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BackgroundThere is a lack of research on the relationship between water fluoridation and pregnancy outcomes.ObjectivesWe assessed whether hypothetical interventions to reduce fluoride levels would improve birth outcomes in California.MethodsWe linked California birth records from 2000 to 2018 to annual average fluoride levels by community water system. Fluoride levels were collected from consumer confidence reports using publicly available data and public record requests. We estimated the effects of a hypothetical intervention reducing water fluoride levels to 0.7 ppm (the current level recommended by the US Department of Health and Human Services) and 0.5 ppm (below the current recommendation) on birth weight, birth-weight-for-gestational age z-scores, gestational age, preterm birth, small-for-gestational age, large-for-gestational age, and macrosomia using linear regression with natural cubic splines and G-computation. Inference was calculated using a clustered bootstrap with Wald-type confidence intervals. We evaluated race/ethnicity, health insurance type, fetal sex, and arsenic levels as potential effect modifiers.ResultsFluoride levels ranged from 0 to 2.5 ppm, with a median of 0.51 ppm. There was a small negative association on birth weight with the hypothetical intervention to reduce fluoride levels to 0.7 ppm [-2.2g; 95% confidence interval (CI): -4.4, 0.0] and to 0.5 ppm (-5.8g; 95% CI: -10.0, -1.6). There were small negative associations with birth-weight-for-gestational-age z-scores for both hypothetical interventions (0.7 ppm: -0.004; 95% CI: -0.007, 0.000 and 0.5 ppm: -0.006; 95% CI: -0.013, 0.000). We also observed small negative associations for risk of large-for-gestational age for both the hypothetical interventions to 0.7 ppm [risk difference (RD)=-0.001; 95% CI: -0.002, 0.000 and 0.5 ppm (-0.001; 95% CI: -0.003, 0.000)]. We did not observe any associations with preterm birth or with being small for gestational age for either hypothetical intervention. We did not observe any associations with risk of preterm birth or small-for-gestational age for either hypothetical intervention.ConclusionWe estimated that a reduction in water fluoride levels would modestly decrease birth weight and birth-weight-for-gestational-age z-scores in California. https://doi.org/10.1289/EHP13732.

BackgroundFluoride exposure during pregnancy has been associated with various effects on offspring, including changes in behavior and IQ. To provide clues to possible mechanisms by which fluoride may affect human fetal development, we completed proteomic analyses of cord blood serum collected from second-trimester pregnant women residing in northern California, USA.ObjectiveTo identify changes in cord blood proteins associated with maternal serum fluoride concentration in pregnant women.MethodsThe proteomes of 19 archived second-trimester cord blood samples from women living in northern California, USA, and having varied serum fluoride concentrations, were analyzed by quantitative mass spectrometry. The 327 proteins that were quantified were characterized by their abundance relative to maternal serum fluoride concentration, and subjected to pathway analyses using PANTHER and Ingenuity Pathway Analysis processes.ResultsPathway analyses showed significant increases in process related to reactive oxygen species and cellular oxidant detoxification, associated with increasing maternal serum fluoride concentrations. Pathways showing significant decreases included complement cascade, suggesting alterations in alterations in process associated with inflammation.ConclusionMaternal fluoride exposure, as measured by serum fluoride concentrations in a small, but representative sample of women from northern California, USA, showed significant changes in the second trimester cord blood proteome relative to maternal serum fluoride concentration.

