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Tuomivaara ST, Goin DE, Fisher SJ, Hall SC, Mattis AN, Den Besten PK. Fluoride-related changes in the fetal cord blood proteome; a pilot study. Res Sq 2024:rs.3.rs-3995767. [PMID: 38464284 PMCID: PMC10925477 DOI: 10.21203/rs.3.rs-3995767/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Background Fluoride 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 affects human fetal development, we completed proteomic analyses of cord blood serum collected from second-trimester pregnant women residing in Northern California with either high or low fluoride exposure, as identified by maternal serum fluoride concentrations. Objective To identify changes in cord blood proteins associated with maternal serum fluoride concentration in pregnant women living in Northern California. Methods The proteomes of 19 archived second-trimester cord blood samples representing highest and lowest serum fluoride concentrations from a cohort of 48 women living in Northern California, previously analyzed for serum, urine and amniotic fluoride concentrations, were characterized by mass spectrometry. Proteins highly correlated to maternal serum fluoride concentrations were identified, and further compared in a group of samples from women with the highest serum fluoride to the group with the lowest maternal serum fluoride concentrations. Results Nine cord blood proteins were significantly correlated with maternal serum fluoride concentrations. Six of these proteins, including apolipoprotein B-100, delta homolog 1, coagulation factor X, mimecan, plasma kallikrein, and vasorin, were significantly decreased in the cord blood from women with the highest serum fluoride levels. Conclusion Changes in the relative amounts of second trimester cord blood proteins included proteins associated with the development of the fetal hematopoetic system.
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Affiliation(s)
| | - Dana E Goin
- University of California, San Francisco San Francisco
| | | | - Steven C Hall
- University of California, San Francisco San Francisco
| | - Aras N Mattis
- University of California, San Francisco San Francisco
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Grandjean P, Meddis A, Nielsen F, Beck IH, Bilenberg N, Goodman CV, Hu H, Till C, Budtz-Jørgensen E. Dose dependence of prenatal fluoride exposure associations with cognitive performance at school age in three prospective studies. Eur J Public Health 2024; 34:143-149. [PMID: 37798092 PMCID: PMC10843960 DOI: 10.1093/eurpub/ckad170] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND Fluoride may be a developmental neurotoxicant at elevated exposures. We merged new data from a prospective Odense Child Cohort (OCC) with results from two previous birth cohort studies from Mexico and Canada to characterize the dose-effect relationship in greater detail. METHODS The OCC contributed 837 mother-child pairs to the total of >1500. We measured creatinine-adjusted urine-fluoride concentrations in maternal urine samples obtained during late pregnancy. Child IQ was determined at age 7 years using an abbreviated version of the Wechsler Intelligence Scales for Children. Findings from the three cohorts were used to calculate the joint benchmark concentration (BMC) and the lower confidence limit (BMCL) after adjustment for covariables. RESULTS In the OCC, urine-fluoride concentrations varied between 0.08 and 3.04 mg/l (median 0.52 mg/l) but were not significantly associated with full-scale IQ at age 7 years (β = 0.08; 95% confidence interval -1.14 to 1.30 for a doubling in exposure). No difference was apparent between boys and girls. In the OCC, the BMC was 0.92 mg/l, with a BMCL of 0.30 mg/l. The joint analysis of all three cohorts showed a statistically significant association between urine-fluoride and IQ, with a BMC of 0.45 mg/l (BMCL, 0.28 mg/l), slightly higher than the BMC previously reported for the two North American cohorts alone. CONCLUSIONS As the BMCL reflects an approximate threshold for developmental neurotoxicity, the results suggest that pregnant women and children may need protection against fluoride toxicity.
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Affiliation(s)
- Philippe Grandjean
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Flemming Nielsen
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
| | - Iben H Beck
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
| | - Niels Bilenberg
- Department of Child and Adolescent Psychiatry, Odense University Hospital, Odense, Denmark
| | - Carly V Goodman
- Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Christine Till
- Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada
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Rasin P, Basheer SM, Haribabu J, Aneesrahman K, Manakkadan V, Vadakkedathu Palakkeezhillam VN, Bhuvanesh N, Echeverria C, Santibanez JF, Sreekanth A. Host-guest interactions of coumarin-based 1,2-pyrazole using analytical and computational methods: Paper strip-based detection, live cell imaging, logic gates and keypad lock applications. Heliyon 2024; 10:e24077. [PMID: 38234888 PMCID: PMC10792585 DOI: 10.1016/j.heliyon.2024.e24077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 12/19/2023] [Accepted: 01/03/2024] [Indexed: 01/19/2024] Open
Abstract
A novel Coumarin-based 1,2-pyrazole, HCPyTSC is synthesised and characterized. The chemosensor has been shown to have efficient colourimetric and fluorescence sensing capabilities for the quick and selective detection of fluoride and copper ions. At 376 and 430 nm, the HCPyTSC exhibits selective sensing for Cu2+ and F- ions. By examining the natural bond orbital (NBO) analysis and the potential energy curve (PES) of the ground state for the function of the C-H bond, it has been determined from the theoretical study at hand that the deprotonation was taken from the 'CH' proton of the pyrazole ring. For F- and Cu2+, the HCPyTSC detection limits were 4.62 nM and 15.36 nM, respectively. Similarly, the binding constants (Kb) for F- and Cu2+ ions in acetonitrile medium were found to be 2.06 × 105 M-1 and 1.88 × 105 M-1. Chemosensor HCPyTSC with and without F- and Cu2+ ions have an emission and absorption response that can imitate a variety of logic gates, including the AND, XOR, and OR gates. Additionally, a paper-based sensor strip with the HCPyTSC was created for use in practical, flexible F- sensing applications. The paper-based sensor was more effective in detecting F- than other anions. The effectiveness of HCPyTSC for the selective detection of F- in living cells as well as its cell permeability were examined using live-cell imaging in T24 cells.
