Urinary Fluoride Concentration Research Articles

Estimation and correlation of the amount of fluoride output in urine after the application of fluoride gel and fluoride varnish in children with early childhood caries

Introduction: As all the topical fluorides contain a high concentration of fluorides and it is started at an early age when the swallowing reflexes are not well established, there is every chance the child may ingest a high amount of fluoride. As there are inconsistencies related to the usage of fluoride varnish in children, there is a need to study the toxicological aspects of fluoride varnish. Objectives: The objectives of this study were to estimate the amount of fluoride output through urine after the application of fluoride varnish and gel and to assess the safety levels of the same in early childhood caries (ECC) patients. Methodology: This study was conducted on twenty ECC-rehabilitated children of age group 4–6 years who were divided into two phases. In Phase I, the children were subjected to acidulated phosphate fluoride (APF) gel, and in Phase II, they were subjected to Fluor Protector varnish. In Phase I, the urine samples of each child were collected for the estimation of fluoride level which was considered as the baseline sample. After the application of APF gel, two urine samples were collected at 24 and 48 h for the estimation of fluoride levels. The same children were included in Phase II and were given placebo dentifrice for 7 days before commencing the procedure. The same experiment was repeated after the application of Fluor Protector varnish, and the collected urine samples were subjected for the estimation of fluoride level in laboratory with the use of fluoride ion-specific electrode and a miniature calomel reference electrode coupled to potentiometer. Values were recorded and the urinary fluoride concentration at different time intervals in each group was compared using the Friedman test followed by the Wilcoxon signed-rank test. Results: The mean urinary fluoride concentration in Group 1 at 24 h was 1.09 (standard deviation [SD] = 0.52) and at 48 h 0.74 (SD = 0.44). The mean urinary fluoride concentration in Group 2 at 24 h was 1.18 (SD = 0.65) and at 48 h 0.94 (SD = 0.59). There was a gradual increase in the 24th-h sample of both the groups, which also showed a decline of fluoride concentration at the 48th h. When both the groups were compared, Group 2 showed a marginal increase in fluoride concentration at different intervals of time, which was statistically nonsignificant. Conclusions: Fluor Protector varnish had an increased sustained release of fluoride ions when compared to APF gel, and there was a gradual decrease in the fluoride concentration which suggested that the fluoride concentration was approximating the baseline level (the safety level). The present study has provided a sound basis of recommendation for the safe and effective use of professionally applied fluoride products.

Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status

BackgroundFluoride exposure has the potential to disrupt thyroid functioning, though adequate iodine intake may mitigate this effect. This is the first population-based study to examine the impact of chronic low-level fluoride exposure on thyroid function, while considering iodine status. The objective of this study was to determine whether urinary iodine status modifies the effect of fluoride exposure on thyroid stimulating hormone (TSH) levels. MethodsThis cross-sectional study utilized weighted population-based data from Cycle 3 (2012−2013) of the Canadian Health Measures Survey (CHMS). Information was collected via a home interview and a visit to a mobile examination centre. The weighted sample represented 6,914,124 adults in Canada aged 18–79 who were not taking any thyroid-related medication. Urinary fluoride concentrations were measured in spot samples using an ion selective electrode and adjusted for specific gravity (UFSG). Serum TSH levels provided a measure of thyroid function. Multivariable regression analyses examined the relationship between UFSG and TSH, controlling for covariates. ResultsApproximately 17.8% of participants fell in the moderately-to-severely iodine deficient range. The mean (SD) age of the sample was 46.5 (15.6) years and the median UFSG concentration was 0.74 mg/L. Among iodine deficient adults, a 1 mg/L increase in UFSG was associated with a 0.35 mIU/L increase in TSH [95% CI: 0.06, 0.64; p = 0.01, one-tailed]. ConclusionsAdults living in Canada who have moderate-to-severe iodine deficiencies and higher levels of urinary fluoride may be at an increased risk for underactive thyroid gland activity.

Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada.

Background:Fluoride exposures have not been established for pregnant women who live in regions with and without community water fluoridation.Objective:Our aim was to measure urinary fluoride levels during pregnancy. We also assessed the contribution of drinking-water and tea consumption habits to maternal urinary fluoride (MUF) concentrations and evaluated the impact of various dilution correction standards, including adjustment for urinary creatinine and specific gravity (SG).Methods:We measured MUF concentrations in spot samples collected in each trimester of pregnancy from 1,566 pregnant women in the Maternal–Infant Research on Environmental Chemicals cohort. We calculated intraclass correlation coefficients (ICCs) to assess variability in MUF concentrations across pregnancy. We used regression analyses to estimate associations between MUF levels, tea consumption, and water fluoride concentrations as measured by water treatment plants.Results:Creatinine-adjusted MUF values (; milligrams per liter) were almost two times higher for pregnant women living in fluoridated regions () compared with nonfluoridated regions (; ). MUF values tended to increase over the course of pregnancy using both unadjusted values and adjusted values. Reproducibility of the unadjusted and adjusted MUF values was modest (). The municipal water fluoride level was positively associated with creatinine-adjusted MUF (, 95% CI: 0.46, 0.57), accounting for 24% of the variance after controlling for covariates. Higher MUF concentrations correlated with numbers of cups of black ( but not green tea (). Urinary creatinine and SG correction methods were highly correlated () and were interchangeable in models examining predictors of MUF.Conclusion:Community water fluoridation is a major source of fluoride exposure for pregnant women living in Canada. Urinary dilution correction with creatinine and SG were shown to be interchangeable for our sample of pregnant women. https://doi.org/10.1289/EHP3546

Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada

Background: Fluoride exposure in pregnant women who live in regions with and without community water fluoridation has not been established.Objective: To measure urinary fluoride levels during pregnancy using urinary creatinine and specific gravity (SG) as dilution correction standards.Methods: We measured maternal urinary fluoride (MUF) concentrations in spot samples collected in each trimester of pregnancy from 1566 pregnant women living in ten Canadian cities and enrolled in the “Maternal-Infant Research on Environmental Chemicals” cohort. We calculated intraclass correlation coefficients (ICCs) to assess variability in MUF concentrations across pregnancy. We estimated associations between MUF levels, tea consumption, and water fluoride concentrations as measured by water treatment plants using regression analyses.Results: Creatinine-adjusted MUF values (M ± SD; mg/L) were almost two-times higher for pregnant women living in fluoridated regions (0.86 ± 0.34) compared with non-fluoridated regions (0.46 ± 0.50; p<0.001). MUF values had modest reproducibility (ICC = 0.41) and tended to increase over the course of pregnancy. Creatinine-adjusted MUF was positively associated with municipal water fluoride level (B=0.52, 95% CI: 0.46, 0.57), accounting for 24% of the variance after controlling for covariates. Higher MUF concentration correlated with number of cups of black (r = 0.31 to 0.32, p<0.005), but not green tea (r = 0.04 to 0.06). Urinary creatinine and SG correction methods were highly correlated (r = 0.91) and interchangeable in models examining predictors of MUF.Conclusion: Community water fluoridation is a major source of fluoride exposure for pregnant women living in Canada. Urinary dilution correction with creatinine and SG are valid and interchangeable methods for pregnant women.