IntroductionSome caregivers are hesitant about topical fluoride for their children despite evidence that fluoride prevents caries and is safe. Recent work described a five domain model of caregivers' topical fluoride hesitancy. We developed the Fluoride Hesitancy Identification Tool (FHIT) item pool based on the model. This study sought to evaluate the FHIT's psychometric properties in an effort to generate a short, simple to score, reliable, and valid tool that measures caregivers' topical fluoride hesitancy.MethodsIn 2021 and 2022, we conducted an observational, cross-sectional study of caregivers, collecting data from two independent caregiver samples (n1 = 523; n2 = 612). The FHIT item pool included 33 items. We used confirmatory factor analyses (CFA) to examine whether the FHIT items measured five separate domains as hypothesized and to reduce the number of items. We then fit item response theory (IRT) models and computed Cronbach's alpha for each domain. Last, we examined the construct validity of the FHIT and evaluated scoring approaches.ResultsAfter dropping 8 items, CFA supported a five factor model of topical fluoride hesitancy, with no cross-loadings (RMSEA = 0.079; SRMR = 0.057; CFI = 0.98; TLI = 0.98). We further reduced the items to four per domain (20 items total). Marginal alphas showed that the item sets provided reliability of ≥0.90 at hesitancy levels at and above average. The domains correlated more strongly with each other and topical fluoride refusal than with other questions on the survey.DiscussionOur results support the FHIT's ability to reliably and validly measure five domains of topical fluoride hesitancy using the average score of the four items in each domain.

The prevalence of osteoarthritis (OA) in Tibetans is higher than that in Han, while Tibetans have a habit of drinking brick tea with high fluoride. A cross-sectional study was conducted to explore the association between fluoride exposure in drinking brick tea and OA. All subjects were divided into four groups by the quartiles (Q) of tea fluoride (TF) and urine fluoride (UF). ROC was plotted and OR were obtained using logistic regression model. The prevalence of OA in the Q3 and Q4 group of TF were 2.2 and 2.7 times higher than in the Q1 group, and the prevalence of OA in the Q2, Q3 and Q4 group of UF were 3.2, 3.5, and 4.1 times higher than in the Q1 group. ROC analysis showed the cutoff values were 4.523 mg/day (TF) and 1.666 mg/L (UF). In conclusion, excessive fluoride in drinking brick tea could be a risk factor for developing OA. [ABSTRACT FROM AUTHOR]

Low‐basicity fluorine‐containing mold flux, which forms a porous slag film with NaF pores, is expected to solve the contradiction between heat transfer and lubrication in the continuous casting of peritectic steel. Herein, the kinetic mechanism and the influence of NaF gas formation based on the different fluorine raw materials (NaF, CaF2, and Na3AlF6) at 0.9 basicity and 6 wt% fluorine are investigated by the combination of experiments and calculations. The results show that CaF2 is the first to generate NaF gas at 1189 K, followed by Na3AlF6 (1238 K) and NaF (1328 K). NaF raw material produces the most NaF gas with the lowest activation energy in the three raw materials, due to high Na ion kinetic energy, the simple degree of polymerization, and Na‐F1 bonds. Correspondingly, NaF bubbles in the molten slag are the largest based on their aggregation. Na3AlF6 and CaF2 raw materials rank second and third, with F atoms primarily bonded as Al‐Fx and Ca‐Fx and the higher proportion of QSi−O−Al2$Q_{\text{Si} - \text{O} - \text{Al}}^{2}$ and QSi−O−Si4$Q_{\text{Si} - \text{O} - \text{Si}}^{4}$ structure. Notably, at 0.9 basicity and 6 wt% fluorine, Na3AlF6 as raw material generates a suitable amount of gas, making diffuse and fine NaF bubbles in the molten slag. [ABSTRACT FROM AUTHOR]

In this study, hydrothermally synthesized magnesium oxide demonstrated effective fluoride adsorption, with a maximum capacity of 199.67 mg g−1 and equilibrium was achieved within 60 min. The morphology of magnesium oxide and the adsorption mechanism were investigated by SEM, FTIR, BET and XPS. The adsorption process conformed to the Freundlich isotherm and pseudo-second-order kinetic models. The ΔH and ΔS of fluoride adsorption by this material were 44.58 kJ mol−1 and 163.31 J mol−1 K−1, respectively, indicating surface heterogeneity and specific adsorption kinetics. Optimal fluoride removal was observed in the pH range of 4–11, with the highest adsorption capacity achieved at pH 5.0. Co-existing ions significantly influenced the adsorption performance (Cl− < NO3− < SO42− < HCO3− < PO43−). These findings underscore the potential application of magnesium oxide in water treatment and suggest avenues for further optimization of synthesis and operational parameters. [ABSTRACT FROM AUTHOR]

