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Water is the most important nutrient for rangeland livestock. However, competition with municipalities, industry, and other water users often results in grazing livestock being forced to use water supplies that are less than perfect. Surface water in western rangleands are often contaminated by mineral extraction, irrigation runoff and other human activities. Mineral contaminants in drinking water are additive with similar contaminants in feedstuffs. The goal of this article is to provide producers and veterinarians with the basic background to make informed decisions about whether a given water supply is "safe" for livestock., Competing Interests: Disclosure This is a compilation of 30 years of clinical experience and research funded by many different agencies, including the Wyoming Dept of Environmental Quality, the US Office of Surface Mining, and smaller in kind contributions by various liproducers., (Copyright © 2020 Elsevier Inc. All rights reserved.)

We evaluated the effects of dietary epigallocatechin gallate (EGCG) on the performance, biochemical parameters, and liver histopathology of fluoride-intoxicated broiler chickens. In total, 160 1-day-old male broiler chicks (Ross PM3 strain) were collected and assigned to four groups (40 animals each), with four replicates. The control group received a basal diet; the F group received 800 mg/kg fluoride; the EGCG group received 400 mg/kg EGCG; and the EGCG+F group received 400 mg/kg EGCG and 800 mg/kg fluoride. The live weight (LW) of F-treated chicks was significantly lower than that of the controls. In the F-treated groups, feed intake (FI) and LW values were lower, but the feed conversion ratio (FCR) was higher than those of the controls. The ratio of heart weight to LW was found to be the highest in the F-treated groups. Alkaline phosphatase (ALP), aspartate aminotransferase (AST), and total oxidant status (TOS) levels in the F-treated groups were significantly higher, whereas the increase in total cholesterol levels was insignificant than those in the control group. In the EGCG+F group, AST, total cholesterol, and TOS levels decreased to a level comparable to those in the control group. Histopathological evaluation revealed that there were mild changes in the portal region in the EGCG+F group; additionally, there was an improvement in liver morphology in the EGCG+F group compared to that in the F group. Thus, EGCG has potent antioxidant and regenerative effects that can ameliorate the detrimental effects of fluoride toxicity on blood parameters and the liver.

The review on fluorosis addresses the genesis of the disease, diagnostic protocols developed, mitigation and recovery through nutritional interventions. It reveals the structural and functional damages caused to skeletal muscle and erythrocytes, leading to clinical manifestations in fluorosis. Hormonal derangements resulting in serious abnormalities in the health of children and adults are discussed. Fluoride toxicity destroys the probiotics in the gut, resulting in vitamin B 12 depletion, an essential ingredient in haemoglobin (Hb) biosynthesis. The article provides an overview of National Technology Mission on Safe Drinking Water and its contributions to fluorosis control. National Programme for Prevention and Control of Fluorosis is presently in operation in India and its focus cited. Major emphasis has been laid on a variety of disorders surfacing in India due to fluoride toxicity/fluorosis as 'fluorosis-linked disorders', viz. anaemia in pregnancy, schoolchildren, thyroid hormone abnormalities, hypertension, iodine deficiency disorders/goitre, renal failure and calcium+vitamin D-resistant rickets in children. The major action taken by the Indian Council of Medical Research (ICMR), Government of India in establishing a Centre of Excellence for Fluorosis Research in India and its contributions are highlighted., Competing Interests: None

Objective: To explore whether the intake of dietary carotenoids could protect against skeletal fluorosis in Guizhou province in which coal-burning fluorosis is endemic., Methods: A case-control study of 196 patients with skeletal fluorosis and 196 age and gender-matched controls was conducted in Zhijin, Guizhou Province. Face-to-face interviews were conducted to assess habitual dietary intake using a 75-item food frequency questionnaire and various covariates with structured questionnaires. Urinary fluoride was measured using an ion-selective electrode method. The genotype of superoxide dismutase 2 (SOD2) rs11968525 was detected by TaqMan method., Results: We observed significant dose-dependent inverse associations of skeletal fluorosis with intake of β-carotene, lutein/zeaxanthin, lycopene, and total carotenoids (P-trend = 0.002 to 0.018), whereas α-carotene and β-cryptoxanthin intakes were not found to be related to skeletal fluorosis, after adjustment for potential confounders. The adjusted ORs and 95% CI of skeletal fluorosis for the highest versus lowest quartile were 0.30 (0.10, 0.86) for β-carotene, 0.23 (0.08, 0.66) for lycopene, 0.26 (0.10, 0.75) for lutein/zeaxanthin and 0.34 (0.14, 0.74) for total carotenoids (all P-trend < 0.05). Stratified analyses showed that the protective effects of lutein/zeaxanthin and total carotenoids on skeletal fluorosis were more evident for individuals with the AG+AA genotypes of SOD2 (rs11968525)., Conclusion: Increased intakes of β-carotene, lutein/zeaxanthin, lycopene, and total carotenoids are independently associated with a lower risk of coal-burning skeletal fluorosis. SOD2 (rs11968525) polymorphisms might modify the inverse associations between dietary carotenoids and skeletal fluorosis., (Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)

