Fluorosis Areas Research Articles

Bone Strength in Growing Rats Treated with Fluoride: a Multi-dose Histomorphometric, Biomechanical and Densitometric Study.

Bone deformation and fragility are common signs of skeletal fluorosis. Disorganisation of bone tissue and presence of inflammatory foci were observed after fluoride (F-) administration. Most information about F- effects on bone has been obtained in adult individuals. However, in fluorosis areas, children are a population very exposed to F- and prone to develop not only dental but also skeletal fluoroses. The aim of this work was to evaluate the bone parameters responsible for the effect of different doses of F- on fracture load of the trabecular and cortical bones using multivariate analysis in growing rats. Twenty-four 21-day-old Sprague-Dawley rats were divided into four groups: F0, F20, F40 and F80, which received orally 0, 20, 40 or 80μmol F-/100g bw/day, respectively, for 30days. After treatment, tibiae were used for measuring bone histomorphometric and connectivity parameters, bone mineral density (BMD) and bone cortical parameters. The femurs were used for biomechanical tests and bone F- content. Trabecular bone volume was significantly decreased by F-. Consistently, we observed a significant decrease in fracture load and Young's modulus (YM) of the trabecular bone in F--treated groups. However, cortical bone parameters were not significantly affected by F-. Moreover, there were no significant differences in cortical nor trabecular BMD. Multivariate analysis revealed a significant correlation between the trabecular fracture load and YM but not with bone volume or BMD. It is concluded that when F- is administered as a single daily dose, it produces significant decrease in trabecular bone strength by changing the elasticity of the trabecular bone.

A comparative study of dental fluorosis and non-skeletal manifestations of fluorosis in areas with different water fluoride concentrations in rural Kolar.

Background:Fluorosis is an endemic disease which results due to excess exposure to high fluoride from different sources. The climatic factors and dependency on ground water add to the risk of fluorosis in Kolar. In addition to it, the epidemiological studies conducted on fluorosis in Kolar are very few.Aims:(1) To estimate age-specific prevalence of dental fluorosis in the study population. (2) To determine the proportion of study subjects with non-skeletal manifestations of fluorosis (3) To assess and compare the influence of various socio-epidemiological factors in the occurrence of dental fluorosis among the study population in areas with high and normal fluoride.Methodology:A cross-sectional study was conducted among the residents of three randomly selected villages, Thimmasandra and Batwarahalli (high fluoride) and Maddinayakanahalli (normal fluoride) belonging to Bangarpet taluk, Kolar for 1 year. Dental fluorosis was assessed by the Dean's grading. Non-skeletal manifestations were elicited based on clinical features. Fluoride levels of drinking water sources were estimated by ion-electrode method. The Chi-square and Fisher's exact tests were used to see the difference in proportions and a P value of <0.05 was considered for statistical significance.Results:The prevalence of dental and non-skeletal fluorosis in the study groups with high and normal fluoride groups were 13.17%, 5.5%, 3.84%, 1.9%, respectively. The prevalence of dental fluorosis was significantly higher among the children and adolescents compared to adults (P < 0.05).Conclusion:Dental fluorosis is a public health problem mainly affecting children and adolescents in Bangarpet.

Fluoride, Thyroid Hormone Derangements and its Correlation with Tooth Eruption Pattern Among the Pediatric Population from Endemic and Non-endemic Fluorosis Areas

To comparatively evaluate the status of fluoride in the body with thyroid activity in the pediatric population of endemic fluorosis areas. The present study also attempted to elucidate whether any correlation exists between fluoride and thyroid hormone derangement with delayed tooth eruption. A total of 400 pediatric subjects were included in the present study. All the patients were divided into two broad groups; groups A and B. Group A included 200 subjects who belonged to the endemic fluorosis area while Group B included remaining 200 subjects, who belonged to the fluorosis non-endemic area. Group B subjects were taken as control. Group A subjects were further divided into two study groups as follows: Group A1: 100 Pediatric subjects with dental fluorosis, and Group A 2: A total of one hundred pediatric subjects without dental fluorosis. Dean's index of fluorosis was calculated in all the patients. Blood samples were collected and were sent to a laboratory for assessment of thyroid hormone levels. All the results were subjected to statistical analysis by Statistical Package for the Social Sciences (SPSS) software. Mean thyroid stimulating hormone (TSH), water fluoride levels, urine fluoride levels and serum fluoride levels of subjects in group 1 were found to be significantly higher than that of subjects of group 2. Delayed tooth eruption was absent in subjects of group B while it was present in 100 subjects of group A. Thyroid hormone level derangement was seen in 54 percent subjects of group B, while it was seen in 67.5% subjects of group A. Positive correlation exists between fluorosis and thyroid functional activity. However; the tooth eruption pattern is independent up on the thyroid hormone derangement. Delayed tooth eruption and alteration in thyroid hormone levels can occur in subjects of the endemic fluoride areas. Therefore, adequate measures should be taken for controlling such adverse effects.