Fluoride Exposure and Thyroid Function among Iodine Deficient Adults in Canada

Background: Fluoride exposure has the potential to disrupt thyroid functioning, though adequate iodine intake may mitigate this effect. This study is the first population-based study to examine the impact of chronic low-level fluoride exposure on thyroid function, while considering iodine status.Objective: This study used weighted population-based data from Cycle 3 (2012-2013) of the Canadian Health Measures Survey (CMHS), a cross-sectional survey designed to collect health and wellness data and biological specimens on Canadians.Methods: The weighted sample represented 7,543,966 adults aged 18-79 who were not taking any thyroid-related medication. Urinary fluoride concentrations were measured in spot samples using an ion selective electrode and adjusted for specific gravity (UFSG) and creatinine (UFCR). Serum TSH levels provided a measure of thyroid function. Multivariable regression analyses examined the relationship between adjusted levels of urinary fluoride and TSH, controlling for covariates. We tested whether TSH levels were more strongly related to urinary fluoride levels in adults who were moderately-to-severely iodine deficient than in adults who were iodine sufficient, according to World Health Organization reference standardsResults: The mean (SD) age of the sample was 46.6 (15.8) years and approximately 17.8% fell in the moderately-to-severely iodine deficient range. Median UFSG and UFCR concentrations were 0.74 mg/L and 0.46 mg/g, respectively. Among iodine deficient adults, a 1 mg/L increase in UFSG was associated with a 0.36 mIU/L increase in TSH [95% CI: -0.03, 0.75; p = 0.03], and a 1 mg/g increase in UFCR was associated with a 0.61 mIU/L increase in TSH [95% CI: 0.22, 0.99; p < 0.01].Conclusion: Adults living in Canada who have moderate-to-severe iodine deficiencies and higher levels of urinary fluoride may be at an increased risk for underactive thyroid gland activity.

Fluoride Exposure during Fetal Development and Childhood IQ: The MIREC Study

Background: The potential neurotoxicity of early life exposure to fluoride, which has sparked controversy about community water fluoridation, is poorly understood.Objective: To test the association between fluoride exposure during fetal development and childhood IQ in a Canadian sample of 510 mother-child pairs enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) birth cohort; 38% received “optimal” levels of community fluoridated water.Methods: We measured three maternal urinary fluoride (MUF) concentrations during pregnancy, averaged them and adjusted them for specific gravity. Children’s cognitive abilities were assessed using the Wechsler Primary and Preschool Scale of Intelligence-III at 3-4 years of age. We used multiple linear regression analyses to examine covariate-adjusted associations between MUF and IQ, and to test for interaction with child’s sex. We retained the following covariates based on theoretical and statistical relevance: city, quality of child’s home environment, maternal education, and race.Results: Average MUF concentrations for all women were 0.51 mg/L (+/-0.36; range=0.06-2.44); MUF concentrations were lower in women supplied with non-fluoridated water (0.40 mg/L +/-0.27) than women supplied with fluoridated water (0.69 mg/L +/-0.41). MUF levels were inversely associated with Full Scale IQ in males (B=-4.51, 95% CI: -8.39, -0.63, p=0.02), but not in females (B=2.43, p=0.33). Among males, higher MUF levels were associated with a significantly larger reduction in Performance IQ (B=-4.63, p=0.04) than Verbal IQ (B=-2.85, p=0.14). Sensitivity analyses using MUF adjusted for creatinine and controlling for other known neurotoxins (i.e., lead, mercury and arsenic) did not substantially change the results.Conclusion: An increase of 1mg/L of MUF during prenatal development was associated with a decrease of Full Scale IQ by 4.5 points in young boys.

Influence of Fluoridated Groundwater and 1,100 Ppm Fluoride Dentifrice on Biomarkers of Exposure to Fluoride.

This research aimed to determine the influence of fluoridated groundwater and 1,100 ppm fluoride dentifrice on biomarkers of exposure to fluoride in preschoolers. A cross-sectional study was performed on thirty preschoolers recruited from naturally fluoridated and non-fluoridated areas (n=15). Total Daily Fluoride Intake (TDFI) from diet and dentifrice, and Daily Urinary Fluoride Excretion (DUFE) was measured over 24 h. Nails samples were collected twice during 30 days. Fluoride analyses were performed using a fluoride-ion-specific electrode. Data were evaluated using the Student and paired t-test, Pearson correlation analysis, multiple linear regression analysis (α≤0.05). Fluoridated groundwater and dentifrice were the dominant sources (r2 > 0.83) of TDFI in children from a naturally fluoridated and a non-fluoridated area, respectively. A positive correlation between TDFI and DUFE (r=0.50), and between [F] in fingernails and toenails (r=0.60) were found in children from a naturally fluoridated area. The [F] in nails of finger and toe were not correlated to TDFI. The consumption of fluoridated groundwater influenced the fluoride concentration in urine. In addition, the use of 1,100 ppm fluoride dentifrice did not influence the fluoride concentration in urine and fingernails.

