High Levels Of Fluoride Research Articles

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

Chasico 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 Chasico 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 Chasico Lake. This fish is both consumed locally and exported to other South-American countries through commercial and sport fishing.

Fluoride contamination in the Bongo District of Ghana, West Africa: geogenic contamination and cultural complexities

This research investigated the extent of fluoride contamination in the Bongo District of northeast Ghana and the relationships of this fluoride contamination to the underlying geology and precipitation patterns, social and cultural attitudes towards water, and age divisions inherent in water usage patterns and the consequent demands placed on a borehole. The fluoride concentrations measured in the area are higher than reported in earlier literature. High fluoride levels are geographically confined to one geologic formation and appear to be inversely correlated to regional precipitation. Fluoride variation studies, tracking concentrations over 8 months, also reflect this link to local precipitation patterns. This localized analysis of water contamination issues addresses broader gender and policy issues inherent in supplying potable water.

High fluoride water in Bondo-Rarieda area of Siaya County, Kenya: a hydro-geological implication on public health in the Lake Victoria Basin.

BackgroundOnly a few studies to evaluate groundwater fluoride in Eastern Africa have been undertaken outside the volcanic belt of the Great Eastern Africa Rift Valley. The extent and impact of water fluoride outside these regions therefore remain unclear. The current study evaluated fluoride levels in household water sources in Bondo-Rarieda Area in the Kenyan part of the Lake Victoria Basin (LVB) and highlighted the risk posed by water fluoride to the resident communities. The results, it was anticipated, will contribute to in-depth understanding of the fluoride problem in the region.MethodsA total of 128 water samples were collected from different water sources from the entire study area and analyzed for fluoride content using ion-selective electrodes.ResultsLake Victoria was the main water source in the area but dams and open pans (39.5%), boreholes and shallow wells (23.5%), and streams (18.5%) were the principal water sources outside walking distances from the lake. The overall mean fluoride content of the water exceeded recommended limits for drinking water. The mean water fluoride was highest in Uyoma (1.39±0.84 ppm), Nyang’oma (1.00±0.59 ppm) and Asembo (0.92±0.46 ppm) and lowest in Maranda Division (0.69±0.42 ppm). Ponds (1.41±0.82 ppm), springs (1.25±0.43 ppm), dams and open pans (0.96±0.79 ppm), and streams (0.95±0.41 ppm) had highest fluoride levels but lake and river water did not have elevated fluoride levels. Groundwater fluoride decreased with increasing distance from the lake indicating that water fluoride may have hydro-geologically been translocated into the region from geochemical sources outside the area.ConclusionsLake Victoria was the main water source for the residents of Bondo-Rarieda Area. Majority of in-land residents however used water from dams, open pans, boreholes, shallow wells, ponds and streams, which was generally saline and fluoridated. It was estimated that 36% of children living in this area, who consume water from ground sources from the area could be at the risk of dental fluorosis.

Hydrochemistry of groundwater (GW) and surface water (SW) for assessment of fluoride in Chinnaeru river basin, Nalgonda district, (AP) India

Hydrochemical studies were conducted in Chinnaeru river basin of Nalgonda district, Andhra Pradesh, India, to explore the causes of high fluorides in groundwater and surface water causing a widespread incidence of fluorosis in local population. The concentration of fluoride in groundwater ranges from 0.4 to 2.9 and 0.6 to 3.6 mg/l, stream water ranges from 0.9 to 3.5 and 1.4 to 3.2 mg/l, tank water ranges from 0.4 to 2.8 and 0.9 to 2.3 mg/l, for pre- and post-monsoon periods, respectively. The modified Piper diagram reflects that the water belongs to Ca2+–Mg2+–HCO3 − to Na+–HCO3 − facies. Negative chloroalkali indices in both the seasons prove that ion exchange between Na+ and K+ in aquatic solution took place with Ca2+ and Mg2+ of host rock. The interpretation of plots for different major ions and molar ratios suggest that weathering of silicate rocks and water–rock interaction is responsible for major ion chemistry of groundwater/surface water. High fluoride content in groundwater was attributed to continuous water–rock interaction during the process of percolation with fluorite bearing country rocks under arid, low precipitation, and high evaporation conditions. The low calcium content in rocks and soils, and the presence of high levels of sodium bicarbonate are important factors favouring high levels of fluoride in waters. The basement rocks provide abundant mineral sources of fluoride in the form of amphibole, biotite, fluorite, mica and apatite.