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Affiliation(s)
- Puthiyavalappil Rasin
- Department of Chemistry, National Institute of Technology-Tiruchirappalli, Tamil Nadu, 620015, India
| | - Sabeel M. Basheer
- Department of Chemistry, National Institute of Technology-Tiruchirappalli, Tamil Nadu, 620015, India
- Dr. Sabeel M Basheer, Department of Chemistry, School of Advanced Sciences, VIT-AP University, 522 237, Andhra Pradesh, India
| | - Jebiti Haribabu
- ATACAMA-OMICS, Facultad de Medicine, Universidad de, Los Carreras 1579, 1532502, Copiapo, Chile
- Chennai Institute of Technology (CIT), Chennai 600069, India
| | - K.N. Aneesrahman
- Department of Chemistry, National Institute of Technology-Tiruchirappalli, Tamil Nadu, 620015, India
| | - Vipin Manakkadan
- Department of Chemistry, National Institute of Technology-Tiruchirappalli, Tamil Nadu, 620015, India
| | | | - Nattamai Bhuvanesh
- Department of Chemistry, Texas A & M University, College Station, TX 77842, USA
| | - Cesar Echeverria
- ATACAMA-OMICS, Facultad de Medicine, Universidad de, Los Carreras 1579, 1532502, Copiapo, Chile
| | - Juan F. Santibanez
- Institute for Medical Research, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
- Integrative Center for Biology and Applied Chemistry (CIBQA), Bernardo O'Higgins University, Santiago, Chile
| | - Anandaram Sreekanth
- Department of Chemistry, National Institute of Technology-Tiruchirappalli, Tamil Nadu, 620015, India
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Hefferon R, Goin DE, Sarnat JA, Nigra AE. Regional and racial/ethnic inequalities in public drinking water fluoride concentrations across the US. J Expo Sci Environ Epidemiol 2024; 34:68-76. [PMID: 37391608 PMCID: PMC10756931 DOI: 10.1038/s41370-023-00570-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/05/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023]
Abstract
BACKGROUND Although the US Centers for Disease Control and Prevention (CDC) considers fluoridation of community water systems (CWSs) to be a major public health achievement responsible for reducing dental disease, recent epidemiologic evidence suggests that chronic exposure to population-relevant levels of fluoride may also be associated with adverse child neurodevelopmental outcomes. To our knowledge, a nationally representative database of CWS fluoride concentration estimates that can be readily linked to US epidemiologic cohorts for further study is not publicly available. Our objectives were to evaluate broad regional and sociodemographic inequalities in CWS fluoride concentrations across the US, and to determine if county-level racial/ethnic composition was associated with county-level CWS fluoride. METHODS We generated CWS-level (N = 32,495) and population weighted county-level (N = 2152) fluoride concentration estimates using over 250,000 routine compliance monitoring records collected from the US Environmental Protection Agency's (EPA) Third Six Year Review (2006-2011). We compared CWS-level fluoride distributions across subgroups including region, population size served, and county sociodemographic characteristics. In county-level spatial error models, we also evaluated geometric mean ratios (GMRs) of CWS fluoride per 10% higher proportion of residents belonging to a given racial/ethnic subgroup. RESULTS 4.5% of CWSs (serving >2.9 million residents) reported mean 2006-2011 fluoride concentrations ≥1500 µg/L (the World Health Organization's guideline for drinking water quality). Arithmetic mean, 90th, and 95th percentile contaminant concentrations were greatest in CWSs reliant on groundwater, located in the Southwest and Eastern Midwest, and serving Semi-Urban, Hispanic communities. In fully adjusted spatial error models, the GMR (95% CI) of CWS fluoride per a 10% higher proportion of county residents that were Hispanic/Latino was 1.16 (1.10, 1.23). IMPACT STATEMENT We find that over 2.9 million US residents are served by public water systems with average fluoride concentrations exceeding the World Health Organization's guidance limit. We also find significant inequalities in community water system fluoride concentration estimates (2006-2011) across the US, especially for Hispanic/Latino communities who also experience elevated arsenic and uranium in regulated public drinking water systems. Our fluoride estimates can be leveraged in future epidemiologic studies to assess the potential association between chronic fluoride exposure and related adverse outcomes.