Dental fluorosis and a polymorphism in the COL1A2 gene in Mexican children

ObjectiveTo determine the allelic and genotypic frequencies of rs 412777 polymorphism in the Collagen type I alpha 2 chain (COL1A2) gene and the association with the severity of dental fluorosis in children between 6 and 12 years old in the State of San Luis Potosi, Mexico. DesignA cross-sectional study was designed; participants were 230 children from two rural communities of San Luis Potosí. Fluoride in drinking water and urine samples was quantified using a potentiometric method with a selective ion electrode. Dental fluorosis was diagnosed using the Thylstrup-Fejerskov index while the identification of the polymorphism was made by allelic discrimination, using allele-specific probes by real-time Polymerase chain reaction (PCR). Statistical analysis was carried out with Student’s t-test and Chi-square and Odds Ratio (OR). A confidence interval of 95% and a value of p < 0.05 were considered. ResultsThe concentration of fluoride in drinking water was 2.36 ± 0.02 mg/L in Ojo Caliente and 4.56 ± 0.07 mg/L in La Reforma, the concentration of fluoride in urine was 2.05 ± 0.62 mg/L and 2.99 ± 0.99 mg/L respectively. The prevalence of dental fluorosis was 100% and the frequency of alleles was 67% wild-type and 33% mutant allelic, alleles were found in Hardy-Weinberg equilibrium (X2 = 0.33, p = 0.89). The association between the degree of dental fluorosis and the evaluated polymorphism was statistically significant (OR = 7.10, 95% CI = 3.96–12.70, p < 0.05). ConclusionsAn association of rs 412777 polymorphism in the COL1A2 gene with dental fluorosis was found. Therefore, genetic variants represent a relevant risk factor to develop dental fluorosis, as it was proven in this study conducted in Mexican children.

Effects of drinking water defluoridation on mineral and haemato-biochemical status in fluorotic buffaloes

Effects of drinking water defluoridation with alum (1.5 g/liter) and lime (200 mg/liter) were assessed on mineral, biochemical status and health of fluorotic buffaloes in fluoride endemic South-West Punjab, India. The fluorotic buffaloes (n=16; plasma fluoride: 0.44-0.97 ppm, urinary fluoride: 18.90-39.30 ppm) were randomly divided into two equal groups (Treatment: TRT; Control: CRL). The TRT was offered defluoridated water while CRL was offered non-treated water, adlib for drinking for 135 days. Other feeding and management practices were similar for both the groups. Plasma and urine samples were collected on day 0, 45, 90 and 135 and health of the buffaloes were monitored. The drinking water defluoridation resulted in significant (p Lass Than 0.01) decline in water fluoride contents from 10.64±0.09 to 1.24±0.03 ppm. There was significant (p Lass Than 0.01) decline in plasma and urinary fluoride concentrations and significant (p Lass Than 0.01) increase in plasma calcium, copper and zinc concentrations in the TRT group. There was no effect of water defluoridation on plasma inorganic phosphorus, magnesium, Hb and TEC, however PCV increased and alkaline phosphatase activity decreased significantly (p Lass Than 0.01) in TRT group. Two buffaloes from CRL showed stiffness on day 64 and 81, respectively, while all the buffaloes from the TRT group remained healthy during the study period. It is concluded that defluoridation of drinking water with alum and lime was effective in reducing water fluoride contents to permissible levels and it improved mineral, biochemical status and health of fluorotic buffaloes.