Geochemical sources, hydrogeochemical behavior, and health risk assessment of fluoride in an endemic fluorosis area, central Iran

The present study is the first attempt to put forward the possible source(s) and health risk assessment of fluoride in Bahabad, central Iran. Fluoride concentrations ranged from 0.22 to 2.35 mg/L and 292–355 mg/kg in the groundwater and soil samples, respectively. Geochemical provenance techniques using major and rare earth elements in soils revealed that local shale is the most probable source rock of fluoride in the area. A two-step chemical fractionation method applied on soil samples demonstrated that residual and water-soluble fractions were the most probable modes of fluoride in soil, whereas exchangeable fraction had a minor role. The coefficient of aqueous migration showed that fluoride in the studied soils behaved as a mobile element. Moreover, the relative mobility indicated that soils played a more important role than rocks in releasing fluoride into groundwater. In groundwater medium, chemical weathering, evaporation, and ion exchange acted as the main geochemical controlling factors of fluoride enrichment. Findings of this study signify that the role of NaCl and NaSO4-type waters should be considered more to recognize susceptible areas to fluoride contamination in groundwater. People in the study area are exposed to high levels of fluoride intake through drinking water, thus making dental fluorosis a major public health concern in the area. Scanning electron microscopy of the dentin's enamel showed morphological modifications (e.g., cracks and fissures) in residents' enamel structures. The results of this study may lead to suitable management strategies to mitigate the endemic fluorosis problem.

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

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

Evaluation of acidity in late Permian outcrop coals and its association with endemic fluorosis in the border area of Yunnan, Guizhou, and Sichuan in China.

The junction area of Yunnan, Guizhou, and Sichuan provinces is the heaviest coal-burning endemic fluorosis zones in China. To better understand the pathogenicity of endemic fluorosis in this area, 87 coal samples from the late Permian outcrop or semi-outcrop coal seams were collected in eight counties of the junction area of Yunnan, Guizhou, and Sichuan provinces. The total fluorine and sulfate content, etc. in the coal was determined using combustion-hydrolysis/fluoride-ion-selective electrode method and ion chromatography, respectively. The results show that the total fluorine concentrations in the samples ranged from 44 to 382µgg-1, with an average of 127µgg-1. The average pH of the coals is 5.03 (1.86-8.62), and the sulfate content varied from 249 to 64,706µgg-1 (average 7127µgg-1). In addition, the coals were medium- and high-sulfur coals, with sulfur mass fraction ranging from 0.08 to 13.41%. By heating the outcrop coals, HF release from the coal was verified quantitatively without exception, while simulated combustion directly confirmed the release of sulfuric acid (H2SO4). The acid in coal may be in the form of acidic sulfate ([Formula: see text]/H2SO4) because of a positive relationship between pH and [Formula: see text] in the acidic coal. The possible reaction mechanism would be that a chemical reaction between the acid (H2SO4 or [Formula: see text]) and fluorine in the coal occurred, thereby producing hydrogen fluoride (HF), which would be the chemical form of fluorine released from coal under relatively mild conditions. The unique chemical and physical property of HF may bring new insight into the pathogenic mechanism of coal-burning endemic fluorosis. The phenomenon of coal-burning fluorosis is not limited to the study area, but is common in southwest China and elsewhere. Further investigation is needed to determine whether other endemic fluorosis areas are affected by this phenomenon.