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Affiliation(s)
- Rose Hefferon
- Department of Environmental Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Dana E Goin
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, CA, USA
| | - Jeremy A Sarnat
- Department of Environmental Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Anne E Nigra
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, USA.
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Taher MK, Momoli F, Go J, Hagiwara S, Ramoju S, Hu X, Jensen N, Terrell R, Hemmerich A, Krewski D. Systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water. Crit Rev Toxicol 2024; 54:2-34. [PMID: 38318766 DOI: 10.1080/10408444.2023.2295338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 11/27/2023] [Indexed: 02/07/2024]
Abstract
INTRODUCTION Fluoride is a naturally occurring substance that is also added to drinking water, dental hygiene products, and food supplements for preventing dental caries. Concerns have been raised about several other potential health risks of fluoride. OBJECTIVE To conduct a robust synthesis of evidence regarding human health risks due to exposure to fluoride in drinking water, and to develop a point of departure (POD) for setting a health-based value (HBV) for fluoride in drinking water. METHODS A systematic review of evidence published since recent reviews of human, animal, and in vitro data was carried out. Bradford Hill considerations were used to weigh the evidence for causality. Several key studies were considered for deriving PODs. RESULTS The current review identified 89 human studies, 199 animal studies, and 10 major in vitro reviews. The weight of evidence on 39 health endpoints was presented. In addition to dental fluorosis, evidence was considered strong for reduction in IQ scores in children, moderate for thyroid dysfunction, weak for kidney dysfunction, and limited for sex hormone disruptions. CONCLUSION The current review identified moderate dental fluorosis and reduction in IQ scores in children as the most relevant endpoints for establishing an HBV for fluoride in drinking water. PODs were derived for these two endpoints, although there is still some uncertainty in the causal weight of evidence for causality for reducing IQ scores in children and considerable uncertainty in the derivation of its POD. Given our evaluation of the overall weight of evidence, moderate dental fluorosis is suggested as the key endpoint until more evidence is accumulated on possible reduction of IQ scores effects. A POD of 1.56 mg fluoride/L for moderate dental fluorosis may be preferred as a starting point for setting an HBV for fluoride in drinking water to protect against moderate and severe dental fluorosis. Although outside the scope of the current review, precautionary concerns for potential neurodevelopmental cognitive effects may warrant special consideration in the derivation of the HBV for fluoride in drinking water.
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Affiliation(s)
- Mohamed Kadry Taher
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
| | - Franco Momoli
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Jennifer Go
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Shintaro Hagiwara
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Siva Ramoju
- Risk Sciences International, Ottawa, ON, Canada
| | - Xuefeng Hu
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| | - Natalie Jensen
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Rowan Terrell
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Alex Hemmerich
- Risk Sciences International, Ottawa, ON, Canada
- Faculty of Education, Queen's University, Kingston, ON, Canada
| | - Daniel Krewski
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
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Godebo TR, Jeuland M, Tekle-Haimanot R, Alemayehu B, Shankar A, Wolfe A, Phan N. Association between fluoride exposure in drinking water and cognitive deficits in children: A pilot study. Neurotoxicol Teratol 2023; 100:107293. [PMID: 37690675 DOI: 10.1016/j.ntt.2023.107293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 09/12/2023]
Abstract
Fluoride (F) exposure in drinking water may lead to reduced cognitive function among children; however, findings largely remain inconclusive. In this pilot study, we examined associations between a range of chronic F exposures (low to high: 0.4 to 15.5 mg/L) in drinking water and cognition in school-aged children (5-14 years, n = 74) in rural Ethiopia. Fluoride exposure was determined from samples of community-based drinking water wells and urine. Cognitive performance was measured using: 1) assessments of ability to draw familiar objects (donkey, house, and person), and 2) a validated Cambridge Neuropsychological Test Automated Battery's (CANTAB) Paired Associate Learning (PAL), which examines memory and new learning and is closely associated with hippocampus function of the brain. Associations between F and cognitive outcomes were evaluated using regression analysis, adjusting for demographic, health status, and other covariates. The median (range) of water and urine F levels was 7.6 (0.4-15.5 mg/L) and 6.3 (0.5-15.7 mg/L), respectively; these measures were strongly correlated (r = 0.74), indicating that water is the primary source of F exposure. Fluoride in drinking water was negatively associated with cognitive function, measured by both drawing and CANTAB test performance. Inverse relationships were also found between F and drawing objects task scores, after adjusting for covariates (p < 0.05). Further analysis using CANTAB PAL tasks in the children confirmed that F level in drinking water was positively associated with the number of errors made by children (p < 0.01), also after adjusting for covariates (p < 0.05). This association between water F and total errors made became markedly stronger as PAL task difficulty increased. Fluoride exposure was also inversely associated with other PAL tasksthe number of patterns reached, first attempt memory score and mean errors to success. These findings provide supportive evidence that high F exposures may be associated with cognitive deficits in children. Additional well-designed studies are critically needed to establish the neurotoxicity of F in children and adults exposed to both low levels known to protect dental caries, as well as excess F levels in drinking water.