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

SummaryChronic 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.IntroductionUnderstanding 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.MethodsDorper 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.ResultsThe 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.ConclusionsOur data suggest that fluoride exposure with concomitant calcium deficit (i) may aggravate bone loss via reductions in mineralized trabecular and cortical bone mass and (ii) can cause fragility fractures and (iii) that the prevalence of skeletal fluorosis especially due to groundwater exposure should be reviewed in many areas of the world as low bone mass alone does not exclude fluorosis.

Is fluoride a risk factor for bone cancer? Small area analysis of osteosarcoma and Ewing sarcoma diagnosed among 0-49-year-olds in Great Britain, 1980-2005.

Background: Artificial fluoridation of drinking water to improve dental health has long been a topic of controversy. Opponents of this public health measure have cited the possibility of bone cancer induction. The study objective was to examine whether increased risk of primary bone cancer was associated with living in areas with higher concentrations of fluoride in drinking water.Methods: Case data on osteosarcoma and Ewing sarcoma, diagnosed at ages 0–49 years in Great Britain (GB) (defined here as England, Scotland and Wales) during the period 1980–2005, were obtained from population-based cancer registries. Data on fluoride levels in drinking water in England and Wales were accessed through regional water companies and the Drinking Water Inspectorate. Scottish Water provided data for Scotland. Negative binomial regression was used to examine the relationship between incidence rates and level of fluoride in drinking water at small area level.Results: The study analysed 2566 osteosarcoma and 1650 Ewing sarcoma cases. There was no evidence of an association between osteosarcoma risk and fluoride in drinking water [relative risk (RR) per one part per million increase in the level of fluoride = 1·001; 90% confidence interval (CI) 0·871, 1·151] and similarly there was no association for Ewing sarcoma (RR = 0·929; 90% CI 0·773, 1·115).Conclusions: The findings from this study provide no evidence that higher levels of fluoride (whether natural or artificial) in drinking water in GB lead to greater risk of either osteosarcoma or Ewing sarcoma.

Update on uncertain etiology of chronic kidney disease in Sri Lanka's north-central dry zone.

This manuscript updates a review previously published in a local journal in 2012, about a new form of chronic kidney disease that has emerged over the past two decades in the north-central dry zone of Sri Lanka, where the underlying causes remain undetermined. Disease burden is higher in this area, particularly North Central Province, and affects a rural and disadvantaged population involved in rice-paddy farming. Over the last decade several studies have been carried out to estimate prevalence and identify determinants of this chronic kidney disease of uncertain etiology. Summarize the available evidence on prevalence, clinical profile and risk factors of chronic kidney disease of uncertain etiology in the north-central region of Sri Lanka. PubMed search located 16 manuscripts published in peer-reviewed journals. Three peer-reviewed abstracts of presentations at national scientific conferences were also included in the review. Disease prevalence was 5.1%-16.9% with more severe disease seen in men than in women. Patients with mild to moderate stages of disease were asymptomatic or had nonspecific symptoms; urinary sediments were bland; 24-hour urine protein excretion was <1 g; and ultrasound demonstrated bilateral small kidneys. Interstitial fibrosis was the main pathological feature on renal biopsy. The possibility of environmental toxins affecting vulnerable population groups in a specific geographic area was considered in evaluating etiological factors. Pesticide residues were detected in affected patients' urine, and mycotoxins detected in foods were below maximum statutory limits. Calcium-bicarbonate-type water with high levels of fluoride was predominant in endemic regions. Significantly high levels of cadmium in urine of cases compared to controls, as well as the disease's dose-related response to these levels, has drawn attention to this element as a possible contributing factor. Familial clustering of patients is suggestive of a polygenic inheritance pattern comparable to that associated with diseases of multifactorial etiology. Available data suggest that chronic kidney disease of uncertain etiology is an environmentally acquired disease, but to date no definitive causal factor has been identified. Geographic distribution and research findings suggest a multifactorial etiology.

