Fluorosis Problem Research Articles

Removal of fluoride from aqueous solution: status and techniques

Presence of various hazardous contaminants like fluoride, arsenic, nitrate, sulfate, pesticides, heavy metals, and other elements in ground water or surface water make the water unsafe and dangerous for the drinking purpose. The presence of any of these elements in drinking water in excess to the permissible limit is harmful for the human life. Fluoride is one of the elements which is very important for health especially for the children during teeth formation as well as harmful for human health if present in water more than permissible limit. Absence or insufficient amount of fluoride in drinking water causes dental caries during teeth formation of children whereas the presence of excess fluoride in drinking water causes dental and skeletal fluorosis. Therefore, maintaining of fluoride concentration within the safe limits is very important. The presence of excess fluoride in drinking water is a global problem. Excessive fluoride concentrations have been reported in ground waters of more than 27 developed and developing countries including India. In India, about 19 states are facing acute fluorosis problem due to excess fluoride concentration. Fluoride is the major inorganic pollutant of natural origin found in ground water. The excessive fluoride from the drinking water should be reduced to the permissible limit. Various technologies such as coagulation–precipitation, ion exchange, electrocoagulation/electrochemical treatment, membrane processes, nanotechnology, and adsorption are being used to remove fluoride from water. Every method of fluoride removal has its advantages and limitations of operations. The selection of treatment process should be site specific as per local needs and prevailing conditions as each technology has some limitations. The present paper deals with the short review on sources of fluoride, its effects on human health, and the techniques available for removal of fluoride from drinking water.

Various Options for Removal of Fluoride from Drinking Water

Excessive fluoride concentrations have been reported in groundwaters of more than 20 developed and developing countries including India where 19 states are facing acute fluorosis problems. Various technologies are being used to remove fluoride from water but still the problem has not been rooted out. In this paper, a broad overview of the available technologies for fluoride removal and advantages and limitations of each one have been presented based on literature survey and the experiments conducted in the laboratory with several processes. It has been concluded that the selection of treatment process should be site specific as per local needs and prevailing conditions as each technology has some limitations and no one process can serve the purpose in diverse conditions. Keywords: Fluoride; Fluorosis; Ground water; Soil water; Drinking water; Treatment

Evaluation of fluoride bottled water and its incidence in fluoride endemic and non endemic areas

Summary Background & aims Water is a vital element for hydratation of the human body. Access to drinking water of good quality became a real problem in many areas of the world and more particularly in Algeria. In the eastern zone of northern Sahara, several epidemiological investigations have revealed the existence of an endemic fluorosis problem associated to excess of fluoride in drinking water. However, in some areas of North Algeria, the prevalence of tooth decay is estimated at 67% in school-children that consume low fluoride water. Thus, the best choice for the population is to consume the local mineral or spring bottled waters although they are expensive. Considering the large variety of the sources of bottled waters in Algeria and the lack of data regarding fluoride content in these waters, it becomes essential to evaluate the fluoride concentration of the consumed water, in order to ensure its benefits on the prevention of caries without incurring the risk of dental or osseous fluorosis. Thus, the aim of this study is to determine the fluoride concentration in bottled waters sold in Algerian market and compare with the stated value in the label. Methods Twenty nine commercial brands of bottled waters were collected from various markets in Algeria. Potentiometric method using a fluoride selective ion electrode (ELIT 8221F − 41936) is carried out to evaluate fluoride content of the water samples. Three readings were taken for each brand and the average was estimated and also compared with the fluoride content printed on the label. Results The obtained results revealed that the fluoride concentration of Algerian bottled waters is ranged from 0.19 ± 0.02 to 1.07 ± 0.026 mg/L. Almost half of the bottled waters (48.28%) did not exceed 0.5 mg F − /L and 37.93% were weakly fluoridated (≤0.3 mg F − /L). Only three (3) among twenty nine (29) brands of bottled waters tested have specified the fluoride concentration on their labels. Conclusions The results show that Algerian bottled waters can be regarded as a relevant source of dietary fluoride. Significant differences were found in fluoride concentration of bottled waters tested. These data are essential to consumer and all health care professionals especially dentists.