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Affiliation(s)
- Tewodros Rango Godebo
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.
| | - Marc Jeuland
- Sanford School of Public Policy and Duke Global Health Institute, Duke University, Durham, NC, 27708, USA
| | - Redda Tekle-Haimanot
- Addis Ababa University, School of Medicine, Department of Neurology, Addis Ababa, Ethiopia
| | - Biniyam Alemayehu
- Addis Ababa University, School of Medicine, Department of Neurology, Addis Ababa, Ethiopia
| | - Arti Shankar
- Department of Biostatistics and Data Science, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Amy Wolfe
- University of Kentucky, Kentucky Geological Survey, Lexington, KY, 40506, USA
| | - Nati Phan
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
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Malin AJ, Hu H, Martínez-Mier EA, Eckel SP, Farzan SF, Howe CG, Funk W, Meeker JD, Habre R, Bastain TM, Breton CV. Urinary fluoride levels and metal co-exposures among pregnant women in Los Angeles, California. Environ Health 2023; 22:74. [PMID: 37880740 PMCID: PMC10601173 DOI: 10.1186/s12940-023-01026-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/13/2023] [Indexed: 10/27/2023]
Abstract
BACKGROUND Fluoride is ubiquitous in the United States (US); however, data on biomarkers and patterns of fluoride exposure among US pregnant women are scarce. We examined specific gravity adjusted maternal urinary fluoride (MUFsg) in relation to sociodemographic variables and metal co-exposures among pregnant women in Los Angeles, California. METHODS Participants were from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort. There were 293 and 490 women with MUFsg measured during first and third trimesters, respectively. An intra-class correlation coefficient examined consistency of MUFsg between trimesters. Kruskal-Wallis and Mann-Whitney U tests examined associations of MUFsg with sociodemographic variables. Covariate adjusted linear regression examined associations of MUFsg with blood metals and specific gravity adjusted urine metals among a subsample of participants within and between trimesters. A False Discovery Rate (FDR) correction accounted for multiple comparisons. RESULTS Median (IQR) MUFsg was 0.65 (0.5) mg/L and 0.8 (0.59) mg/L, during trimesters one and three respectively. During both trimesters, MUFsg was higher among older participants, those with higher income, and White, non-Hispanic participants than Hispanic participants. MUFsg was also higher for White, non-Hispanic participants than for Black, non-Hispanic participants in trimester three, and for those with graduate training in trimester one. MUFsg was negatively associated with blood mercury in trimester one and positively associated with blood lead in trimester three. MUFsg was positively associated with various urinary metals, including antimony, barium, cadmium, cobalt, copper, lead, nickel, tin, and zinc in trimesters one and/or three. CONCLUSIONS MUFsg levels observed were comparable to those found in pregnant women in Mexico and Canada that have been associated with poorer neurodevelopmental outcomes. Lower urinary fluoride levels among Hispanic and non-Hispanic Black participants in MADRES compared to non-Hispanic White participants may reflect lower tap water consumption or lower fluoride exposure from other sources. Additional research is needed to examine whether MUFsg levels observed among pregnant women in the US are associated with neurodevelopmental outcomes.
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Affiliation(s)
- Ashley J Malin
- Department of Epidemiology, College of Public Health and Health Professions and College of Medicine, University of Florida, 2004 Mowry Rd, Gainesville, 32603, USA.
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - E Angeles Martínez-Mier
- Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry, Indiana University, 1121 W. Michigan St., Indianapolis, IN, 46202-2876, USA
| | - Sandrah P Eckel
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Shohreh F Farzan
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Caitlin G Howe
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, 1 Medical Center Drive, Williamson Translational Research Building, 7th Floor, Lebanon, NH, 03756, USA
| | - William Funk
- Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, 680 N Lake Shore Dr Ste 1400, Chicago, IL, 60611, USA
| | - John D Meeker
- Department of Environmental Health Sciences, University of Michigan School of Public Health, 1420 Washington Hts, Ann Arbor, MI, 48109, USA
| | - Rima Habre
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Theresa M Bastain
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Carrie V Breton
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
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Ibarluzea J, Subiza-Pérez M, Arregi A, Molinuevo A, Arranz-Freijo E, Sánchez-de Miguel M, Jiménez A, Andiarena A, Santa-Marina L, Lertxundi A. Association of maternal prenatal urinary fluoride levels with ADHD symptoms in childhood. Environ Res 2023; 235:116705. [PMID: 37479215 DOI: 10.1016/j.envres.2023.116705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/17/2023] [Accepted: 07/18/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND Health concerns about the potential impact of exposure to fluoride via drinking water (DW) on neuropsychological development include behavioral outcomes such as ADHD. OBJECTIVE We aimed to examine the association between prenatal maternal urinary fluoride and symptoms associated with attention-deficit/hyperactivity disorder (ADHD) at the age of 8 and 11 years. METHOD Data from 255 to 236 mother-child pairs from the "Infancia y Medio Ambiente" (INMA) birth cohort (Gipuzkoa; Spain) with maternal urinary F adjusted for creatinine (MUFcr) during pregnancy (first and third trimester) and child assessments of ADHD-like symptoms reported by Conners' Rating Scales-Revised at age of 8 and 11 years was available. Clinical approach was also used: cut off criteria (T > 66). Multiple linear regression models were fitted when outcomes were analyzed as continuous, and logistic regression models when the outcomes were analyzed with a categorical clinical approach. Covariates related to maternal characteristics, birth outcomes, childhood, quality of family context and biomarkers of neuro-toxicants were used. RESULTS No association was found between MUFcr levels during pregnancy and cognitive problems-inattention, hyperactivity or ADHD index score of symptoms at 8 or 11 years. When results were analyzed from the perspective of a clinical approach, at the age of 11 years, there were significant inverse association between MUFcr and being categorized as a cognitive problems-inattention case. ORs were also indicative of a lower risk, although not significant, for ADHD index at age 11. Sensitivity analyses, taking into consideration quality of family context or the levels of other toxicants during pregnancy showed similar results. CONCLUSIONS Higher levels of MUFcr in pregnant women were associated with a lower risk of cognitive problems-inattention at 11 years. These findings are inconsistent with those from previous studies and indicate the need for other population-based studies to confirm or overturn these results.
