho, Michael G

    2018-05-01

    To screen the possible antimicrobial activity of a range of clinically used, silver-based compounds on cariogenic organisms: silver diamine fluoride (SDF), silver fluoride, and silver nitrate. Preliminary screening disk-diffusion susceptibility tests were conducted on Mueller-Hinton agar plates inoculated with Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces naeslundii, organisms known to be cariogenic. In order to identify which component of the silver compounds was responsible for any antibacterial (AB) effect, and to provide controls, the following were also investigated at high and low concentrations: sodium fluoride, ammonium fluoride, ammonium chloride, sodium fluoride, sodium chloride, and sodium nitrate, as well as deionized water as control. A volume of 10 pL of a test solution was dispensed onto a paper disk resting on the inoculated agar surface, and the plate incubated anaerobically at 37°C for 48 hours. The zones of inhibition were then measured. Silver diamine fluoride, silver fluoride, silver nitrate, and ammonium fluoride had significant AB effect (p effect at low concentration; the remaining other compounds had no effect. Silver ions appear to be the principal AB agent at both high and low concentration; fluoride ions only have an AB effect at high concentration, while ammonium, nitrate, chloride and sodium ions have none. The anticaries effect of topical silver solutions appears restricted to that of the silver ions. Silver compounds, such as SDF, silver fluoride, and silver nitrate have AB effect against cariogenic organisms and these may have clinical impact in arresting or preventing dental decay. Sodium fluoride did not have AB effect under the conditions tested.

  10. Critical water stress levels in Pinus patula seedlings and their ...

    African Journals Online (AJOL)

    Critical water stress levels in Pinus patula seedlings and their relation to measures of seedling morphology. ... Southern Forests: a Journal of Forest Science ... A pot trial was implemented to determine the effect of soil water stress following transplanting on shoot water potential and stomatal conductance of Pinus patula ...

  11. Radio Frequency Based Water Level Monitor and Controller for ...

    African Journals Online (AJOL)

    Similarly, the control unit of the prototype performs automatic switching control of on and off on a single phase centrifugal water pump, 220volts, 0.5hp motor via a motor driver circuit (relay). It also incorporates a buzzer that beeps briefly when water level hits 100%, thus causing the pump to be switched off but when water ...

  12. Short-time variations of the ground water level

    International Nuclear Information System (INIS)

    Nilsson, Lars Y.

    1977-09-01

    Investigations have demonstrated that the ground water level of aquifers in the Swedish bedrock shows shorttime variations without changing their water content. The ground water level is among other things affected by regular tidal movements occuring in the ''solid'' crust of the earth variations in the atmospheric pressure strong earthquakes occuring in different parts of the world These effects proves that the system of fissures in the bedrock are not stable and that the ground water flow is influenced by both water- and airfilled fissures

  13. Fluoride uptake from restorative dental materials by human enamel

    International Nuclear Information System (INIS)

    Forsten, L.; Rytoemaa, I.; Anttila, A.; Keinonen, J.

    1976-01-01

    The purpose of the study was to determine the uptake in vitro of fluoride from restorative materials by tooth enamel and whether prior etching of the enamel causes a change of uptake. The outermost layer of the labial surface of extracted canines was removed by grinding and the enamel was covered with five different fluoride-containing materials ; a silicate, a composite resin, an amalgam, a silicophosphate, and a polycarboxylate luting cement. The material was either removed immediately or after storing the tooth in distilled water. The fluoride content was determined using a sensitive physical method based on the 19 F (p, αγ) 16 O reaction. In addition, the fluoride content of enamel after etching for different periods of time and of etched enamel which had been in contact with silicate cement was determined. The mean fluoride content of uncovered interior enamel was 226 parts 10 6 . All materials, except the composite, increased clearly the fluoride content of the underlying enamel. Etching of interior enamel also increased the fluoride values. No difference could be shown in fluoride uptake from silicate and composite resin between etched and unetched enamel. (author)