Occurrence and mobility of toxic elements in coals from endemic fluorosis areas in the Three Gorges Region, SW China

Fluorine (F) is a topic of great interest in coal-combustion related endemic fluorosis areas. However, little extent research exists regarding the environmental geochemistry of toxic elements that are enriched in coals and coal wastes in traditional endemic fluorosis areas, particularly focusing on their occurrences and mobilities during the weathering-leaching processes of coals and coal wastes in the surface environment. This paper addressed the issue of toxic elements in coals and coal wastes in the Three Gorges Region, Southwest (SW) China, where endemic fluorosis has historically prevailed, and investigated the distribution, occurrence, mobility features, and associated potential health risks. For this purpose, a modified experiment combined with long-term humidity cell test and column leaching trial was applied to elucidate the mobility of toxic elements in coals and coal wastes. In addition, sequential chemical extraction (SCE) was used to ascertain the modes of occurrence of toxic elements. The results demonstrated that the contents of toxic elements in the study area followed the order: stone coals > gangues > coal balls > coals. Furthermore, modes of occurrence of toxic elements were obviously different in coals and coal wastes. For example, cadmium (Cd) was mainly associated with monosulfide fraction in coals, molybdenum (Mo) and arsenic (As) were mainly associated with carbonate and silicate in coal gangues and stone coals, chromium (Cr) mainly existed in silicate and insoluble matter in coal gangues and coal balls, thallium (Tl) mainly occurred in organic matter in stone coals and sulfide in coals, and the occurrence of antimony (Sb) varied with different kinds of samples. Moreover, a large amount of toxic elements released to the leachates during the weathering and leaching process, which might pollute the environment and threaten human health. Based on the geo-accumulation index (Igeo), single factor index (Pi) and Nemerow index (PN), soils in the study area were mainly polluted by Cd, which constituted a potential risk to locally planted crops.

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

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

Fluoride content of minerals in gneissic rocks at an area of endemic dental fluorosis in Sri Lanka: estimates from combined petrographic and electron microprobe analysis

A mass balance of the mineralogical sources of fluoride in charnockitic gneiss bedrock and regolith (weathered rock) in Sri Lanka has been undertaken, using optical petrography and Scanning Electron Microscopy (SEM) with energy dispersive X-ray spectrometry (EDX) to support development of a conceptual model of fluoride release to groundwater. Bedrock and regolith samples were collected in Polonnaruwa where there is a widespread occurrence of dental fluorosis attributed to excessive fluoride (up 5.25mg/L) in groundwater, while primary minerals of the gneissic bedrock are identified as the ultimate source of fluoride. Fluoride leaching related to long-term weathering of the bedrock and development of the regolith, control the occurrence of F in the groundwater system which is yet unresolved. In the study area, the charnockitic gneiss bedrock is mantled by a few meters thick regolith within which the groundwater table fluctuates seasonally. Mineral abundance and mineral fluoride content were estimated using petrographic and SEM analysis. Plagioclase, hornblende, pyroxene, K-feldspar, quartz, biotite and titanite (sphene) were the major minerals of the rock though the mineral proportions vary widely over the area. Apatite and magnetite were present as accessory minerals. Fluoride concentrations obtained from SEM-EDX analysis were combined with the volume percentage of minerals from petrography to estimate the total rock fluoride concentration. The order of fluoride abundance was apatite (highest), biotite, titanite, and hornblende. Plagioclase, K feldspar, pyroxene and magnetite did not have any noticeable fluoride concentrations. Loss of fluoride from the rock mass upon weathering was clearly evident and hornblende appeared to be the most significant fluoride releasing agent through weathering. Apatite, though present in accessory amounts, is distributed evenly in the rock and hence may be considered as a steady fluoride donor causing elevated and uniform fluoride distribution in groundwater. On the other hand, hornblende and biotite though of irregular occurrence (area wise), may cause high fluoride anomalies in groundwater in areas of high abundance.