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Affiliation(s)
- Jesús Ibarluzea
- Ministry of Health of the Basque Government, Sub-Directorate for Public Health and Addictions of Gipuzkoa, 20013, San Sebastián, Spain; Faculty of Psychology of the University of the Basque Country (UPV-EHU), 20018, San Sebastian, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), 28029, Madrid, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain
| | - Mikel Subiza-Pérez
- Faculty of Psychology of the University of the Basque Country (UPV-EHU), 20018, San Sebastian, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), 28029, Madrid, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain; Bradford Institute for Health Research, Temple Bank House, Bradford Royal Infirmary, BD9 6RJ, Bradford, United Kingdom
| | - Ane Arregi
- Faculty of Psychology of the University of the Basque Country (UPV-EHU), 20018, San Sebastian, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain.
| | - Amaia Molinuevo
- Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain
| | - Enrique Arranz-Freijo
- Faculty of Psychology of the University of the Basque Country (UPV-EHU), 20018, San Sebastian, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain
| | - Manuel Sánchez-de Miguel
- Faculty of Psychology of the University of the Basque Country (UPV-EHU), 20018, San Sebastian, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain
| | - Ana Jiménez
- Ministry of Health of the Basque Government, Sub-Directorate for Public Health and Addictions of Gipuzkoa, 20013, San Sebastián, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), 28029, Madrid, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain
| | - Ainara Andiarena
- Faculty of Psychology of the University of the Basque Country (UPV-EHU), 20018, San Sebastian, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain
| | - Loreto Santa-Marina
- Ministry of Health of the Basque Government, Sub-Directorate for Public Health and Addictions of Gipuzkoa, 20013, San Sebastián, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), 28029, Madrid, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain
| | - Aitana Lertxundi
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), 28029, Madrid, Spain; Biodonostia Health Research Institute, Environmental Epidemiology and Child Development Group, 20014, San Sebastian, Spain; Faculty of Medicine and Nursery of the University of the Basque Country (UPV/EHU), 48940, Leioa, Spain
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Xin J, Zhu B, Wang H, Zhang Y, Sun N, Cao X, Zheng L, Zhou Y, Fang J, Jing B, Pan K, Zeng Y, Zeng D, Li F, Xia Y, Xu P, Ni X. Prolonged fluoride exposure induces spatial-memory deficit and hippocampal dysfunction by inhibiting small heat shock protein 22 in mice. J Hazard Mater 2023; 456:131595. [PMID: 37224709 DOI: 10.1016/j.jhazmat.2023.131595] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 04/08/2023] [Accepted: 05/05/2023] [Indexed: 05/26/2023]
Abstract
Millions of residents in areas with high-fluoride drinking water supply ingest excessive levels of fluoride for long periods. This study investigated the mechanisms and impacts of lifelong exposure to naturally occurring moderate-high-fluoride drinking water on spatial-memory function by studying mice in controlled experiments. Spatial-memory deficits and disorders of hippocampal neuronal electrical activity were observed in mice exposed to 25-ppm or 50-ppm-fluoride drinking water for 56 weeks, but not in adult or old mice exposed to 50 ppm fluoride for 12 weeks. Ultrastructural analysis showed severely damaged hippocampal mitochondria, evidenced by reduced mitochondrial membrane potential and ATP content. Mitochondrial biogenesis was impaired in fluoride-exposed mice, manifesting as a significantly reduced mtDNA content, mtDNA-encoded subunits mtND6 and mtCO1, and respiratory complex activities. Fluoride reduced expression of Hsp22, a beneficial mediator of mitochondrial homeostasis, and decreased levels of signaling for the PGC-1α/TFAM pathway-which regulates mitochondrial biogenesis-and the NF-κβ/STAT3 pathway-which regulates mitochondrial respiratory chain enzyme activity. Hippocampus-specific Hsp22-overexpression improved fluoride-induced spatial-memory deficits by activating the PGC-1α/TFAM and STAT3 signaling pathways, while Hsp22-silencing aggravated the deficits by inhibiting both pathways. Downregulation of Hsp22 plays a vital role in fluoride-induced spatial-memory deficits by impacting mtDNA-encoding subsets and mitochondrial respiratory chain enzyme activity.