Since the classical epidemiological studies by Dean, it has been known that there should be an optimum level of exposure to fluoride that would be able to provide the maximum protection against caries, with minimum dental fluorosis. The "optimal" daily intake of fluoride for children (0.05-0.07 mg per kilogram bodyweight) that is still accepted worldwide was empirically determined. In the present review, we discuss the appropriateness of the current guidance for fluoride intake, in light of the windows of susceptibility to caries and fluorosis, the modern trends of fluoride intake from multiple sources, individual variations in fluoride metabolism, and recent epidemiological data. The main conclusion is that it is very difficult to think about a strict recommendation for an "optimal" range of fluoride intake at the individual level in light of existing knowledge of 1) the mechanisms of action of fluoride to control caries, 2) the mechanisms involved in dental fluorosis development, 3) the distinct factors that interfere in the metabolism of fluoride, and 4) the windows of susceptibility to both dental caries and fluorosis development. An "optimal" range of fluoride intake is, however, desirable at the population level to guide programs of community fluoridation, but further research is necessary to provide additional support for future decisions on guidance in this area. This list includes the effect of factors affecting fluoride metabolism, clinical trials on the effectiveness of low-fluoride dentifrices to prevent caries in the primary dentition, and validation of biomarkers of exposure to fluoride.

The purpose of this report is to examine critically the appropriateness of the current guidance for fluoride intake in the population (0.05-0.07 mg F/kg bodyweight/d), consider whether changes to the current guidance are desirable, and suggest further research that will strengthen the evidence base for future decisions on guidance/advice in this area. The benefits and the risks of using fluoride particularly concern preschool children because it is at this age that excessive fluoride intake may result in dental fluorosis. Data from mostly cross-sectional studies show a wide variation in exposure and a considerable variation in the amount of fluoride ingested. Fluorosis, mostly mild, is commonly observed. For considering changes in current guidance, there is a need for more knowledge on the relationship between exposure to fluoride at an early age and the development of fluorosis. For that, prospective epidemiological studies with sufficiently large and representative samples of children are required. It is also important to study children in communities both with and without water fluoridation and to include populations where salt or milk fluoridation is used. There is also a need for professional agreement on acceptable levels of mild and moderate/severe fluorosis and a more comprehensive knowledge on the appreciation of mild fluorosis among the public.

India is one of the fluoride-endemic countries where the maximum numbers of ground or drinking water sources are naturally fluoridated. In India, a total of 23, out of 36 states and union territories have drinking water contaminated with fluoride in varying concentration. In the present scenario, especially in rural India, besides the surface waters (perennial ponds, dams, rivers, etc.), bore wells and hand pumps are the principal drinking water sources for domestic animals such as cattle (Bos taurus), water buffaloes (Bubalus bubalis), sheep (Ovis aries), goats (Capra hircus), horses (Equus caballus), donkeys (Equus asinus) and dromedary camels (Camelus dromedarius). Out of 23 states, 17 states, namely Andhra Pradesh, Assam, Bihar, Chhattisgarh, Gujarat, Haryana, Jharkhand, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Odisha (Orissa), Punjab, Rajasthan, Telangana, Uttar Pradesh and West Bengal, have fluoride beyond the maximum permissible limit of 1.0 or 1.5 ppm in drinking water. This situation is a great concern for the animal health because fluoride is a slow toxicant and causes chronic diverse serious health hazards or toxic effects. Despite the fact that domestic animals are the basic income sources in rural areas and possess a significant contributory role not only in the agriculture sector but also in the strengthening of economy as well as in sustainable development of the country, research work on chronic fluoride intoxication (hydrofluorosis) due to drinking of fluoridated water in domestic animals rearing in various fluoride-endemic states is not enough as compared to work done in humans. However, some interesting and excellent research works conducted on different aspects of hydrofluorosis in domesticated animals rearing in different states are briefly and critically reviewed in the present communication. Author believes that this review paper not only will be more useful for researchers to do some more advance research work on fluoride-induced toxicosis in different species of animals but will also be helpful in the making of health policy for domestic animals at state and national level for the mitigation of hydrofluorosis in India.

