May 24, 2013
Objective. To explore the influence of high fluoride exposure on reproductive hormones in male living in endemic fluorosis villages in China.
Methods. A cross sectional study was conducted in Tongxu county in Henan Province, China. Endemic fluorosis villages and control villages were selected by random sampling according to fluoride concentration in drinking water and the prevalence of endemic fluorosis. Local male residents aged from 18 to 50 years old who were born and grew up in the investigated villages were recruited as subjects by cluster sampling. Fasting blood and urine samples were collected. The serum level of GnRH was detected using ELISA. The serum level of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), and testosterone (T) were determined by chemiluminesence immunoassay (CLIA).
Results. The serum levels of FSH were 7.82 mlU/ml, 10.20 mIU/ml and 9.57 mIU/ml in male from defluoridation villages (DFPG), high fluoride villages (HFG) and control villages (CG) respectively. FSH level in male from DFPG was significant lower than that from HFG and CG (P<0.05). The serum levels of E2 were 33.67 ng/mL, 29.17 ng/mL and 28.99 ng/mL in DPFG, HFG and CG respectively. E2 level in male from DFPG was significant higher than that from HFG and CG (P<0.05). Serum levels of E2 in CG were associated with LH (r=0.343, P=0.000), age (r=0.195, P=0.015), and inversely associated with serum FSH (r=-0.237, P=0.003), whereas this correlation was not observed for serum E2 level in DFPG and HFG.
Conclusion. Long-term fluoride exposure in drinking water may influence the reproductive hormones in males living in endemic fluorosis villages.
Background: Although fluoride may cause neurotoxicity in animal models and acute fluoride poisoning causes neurotoxicity in adults, very little is known of its effects on children’s neurodevelopment.
Objective: We performed a systematic review and meta-analysis of published studies to investigate the effects of increased fluoride exposure and delayed neurobehavioral development.
Methods: We searched the MEDLINE, EMBASE, Water Resources Abstracts, and TOXNET databases through 2011 for eligible studies. We also searched the China National Knowledge Infrastructure (CNKI) database, as many studies on fluoride neurotoxicity have been published in Chinese journals only. In total, we identified 27 eligible epidemiological studies with high and reference exposures, endpoints of IQ scores or related cognitive function measures with means and variances for the two exposure groups. We estimated the standardized mean difference (SMD) between exposed and reference groups across all studies using random effects models. We conducted sensitivity analyses restricted to studies using the same outcome assessment and having drinking water fluoride as the only exposure. Cochran test for heterogeneity between studies, Begg’s funnel plot and Egger test to assess publication bias were performed. Metaregressions to explore sources of variation in mean differences among the studies were conducted.
Results: The standardized weighted mean difference in IQ score between exposed and reference populations was -0.45 (95% CI -0.56 to -0.35) using a random-effects model. Thus, children in high fluoride areas had significantly lower IQ scores than those who lived in low fluoride areas. Subgroup and sensitivity analyses also indicated inverse associations, although the substantial heterogeneity did not appear to decrease.
Conclusions: The results support the possibility of an adverse effect of high fluoride exposure on children’s neurodevelopment. Future research should include detailed individual-level information on prenatal exposure, neurobehavioral performance, and covariates for adjustment.
A link between oral health and cardiovascular disease has been proposed for more than a century. Recently, concern about possible links between periodontal disease (PD) and atherosclerotic vascular disease (ASVD) has intensified and is driving an active field of investigation into possible association and causality. The 2 disorders share several common risk factors, including cigarette smoking, age, and diabetes mellitus. Patients and providers are increasingly presented with claims that PD treatment strategies offer ASVD protection; these claims are often endorsed by professional and industrial stakeholders. The focus of this review is to assess whether available data support an independent association between ASVD and PD and whether PD treatment might modify ASVD risks or outcomes. It also presents mechanistic details of both PD and ASVD relevant to this topic. The correlation of PD with ASVD outcomes and surrogate markers is discussed, as well as the correlation of response to PD therapy with ASVD event rates. Methodological issues that complicate studies of this association are outlined, with an emphasis on the terms and metrics that would be applicable in future studies. Observational studies to date support an association between PD and ASVD independent of known confounders. They do not, however, support a causative relationship. Although periodontal interventions result in a reduction in systemic inflammation and endothelial dysfunction in short-term studies, there is no evidence that they prevent ASVD or modify its outcomes.