Assessment of the anthropogenic fluoride export in Addis Ababa urban environment (Ethiopia)

Protection of natural waters against excess of fluoride is a priority in the Middle Ethiopian Rift where high concentrations of fluoride occur in groundwater, lakes and hot springs. In recent years, a growing attention has been paid to geogenic sources of fluoride, while anthropogenic sources have been completely disregarded. Ethiopian people are subject to high levels of fluoride intake via food or drinks, resulting in elevated concentrations of fluoride in urine and subsequently in the human slurry waste. In Addis Ababa, 3 millions of people live without a suitable sewage waste collection/treatment facility and the superficial water system of the city often receives untreated domestic and municipal effluents. In this study, the impact of fluoride-rich human slurry on surface waters quality in Addis Ababa was evaluated. Physical-chemical and bacteriological assessments of rivers and shallow groundwater samples were performed. Several samples displayed critical levels of fluoride and faecal coliforms bacteria in the north-western part of the city. When uncontaminated fresh water flowing from the highland travels through the city, it experiences a rapid deterioration because of the interaction with untreated sewage outlets. This was clearly inferred by the combined analysis of water stable isotopes, fluoride and faecal coliforms bacteria. The methodological results of this study could be used to distinguish anthropogenic from geogenic sources of fluoride in urban environments of developing countries, which are often affected by multiple sources of fluoride.

Assessment of fluoride in groundwater and urine, and prevalence of fluorosis among school children in Haryana, India

Considering the health effects of fluoride, the present study was undertaken to assess the concentration of fluoride in groundwater, and urine of school children in Bass region of Haryana state. Fluoride in groundwater was observed to vary from 0.5 to 2.4 mg/l with an average concentration of 0.46 mg/l. On the other hand, F− in urine ranged from below the detection limit to 1.8 mg/l among girls and 0.17–1.2 mg/l among the boys. Higher average concentration of fluoride in urine (0.65 mg/l for boys and 0.34 mg/l for girls) may be ascribed to exposure to bioavailable fluoride through food, milk, tea, toothpaste, etc., in addition to intake through groundwater. Relatively more intake of water and food by the boys might be the reason for more cases of severe dental fluorosis (44%) among boys compared to girls (29% cases of moderate to severe dental fluorosis). The groundwater quality for drinking was compromised with respect to dissolved solids, hardness, magnesium ions, and dissolved iron. Hydro-geochemical investigation revealed that rock–water interaction, in terms of direct cation exchange, dominantly regulates groundwater chemistry, and groundwater is of Ca-Na-HCO3 type.

Fluoride-associated ultrastructural changes and apoptosis in human renal tubule: a pilot study.

The susceptibility of the kidneys to fluoride toxicity can largely be attributed to its anatomy and function. As the filtrate moves along the complex tubular structure of each nephron, it is concentrated in the proximal and distal tubules and collecting duct. It has been frequently observed that the children suffering from renal impairments also have some symptoms of dental and skeletal fluorosis. The findings suggest that fluoride somehow interferes with renal anatomy and physiology, which may lead to renal pathogenesis. The aim of this study was to evaluate the fluoride-associated nephrotoxicity. A total of 156 patients with childhood nephrotic syndrome were screened and it was observed that 32 of them had significantly high levels ( p ≤ 0.05) of fluoride in urine (4.01 ± 1.83 ppm) and serum (0.1 ± 0.013 ppm). On the basis of urinary fluoride concentration, patients were divided into two groups, namely group 1 (G-1) ( n = 32) containing normal urine fluoride (0.61 ± 0.17 ppm) and group 2 (G-2) ( n = 32) having high urine fluoride concentration (4.01 ± 1.83 ppm). Age-matched healthy subjects ( n = 33) having normal levels of urinary fluoride (0.56 ± 0.15 ppm) were included in the study as control (group 0 (G-0)). Kidney biopsies were taken from G-1 and G-2 only, who were subjected to ultrastructural (transmission electron microscopy) and apoptotic (terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling) analysis. Various subcellular ultrastructural changes including nuclear disintegration, chromosome condensation, cytoplasmic ground substance lysis, and endoplasmic reticulum blebbing were observed. Increased levels of apoptosis were observed in high fluoride group (G-2) compared to normal fluoride group (G-1). Various degrees of fluoride-associated damages to the architecture of tubular epithelia, such as cell swelling and lysis, cytoplasmic vacuolation, nuclear condensation, apoptosis, and necrosis, were observed.