Introduction: Although most poisoning deaths are not preventable with current medical technology, in some cases different management decisions may have prevented fatal outcomes., Objective: This study aims to review reported poisoning-related deaths for preventability to provide insight to improve future care., Methods: Fatality abstracts published in the US National Poison Data System (NPDS) Annual Reports (2008-2012) were analyzed. Preventability was graded using a Likert scale of 1 (definitely non-preventable) to 6 (definitely preventable). Two medical toxicologists screened all cases. Cases deemed definitely not preventable (score 1) by both reviewers were excluded from further review and considered to be "non-preventable". All cases considered at least possibly preventable by either screener were reviewed by a multidisciplinary panel of 5 physicians for preventability scoring. Differences were resolved by consensus. Cases determined to be "preventable" (scores 4-6) were characterized by type of improvement issue involved (diagnosis, treatment, monitoring, other) and recurring scenarios., Results: Of 390 published abstracts, 78 (20.0%) deaths were considered at least possibly preventable by at least one screener. Of these, 34 (8.7%) deaths were determined to be "preventable" by the panel. Inter-observer agreement by weighted kappa analysis was 0.58 for screening, 0.24 for preventability, and 0.44 for specific aspects of care. The most common toxicants were salicylates (n = 9), opioids (n = 4), toxic alcohols (n = 3), fluoride containing product (n = 3), and bupropion (n = 3). The most common improvement opportunities involved treatment and monitoring., Discussion: Most of the ingested substances in preventable deaths have delayed GI absorption or require metabolic activation to produce a delayed effect (such as salicylates, opioids, and toxic alcohols), and therefore provide an opportunity for early recognition and successful interventions. Most improvement opportunities are clearly described in the literature but may be not recognized., Conclusions: Based on an analysis of published NPDS data, a considerable number of poisoning-related deaths reaching medical attention may be preventable. The most common scenarios involved in potentially preventable poisoning fatalities related to monitoring and treatment. Salicylates and opioids were the most common agents involved in preventable deaths.

Fluoride is a naturally occurring contaminant in groundwater in Estonia. There are several regions in Estonia with fluoride contents in public water supplies as high as 7 mg/L. Long-term exposure to high-fluoride drinking water may have several adverse health effects, primarily dental fluorosis. The opportunities for exposure reduction rely highly on water treatment technologies. Since 2004 public water suppliers in Estonia have made efforts to diminish fluoride content in drinking water systems. A follow-up study on a country level was carried out in 2004-2012 to analyze the changes in population exposure to excessive (over 1.5 mg/L) fluoride in drinking water and to get information about the reduction methods applied by public water supplies (PWS) to optimize the fluoride levels in public water system. The results showed that bigger PWS have been more effective in fluoride reduction measures than small PWS. The main methods used to lower the fluoride content were reverse osmosis technology and replacement of water sources with new ones (new drilled wells). As a result of all the measures taken the overall high-fluoride exposure has been reduced substantially (82%).

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.)

Anthocyanins are polyphenols and well known for their biological antioxidative benefits. Maize purple plant pigment (MPPP) extracted and separated from maize purple plant is rich in anthocyanins. In the present study, MPPP was used to alleviate the adverse effects generated by fluoride on liver and kidney in rats. The results showed that the ultrastructure of the liver and kidney in fluoride treated rats displayed shrinkage of nuclear and cell volume, swollen mitochondria and endoplasmic reticulum and vacuols formation in the liver and kidney cells. MPPP significantly attenuated these fluoride-induced pathological changes. The MDA levels in serum and liver tissue of fluoride alone treated group were significantly higher than those of the control group (p < 0.05). The presence of 5 g/kg MPPP in the diet reduced the elevation of MDA levels in blood and liver, and increased the SOD and GSH-Px activities in kidney and GSH level in liver and kidney compared with the fluoride alone treated group (p < 0.05). In addition, MPPP alleviated the decrease of Bcl-2 protein expression and the increase of Bax protein expression induced by fluoride. This study demonstrated the protective role of MPPP against fluoride-induced oxidative stress in liver and kidney of rats.