  14. Excessive apoptosis and defective autophagy contribute to developmental testicular toxicity induced by fluoride

    International Nuclear Information System (INIS)

    Zhang, Shun; Niu, Qiang; Gao, Hui; Ma, Rulin; Lei, Rongrong; Zhang, Cheng; Xia, Tao; Li, Pei; Xu, Chunyan; Wang, Chao; Chen, Jingwen; Dong, Lixing; Zhao, Qian; Wang, Aiguo

    2016-01-01

    Fluoride, a ubiquitous environmental contaminant, is known to impair testicular functions and fertility; however the underlying mechanisms remain obscure. In this study, we used a rat model to mimic human exposure and sought to investigate the roles of apoptosis and autophagy in testicular toxicity of fluoride. Sprague–Dawley rats were developmentally exposed to 25, 50, or 100 mg/L sodium fluoride (NaF) via drinking water from pre-pregnancy to post-puberty, and then the testes of offspring were excised on postnatal day 56. Our results demonstrated that developmental NaF exposure induced an enhanced testicular apoptosis, as manifested by a series of hallmarks such as caspase-3 activation, chromatin condensation and DNA fragmentation. Further study revealed that fluoride exposure elicited significant elevations in the levels of cell surface death receptor Fas with a parallel increase in cytoplasmic cytochrome c, indicating the involvement of both extrinsic and intrinsic apoptotic pathways. Intriguingly, fluoride treatment also simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II but not Beclin1. Unexpectedly, the expression of p62, a substrate that is degraded by autophagy, was also significantly elevated, suggesting that the accumulated autophagosomes resulted from impaired autophagy degradation rather than increased formation. Importantly, these were associated with marked histopathological lesions including spermatogenic failure and germ cell loss, along with severe ultrastructural abnormalities in testes. Taken together, our findings provide deeper insights into roles of excessive apoptosis and defective autophagy in the aggravation of testicular damage, which could contribute to a better understanding of fluoride-induced male reproductive toxicity. - Highlights: • Rats were developmentally exposed to fluoride from pre-pregnancy to post-puberty. • Both excessive apoptosis and defective autophagy are involved in

  15. Contamination levels of domestic water sources in Maiduguri ...

    African Journals Online (AJOL)

    The study examines the levels of contamination of domestic water sources in Maiduguri Metropolis area of Borno State based on their physicochemical and bacteriological properties. It was informed by the global concern on good drinking water quality which is an indicator of development level; hence the focus on domestic ...

  16. Streptozotocin Aggravated Osteopathology and Insulin Induced Osteogenesis Through Co-treatment with Fluoride.

    Science.gov (United States)

    Yang, Chen; Zhang, Mengmeng; Li, Yagang; Wang, Yan; Mao, Weixian; Gao, Yuan; Xu, Hui

    2015-12-01

    The role of insulin in the mechanism underlying the excessive fluoride that causes skeletal lesion was studied. The in vitro bone marrow stem cells (BMSC) collected from Kunming mice were exposed to varying concentrations of fluoride with or without insulin. The cell viability and early differentiation of BMSC co-treated with fluoride and insulin were measured by using cell counting kit-8 and Gomori modified calcium-cobalt method, respectively. We further investigated the in vivo effects of varying dose of fluoride on rats co-treated with streptozotocin (STZ). Wistar rats were divided into six groups which included normal control, 10 mg fluoride/kg day group, 20 mg fluoride/kg day group, STZ control, STZ+10 mg fluoride/kg day group, and STZ+20 mg fluoride/kg day group. The rats were administered with sodium fluoride (NaF) by gavage with water at doses 10 and 20 mg fluoride/kg day for 2 months. In a period of one month, half of rats in every group were treated with streptozotocin (STZ) once through intraperitoneal injection at 52 mg/kg body weight. The serum glucose, HbA1c, and insulin were determined. Bone mineral content and insulin release were assessed. The results showed insulin combined with fluoride stimulated BMSC cell viability in vitro. The bone mineral content reduced in rats treated with higher dose of fluoride and decreased immensely in rat co-treated with fluoride and STZ. Similarly, a combination treatment of a high dose of fluoride and STZ decreased insulin sensitivity and activity. To sum up, these data indicated fluoride influenced insulin release, activity, and sensitivity. Furthermore, the insulin state in vivo interfered in the osteogenesis in turn and implied there was a close relation between insulin and bone pathogenesis in the mechanism of fluoride toxicity.