Fluoride levels in drinking water and other surface water of an industrial area belt of Orissa State in India

The fluorosis problem along with endemicity characterised by high degree of industries releasing fluorides into the environment was studied to quantify the fluoride levels in the different water sources. The analysis showed that out of 17 tube wells monitored, three (17.65%) showed higher fluoride levels. Among the open well monitored, 17 (58.54%) had higher fluoride content out of 41. The samples collected at open ponds showed that nine (47.37%) samples had higher fluoride content. The comparisons were made with the control samples.

Fluoride pollution in soils and waters of Koohbanan region, southeastern Iran

Dental fluorosis occurs because of fluoride over-absorption during tooth calcification and maturation. We studied fluoride concentration in water and soil samples of the Koohbanan region in Kerman province of southeastern Iran and the effects of calcium chloride and gypsum treatments in decreasing the amount of fluoride in water samples of this region. The results indicate that the high amount of fluoride in the water samples of Koohbanan region is not in agreement with the recommended amount of fluoride concentration for drinking water by World Health Organization (that is 1–1/5 mg/l). Applying calcium chloride and gypsum treatments decreased the amount of fluoride in the water samples showing that utilizing calcium chloride (6 mg/l) or gypsum (12 mg/l) can lower the fluoride concentration in the water samples of Koohbanan, and thus solve the observed dental fluorosis problem.

De-fluoridation of groundwater using magnesium oxide

Fluorosis, which severely affects teeth and bones, is one of the common water-related diseases listed by the World Health Organization. Fluorosis is caused by ingestion of groundwater containing fluoride in excess of 1.5 mg/l and is widespread in about 25 countries. As majority of fluorosis affected regions occur in arid or semi-arid regions of the world, de-fluoridation of the limited available water resource forms the viable solution. Though several methods of de-fluoridation have been proposed, only few are implemented in field. Further, the existing field methods have various limitations such as cost, efficiency, quality of treated water and disposal of byproducts of treatment. In search of a sustainable solution towards mitigating the fluorosis problem, a new method of de-fluoridation using magnesium oxide has been developed in laboratory. Present study addresses issues that will assist in successful implementation of the new de-fluoridation method in field, using a domestic de-fluoridation unit.

Role of Selenium in Alteration of Erythrocyte Parameters in Bovine Fluorosis

Signs of dental discolouration, difficulty in mastication, bony exostosis and debility were observed in cattle from Qingtongxia Ningxia, China where fluoride concentration in drinking water, soil, fodder, serum, bone, teeth, haircoat and urine were significantly higher than the corresponding health site. The problem of fluorosis in beef cattle is attributable to water containing toxic levels of fluoride. The objective of this paper was therefore to evaluate the influence of fluoride on erythrocyte parameters in cattle under high fluoride and low selenium conditions, as well as the protective efficacy of selenium exposure in feedstuff for bovine endemic fluorosis. Sixteen 6 to 7 year-old high fluoride beef cattle were randomly allotted into two groups each with eight cows: high fluoride control group, and supplemented with 0.25 mg/kg selenium per day for 83 days respectively. In addition, eight 6 to 7 year-old normal control beef cattle were selected from a non-high fluoride site. Blood samples were collected on day 0, 30 and 83 for erythrocyte parameters analysis and scanning electronic microscopy. The results indicated that erythrocytes, hemoglobin, packed cell volume values and Na + -K + ATPase activity from affected cattle on the high fluoride site were significantly reduced during the period as compared with the corresponding samples of normal control cattle, a great number of echinocytes were present in peripheral blood, and subsequent anaemia. However, affected cattle exposed to selenium revealed increasable erythrocyte parameters, the extent of elevation in these values being dependent on the duration of supplementation with selenium. These findings suggest that fluoride exposure can cause erythrocyte damage, whereas selenium supplementation can antagonize fluoride-induced generation of free radicals and cumulative effects of lipid peroxidation in erythrocytes. Selenium supplementation may help to alleviate the possible hazards associated with bovine endemic fluorosis. (Asian-Aust. J. Anim. Sci. 2006. Vol 19, No. 6 : 865-871)

Fluoride in drinking water and its removal

Excessive fluoride concentrations have been reported in groundwaters of more than 20 developed and developing countries including India where 19 states are facing acute fluorosis problems. Various technologies are being used to remove fluoride from water but still the problem has not been rooted out. In this paper, a broad overview of the available technologies for fluoride removal and advantages and limitations of each one have been presented based on literature survey and the experiments conducted in the laboratory with several processes. It has been concluded that the selection of treatment process should be site specific as per local needs and prevailing conditions as each technology has some limitations and no one process can serve the purpose in diverse conditions.