Context: Oxidative damage to cellular components such as lipids and cell membranes by free radicals and reactive oxygen species (ROS) is thought to be associated with the development of degenerative diseases. Fluoride intoxication is associated with oxidative stress and altered anti-oxidant defense mechanism. Lycopene is a lipid-soluble powerful anti-oxidant that scavenges free radicals and ROS., Objective: This study was extended to investigate lycopene anti-oxidant efficacy in different organs of fluoride-intoxicated rats., Methods: Twenty-four adult rats were randomly divided into four groups of six animals each. Rats in group I received daily doses of vehicle. Group II rats were given lycopene (10 mg/kg body weight/day), by tubes, dissolved in 0.5 ml of corn oil for 5 weeks. Group III rats were given sodium fluoride (NaF) (10.3 mg/kg body weight/day), by tubes, for 5 weeks. In group IV rats, lycopene was administered 1 h later and NaF was administered for 5 weeks., Results: NaF administration induced oxidative stress as evidenced by elevated levels of lipid peroxidation (51.3, 65.9 and 67.6%) measured as malondialdehyde and total nitrate/nitrite (61.0, 59.7 and 68.9%) in red blood cells, heart and brain tissues. Moreover, significantly decreased reduced glutathione level, total anti-oxidant capacity and superoxide dismutase activity were observed in the examined tissues. The induced oxidative stress and the alterations in anti-oxidant system were normalized by the oral administration of lycopene treatment., Conclusion: Lycopene administration could minimize the toxic effects of fluoride indicating its free-radical scavenging and powerful anti-oxidant activities.

Multi-year follow-up of 358 workers of aluminum pot rooms, including 165 individuals suffering from fluorosis, has shown significant changes in the clinical picture of the chronic occupational fluorine intoxication, developed under modern conditions of production, at lower concentrations of fluorine compounds in the air of working area. In this connection, the pathology of the musculoskeletal system plays the dominating role in this clinical picture and has the large variability of combinations of the individual sections destructions of the bone tissue. The main criterion to establish the phase of the disease is still the number and severity of the signs of this destruction. The visceral pathology in contemporary production circumstances is registered with less frequency and loses a number of the previously described clinical manifestations, however, is still of some importance to identify the early signs of the disease and to prevent the dental fluorosis on time.

This study was conducted to further explore the effects of selenium on the blood antioxidant capacity in rats exposed to fluoride to find out the optimal dosage level of selenium. Animals were divided into prevention sequence (Selenium → NaF, water → NaF) and treatment sequence (NaF → Selenium, NaF → water) (sodium fluoride 50 mg/L; sodium selenite 0.375, 0.75, 1.5 mg/L). The exposure time was 12 months. Then, the fluidity of erythrocyte membrane by electron spin resonance was analyzed, and the blood was collected for GSH-Px and SOD activity, total antioxidant capacity (T-AOC) and uric acid assay, sialic acid and MDA content. The results showed that, compared with control group, GSH-Px activity and T-AOC level increased significantly (P < 0.05), and SOD activity was raised in varying degrees in prevention and treatment groups, respectively. Uric acid level was up-regulated, but no significant differences were observed (P > 0.05). The fluidity of erythrocyte membrane showed significant increase (P < 0.05). As evident in this study, when the dose of selenium was 0.75 mg/L, all the activities of antioxidant enzymes increased significantly in prevention sequence; but in treatment sequence, the optimum intervention concentration was 1.5 mg/L. On the basis of results, the preventive effect of selenium was superior to treatment effect on the oxidative stress induced by an overdose of fluoride.

This chapter discusses the characteristics and treatment of acute fluoride toxicity as well as the most common sources of overexposure, the doses that cause acute toxicity, and factors that can influence the clinical outcome. Cases of serious systemic toxicity and fatalities due to acute exposures are now rare, but overexposures causing toxic signs and symptoms are not. The clinical course of systemic toxicity from ingested fluoride begins with gastric signs and symptoms, and can develop with alarming rapidity. Treatment involves minimizing absorption by administering a solution containing calcium, monitoring and managing plasma calcium and potassium concentrations, acid-base status, and supporting vital functions. Approximately 30,000 calls to US poison control centers concerning acute exposures in children are made each year, most of which involve temporary gastrointestinal effects, but others require medical treatment. The most common sources of acute overexposures today are dental products - particularly dentifrices because of their relatively high fluoride concentrations, pleasant flavors, and their presence in non-secure locations in most homes. For example, ingestion of only 1.8 ounces of a standard fluoridated dentifrice (900-1,100 mg/kg) by a 10-kg child delivers enough fluoride to reach the 'probably toxic dose' (5 mg/kg body weight). Factors that may influence the clinical course of an overexposure include the chemical compound (e.g. NaF, MFP, etc.), the age and acid-base status of the individual, and the elapsed time between exposure and the initiation of treatment. While fluoride has well-established beneficial dental effects and cases of serious toxicity are now rare, the potential for toxicity requires that fluoride-containing materials be handled and stored with the respect they deserve., (Copyright © 2011 S. Karger AG, Basel.)