  17. Developmental and Post-Eruptive Defects in Molar Enamel of Free-Ranging Eastern Grey Kangaroos (Macropus giganteus Exposed to High Environmental Levels of Fluoride.

    Directory of Open Access Journals (Sweden)

    Uwe Kierdorf

    Full Text Available Dental fluorosis has recently been diagnosed in wild marsupials inhabiting a high-fluoride area in Victoria, Australia. Information on the histopathology of fluorotic marsupial enamel has thus far not been available. This study analyzed the developmental and post-eruptive defects in fluorotic molar enamel of eastern grey kangaroos (Macropus giganteus from the same high-fluoride area using light microscopy and backscattered electron imaging in the scanning electron microscope. The fluorotic enamel exhibited a brownish to blackish discolouration due to post-eruptive infiltration of stains from the oral cavity and was less resistant to wear than normally mineralized enamel of kangaroos from low-fluoride areas. Developmental defects of enamel included enamel hypoplasia and a pronounced hypomineralization of the outer (sub-surface enamel underneath a thin rim of well-mineralized surface enamel. While the hypoplastic defects denote a disturbance of ameloblast function during the secretory stage of amelogenesis, the hypomineralization is attributed to an impairment of enamel maturation. In addition to hypoplastic defects, the fluorotic molars also exhibited numerous post-eruptive enamel defects due to the flaking-off of portions of the outer, hypomineralized enamel layer during mastication. The macroscopic and histopathological lesions in fluorotic enamel of M. giganteus match those previously described for placental mammals. It is therefore concluded that there exist no principal differences in the pathogenic mechanisms of dental fluorosis between marsupial and placental mammals. The regular occurrence of hypomineralized, opaque outer enamel in the teeth of M. giganteus and other macropodids must be considered in the differential diagnosis of dental fluorosis in these species.

  18. Developmental and Post-Eruptive Defects in Molar Enamel of Free-Ranging Eastern Grey Kangaroos (Macropus giganteus) Exposed to High Environmental Levels of Fluoride

    Science.gov (United States)

    Kierdorf, Uwe; Death, Clare; Hufschmid, Jasmin; Witzel, Carsten; Kierdorf, Horst

    2016-01-01

    Dental fluorosis has recently been diagnosed in wild marsupials inhabiting a high-fluoride area in Victoria, Australia. Information on the histopathology of fluorotic marsupial enamel has thus far not been available. This study analyzed the developmental and post-eruptive defects in fluorotic molar enamel of eastern grey kangaroos (Macropus giganteus) from the same high-fluoride area using light microscopy and backscattered electron imaging in the scanning electron microscope. The fluorotic enamel exhibited a brownish to blackish discolouration due to post-eruptive infiltration of stains from the oral cavity and was less resistant to wear than normally mineralized enamel of kangaroos from low-fluoride areas. Developmental defects of enamel included enamel hypoplasia and a pronounced hypomineralization of the outer (sub-surface) enamel underneath a thin rim of well-mineralized surface enamel. While the hypoplastic defects denote a disturbance of ameloblast function during the secretory stage of amelogenesis, the hypomineralization is attributed to an impairment of enamel maturation. In addition to hypoplastic defects, the fluorotic molars also exhibited numerous post-eruptive enamel defects due to the flaking-off of portions of the outer, hypomineralized enamel layer during mastication. The macroscopic and histopathological lesions in fluorotic enamel of M. giganteus match those previously described for placental mammals. It is therefore concluded that there exist no principal differences in the pathogenic mechanisms of dental fluorosis between marsupial and placental mammals. The regular occurrence of hypomineralized, opaque outer enamel in the teeth of M. giganteus and other macropodids must be considered in the differential diagnosis of dental fluorosis in these species. PMID:26895178

  19. Absorption, distribution and excretion of inhaled hydrogen fluoride in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.B.