Objectives: To measure the fluoride (F) content of infant foods and drinks requiring reconstitution with liquids prior to consumption and to determine the impact of water F concentration on their F content, as consumed, by measuring F content before and after preparation. Methods: In total, 58 infant powdered formula milks, dry foods and concentrated drinks were prepared with deionized water (<0.02 ppm F) nonfluoridated (0.13 ppm F) and fluoridated (0.90 ppmF) water. The F concentrations of drink samples were measured directly using a fluoride-ion-selective electrode after addition of TISAB III, and food samples and formula milks measured indirectly by an acid diffusion method. Results: The overall range of F concentrations of all the nonreconstituted samples, in their prepreparation dry or concentrated forms, was from 0.06 to 2.99 lg/g with the highest F concentration for foods found in
the dry ‘savoury meals’ (a combination of vegetables and chicken or cheese or rice) group. However, when the samples were reconstituted with nonfluoridated water, the mean F concentrations of prepared ‘concentrated juices’, ‘pasta and rice’, ‘breakfast cereals’, ‘savoury meals’ and ‘powdered infant formula milks’ were 0.38, 0.26, 0.18, 0.16 and 0.15 lg/g, respectively. The corresponding mean F concentrations were 0.97, 1.21, 0.86, 0.74 and 0.91 lg/g, respectively, when the same samples were prepared with fluoridated water.
Conclusion: Although some nonreconstituted infant foods/drinks showed a high F concentration in their dry or concentrated forms, the concentration of F in prepared foods/drinks primarily reflected the F concentration of liquid used for their preparation. Some infant foods/drinks, when reconstituted with fluoridated water, may result in a F intake in infants above the suggested optimum range (0.05–0.07 mg F/kg body weight) and therefore may put infants at risk of developing dental fluorosis. Further research is necessary to determine the actual F intake of infants living in fluoridated and nonfluoridated communities using reconstituted infant foods and drinks.
Zohoori et al, Impact Of Water Fluoride Concentration On The Fluoride Content Of Infant Foods And Drinks Requiring Preparation With Liquids Before Feeding, Community Dentistry And Oral Epidemiology 01-Mar-2012
Objective: The objective of this study was to evaluate associations between patterns of infant formula feeding and dental fluorosis and caries in a representative sample of Australian children.
Methods: A population-based study gathered information on fluoride exposure in early childhood. Information on infant formula feeding and fluoridation status was used to group children: three groups in nonfluoridated areas (formula nonuser, user for <6 months, and user for 6+ months) and four groups in fluoridated areas (nonuser, user with nonfluoridated water, user with fluoridated water for <6 months, and user with fluoridated water for 6+ months). Children aged 8-13 years were examined for fluorosis using the Thylstrup and Fejerskov (TF) Index. Primary tooth caries experience recorded at age 8-9 years was extracted from clinical records. Fluorosis cases were defined as having TF 1+ on maxillary incisors. Fluorosis prevalence and primary caries experience were compared across formula user groups in multivariable regression models adjusting for other factors.
Results: Total sample was 588 children. Children in fluoridated areas had higher prevalence of very mild to mild fluorosis, but lower caries experience than those in nonfluoridated areas. Among children in nonfluoridated areas, formula users for 6+ months had significantly higher prevalence of fluorosis compared with nonusers. There was no significant difference in fluorosis prevalence among the formula users in fluoridated areas. Among children in fluoridated areas, formula users with nontap water had higher caries experience.
Conclusion: Infant formula use was associated with higher prevalence of fluorosis in nonfluoridated areas but not in fluoridated areas. Type of water used for reconstituting infant formula in fluoridated areas was associated with caries experience.