To evaluate the application potentiality pf a new type drinking-water defluoridation adsorbent Bio-F, comparative study on the defluoridation characteristics of common adsorbents activated alumina (AA), bone char (BC), activated clinoptilolite (AC) with Bio-F was conducted. The defluoridation characteristics under different conditions, such as particle diameter, pH, retention time, fluorine concentration, regeneration stability, were investigated by continuous-flow column experiments and static tests. The defluoridation efficiency of high fluoride underground water by four types of adsorbents was also compared. The results showed that F(-) adsorption kinetics of Bio-F fitted the Lagergren First-order equation (R2 = 0.9580). F(-) adsorption by Bio-F was found to fit the Langmuir adsorption isotherm (R2 = 0.9992). The results indicated that the static defluoridation capacity (DC) of Bio-F was 4.0883 mg x g(-1), which was about 1.8 folds and 5.8 folds of those of AA and AC respectively. DC of all four adsorbents was positively correlated with F(-) concentration and negatively correlated with particle size. High concentration of CO3(2-) and HCO3(-) reduced the DC of Bio-F (p < 0.05), while high concentration of Ca2+, NO3(-), HPO4(2-) favored defluoridation by Bio-F (p < 0.001). The optimal retention time of Bio-F was 3-4 min, which was less than that of AC (20 min) and AA (11 min). The DC of Bio-F remained relatively stable in pH 4.0-9.0 and in regeneration since the DC variation was not more than 15%. The above results indicated that Bio-F was superior to AA, BC and AC in drinking-water defluoridation.

Twelve male buffalo calves of 10 to 12 months of age were divided into 3 groups of four each. They were fed wheat straw+concentrate mixture +3 Kg greens. The chemical composition of the diet was same in all the three groups except fluoride which was added (as NaF) in concentrate mixture of group B and C to make the final fluoride concentration 30 ppm and 60 ppm respectively. The animals were kept on scheduled diet for a period of 90 days. Body weights were recorded at the start of the experiment and at fortnightly interval thereafter. Analysis of data revealed that the dry matter intake decreased non significantly in group B and C as compared to control group. A significant decrease in serum calcium and a significant increase in phosphorus concentration were observed in group C animals. A significant increase was observed in alkaline phosphatase activity in group C animals. A non significant decrease was observed in T4 values in group C animals. On the basis of these results it could be concluded that fluoride in the diet of buffalo calves @ 30 ppm is a safe level whereas 60 ppm has affected the blood metabolites.

Endemic skeletal fluorosis is widely prevalent in India and is a major public health problem. The first ever report of endemic skeletal fluorosis and neurological manifestation was from Prakasam district in Andhra Pradesh in the year 1937. Epidemiological and experimental studies in the endemic areas suggest the role of temperate climate, hard physical labor, nutritional status, presence of abnormal concentrations of trace elements like strontium, uranium, silica in water supplies, high fluoride levels in foods and presence of kidney disease in the development of skeletal fluorosis. Neurological complications of endemic skeletal fluorosis, namely radiculopathy, myelopathy or both are mechanical in nature and till date the evidence for direct neurotoxicity of fluoride is lacking. Prevention of the disease should be the aim, knowing the pathogenesis of fluorosis. Surgery has a limited role in alleviating the neurological disability and should be tailored to the individual based on the imaging findings.

Model-La cation exchange resin was transformed from strong acid cation exchange resin, which was used for the defluoridation of drinking water. The 001 x 7 strong acid cation exchange resin was transformed into model-La cation exchange by soaking in the La(NO3)3 solution. The F- in the water was removed by model-La cation exchange resin under the optimum condition because it was combined into fluoride with the La3+ in the model-La cation exchange resin. The used resin was regenerated with the La(NO3)3 solution and was used to defluoridate many times. The optimum conditions of transform and defluoridation and regeneration were d(rasin) = 0.315-0.600 mm, V(rasin):V(regeneration) = 1:6, t(transform) = 48 h, T = 298.16 K(25 degrees C). The defluoridation capacity was 5.60 mg/g in column test, and 4.08 mg/g in batch test. The model-La cation exchange resin could be used for defluoridation for 8 times. The results suggest that the model-La cation exchange resin is a novel material of defluoridation. This method is easy to master and the pH value of the solution doesn't need to be regenerated that the cost of defluoridation can be reduced significantly and it can be used for a long time.