The cause of endemic fluorosis in western Guizhou Province, Southwest China

The endemic fluorosis in western Guizhou Province, southwest China is usually attributed to a high-fluorine content in Late Permian coals. This study found that the average fluorine content in 50 coal channel samples from western Guizhou Province ranges from 16.6 to 500 μg/g, with an average of 83.1 μg/g, which is close to the world average (80 μg/g) and that of Chinese coals (82 μg/g). Additionally, the fluorine content of drinking water and fresh corn is too low to lead to fluorosis in western Guizhou Province. However, the clay used as an additive for coal-burning and as a binder in briquette-making by local residents has a very high content of fluorine, ranging from 100.8 to 2455.7 μg/g, with an average of 1027.6 μg/g. The endemic fluorosis is likely caused by fluorine in the clay. Therefore, in areas where unhealthy traditional coal-burning habits and customs are kept and furnaces without chimneys are used, the more clay used for a coal-burning additive and as a binder for briquettes, the more serious the fluorosis problem is.

Distribution of fluoride and fluorosis in Ethiopia and prospects for control.

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.

Potential fluorosis problems around Chandidongri, Madhya Pradesh, India

The area around Chandidongri (latitude 21 deg 02 prime N and longitude 80 deg 37 prime E) is covered by granitic gneisses and amphibolites of the Amgaon Group and granites and rhyolites of the Dongargarh super group. The granites which cover the major portion of the area have been intruded into by a number of dolerite and epidiorite dykes and traversed by a few N–S trending shear zones. A well-known fluorite deposit is located along the Lamtidongri–Kotnapani shear zone. Besides this deposit, the authors have located a few occurrences of fluorite along other shear zones where epidiorite dykes are in association with granites. A number of cases of fluorosis have been reported from those parts of Rajasthan and Andhra Pradesh which are covered by granitic rocks and also from the eastern parts of Bhandara district which are adjacent to the area described here. The Chandidongri area is mainly covered by granitic rocks, which at places show the presence of fluorite mineralisation. Taking into consideration these facts, the authors have investigated the area to study the cases of fluorosis if any, and the impact of geology and fluorite mining on the water quality in this region. During the survey, we have not come across any cases of fluorosis in this region. The pH is more than 7 and the fluoride concentration is within the permissible limit.

Hydrofluorosis in water buffalo ( Bubalus bubalis) in India

The concentration of fluoride was determined in water, forage and urine and serum samples of buffaloes from the Unnao district of India. The water and forage samples contained 2.01 ± 0.51 and 22.50 ± 0.82 ppm of fluoride, respectively. The analysis of biosamples collected from the affected animals revealed higher levels of fluoride in serum (0.58 ± 0.05 ppm) and urine (10.64 ± 1.23 ppm). Clinical examination identified a 40.34% prevalence rate of clinical lesions suggestive of fluorosis in buffalo of this locality. Dental lesions were present invariably in all affected animals whereas lameness, painful bony exostosis and emaciation were recorded in 28.17%, 8.45% and 76.00% of the animals. Based on the clinical lesions and fluoride content in water, serum and urine, it was concluded that the problem of fluorosis in buffalo is attributable to drinking water containing toxic levels of fluoride.

Water quality and dental health in the Dry Zone of Sri Lanka

Abstract The Dry Zone of Sri Lanka has mostly poor rural folk, who live in very close association with the immediate physical environment, depending on it for their living. Many of these people have lived in such a confined environment throughout their lives and it is reasonable to assume that at least some aspects of their health could be correlated with the geochemistry of their immediate environment. Hydrogeochemical investigations of surface well water and deep well water in parts of the Dry Zone notably in the North Central Province, have shown that the fluoride concentrations often reach anomalously high levels, of the order of 10 mg −1 in some instances. As a result of this, dental fluorosis is increasing in its prevalence among school children. With over 13 000 tube wells with hand pumps, mostly in the Dry Zone, the problem of dental fluorosis will assume serious proportions in the future unless methods of defluoridating household water supplies are developed. An attempt has been made to implement a programme of defluoridating water supplies with a defluoridator using charcoal and charred bone meal. However, a major awareness programme is needed to educate the villagers of the dangers of excessive fluoride in drinking water and the need for community participation in maintaining household defluoridators.