There has been public concern about children’s intellectual performance at high levels of fluoride exposure, but few studies provide data directly to the question of whether low fluoride exposure levels less than 3.0 mg/L in drinking water adversely associated with children’s intelligence. In this survey,weinvestigated the effects of low fluoride exposure on children’s intelligence and dental fluorosis. 331 children aged from 7 to 14 were randomly recruited from four sites in Hulunbuir City, China. Intelligence was assessed using Combined Raven Test-The Rural in China while dental fluorosis was diagnosed with Dean’s index. Mean value of fluoride in drinking water was 1.31±1.05 mg/L (range 0.24–2.84). Urine fluoride was inversely associated with IQ in the multiple linear regression model when children’s age as a covariate variable was taken into account (P < 0.0001). Each increase in 1 mg/L of urine fluoride associated with 0.59-point decrease in IQ (P = 0.0226). Meanwhile, there was a dose–response relationship between urine fluoride and dental fluorosis (P < 0.0001). In conclusion, our study suggested that low levels of fluoride exposure in drinking water had negative effects on children’s intelligence and dental health and confirmed the dose–response relationships between urine fluoride and IQ scores as well as dental fluorosis.
Ding et al, The Relationships Between Low Levels Of Urine Fluoride On Children’s Intelligence, Dental Fluorosis In Endemic Fluorosis Areas In Hulunbuir, Inner Mongolia, China, J. of Hazardous Materials 186 (2011) 1942–1946
The purpose of this research project was to assess community members understanding of water fluoridation, and whether benefit and risk education changes perspective toward water fluoridation. The study used quantitative method research design. A survey was conducted in which fifty nine participants were surveyed before and after educational material about water fluoridation. This research design focused on 1) what are the risks and benefits of water fluoridation, 2) how much docs the public understand about water fluoridation, 3) should there be more educational material about water fluoridation.
The results indicated that with education about water fluoridation there is a shift in attitude towards water fluoridation. Understanding of the risks and benefits increased from 10.2% to 84.7%, and indicated that with more education participants were less likely to drink fluoridated water.
Higher blood lead (BPb) levels have been reported in children living in communities that receive fluoride treated water. Here, we examined whether fluoride co-administered with lead increases BPb and lead concentrations in calcified tissues in Wistar rats exposed to this metal from the beginning of gestation.We exposed female rats and their offspring to control water (Control Group), 100 mg/L of fluoride (F Group), 30 mg/L of lead (Pb Group), or 100 mg/L of fluoride and 30 mg/L of lead (F + Pb Group) from 1 week prior to mating until offspring was 81 days old. Blood and calcified tissues (enamel, dentine, and bone) were harvested at day 81 for lead and fluoride analyses. Higher BPb concentrations were found in the F + Pb Group compared with the Pb Group (76.7±11.0 μg/dL vs. 22.6±8.5 μg/dL, respectively; p < 0.001). Two to threefold higher lead concentrations were found in the calcified tissues in the F + Pb Group compared with the Pb Group (all p < 0.001). Fluoride concentrations were similar in the F and in the F + Pb Groups. These findings show that fluoride consistently increases BPb and calcified tissues Pb concentrations in animals exposed to low levels of lead and suggest that a biological effect not yet recognized may underlie the epidemiological association between increased BPb lead levels in children living in water-fluoridated communities.
Background: Community water fluoridation (CWF) is currently experiencing social resistance in Canada. Petitions have been publicly registered, municipal plebiscites have occurred, and media attention is growing. There is now concern among policy leaders whether the practice is acceptable to Canadians. As a result, this study asks: What are public opinions on CWF?
Methods: Data were collected in April 2008 from 1,005 Canadian adults by means of a national telephone interview survey using random digit dialling and computer-assisted telephone interview technology. Descriptive and bivariate and multivariate logistic regression analyses were undertaken.
Results: Approximately 1 in 2 Canadian adults surveyed knew about CWF. Of these, 80% understood its intended use, approximately 60% believed that it was both safe and effective, and 62% supported the idea of having fluoride added to their local drinking water. Those with greater incomes [OR=1.4; p<0.001] and education [OR=1.6; p<0.001] were more likely to know about CWF. Those with greater incomes [OR=1.3; p<0.03] and those who visited the dentist more frequently [OR=1.8; p<0.002] were more likely to support CWF, and those with children [OR=0.5; p<0.02], those who accessed dental care using public insurance [OR=0.2; p<0.03], and those who avoided fluoride [OR=0.04; p<0.001] were less likely to support CWF.
Conclusion: It appears that Canadians still support CWF. In moving forward, policy leaders will need to attend to two distinct challenges: the influence of anti-fluoride sentiment, and the potential risks created by avoiding fluoride.
Copyright © 2013 COF-COF