This study was undertaken to assess the success of the intervention programmes of Centre for Community Economics and Developmental Consultants Society (CECOEDECON) initiated in the rural areas of Jaipur district of Rajasthan, India. The programme focussed on capacity building among villagers to create awareness about fluorosis and used Nalgonda technique for removal of excess florides from ground water in selected areas. The data and information were collected from respondents in six village related to aworeness and incidence of fluorosis, awareness regarding the CECOEDECON project and the use and effectiveness of domestic defluoridation technology. Analysis of collected data revealed that level of awareness was highest (68%) among the respondents of Barkheda and Yarlipura villages where the project was withdrawn in 1998. It was observed that the level of awareness decreased over time and it was found lowest in the villages where project was withdrawn in 1996. About 87% of the respondents reported that most of the women are members of the Mahila Mandal started under CECOEDECON project. Some of the respondents (38%) mentioned that they were experiencing problems after the withdrawal of project teams. Thus, it is evident that follow up programmes play an important role in sustenance of the use of defluoridation techniques in villages along with the infrastructure to take care of minor repairs and supply of chemicals.

Dietary fluoride intake should always be estimated before prescribing fluoride supplements.

The current health care trend is to provide evidence-based recommendations and treatment. Many literature reviews have shown fluoride's effectiveness against caries. The current use of fluoride in the prevention of dental caries is based on community, professional, and individual strategies. Personalized fluoride regimens should include a risk analysis and a review of the patient's current fluoride exposure. The future of fluoride may be found in its slow release and retention in the oral cavity through various modalities. Because of the many uncertainties still associated with fluoride, further research is needed.

Water fluoridation is known to be the most successful public health measure of the 20th century. More than half a century later, we are still reaping the benefits of fluoridation. We now know that the most important mechanism of fluoride action occurs through daily low-dose exposures. The battle between demineralization and remineralization occurs constantly, and fluoride shifts the balance to the latter. This dynamic, daily process far supersedes the pre-eruptive fluoride incorporation in importance. Fluoride, however, is now available in a variety of very different forms, useful in waging the war on caries. Nevertheless, opponents of this therapeutic agent maintain that its widespread use should be curtailed. Although the benefits of fluoride can no longer be disputed, fluoride supplementation must be supported and approached with consideration of total fluoride exposure.

In order to study the effect of cristata L for preventing fluoride toxicity, forty male SD rats were randomly divided into five groups. The control group(NC) was fed with staple feed stuff and tap water, the other four groups were fed with staple feed-stuff and high fluorine water. Except the high fluorine group(F), the other groups were fed with cristata L(FC), high calcium(FCa) and cristata L with high calcium(FCCa) respectively. The results showed that the serum calcium, urinary sodium, calcium, hydroxyproline(HOP) and fluorine contents of high fluorine groups were higher than that of control group; and the urinary calcium content of high calcium group was higher than that of control group. The body weight, BMC and BMD of high fluorine groups was lower than that of control group. The weight of groups FC, FCa and FCCa were significantly higher than that of group F. The BMC and BMD of group FCCa were significantly higher than that of group F. This implies that the food high in fluorine can affect the bone mineral density and urinary minerals of rats, the food supplemented with calcium can reduce the effect of high fluorine, and the food supplemented with both calcium and cristata L is better.

A review and mapping of fluoride test data for 270 water sources in 126 communities and examination of the literature of fluorosis distribution in Ethiopia show that this health problem extends beyond the Rift Valley into some highland communities. Fluoride concentrations above 5.0 mg/l in the Rift Valley were found mostly in hot springs (100% of all sources), lakes (78%), shallow wells (54%) and boreholes (35%) and the lowest concentrations (below 1.5 mg/l) in springs and rivers. Analysis of hydrochemical, economic and demographic factors in the spatial distribution of high-fluoride domestic water sources indicates that the fluorosis problem has become more serious in the Rift Valley in recent decades. Considerable spatial variation in the occurrence of fluoride, even within the same communities, and the presence of some low-fluoride water sources in the Rift Valley offer possibilities for geochemical exploration for acceptable domestic sources. The defluoridation programme in the Wonji irrigation scheme illustrates the problems faced by a large rural community in a developing country. Possibilities for control are examined and recommendations made for the development of alternative water sources and promising defluoridation methods using locally available materials and technologies.