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Affiliation(s)
- Jinge Xin
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Bin Zhu
- Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, Center for Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Hesong Wang
- Baiyun Branch, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yong Zhang
- Baiyun Branch, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ning Sun
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xi Cao
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Liqin Zheng
- Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, Center for Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yanxi Zhou
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Jing Fang
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Bo Jing
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Kangcheng Pan
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yan Zeng
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Dong Zeng
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Fali Li
- Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, Center for Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yang Xia
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Peng Xu
- Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, Center for Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.
| | - Xueqin Ni
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
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10
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Kumar JV, Moss ME, Liu H, Fisher-Owens S. Association between low fluoride exposure and children's intelligence: a meta-analysis relevant to community water fluoridation. Public Health 2023; 219:73-84. [PMID: 37120936 DOI: 10.1016/j.puhe.2023.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 03/05/2023] [Accepted: 03/13/2023] [Indexed: 05/02/2023]
Abstract
OBJECTIVES Previous meta-analyses have mainly focused on studies conducted in endemic fluorosis areas with relatively high fluoride concentrations. These are impoverished rural communities in China, India, and Iran, and the findings cannot be generalised to developed countries. Therefore, we investigated the association between fluoride concentrations relevant to community water fluoridation and children's cognition measured with IQ scores by synthesising effect sizes reported in observational studies. METHODS A previous meta-analysis and the National Toxicology Program database that included a search of multiple databases and the authors' search of PubMed, Google Scholar, and Mendeley provided the data. Cross-sectional and cohort studies examining the association between fluoride and children's cognition and intelligence scores were selected. Two reviewers abstracted data using standard procedures. We performed three meta-analyses to synthesise the effects using the random effects models. RESULTS Eight studies of standardized mean difference in IQ scores from non-endemic fluorosis areas found no statistically significant difference between recommended and lower levels of fluoride (standardized mean difference = 0.07; 95% confidence interval: -0.02, 0.17; I2 = 0%), and no significant fluctuation in IQ scores across the differences in fluoride concentrations by non-linear modeling with restricted cubic spline (P = 0.21). Meta-analyses of children's and maternal spot urinary fluoride associated pooled regression coefficients (Betachildren = 0.16; 95% confidence interval: -0.40, 0.73; P = 0.57; I2 = 0%, Betamaternal = -0.92; 95% CI: -3.29, 1.46; P = 0.45; I2 = 72%) were not statistically significant. Further regression analysis by standardizing absolute mean IQ scores from lower fluoride areas did not show a relationship between F concentration and IQ scores (Model Likelihood-ratio test: P-value = 0.34.) CONCLUSIONS: These meta-analyses show that fluoride exposure relevant to community water fluoridation is not associated with lower IQ scores in children. However, the reported association observed at higher fluoride levels in endemic areas requires further investigation.
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Affiliation(s)
- Jayanth V Kumar
- California Department of Public Health, MS 7208, 1616 Capitol Ave, Sacramento, CA 95814, USA.
| | - Mark E Moss
- ECU School of Dental Medicine, 1851 MacGregor Downs Road - MS 701, East Carolina University, Greenville, NC 27834-4354, USA
| | - Honghu Liu
- Public and Population Health, School of Dentistry, Department of Medicine, University of California, Los Angeles (UCLA), CA 90095, USA
| | - Susan Fisher-Owens
- School of Medicine and School of Dentistry, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
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11
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Fiore G, Veneri F, Di Lorenzo R, Generali L, Vinceti M, Filippini T. Fluoride Exposure and ADHD: A Systematic Review of Epidemiological Studies. Medicina (Kaunas) 2023; 59:medicina59040797. [PMID: 37109754 PMCID: PMC10143272 DOI: 10.3390/medicina59040797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/12/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023]
Abstract
Background and objectives: Attention deficit hyperactivity disorder (ADHD) is a childhood-onset neurodevelopmental disorder characterized by two dimensions: inattentiveness and hyperactivity/impulsivity. ADHD may be the result of complex interactions between genetic, biological and environmental factors possibly including fluoride exposure. Materials and methods: A literature search was performed on 31 March 2023 in the following databases: PubMed, Embase and Web of Science. We defined the following inclusion criteria according to the PECOS statement: a healthy child and adolescent population (P), fluoride exposure of any type (E), comparison with low or null exposure (C), ADHD spectrum disorder (O), and ecological, cross-sectional, case-control and cohort studies (S). Results: We found eight eligible records corresponding to seven different studies investigating the effect of fluoride exposure on children and adolescents. One study had a cohort design and one a case-control one, while five were cross-sectional. Only three studies applied validated questionnaires for the purpose of ADHD diagnosis. As regards exposure assessment, levels of fluoride in urine and tap water were, respectively used in three and two studies, while two used both. Three studies reported a positive association with ADHD risk, all assessing exposure through fluoride levels. By using urinary fluoride, conversely, a positive correlation with inattention, internalizing symptoms, cognitive and psychosomatic problems was found in three studies, but no relation was found in the other one. Conclusions: The present review suggests that early exposure to fluoride may have neurotoxic effects on neurodevelopment affecting behavioral, cognitive and psychosomatic symptoms related to ADHD diagnosis. However, due to the heterogeneity of the studies included, current evidence does not allow to conclusively confirm that fluoride exposure is specifically linked to ADHD development.