Sets of electrophilic probes are generally prepared using a narrow toolkit of robust reactions, which tends to limit both their structural and functional diversity. A unified synthesis of skeletally-diverse sulfonyl fluorides was developed that relied upon photoredox-catalysed dehydrogenative couplings between hetaryl sulfonyl fluorides and hydrogen donor building blocks. A set of 32 diverse probes was prepared, and then screened against Trypanosoma brucei. Four of the probes were found to have sub-micromolar anti-trypanosomal activity. A chemical proteomic approach, harnessing an alkynylated analogue and broad-spectrum fluorophosphonate tools, provided insights into the observed anti-trypanosomal activity, which likely stems from covalent modification of multiple protein targets. It is envisaged that the unified diversity-oriented approach may enable the discovery of electrophilic probes that have value in the elucidation of biological and biomedical mechanisms. Electrophilic bioactive compounds are useful chemical tools for identifying and modulating protein targets through reaction with nucleophilic amino acid side chain residues. Here, the authors report a modular synthesis of electrophilic sulfonyl fluoride probes, and evaluate their anti-trypanosomal activity using a chemoproteomics approach [ABSTRACT FROM AUTHOR]

Purpose: No information on the fluoride concentration in orthodontic tooth pastes sold in Iraq is presently available. The goal of this investigation was to establish and compare the fluoride content of five orthodontic tooth pastes offered in Iraqi drugstores, as well as testing the null hypothesis that entails the consistency of fluoride concentration measured over time may not deviate from the labelled amounts. Methods: Laboratory investigation on five brands of orthodontic tooth pastes namely Wisdom, Ortho Kin, Kemphor Ortho, VITIS Orthodontic and G.U.M. Ortho to determine the fluoride concentration in triplicate using a fluoride ion-selective electrode at two time points. A paired sample t-test and a one-sample t-test were used to determine the difference between the fluoride concentration reported on the tube and the observed value in both time intervals. Results: Initially all brands exhibited levels exceeding 1000 ppm with mean concentrations as follows; Wisdom Orthoclean (1355 ppm) Ortho Kin (1349 ppm) Kemphor Ortho (1361 ppm) VITIS Orthodontic (1348 ppm) and G.U.M. Ortho (1494 ppm) which were significantly lower than stated on the tube. After one month, a significant drop was noticed in the levels of fluoride in all tooth pastes (p-value ≤ 0.05). Conclusions: The fluoride concentration in orthodontic tooth pastes decreases over time and does not reach the levels stated on the packaging. It is advisable to recommend tooth pastes that retain their effectiveness even after being opened for some time. [ABSTRACT FROM AUTHOR]

In the current study, aluminum electrodes have been employed in electrocoagulation (EC) to remove fluoride ions from groundwater. The effects of various operating process variables of EC, including pH, salt dosage, stirring speed, inter-electrode distance, and current density have been studied, as well as the operating cost and kinetics of the process. The most favorable values of the EC process parameters have been observed, which are effective for the removal of 97.6% fluoride, such as an initial value of pH 7.0, a current density value of 105.86 A/m2, an IED of 1 cm, a dose of salt of 0.33 g/L, a rotating speed of 700 RPM, and a time 40 min. The operating cost for the removal of fluoride (97.6% efficiency) from groundwater by EC was found to be 0.27 US$/m3. The effectiveness of the EC process in the removal of turbidity and TDS from different operating circumstances have also been investigated. First-order kinetics was observed in the kinetic study. The reaction rate constant k increases with CD increase, k decreases with IED increase, and k decreases with initial concentration increase. EDX analysis and FTIR spectra of the sludge confirm the availability of trace amounts of fluoride in the sludge produced. The EC process can effectively reduce the fluoride concentration from synthetic water as well as real groundwater up to below 1.5 mg/L as per WHO recommendations for drinking water. [ABSTRACT FROM AUTHOR]