Surveillance on drinking-water-born endemic fluorosis in China, 2013

To investigate the prevalence of fluorosis and related control measures on drinking water type of endemic fluorosis in China. According to the national program- "Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis" , 136 counties were selected in 29 provinces, autonomous regions and municipalities. Three epidemic villages were randomly selected as fixed monitoring sites in each county. Dental fluorosis of all the children aged 8-12 living in the villages under the monitoring program, was identified under the ariteria from "Diagnosis of dental fluorosis" (WS/T 208-2011). Operating conditions and contents of fluoride in all the'water-improved projects' were investigated. Contents of fluoride in drinking water were tested in villages without the 'water-improved projects'. "Standard Test Method for Drinking Water" (GB/T 5750.5-2006) was used to detect the water fluoride. The overall prevalence of dental fluorosis among children aged 8-12 in all the villages under monitor program, was 28.58% (7 950/27 817), with the dental fluorosis index (DFI) as 0.58. Among them, the prevalence was 22.28% (3 917/17 583) and DFI was 0.44 in the'water-improved projects' villages that under normal operation and with qualified fluoride contents. The prevalence appeared as 38.74% (1 926/4 971) with DFI as 0.84 in those villages with 'water-improved projects' but mal-operated or with excessive fluoride. The prevalence was 40.03% (2 107/5 263), and DFI was 0.81 in those villages without 'water-improved projects'. The prevalence rates of dental fluorosis in children from the three types of endemic areas were significantly different. For 'water-improved projects', the normal opration rate was 93.77% (286/305) and the qualification rate of fluoride content was 76.77% (228/297). Dental fluorosis in children living in the drinking-water-born endemic fluorosis areas was on the edge of epidemics in China. Effective improvement on the quality of drinking water can significantly reduce the severity of dental fluorosis in children. The rate of proper operation on 'water-improved projects' was near to 95% in the endemic area. However, rate that met the criteria on qualified fluoride contents of these projects was still below 80%.

Cognitive Impairment and Risk Factors in Elderly People Living in Fluorosis Areas in China.

Residents living in fluorosis areas generally experienced long-term exposure to excessive fluoride in drinking water. The adverse effects of high fluoride levels on the nervous system have been studied; however, the effect of fluoride exposure on cognitive functions of elderly people in fluorosis areas is rarely reported. This study was aimed to find out the potential risk factors of cognitive impairment among elderly people who lived in fluorosis areas of China. A total of 511 subjects, aged 60years or above, were investigated in fluorosis areas of Heilongjiang Province, Inner Mongolia Autonomous Region, Qinghai Province, and Xinjiang Uygur Autonomous Region. The Mini-Mental State Examination (MMSE) was used to examine cognitive functions of the study subjects. Based on the MMSE scores, the study subjects were divided into normal group and cognitive impairment group that consisted of mild, moderate, and severe groups. Multivariable logistic regression showed that a higher risk of cognitive impairment was associated with increased age and decreased education levels. Multiple linear regression analysis revealed that MMSE scores were negatively associated with serum homocysteine (Hcy) levels. However, both urinary fluoride and serum Hcy levels in the normal group were not the lowest among the four groups. Spearman's correlation analysis showed that urinary fluoride levels were positively correlated with serum Hcy (r s = 0.209, P < 0.01). Our study suggests that people with cognitive impairment in fluorosis areas have elevated serum Hcy levels, which was positively correlated with urinary fluoride concentrations. A certain low dose of fluoride intake may play a potential protective rather than harmful role in cognitive functions; however, high fluoride exposure is a potential risk factor for cognitive impairment.

Mechanism of fluorine releasing in coal and clay and its effects on environment in Zhaotong, Yunnan Province.

Objective To study the real releasing of fluorine (F) and its effects on environmen in coalburning-borne fluorosis areas. Methods The coal, clay, briquette, cinder, fresh corn and roasted corn samples from 24 households were collected systematically in Zhaotong of City, Yunnan Province, and the F concentration in all samples was measured using the combustion hydrolysis/fluoride- ion selective electrode method, and the released amount and rate of F in briquette was calculated, and the relation between the released amount of F from briquette and the increase of F in roasted corn was analyzed. Results The F concentration of clay ranged from 266.4 to 2 536.7 mg/kg with a median of 1 087.1 mg/kg; the F concentration of briquette ranged from 115.9 to 635.0 mg/kg with a median of 308.8 mg/kg. The released amount of F in briquette ranged from 63.5 to 432.2 mg/kg with a median of 248.2 mg/kg. The releasing rate of F in briquette ranged from 30.3% to 91.5% with a average of 73.8%. The F concentration in fresh corn ranged from 0.43 to 2.00 mg/kg with a median of 1.31 mg/kg; the F concentration in roasted corn ranged from 2.21 to 44.88 mg/kg with a median of 10.49 mg/kg. The increased amount of roasted corn ranged 0.90 to 44.46 mg/kg. There was a significant correlation between the emission amounts of F from briquette and the F concentration in binder clay (r = 0.714, P 0.05). Conclusion The clay is an important source of F pollution, and the F increase in roasted corn is not only determined by the released amount of F in briquette, but also by several factors. Key words: Coal; Fluorine; Fluorosis, dental