Objective: To detect, diagnose and treat for endemic fluorosis earlier., Methods: Six kinds of indices, such as environmental fluoride level, were collected from the population in epidemic and non-epidemic areas of endemic fluorosis with a 1:1 paired-match design. A discriminant analysis model was established by multivariate analysis. Levels of fluoride in environment and biological materials were determined by fluoride electrode method. Living condition of the subjects were measured and interviewed. Function of skeletons and joints was measured. Biochemical and enzyme indices were measured with reagent kits and gel electrophoresis. Other indices were measured by interview. All data collected were analyzed by SAS and MDAS computer software., Results: There was significant overall difference between four kinds of discriminant functions, with an overall agreement of 85.78% (83.33% to 98.86%), based on resubstitution with sampled data. Posterior probabilities for new classification of sampled data automatically and randomly produced from a computer were 86.39% to 99.99%., Conclusion: The discriminant functions mentioned above, except for the third one with a too small sample size, can be used in early discrimination of endemic fluorosis caused by exposure to coal burning, or in evaluation for the effectiveness of pharmaceutical therapy, with a power of 95%.

In order to find out the situation of management and application of water defluoridation measures, as well as the effects on the prevention of endemic fluorosis in 10 provinces and cities with heavy endemic fluorosis from the drinking water sources, 1960 water engineering projects accounting for about 10% of all projects were investigated. The authors applied uniform method, criteria and forms to carry out the retrospective investigation. The data were entered into the computer database and analyzed statistically. The results demonstrate that all the defluoridation projects have significant effectiveness on the prevention of endemic fluorosis. The concentrations of water fluoride were below 1 mg/L. The prevalences of dental fluorosis were 30%-40% and the main type was light dental fluorosis. But with the time prolonging, less attention has been paid in man.

Objective: This paper analyzes reports to the American Association of Poison Control Centers (AAPCC) of suspected overingestion of fluoride by children younger than 6 years of age between 1989 and 1994, and estimates the probably toxic amounts of various home-use fluoride products in children younger than 6 years of age., Methods: Annual incidence rates of reported fluoride exposures attributed to dietary supplements, toothpaste, and rinses were calculated. Probably toxic amounts of each product were calculated using the frequently cited dose of 5 mg/kg., Results: Children younger than 6 years of age accounted for more than 80 percent of reports of suspected overingestion. While the outcomes were generally not serious, several hundred children were treated at health care facilities each year. A 10 kg child who ingests 50 mg fluoride (10.1 g 1.1% NaF gel; 32.7 g 0.63% SnF2 gel; 33.3 g 1,500 ppm F toothpaste; 50 g 1,000 ppm F toothpaste; and 221 mL 0.05% NaF rinse) will have ingested a probably toxic dose., Conclusions: Overingestion of fluoride products in the home is preventable. Dentists and other health care providers should educate parents and child care providers about the importance of keeping fluoride products out of reach of children. Manufacturers should be encouraged by the ADA and the FDA to use child-resistant packaging for all fluoride products intended for use in the home.

Water fluoridation was instituted as a public health measure more than 50 years ago to help limit dental caries. However, with the advent of fluoridated dentifrices, fluoridated infant formulas, and commercially prepared beverages with fluoridated water, the incidence of dental fluorosis is increasing. Health care professionals need to understand the history of water fluoridation, examine the benefits and complications of fluoride, and, if need be, take an informed political stance on an issue that is affecting large numbers among our pediatric population.

Fluoride intoxication is a serious public health problem in Senegal. The concentration of fluoride ions in underground water in Senegal is higher than the acceptable standard (0.7 mg/l at 25 degrees C) varying between 5 and 15 mg/l according to the season. The hydrological pattern of fluoride ions in Senegalese water is presented. The high levels of fluoride ions are due to the presence of phosphate ores. The health problems associated with the ingestion of toxic doses (about 4 mg/l) are discussed. Epidemiological investigation shows that the intoxication in Senegal is serious. In addition to fluoride in drinking water, high levels are also found in food, particularly tea and vegetables. Nanofiltration is a low cost membrane-based process which can be used to eliminate fluoride from drinking waters. Also known as low pressure reverse osmosis, this process is selective for small molecules and ions. It can thus sterilize and partially demineralize water. Furthermore, it can require only small amounts of energy, such that it can be run from photoelectric cells.

Relationship between bone fluoride content, pathological change in bone of aborted fetuses and maternal fluoride level was studied in 46 pregnant women and their inducedly-aborted fetuses. Results showed fluoride content in fetal femur averaged 368.2 micrograms/g, and 41.4% of the bone with pathological change. Fluoride levels in maternal urine and amniotic fluid and fluoride content in fetal femur and pathological change in fetal femur appeared a positive correlation between them. Femur fluoride content and pathological change of bone in fetuses born to mothers with mottling teeth were significantly greater than to those without them. Pathological change in fetal femur presented dose-response relationship with their bone fluoride content. When the latter reached greater than 500 micrograms/g, pathological changes occurred in 90% of the bone.