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Affiliation(s)
- Gianluca Fiore
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Section of Public Health, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Federica Veneri
- Unit of Dentistry & Oral-Maxillo-Facial Surgery, Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy
- PhD Program in Clinical and Experimental Medicine, Department of Biomedical, Metabolic and Neural Sciences-University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Rosaria Di Lorenzo
- Service of Psychiatric Diagnosis and Care (SPDC), Department of Mental Health and Drug Abuse, AUSL Modena, 41124 Modena, Italy
| | - Luigi Generali
- Unit of Dentistry & Oral-Maxillo-Facial Surgery, Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy
| | - Marco Vinceti
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Section of Public Health, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Department of Epidemiology, Boston University School of Public Health, Boston, MA 02118, USA
| | - Tommaso Filippini
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Section of Public Health, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
- School of Public Health, University of California Berkeley, Berkeley, CA 94704, USA
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12
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Ottappilakkil H, Babu S, Balasubramanian S, Manoharan S, Perumal E. Fluoride Induced Neurobehavioral Impairments in Experimental Animals: a Brief Review. Biol Trace Elem Res 2023; 201:1214-1236. [PMID: 35488996 DOI: 10.1007/s12011-022-03242-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/09/2022] [Indexed: 02/07/2023]
Abstract
Fluoride is one of the major toxicants in the environment and is often found in drinking water at higher concentrations. Living organisms including humans exposed to high fluoride levels are found to develop mild-to-severe detrimental pathological conditions called fluorosis. Fluoride can cross the hematoencephalic barrier and settle in various brain regions. This accumulation affects the structure and function of both the central and peripheral nervous systems. The neural ultrastructure damages are reflected in metabolic and cognitive activities. Hindrances in synaptic plasticity and signal transmission, early neuronal apoptosis, functional alterations of the intercellular signaling pathway components, improper protein synthesis, dyshomeostasis of the transcriptional and neurotrophic factors, oxidative stress, and inflammatory responses are accounted for the fluoride neurotoxicity. Fluoride causes a decline in brain functions that directly influence the overall quality of life in both humans and animals. Animal studies are widely used to explore the etiology of fluoride-induced neurotoxicity. A good number of these studies support a positive correlation between fluoride intake and toxicity phenotypes closely associated with neurotoxicity. However, the experimental dosages highly surpass the normal environmental concentrations and are difficult to compare with human exposures. The treatment procedures are highly dependent on the dosage, duration of exposure, sex, and age of specimens among other factors which make it difficult to arrive at general conclusions. Our review aims to explore fluoride-induced neuronal damage along with associated histopathological, behavioral, and cognitive effects in experimental models. Furthermore, the correlation of various molecular mechanisms upon fluoride intoxication and associated neurobehavioral deficits has been discussed. Since there is no well-established mechanism to prevent fluorosis, phytochemical-based alleviation of its characteristic indications has been proposed as a possible remedial measure.
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Affiliation(s)
| | - Srija Babu
- Bharathiar University, Coimbatore, Tamilnadu, India
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13
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Griebel-Thompson AK, Sands S, Chollet-Hinton L, Christifano D, Sullivan DK, Hull H, Carlson SE. A Scoping Review of Iodine and Fluoride in Pregnancy in Relation to Maternal Thyroid Function and Offspring Neurodevelopment. Adv Nutr 2023; 14:317-38. [PMID: 36796438 DOI: 10.1016/j.advnut.2023.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/05/2023] [Accepted: 01/11/2023] [Indexed: 02/04/2023] Open
Abstract
Iodine (I), an essential nutrient, is important for thyroid function and therefore growth and development. Fluoride (F), also an essential nutrient, strengthens bones and teeth, and prevents childhood dental caries. Both severe and mild-to-moderate I deficiency and high F exposure during development are associated to decreased intelligence quotient with recent reports associating high levels of F exposure during pregnancy and infancy to low intelligence quotient. Both F and I are halogens, and it has been suggested that F may interfere with the role of I in thyroid function. We provide a scoping review of the literature on I and F exposure dur pregnancy and their individual effects on thyroid function and offspring neurodevelopment. We first discuss I intake and status in pregnancy and the relationship to thyroid function and offspring neurodevelopment. We follow with the F in pregnancy and offspring neurodevelopment. We then review the interaction between I and F on thyroid function. We searched for, and found only one study that assessed both I and F in pregnancy. We conclude more studies are needed.