Эффективность профилактического комплекса сопровождения ортодонтического лечения детей с флюорозом зубов = The effectiveness of preventive complex support orthodontic treatment of children with dental fluorosis

Gorohivsky V N. Эффективность профилактического комплекса сопровождения ортодонтического лечения детей с флюорозом зубов = The effectiveness of preventive complex support orthodontic treatment of children with dental fluorosis. Journal of Education, Health and Sport. 2015;5(2):157-164. ISSN 2391-8306 . DOI: 10.5281/zenodo.15715 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%282%29%3A157-164 https://pbn.nauka.gov.pl/works/541793 http://dx.doi.org/10.5281/zenodo.15715 F ormerly Journal of Health Sciences. ISSN 1429-9623 / 2300-665X. Archives 2011 – 2014 http://journal.rsw.edu.pl/index.php/JHS/issue/archive Deklaracja. Specyfika i zawartośc merytoryczna czasopisma nie ulega zmianie. Zgodnie z informacją MNiSW z dnia 2 czerwca 2014 r., ze w roku 2014 nie bedzie przeprowadzana ocena czasopism naukowych; czasopismo o zmienionym tytule otrzymuje tyle samo punktow co na wykazie czasopism naukowych z dnia 31 grudnia 2014 r. The journal has had 5 points in Ministry of Science and Higher Education of Poland parametric evaluation. Part B item 1089. (31.12.2014). © The Author (s) 2015; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland and Radom University in Radom, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 20.10.2014. Revised 18.01.2015. Accepted: 25.02.2015. УДК 616.31-085-053.2/.6-089.23+003.663.4 эффективность профилактического комплекса сопровождения ортодонтического лечения детей с флюорозом зубов The effectiveness of preventive COMPLEX SUPPORT orthodontic treatment OF CHILDREN WITH dental fluorosis В. Н. Горохивский V N Gorohivsky Г У «Институт стоматологии Национальной академии медицинских наук Украины» State Enterprise Institute of Stomatology National Academy of Medical Sciences of Ukraine, Odessa, Ukraine Р еферат Показано, что комплексные патогенетически обоснованные профилактика и лечение основных стоматологических заболеваний при ортодонтическом лечении зубо-челюстных аномалий у детей с флюорозом зубов улучшает показатели твердых тканей зубов, тканей пародонта, уровня гигиены полости рта, нормализует функциональные реакции, ответственные за гомеостаз ротовой жидкости, улучшает барьерную защиту десны от проникновения красителей и, следовательно, микроорганизмов. Ключевые слова: флюороз зубов, ортодонтическое лечение, лечебно-профилактический комплекс. Abstract Orthodontic movement of teeth in children living in areas of endemic fluorosis requires the development of specific pathogenetically grounded complexes preventive maintenance of orthodontic treatment. The objective of this work was to evaluate the effectiveness of the integrated prevention and treatment of major dental diseases in children with dental fluorosis in orthodontic treatment of dento-alveolar anomalies. Materials and methods. Clinical trials involved 47 children with dental fluorosis age 12-14 years. In the comparison group performed sanitation and professional hygiene. Children of the main group additionally received prophylactic complex, which included detoxicant, adaptogenic, antioxidant and other drugs. Results. Conclusions. It is shown that the complex pathogenetically-based prevention and treatment of major dental diseases in orthodontic treatment of dento-alveolar anomalies in children with dental fluorosis improves indices of hard tissues teeth, periodontal tissues, oral hygiene, normalizes functional reactions responsible for the homeostasis of oral liquid, improves the barrier gum protection against penetration of dyes and hence microorganisms. Keywords: dental fluorosis, orthodontic treatment, therapeutic and preventive complex.

Chronic fluorosis in buffaloes: Clinico-pathological studies

Five villages each from Kunkavav, Lathi and Liliya talukas from the Amreli district of Gujarat State were selected in the present study. A total of 336 blood and urine samples each were collected randomly from buffaloes exhibiting clinical signs of dental fluorosis in areas where water fluoride level was above 1.12 ppm. Hemoglobin and total erythrocyte count were significantly reduced in buffaloes exposed to higher concentrations of fluoride in the water whereas higher eosinophil count was reported in affected buffaloes as compared to control animals in all three talukas. Significantly reduced concentration of calcium, phosphorus, total protein and increased activity of alkaline phosphatase was found in serum samples of affected buffaloes as compare to controls. The fluoride concentration in urine, serum and bone samples was higher in affected buffaloes. Grossly ankylosis of knee joint was evident in one of the affected buffaloes which died during the course of the study. Microscopically sections of bones revealed dilated and irregular haversian canals with thick trabaculae having sharp heavy outlines. It was concluded that higher serum/urine fluoride level and increased serum ALP activity might be used as screening parameter for chronic fluorosis in buffaloes maintained in fluoride affected zones.