Circulating levels of haptoglobin and C-reactive protein were studied in patients of skeletal fluorosis and compared with two types of controls. The first type of control included normal healthy individuals consuming water containing permissible levels of fluoride (up to 1 mg/L). The second type of control included individuals consuming water contaminated with fluoride (1.2-14.5 mg/L) but not exhibiting clinical manifestations of skeletal fluorosis. A significant increase in the levels of haptoglobin (p < 0.01) and C-reactive protein (p < 0.01) as well as a raised erythrocyte sedimentation rate were seen in patients of skeletal fluorosis as compared to both types of controls. The present study suggests the possibility of a subclinical inflammatory reaction occurring in patients with skeletal fluorosis.

Polypeptide cytomedine, isolated from renal tissues has been studied for its regulatory effect on hemocoagulation and lipid peroxidation with fluoric intoxication (FI). FI was caused by inoculation of laboratory animals (guinea pigs) with sodium fluoride (100 mg/kg) for 14 days. Following it polypeptide (0.1 mg/kg) was introduced intramuscularly for 7 days. The development of FI was expressed by hypercoagulation delay of fibrinolysis with para-coagulation products appearing in blood decrease of antiaggregation activity of the renal tissue. These phenomena were estimated as manifestations of the first phase of disseminated intravascular blood coagulability (DIC-syndrome). The above reactions proceeded simultaneously with lipid peroxidation activation decrease of the antioxidant protection. The necrotic-dystrophic processes developed in renal and hepatic parenchyma. The renal peptide-cytomedine induced the normalization of lipid peroxidation in blood and renal tissues and fibrinolysis, the decrease in the concentration of para-coagulation products. The pathological changes decreased both in the renal and hepatic tissues. It is possibly, a result of the normalization of secretion and reabsorption in the kidneys. Thus, cytomedine of the kidney exerts a pronounced regulatory and protective effect in the case of acute renal pathology. These results correspond to the conception of the peptidergic organism regulation.

To define the relationship between ionic fluoride concentration in the serum of workers and the amount of hydrofluoric acid (HF) in the work environment, pre-and postshift serum and urine samples of 142 HF workers and 270 unexposed workers were examined. The maximum and minimum concentrations of HF in the air in each workshop varied from the mean by less than 30%. The preexposure levels of serum and urinary fluoride in HF workers were higher (P < 0.001) than the control values. This suggests that fluoride excretion from the body continues for at least 12h. The postshift serum and urinary fluoride concentrations of these workers were significantly higher (P < 0.001) than the preshift concentrations. A good correlation (r = 0.64) was obtained between postshift serum fluoride and postshift urine fluoride. There was a linear relationship between mean serum fluoride concentration and HF concentration in the workshop. A mean fluoride concentration of 82.3 micrograms/l with a lower fiducial limit (95%, P = 0.05) of 57.9 micrograms/l was estimated to correspond to an atmospheric HF concentration of 3 ppm. This is the maximum allowable environmental concentration recommended by the Japanese Association of Industrial Health, and it is also the threshold limit value suggested by the American Conference of Governmental Industrial Hygienists. The results demonstrate that exposure to HF can be monitored by determining the serum fluoride concentration.

Effects of reducing fluoride content of indoor air by the Mushan improve coal range, and the heated bed designed and made by these authors are quantitatively evaluated in this paper. The result shows that only heated bed can be effective to prevent fluorosis caused by burning coal containing fluoride.

An increase in the number of methods of fluoride administration over and above traditional modes, while offering new caries-preventive possibilities, has also created problems. These cannot be solved by the purely scientific, objective approach, since emotional resistance to fluoride has increased in some countries in parallel to environmental pollution. In most of the highly developed countries, the decrease of caries prevalence has dramatically lowered the number of children in need of concentrated preventive programs. On the other hand, dental awareness and multiple sources of fluoride have increased the risk of chronic fluoride overdosage. Means to avoid the latter problem are discussed. In addition to community-delivered fluoridation programs, individual counseling and "tailor-made" preventive measures are of increasing importance.

Magnesium chloride, administered by gavage to fasting young rats, 30 min prior to sodium fluoride, elevated the LD50 for fluoride from 76 to 104 mg/kg body wt. The LD50 was elevated to greater than 180 mg/kg when magnesium was given in a dose equivalent to 2 or 3 times that of fluoride. In two experiments, a dose of 50 mg F/kg caused a mean 14- and 19-fold increase above the level of the control animals in the renal calcium content. The nephrocalcinotic effect of fluoride was nearly completely prevented by administering magnesium in a dose which is 3-fold the equivalent of the fluoride dose 30 min prior to fluoride.