High fluoride and low pH level have been detected in popular flavoured beverages in Malaysia

High fluoride and low pH level have been detected in popular flavoured beverages in Malaysia

Use of Activated Red Clay Soil from Kiteto District, Tanzania, as a Remedial Method for High Fluoride Levels in Drinking Water

The fluoride levels in the water samples were determined potentiometrically using a fluoride ion selective electrode. Different experiments on remediation of fluoride containing water with activated clay soil were carried out. Studies on effect of calcination temperature on activation of clay, minimum amount of calcinated clay soil giving optimum defluoridation, effect of contact time for optimal defluoridation and reusing activated soil for defluoridation of water were performed. The best activation temperature for the red clay soil from Kiteto District was found to be 700 °C. For best results, the clay should be heated at this temperature for 3 hours, allowed to cool then used. The optimum water defluoridation contact time was found to be 8 hours. It was established that for 100 mL of fluoridated water with 4.59 mg-F L-1, a minimum of 10 g of calcinated clay soil was required to reduce the concentration of fluoride ions to ≤1.1 mg-F L-1 which is well below the WHO recommended level of 1.5 mg-F L-1 for potable drinking water. The results also showed that the activated red clay soil can be repeatedly dried and re-used for the defluoridation process for a maximum of four times. It is recommended that the local red clay soil properly activated as described be used for the defluoridation of drinking water from Kiteto district, Tanzania. Investigation of possible usage of the activated clay soil for defluoridation of drinking water of other areas in the country is advocated.

The effect of ozone on progression or regression of artificial caries-like enamel lesions in vitro

ObjectiveThis study investigated the effect of ozone on the progression or regression of artificial caries-like lesions on enamel following pH cycling conditions in vitro. MethodsA randomized, single blind, four legs design was used. 20 full thickness enamel slabs were allocated to each of the four groups which were: Fluoride free toothpaste (control); ozone alone; Reductant/Patient Kit alone and a combination of both ozone/Reductant/Patient Kit. Artificial lesions were created and subjected to the pH cycling regime for a 14 days period. Assessments were carried out before and after the pH cycling on the slabs using the microhardness testing and Quantitative Light-induced Fluorescence (QLF). ResultsStatistical significant difference were found in the percentage change of enamel microhardness before and after pH cycling between ozone/Reductant/Patient Kit group and all the other three groups of the study, as well as between Reductant/Patient Kit group and control. There was a statistical significant difference in the change of size and severity of the lesion (ΔQ) between all the three regimes tested and the control with a trend favouring ozone/Reductant/Patient Kit group. ConclusionsIn our model, it appeared that ozone treatment alone is not effective in protecting the enamel against demineralisation or promoting remineralisation, unless combined with the Reductant/Patient Kit, which contain high levels of fluoride.

Lead enhances fluoride influence on apoptotic processes in the HepG2 liver cell line