    1979-01-01

    Rats were subjected to whole body HF exposure for 6 hrs or to nose-only HF exposure for 1 hr. Total and/or ionic fluoride concentrations in selected tissues were determined at various times following exposure. In rats sacrificed 6 hrs after whole body exposure, dose-dependent increases in lung, plasma, and kidney total and ionic fluoride concentration occurred. Rats excreted more fluoride in the urine after whole body exposure than could be explained by the amount of HF inhaled. Considerable evidence suggests that airborne HF deposits on fur and is then ingested due to preening activity. Urinary fluoride excretion was increased by nose-only exposure. The urinary fluoride excretion accounted for approximately twice the fluoride estimated to be inhaled during exposure. Tissue fluoride concentrations were elevated immediately after nose-only exposure. Fluoride concentrations in lung and kidney returned to control levels within 12 hrs. Plasma fluoride concentration was slightly elevated 24 hrs after the start of the 1 hr exposure but was at control levels at 96 hrs. Immediately following nose-only exposure, lung ionic fluoride concentrations were less than plasma ionic fluoride concentrations suggesting that the fluoride in the lung had reached that site via plasma transport rather than by inhalation. A dose-dependent increase in plasma ionic fluoride concentration occurred after upper respiratory tract HF exposure providing strong evidence that fluoride is absorbed systemically from that site. The plasma ionic fluoride concentration after upper respiratory tract exposure was of sufficient magnitude to account for the plasma fluoride concentrations observed in intact nose-only exposed rats. (ERB)

  20. Fluoride resistance in Streptococcus mutans

    NARCIS (Netherlands)

    Liao, Ying

    2017-01-01

    Fluoride has been used as the most effective anti-caries agent for over five decades. It functions not only on the dental hard tissues, but also as an antimicrobial agent. It is known that oral bacteria are able to develop resistance to fluoride, which may affect the effectiveness of fluoride in

  1. Fluoride release from fluoride varnishes under acidic conditions.

    Science.gov (United States)

    Lippert, F

    2014-01-01

    The aim was to investigate the in vitro fluoride release from fluoride varnishes under acidic conditions. Poly(methyl methacrylate) blocks (Perspex, n=3 per group) were painted with 80 ± 5 mg fluoride varnish (n=10) and placed into artificial saliva for 30 min. Then, blocks were placed into either 1% citric acid (pH 2.27) or 0.3% citric acid (pH 3.75) solutions (n=3 per solution and varnish) for 30 min with the solutions being replaced every 5 min. Saliva and acid solutions were analyzed for fluoride content. Data were analyzed using three-way ANOVA (varnish, solution, time). The three-way interaction was significant (p>0.0001). Fluoride release and release patterns varied considerably between varnishes. Fluoride release in saliva varied by a factor of more than 10 between varnishes. Some varnishes (CavityShield, Nupro, ProFluorid, Vanish) showed higher fluoride release in saliva than during the first 5 min of acid exposure, whereas other varnishes (Acclean, Enamel-Pro, MI Varnish, Vella) showed the opposite behavior. There was little difference between acidic solutions. Fluoride release from fluoride varnishes varies considerably and also depends on the dissolution medium. Bearing in mind the limitations of laboratory research, the consumption of acidic drinks after fluoride varnish application should be avoided to optimize the benefit/risk ratio.

  2. Amelioration of Fluoride Toxicity with the Use of Indigenous Inputs

    Directory of Open Access Journals (Sweden)

    Maitra A.

    2013-08-01

    Full Te