A simple defluoridator for removing excess fluorides from fluoride‐rich drinking water

Dental and skeletal fluorosis caused by ingestion of fluoride‐rich waters has affected millions of people, particularly in the developing countries. In view of the lack of awareness of the cause of the problem among the inhabitants in such areas, and also on account of economic constraints, a simple, easy to operate household defluoridator is most essential to alleviate the problem. Such a low cost household defluoridator using burnt bricks was developed and tested in fluoride‐rich regions of Sri Lanka. The results were promising and if distributed properly, the problem of dental and skeletal fluorosis in Sri Lanka could be alleviated.

台湾省中興新村におけるＦｌｕｏｒｉｄａｔｉｏｎ中止後の歯科的影響

In 1972 water fluoridation was begun in Chung-Hsing New Village, Taiwan and it was discontinued in 1986. At the first stage, fluoride concentration was 0.6ppm, and was changed to 1.0ppm in 1978. Chung-Hsing New Village is located about 20km south-east of Taichung city and the mean temperature is 73.4 degrees Fahrenheit.In July 1991, to survey the dental effects in the 5 years after the water fluoridation discontinued, we conducted a dental survey in Chung-Hsing New Village and in Tsao-Tun as a control area. Two dentists examined dental caries with the criteria of WHO and one dentist examined dental fluorosis with Dean's criteria. The subjects in Chung-Hsing New Village were 93 schoolchildren aged 10-12 who had been drinking fluoridated water from birth to 5-7 years of age and 80 schoolchildren aged 14 or 15 who had been drinking from birth to 9 or 10years of age. In Tsao-Tun, the control group was 99 schoolchildren aged 10-12 and 78 schoolchildren aged 14 or 15. In the 10-12-year old schoolchildren, the mean DMFT was 1.19 (SE=0.17) in Chung-Hsing New Village and 2.55 (0.26) in Tsao-Tun. The difference was 53.3% (p<0.001). In 14 or 15-year-old schoolchildren, the DMFT was 2.38 (0.35) and 3.39 (0.34), respectively. The difference was 29.8% (p<0.05). The mean DMFS for each tooth type in Chung-Hsing New Vlliage was smaller than in Tsao-Tun. We found more effectiveness in the 1st molars and the incisors than in the other teeth. High caries preventive effects were produced by fluoride exposure not only in the calcification period, but also in the post-eruptive maturation period.In both areas, we could not find moderate or severe dental fluorosis. The prevalence rate of dental fluorosis was low and the difference between Chung-Hsing New Village and Tsao-Tun was not significant. CFI varied from 0.05 to 0.15. The present study proved that the water fluoridation produced caries preventive effects and the favorable effects remained for 5 years after discontinuation of the projects. In addition, there was no public health problem of dental fluorosis.

Fluorine toxicosis and industry.

With the expansion of certain types of industrialization into agricultural areas, fluorosis in livestock has become an important toxicologic problem in some places in the United States and many other countries. Fluorine has beneficial effects when ingested in small amounts, but toxic and adverse effects when ingested in excessive amounts. Many sources may contribute to the total fluorine intake of animals. Various factors influence biologic responses of livestock to ingested fluorides. Fluorosis can be correctly diagnosed and evaluated by qualified individuals. Some methods and procedures are helpful in alleviating fluorine toxicosis. Several programs may be used for settlements and solutions of fluorosis problems. Standards and a comprehensive guide for use in diagnosing and evaluating fluorosis in livestock have been compiled.

Fluorine in drinking water

The modern study of the problem of fluorosis (chronic fluorine poisoning) became possible when an Italian, Stefano Chiaie, described, as quoted by Eager (1901), an unsightly dental dystrophy, now known as ‘mottled teeth’. The efforts to trace its aetiology have been ceaselessly continued ever since, mainly by American investigators. Outstanding amongst these were Black &amp; McKay (1916), pioneers whose researches led to the discovery made by Smith, Lantz &amp; Smith (1931) that it was the fluorine, contained in drinking water, in a concentration of not less than 1 part per million (1 p.p.m.) and ingested during the period of calcification of the teeth, which was the direct cause of the dental dystrophy. This result was soon followed up by a number of observers, mainly in the United States under the leadership of the dental profession, amongst them physiologists, experimental pathologists, pharmacologists, veterinary surgeons, geologists and analytical chemists. The gate for further research, which in view of its magnitude and importance must be considered as being still in its infancy, has thus been thrown wide open.