Chronic long-term exposure to high levels of fluoride leads to fluorosis, manifested by skeletal fluorosis and damage to internal organs, including kidneys, liver, parathyroid glands, and brain. Excess fluoride can also cause DNA damage, trigger apoptosis, and change cell cycle. The effect of fluoride may be exacerbated by lead (Pb), a potent inhibitor of many enzymes and a factor causing apoptosis, still present in the environment in excessive amounts. Therefore, in this study, we investigated the effects of sodium fluoride (NaF) and/or lead acetate (PbAc) on development of apoptosis, cell vitality, and proliferation in the liver cell line HepG2. We examined hepatocytes from the liver cell line HepG2, incubated for 48 h with NaF, PbAc, and their mixture (NaF + PbAc), and used for measuring apoptosis, index of proliferation, and vitality of cells. Incubation of the hepatocytes with NaF or PbAc increased apoptosis, more when fluoride and Pb were used simultaneously. Vitality of the cells depended on the compound used and its concentration. Proliferation slightly increased and then decreased in a high fluoride environment; it decreased significantly after addition of Pb in a dose-dependent manner. When used together, fluoride inhibited the decreasing effect of Pb on cell proliferation.

Protective effect of ascorbic acid and Ginkgo biloba against learning and memory deficits caused by fluoride

Fluoride is present in the ground water, World Health Organization permitted level of fluoride in the ground water is 0.5 ppm. Tooth pastes, mouth washes, tea and sea fish are the sources of fluoride. Exposure to these multiple sources results in several adverse effects in addition to the fluorosis. The present study aimed to test the effect of vitamin C and Ginkgo biloba against the behavioural deficits caused by fluoride. Rats were divided into five groups with six animals in each group (n = 6). Control group received ordinary tap water with 0.5 ppm of fluoride, the remaining groups received 100 ppm of fluoride for 30 days prior to fluoride exposure. Two groups of animals received 100 mg/kg body weight of vitamin C and G. biloba for 15 days prior to fluoride exposure. After 45 days, behavioural studies (T-Maze, passive avoidance) were conducted on the experimental animals. The results of the present study showed no behavioural deficits in the control group of animals however, the rats that received fluoride water exhibited impairment in their spatial learning and memory deficits. The deficits are not marked in the vitamin C and G. biloba groups. To conclude chronic exposure to high levels of fluoride causes severe impairment in the spatial learning and memory, these deficits can be ameliorated with the vitamin C and G. biloba.

A CROSS SECTIONAL STUDY ON DENTAL FLUOROSIS AMONG SCHOOL CHILDREN INCLUDING CHEMICAL ANALYSIS OF POTABLE WATER SOURCES IN ADPALLI PHC, MULCHERA, GADCHIROLI, MAHARASHTRA, INDIA

Dental fluorosis is a developmental disturbance of dental enamel, caused by successive exposures to high concentrations of fluoride during tooth development, leading to enamel with lower mineral content and increased porosity. The condition is more common in school children owing to their development stage. A study was carried out to assess the prevalence of dental fluorosis among school children with chemical analysi s of potable water sources in and around the villages of Adapalli PHC, Gadchiroli. Survey method was adopted to assess the prevalence by previously trained health workers and the chemical analysis was carried out in the District Public Health lab, Gadchiro li, India. It was found that the prevalence of dental fluorosis among school children is highest in Kalinagar (76.62 %) and Laxmipur (57.65 %), Tumadi (44.44 %), Gandhinagar (39.25 %) and Bhaskarnagar (34.50 %) follow a descending order. On the other hand chemical analysis of potable water sources more especially ground water shows that Kalinagar has the highest Fluoride level in its water sources, such as 4.5 PPM in bore well, 8.0 PPM in well, 8.0 PPM in hand pump. Next to Kalinagar villages like Haripur ( 1.4 PPM), Vasantapur (1.0 PPM), Thakurnagar (1.0 PPM), Gundapalli (1.0 PPM) shows moderate level of Fluoride in hand pump water. Apart from dental fluorosis the level of Fluoride in drinking water in some of the villages may lead to skeletal fluorosis whic h may incapacitate the normal functioning of the inhabitants causing economic damage. The district public health authority has recommended a fluoride treatment plant and has also recommended “Nalgonda Process” for water treatment.

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

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.