温度变化条件下高氟水的降氟处理研究

饮水型氟中毒遍布世界多数国家。中国是发病率最高的国家之一，主要分布在华北、东北及西北地区的部分省、自治区。但目前对于高氟水的处理方法仍然是改水和化学处理，难以解决成本高和二次污染问题。本文以河南省的氟病区信阳市为例进行高氟地下水取样，选取具有代表性的样品，运用温度变化方法进行降氟实验，结果证明在冰冻和煮沸条件下，水中的负离子含量明显下降，基本达到饮用水标准。说明这是一种具有推广价值的降氟方法。但是必须在对其降氟的机理及其病理学影响进行深入研究，有明确结论的情况下方可以推广使用。 Fluorosis caused by drinking water happens in many countries around the world. China is one of countries with the highest fluorosis incidence, and fluorosis areas mainly distribute in north, north-east, and parts of northwest of China. Now the treatments for high-fluorine water are still looking for new water source and chemical treatment, these two methods can not solve the problem of high cost and secondary pollution. This paper takes Xinyang City, a fluorosis ward in Henan Province, as an example, samples high-fluoride groundwater, selects representative samples, changes the temperature and tests the fluorine content of the samples, and the results show that under the freezing and boiling conditions, the fluorine content of groundwater samples significantly decreases, can basically meet the drinking water standard. It proves that freezing and boiling groundwater are valuable ways to reduce fluorine, but it still needs further study about the mechanism and the impact of pathology of this method; this method can be widely used with clear conclusions.

Dental fluorosis: A histological study using Light and Confocal microscopy.

To observe and characterize the histological features of fluorosed teeth under light and confocal microscope (CFM). A total of 25 fluorosed teeth and 5 normal teeth were collected from dentists across Dindigul, a known endemic area of fluorosis in South India. Ground sections of respective teeth were observed under light microscope and the sections were subsequently stained with acridine orange and studied under CFM. Histological changes were observed in the ground sections of fluorosed teeth as compared with the normal teeth. Depending on the degree of fluorosis, the affected teeth showed various features of hypomineralization in enamel and dentin. Fluoride interacts with both mineral phases and organic macromolecules by strong ionic and hydrogen bonds resulting in incomplete crystal growth at prism peripheries. This presents as hypomineralization of enamel and dentin.

Modifying effect of COMT gene polymorphism and a predictive role for proteomics analysis in children's intelligence in endemic fluorosis area in Tianjin, China.

Cumulative fluoride exposure has adverse influences on children's intelligence quotient (IQ). In addition, catechol-O-methyltransferase (COMT) gene Val158Met polymorphism (rs4680) is associated with cognitive performance. This study aimed to evaluate the associations of COMT polymorphism and alterations of protein profiles with children's intelligence in endemic fluorosis area. We recruited 180 schoolchildren (10-12 years old) from high fluoride exposure (1.40 mg/l) and control areas (0.63 mg/l) in Tianjin City, China. The children's IQ, fluoride contents in drinking water (W-F), serum (S-F), and urine (U-F); serum thyroid hormone levels, COMT Val158Met polymorphism, and plasma proteomic profiling were determined. Significant high levels of W-F, S-F, U-F, along with poor IQ scores were observed in the high fluoride exposure group compared with those in control (all P < 0.05). S-F and U-F were inversely related with IQ (r(s) = -0.47, P < 0.01; r(s) = -0.45, P = 0.002). Importantly, higher fluoride exposure was associated with steeper cognitive decline among children with the reference allele Val compared with those homozygous or heterozygous for the variant allele Met (95% CI, -16.80 to 2.55; P interaction < 0.01). Additionally, 5 up-regulated protein spots related to cell immunity and metabolism were detected in children with high fluoride exposure compared with the control. In conclusion, fluoride exposure was adversely associated with children's intelligence, whereas the COMT polymorphism may increase the susceptibility to the deficits in IQ due to fluoride exposure. Moreover, the proteomic analysis can provide certain basis for identifying the early biological markers of fluorosis among children.