Evaluation of a fluorosis prevention educational program: A randomized field trial.

BackgroundA 2-group randomized field trial was conducted to evaluate the impact of a fluorosis educational preventive program in mother´s knowledge and practices, and on the urine fluoride concentration of their preschool children.Material and MethodsA group of 139 mother-child pairs participated in the study. Randomly, children were assigned to an intervention group, their mothers were participants of an educational program, or a control group (CG); including 69 and 70 child-mother pairs, respectively, the follow-up period was six months. Mother´s knowledge and practices were evaluated and children´s first urine sample was used to measure fluoride concentration at the beginning of the study and at the end of the follow-up period.ResultsThe mean age of the children was 4.18 (sd 0.62) years-old at baseline. Mothers in the IG improved their knowledge and practices associated with fluorosis risk factors. Adequate knowledge about the amount of toothpaste to use for brushing improved in the IG (p=0.006). In 82.1% of the children in the IG showed decrease in urine fluoride concentration was observed (p< 0.001), no significant differences were shown in the CG.ConclusionsMothers participating in an education program improved their knowledge and practices, reducing the risk of dental fluorosis in their children who showed a decreased on their urine F concentration. Key words:Knowledge, practices, urinary fluoride, water fluoride, preschool children, mothers.

Fluoride concentration in urine after silver diamine fluoride application on tooth enamel

Silver Diammine Fluoride (SDF), which contains fluoride, is known to inhibit tooth enamel demineralization and increase fluoride concentrations in saliva and urine. The aim of this study is to analyze the fluoride concentration in urine after application of SDF on tooth enamel. Urine from four subjects was collected prior to, 30 minutes after, and two and three hours after the application of SDF, and an ion-selective electrode was used to measure the fluoride concentrations. There was no significant difference between time 1 and time 2, time 1 and time 3, time 1 and time 4, time 2 and 3 (p > 0.05), and there was a significant difference between time 2 and time 4 as well as time 3 and time 4 (p < 0.05). There was a decrease in the concentration of fluoride ions in urine from the baseline to 30 minutes after application, and an increase from baseline to two and three hours after the application of SDF.

Do Environmental Fluoride Exposure and ESRα Genetic Variation Modulate Methylation Modification on Bone Changes in Chinese Farmers?

Although increasing evidence suggests that estrogen receptor α (ESRα) genetic variation could modify bone damage caused by environmental fluoride exposure, little is known about epigenetic mechanisms in relation to bone changes. A case-control study was conducted among farmers aged 18-55 years in Henan Province, China. X-ray was used to detect bone changes. Methylation status was determined by methylation-specific PCR. Genotypes were identified by Taqman probe and real-time PCR. In this study, we found that methylation status in the promoter region of the ESRα gene was lower in bone change cases than that in controls, which was only observed in male farmers after stratification by gender. Furthermore, methylation level was negatively associated with the urinary fluoride concentration in male farmers. No significant association was found between the distribution of ESRα rs2941740 genotypes and the risk of bone changes. Multivariate logistic regression analysis showed that after adjusting for age and gender, increased serum calcium and methylation status were protective factors for bone changes. No interaction effect was observed between fluoride exposure and ESRα rs2941740 polymorphism on bone changes. In conclusion, the current work suggests that bone changes are associated with methylation status, which might be modulated by fluoride exposure in male farmers. Methylation status and bone changes were not modified by ESRα gene rs2941740 polymorphism in the promoter region.