학교구강보건실 운영사업의 영향분석

Objectives : The aim of the study is to propose the fundamental data for further developments of the school dental clinic program through evaluating comprehensive improvements of the indices and the oral health status. Methods : This studied was carried out from December 2010 to September 2012. Subjects were 239 elementary school 4th, 5th, 6th grade students having no school dental clinic and 195 elementary school 4th, 5th, 6th grade students having school dental clinic in Busan. They completed self-reported questionnaires after accepting informed consent. The questionnaire included knowledges, attitudes and practices for oral health recognition and supports of the school dental clinic program. Results : Permanent tooth caries prevention rate revealed 59.0%, 53.3%, and 62.0%. in 4th, 5th, and 6th respectively. Rate of Care Group with fissure sealant permanent teeth showed 80.3%, 88.0%, and 88.9% respectively. Index of Care Group with fissure sealant permanent teeth revealed 2.68, 2.90, and 3.97, respectively. DMFT index of Care Group was 1.11, 1.35, and 1.51, respectively. Active D rate of Care Group resulted in 16.7%, 24.1%, and 16.7%, respectively. Dental health education group showed high awareness level of fluoride and sealant effect for caries prevention. Tooth brushing of three times per day was more effective when using rolling tooth brushing. On the other hand, oral health recognition and oral status in the control group was low. Conclusions : Oral health recognition was closely related to good oral care. Expansion of oral health care business is important to prevent dental caries. Systematic approach for oral health education programs and human resources development is very important to improve oral health care.

Fluoride sorption by treated fly ash: kinetic and isotherm studies

High fluoride levels in drinking water have become a critical health hazard. In the present study, the performance of magnesia-loaded fly ash adsorption in the removal of fluoride from aqueous solution was investigated in a batch study. The effect of contact time, dosage, pH, temperature and agitation speed was studied at different values. The maximum removal efficiency was 88 % at 150 min. The effective dose of adsorbent was found to be 2.5 g/l. The optimum pH was found to be at pH 4. Kinetic studies and isotherm studies were also performed to understand the ability of the adsorbents. The monolayer adsorption capacity determined from the Langmuir adsorption equation was found to be 11.61 mg/g. The kinetic measurements suggested the involvement of pseudo-second-order kinetics in adsorption and were controlled by a particle diffusion process. Overall, the results of this study suggest that magnesia-loaded fly ash is an environmentally friendly, efficient and low-cost adsorbent, useful for the removal of fluoride from aqueous solution.

Application of a tooth-surface coating material to teeth with discolored crowns

Crown discoloration of permanent teeth is caused by trauma, periapical lesions of the deciduous teeth, pharmaceuticals, and systemic diseases. Crown discoloration has been treated with bleaching or crown restoration. However, these methods are not appropriate during the growth and development period of children.In this study, we used BeautiCoat™ (Shofu Inc., Kyoto, Japan), a tooth-surface coating material that contains high levels of controlled-release fluoride, that temporarily improves crown color. We evaluated the effect of the primer on tooth-surface characteristics in addition to the coating agent's shear bond strength, tooth-surface condition, and duration of attachment. Additionally, we surveyed patients' satisfaction with the color improvement.The results showed no adverse effects of the primer on the enamel surface. The coating material itself showed a high degree of shear bond strength. Based on observations of shedding and fracturing in clinical applications, we found that the coating material maintained long-term attachment if applied under conditions of strict moisture prevention and it avoided areas of occlusion. Treated children and their parents were highly satisfied with the color improvement. These results suggest that this coating material is appropriate for improving the color of discolored teeth during childhood.