Extent and Severity of Caries Among 12 year-old Students in an Endemic Fluorosis Area in Senegal

The aim of this study was to measure the extent and severity of caries among 12 year-old students in an endemic fluorosis area of Senegal. This was a descriptive and cross sectional study covering 253 elementary school students aged 12 years and attending public, confessional and Franco-Arab schools in the city of Kaolack (Senegal). These students were in grades 4 or 5 and obtained parental permission to participate in the survey. They were selected through a cluster sampling; twenty two clusters were drawn at random. The socio-demographic information, the caries prevalence, the DMFteeth (DMFt) index and the degree of fluorosis were collected. The data was analysed using Epi info with a significance level of 5%. Girls constituted 54.2% of the sample; students in public schools were 46.8% and those in confessional schools were 31.23%. The prevalence of dental caries was 28.1%; the DMFt mean was 0.52 (sd 0.41), while 90.5% of the school population were affected by fluorosis. The prevalence of caries was significantly higher in the Franco-Arab schools than in confessional and public schools with a p-value = 0.0105. The caries prevalence and the mean DMFt remain relatively low in an area where 9/10 of the school population were affected by fluorosis. Prevention programs based on inequalities related to the types of schools are an efficient strategy to fight dental caries in the city of Kaolack.

The daily fluorine and arsenic intake for residents with different dietaries and fluorosis risk in coal-burning fluorosis area, Yunnan, Southwest China

The daily fluorine (F)/arsenic (As) intake (DFI/DAsI) for residents at different ages with different dietaries and dietary changes was investigated to analyze the fluorosis risk in coal-burning fluorosis area in Yunnan, Southwest China. The DFI for residents with a dietary of roasted corn and roasted chili was 5.06, 9.60, and 14.38 mg for age groups 3-7, 8-15, and over 15 years, respectively. Over 90 % of DFI was from roasted foodstuffs. The DFI for residents of the same age group living on rice and roasted chili was 1.94, 3.50, and 4.95 mg, respectively, which were less than that for the former dietary type, and 65 % of DFI was from roasted chili. The main sources for their DFI are roasted foodstuffs. Both were higher than the dietaries with non-roasted foodstuffs and the recommended daily allowances (RDAs) for USA and China at different levels. The DAsI for all residents ranged from 25 to 135 μg, and at this level of DAsI, it would not influence human health. However, As pollution of roasted foodstuffs might have an important influence for the fluorosis. Residents are changing their staple food from roasted corn to rice, and especially, younger people are more focused on quality life. However, even if residents change their staple food, the habit of eating chili will not change, which also may cause them getting fluorosis. Developing economy, changing dietary types, and changing the habit of drying and keeping chili will help to reduce the fluorosis risk in coal-burning fluorosis area of Southwest China.

A comparative study of fluoride ingestion levels, serum thyroid hormone &amp; TSH level derangements, dental fluorosis status among school children from endemic and non-endemic fluorosis areas

The study was undertaken to determine serum/urinary fluoride status and comparison of free T4, free T3 and thyroid stimulating hormone levels of 8 to 15 years old children with and without dental fluorosis living in an endemic and non-endemic fluorosis area. A sample group of 60 male and female school children, with or without dental fluorosis, consuming fluoride-contaminated water in endemic fluoride area of Udaipur district, Rajasthan were selected through a school dental fluorosis survey. The sample of 10 children of same age and socio-economic status residing in non endemic areas who did not have dental fluorosis form controls. Fluoride determination in drinking water, urine and blood was done with Ion 85 Ion Analyzer Radiometer with Hall et al. method. The thyroid gland functional test was done by Immonu Chemiluminiscence Micropartical Assay with Bayer Centaur Autoanalyzer.The significantly altered FT3, FT4 and TSH hormones level in both group1A and 1B school children were noted. The serum and urine fluoride levels were found to be increased in both the groups. A significant relationship of water fluoride to urine and serum fluoride concentration was seen. The serum fluoride concentration also had significant relationship with thyroid hormone (FT3/FT4) and TSH concentrations. The testing of drinking water and body fluids for fluoride content, along with FT3, FT4, and TSH in children with dental fluorosis is desirable for recognizing underlying thyroid derangements and its impact on fluorosis.