Biomarkers of chronic fluoride exposure in groundwater in a highly exposed population

This study examined the relation between fluoride (F−) concentrations in fingernail clippings and urine and the prevalence and severity of enamel fluorosis (EF) among Ethiopian Rift Valley populations exposed to high levels of F− in drinking water. The utility of fingernail clippings as a biomarker for F− exposure and EF was also assessed for the first time in a high-F− region. The study recorded the EF status of 386 individuals (10 to 50years old), who consume naturally contaminated groundwater with widely varying F− concentration (0.6–15mg/L). The mean F− concentrations among residents of communities with primary reliance on groundwater were 5.1mg/kg (range: 0.5–34mg/kg) in fingernails and 8.9mg/L (range: 0.44–34mg/L) in urine. We show strong positive correlations between F− in drinking water and 12-hour urinary excretion (r=0.74, p<0.001, n=287), fingernail F− content (r=0.6, p<0.001, n=258), and mean individual measures of EF severity as measured using the Thylstrup and Fejerskov (TF) Index (r=0.42, p<0.001, n=316). The data indicate that both fingernail and urine measures are good biomarkers for F− exposure and EF outcomes, the latter being slightly more sensitive. Cases of moderate/severe EF were significantly more common among younger subjects (10 to 15years old) than older subjects (mostly >25years old) (p<0.001), consistent with their greater exposure to F− during early childhood, which is the only period of life the enamel is at risk of fluorosis. In this younger population, EF may be useful as a biomarker for identifying individuals with other potential health effects that depend on a specific age window of susceptibility. The finding of exceptionally high F− concentrations in water, fingernail clippings and urine in this region should motivate further investigations of other potential health consequences such as bone disease and abnormalities in the function of the neurological and endocrine systems.

Groundwater fluoride contamination and its possible health implications in Indi taluk of Vijayapura District (Karnataka State), India.

Groundwater fluoride concentration and fluoride-related health problems were studied in twenty-two villages of Indi taluk of Vijayapura district, Karnataka, India. Present study (2015) was also used to compare groundwater fluoride concentration in same 22 villages with previous government report (2000). Groundwater fluoride concentrations of 62 bore wells of 22 villages were analyzed by using an ion-sensitive electrode. A total of 660 adults and 600 children were screened for fluorosis symptoms and signs. Sixty clinically suspected fluorosis patients' urine samples were further analyzed for fluoride. The mean value (1.22±0.75mg/L) of fluoride concentration of 62 bore wells and 54.83% bore wells with ≥1.0mg/L of fluoride concentrations in Indi taluk indicates higher than the permissible limit of drinking water fluoride concentration recommended for India. Clinical symptoms like arthritis, joint pains, gastrointestinal discomfort and lower limb deformities with high urinary fluoride concentrations in some subjects suggest fluorosis. Results also showed an increase in groundwater fluoride concentration of the same 22 villages between previous and present study. Preliminary arthritis symptom of the villagers could be due to drinking fluoride-contaminated water. Increase in fluoride concentration with time to the bore wells definitely indicates future danger.