Geographical Distribution of Dental Caries Prevalence and Associated Factors in Young Adults in Finland

Oral health of the young has been reported to be associated with the place of residence, due to differences in socio-economic status. The results of studies on the effect of fluoride in drinking water on caries prevalence have been contradictory. The main aim of our study was to investigate the geographical distribution of dental caries prevalence in Finland and analyse possible regional, associated factors. Oral health of 13,564 men born between 1990 and 1992 was screened using a method based on criteria of the World Health Organization for epidemiological studies by 15 calibrated dentists in 20/24 garrisons of the Finnish Defence Forces in 2011. Mean DMFT and DT values in provinces were calculated. Multilevel analysis was applied to the data using generalized linear mixed models and a logit link function. The binary outcome variable was the cariological treatment need (yes/no) and the garrison was treated as random effect. Mean DMFT and DT values varied significantly between provinces in Finland. Increased levels of fluoride in drinking water, Swedish as the main language in the municipality, and living in urban areas were protective factors against cariological treatment need. Dentist density did not affect caries prevalence. The geographical distribution of dental caries further supported estimates of the protective effects of high fluoride levels in drinking water, Swedish as the main language in the municipality, as well as living in urban areas. Effect of fluoride on caries prevalence still exists, and association with the socio-economic status was confirmed.

Fluoride levels and its safety in Tea (&lt;i&gt;Camellia sinensis&lt;/i&gt;) and Khat (&lt;i&gt;Catha edulis&lt;/i&gt;) imported and produced in Ethiopia

The fluoride contents of sixteen(16) different packed tea leaves ( Camellia sinensis ) available in Ethiopian market and ten(10) samples of Khat leaves ( Catha edulis ) obtained from different localities were assessed using fluoride ion selective electrode. Amounts measured varies from 33.29 to 946 μg/gm on dried weight basis (DW) with an average value of 321.27±234.1 in tea samples and 13 to 20.01 μg/gm with a mean quantity of 14.94 ±1.45 in khat Samples. Based on the common practice of drinking tea three times a day by most people which is usually prepared using six grams of tea leaves and 100 to 200 gm chewing of khat leaves for those habitual users, possible daily intake of fluoride is calculated to be 1972.62 μg and 224.1-448.2 μg from tea and khat respectively based on the average fluoride quantity data from all the samples investigated. These values alone are within acceptable range of RDA (recommended daily allowance) of 2-4 mg fluorine by World Health Organization (WHO) except in one Ethiopian brand of tea where in its possible consumption the RDA limit was surpassed. Although dental problems were commonly reported in habitual khat chewers, the fluoride content of this plant is insignificant thus the chemical principle associated with such problems might be due to other ingredient(s) than fluorine. However the contribution of these plants to the overall dietary fluoride exposure should not be undermined and attention should be given to that of high values reported in tea leaves. Therefore drinking tea in areas with high fluoride levels from water sources should be cautioned to avoid the potential acute and chronic effects of fluoride. Key Words: Fluoride, Tea, Khat, Ethiopia, Ion selective electrode

Adsorption of fluoride from aqueous solution using low cost adsorbent

High fluoride levels beyond the recommended value of 1.5 mg/L have been detected in several groundwater wells in Northern Ghana. This occurrence has led to the capping of many high yielding wells that hitherto have been major sources of drinking water for the populace in these arid areas. Most of the fluoride removal technologies applied in the area has not been versatile in effectively removing fluoride because of the varying water qualities. This study focused on screening adsorbents including high aluminium or iron containing bauxite ores, fabricated zeolite and activated Neem seeds for removal of fluoride from drinking water. The model water used was prepared by simulating the prevailing groundwater quality in Northern Ghana. The high aluminium bauxite ore (HABO) had the highest fluoride removal capacity. Within the pH range tested (5–7), the fluoride removal decreased with increasing pH. Occurrence of sulfate, chloride and nitrate in the model water reduced the fluoride removal capacity by 57, 24 and 38% respectively. The combined effect of these anions showed a 60% reduction in the fluoride removal capacity. The Freundlich and Langmuir isotherms gave an adsorption capacity (K) of 0.90 mg/g for the HABO. The adsorption kinetics fitted well the pseudo second-order kinetic model. The HABO is thermally stable and has kaolinite [Al2Si2O5(OH)5] and gibbsite [Al(OH)3] as its major components. X-ray fluorescence (XRF) and energy dispersive X-ray (EDX) results showed Al, Fe, Ti, O, C and Si as the predominant elements in the HABO.