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

There has been growing public concern about intellectual performance of children at high levels of fluoride exposure. A cross-sectional study was conducted in Simlapal Block of Bankura District, West Bengal, to find out the relationship between fluoride (F) exposure as exposure dose (ED) with dental fluorosis (DF), urinary fluoride concentration (UF), intelligence quotient (IQ) and body mass index (BMI). Fifty groundwater samples were collected from the target area. One hundred forty-nine children belonging to age group 6 to 18years were considered for this study. Experimental results reveal that mean F(-) concentration of that area is 2.11mg/L (±SD 1.64). On the basis of F concentration in groundwater and water consumption pattern, ED was calculated to explore the impact of F(-) on DF, UF, IQ, and BMI. Paired t test results suggest that exposure rate of F does not show any significant differences (<0.05) among the children of 12 different places. As a result of F exposure, DF cases are mostly found in the order of moderate > severe > mild > very mild > questionable > normal conditions. The highest UF concentration was recorded as 17mg/L, but the status of DF in the affected children was recorded as moderate. The results also reveal that ED has a positive correlation with DF (r = 0.299, P < 0.01) and UF (r = 0.513, P < 0.01) and a negative correlation with IQ (r = -0.343, P < 0.01) along with BMI (r = 0.083, non-significant). Therefore, from this study, it may be concluded that UF and DF concentration could act as a biomarker of fluoride toxicity.

Dental fluorosis, fluoride in urine, and nutritional status in adolescent students living in the rural areas of Guanajuato, Mexico.

Objective:The aim of this study was to assess urine fluoride concentration, nutritional status, and dental fluorosis in adolescent students living in the rural areas of Guanajuato, Mexico.Materials and Methods:A cross-sectional study was conducted including participants aged 11–20 years. The presence and severity of dental fluorosis was registered according to the Thylstrup and Fejerskov index (TFI) criteria. Anthropometric measures were also recorded. Urine sample of the first morning spot was recollected to assess urine fluoride concentration by using the potentiometric method with an ion-selective electrode. Water samples were also recollected and analyzed. Bivariate tests were performed to compare urine fluoride concentration according to different variables such as sex, body mass index, and TFI. Nonparametric tests were used. A logistic regression model was performed (SPSS® 21.0).Results:This study included 307 participants with a mean age of 15.6 ± 1.6; 62.5% of the participants showed normal weight. A total of 91.9% of the participants had dental fluorosis, and 61.6% had TFI > 4. Mean fluoride content in urine ranged between 0.5 and 6.65 mg/L, with a mean of 1.27 ± 1.2 mg/L. Underweight children showed greater urine fluoride concentration. The increment of urine fluoride was a related (OR = 1.40) to having severe dental fluorosis.Conclusions:Most of the studied population had moderate or severe dental fluorosis. Urine fluoride concentration was related to fluorosis severity and nutritional status. Underweight children showed greater urine fluoride concentration as well as severe dental fluorosis.

Prevalence of Brick Tea-Type Fluorosis in the Tibet Autonomous Region.

BackgroundThe prevalence of brick tea-type fluorosis is high in Tibet because of the habit of drinking brick tea in this region. Brick tea-type fluorosis has become an urgent public health problem in China.MethodsA cross-sectional survey was conducted to investigate prevalence of brick tea-type fluorosis in all districts of Tibet using a stratified cluster sampling method. Dental fluorosis in children aged 8–12 years and clinical skeletal fluorosis in adults were diagnosed according to the national criteria. A total of 423 children and 1320 adults participated in the study. Samples of drinking water, brick tea, brick tea infusion (or buttered tea), and urine were collected and measured for fluoride concentrations by the fluoride ion selective electrode method.ResultsThe fluoride level in all but one of the brick tea samples was above the national standard. The average daily fluoride intake from drinking brick tea in all seven districts in Tibet was much higher than the national standard. The prevalence of dental fluorosis was 33.57%, and the prevalence of clinical skeletal fluorosis was 46.06%. The average daily fluoride intake from drinking brick tea (r = 0.292, P < 0.05), urine fluoride concentrations in children (r = 0.134, P < 0.05), urine fluoride concentrations in adults (r = 0.162, P < 0.05), and altitude (r = 0.276, P < 0.05) were positively correlated with the prevalence of brick tea-type fluorosis. Herdsmen had the highest fluoride exposure and the most severe skeletal fluorosis.ConclusionsBrick tea-type fluorosis in Tibet is more serious than in other parts of China. The altitude and occupational factors are important risk factors for brick tea-type fluorosis.