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14
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Somporn R, Lapinee C, Umponstira C, Weterings R, Chaiwong S. Iodine Status in Pregnant Women Having Urinary Fluoride in Contaminated Areas: A Case Study of Phayao Province. J Environ Public Health 2023; 2023:3677359. [PMID: 36755777 DOI: 10.1155/2023/3677359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 07/22/2022] [Accepted: 01/02/2023] [Indexed: 01/31/2023]
Abstract
Fluoride naturally occurs in the Earth's crust and is widely dispersed in groundwater. The high consumption of fluoride can inhibit iodine metabolism in the human body, especially in the thyroid gland. This study assessed iodine knowledge, iodine consumption behavior, urinary iodine (UI), thyroid stimulating hormone (serum TSH), and free triiodothyronine3 (serum FT3) and examined the connection between fluoride exposure and UI and thyroid function as serum concentrations of TSH and FT3 in pregnant women dwelling in an area of endemic fluorosis. This was a cross-sectional study. The population included 152 pregnant women within the 1st trimester of pregnancy, during which they were provided antenatal care (ANC) in seven public community hospitals in Phayao province, Thailand. The study consisted of two components. First, the study consisted of a questionnaire in which we evaluated the iodine knowledge and iodine consumptive behaviors in subjects. Second, biochemical data were investigated to evaluate thyroid function in the subjects. The gestational age of most subjects was 8-12 weeks. The study population has lived in fluoride-contaminated areas since birth (76.97%). The iodine and iodine consumption levels were moderate (50.00%). Their food iodine consumption was 3-4 days/week, and the top five consumption ranks were iodized salt, cooked pork, eggs, sticky rice, and iodine fish sauce. In terms of biochemical parameters, 63.16% of respondents had UI levels below 150.00 g/L, which is below the normal reference range of 150.00-249.00 g/L. 89.47% of the risk of hypothyroidism was associated with serum TSH levels below 2.50 g/L. In 38.16% of the samples, normal levels of serum FT3 (2.00-4.40 pg/L) were identified in the subjects. In addition, 61.84% of the samples had FT3 concentrations greater than 4.40 pg/L (high intake of iodine). The approved association between positive serum FT3 data and serum TSH was positive (r = 260 and p < 0.05). These studies imply that these elevated levels of TSH and FT3 place pregnant women in their first trimester at risk for hypothyroidism.
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15
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Gopu BP, Azevedo LB, Duckworth RM, Subramanian MKP, John S, Zohoori FV. The Relationship between Fluoride Exposure and Cognitive Outcomes from Gestation to Adulthood-A Systematic Review. Int J Environ Res Public Health 2022; 20:22. [PMID: 36612346 PMCID: PMC9819484 DOI: 10.3390/ijerph20010022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Chronic exposure to high levels of fluoride may cause health concerns, including in cognitive function. This study reviewed the evidence on the association between fluoride exposure and cognitive outcomes in children from gestation up to 18 years old. A literature search was conducted for studies on pregnant women and children below 18, exposed to any source of fluoride, and assessed with a validated cognitive tool. The data were analyzed using a systematic narrative synthesis approach and by subgroup: study design, age of participants, levels of fluoride exposure and methodological quality. Our search retrieved 15,072 articles, of which 46 met the inclusion criteria. Only 6 of the studies had a longitudinal design; the remainder were cross-sectional. The levels of fluoride exposure were ≥2 mg/L in 27 studies and <2 mg/L in 13 studies; 6 studies did not report levels of fluoride exposure. Only 1 of 5 studies graded as excellent quality showed a negative association between fluoride exposure and cognitive outcomes, whereas 30 of 34 poor and fair quality studies reported a negative association. The overall evidence from this review suggests that high fluoride exposure might be associated with negative cognitive outcomes in children. However, more longitudinal studies with high methodological quality are needed on this topic.
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Affiliation(s)
- Banu Preethi Gopu
- School of Health &and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK
| | - Liane B. Azevedo
- School of Human and Health Sciences, University of Huddersfield, Huddersfield HD1 3DH, UK
| | - Ralph M. Duckworth
- School of Health &and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK
| | | | - Sherley John
- School of Health &and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK
| | - Fatemeh Vida Zohoori
- School of Health &and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK
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16
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Xu W, Hu Z, Tang Y, Zhang J, Xu S, Niu Q. Excessive Lysosomal Stress Response and Consequently Impaired Autophagy Contribute to Fluoride-Induced Developmental Neurotoxicity. Biol Trace Elem Res 2022:10.1007/s12011-022-03511-0. [PMID: 36464725 DOI: 10.1007/s12011-022-03511-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 11/27/2022] [Indexed: 12/11/2022]
Abstract
Fluoride can cause developmental neurotoxicity; however, the precise mechanism has yet to be determined. We aimed to explore the possible role and mechanism of fluoride-induced developmental neurotoxicity, specifically the significance of the lysosomal stress response. As an in vivo model, Sprague Dawley rats were exposed to sodium fluoride (NaF) from embryo to 2 months of age. We found that NaF caused autophagic flux blockage and apoptosis in the rat hippocampus. These results were validated in human neuroblastoma (SH-SY5Y) cells in vitro. In addition, in SH-SY5Y cells, NaF hindered autophagosome-lysosome fusion, decreased lysosomal degradation, and elevated lysosomal pH, which is the most prominent hallmark of a lysosomal stress response. Interestingly, rapamycin promoted autophagosome-lysosome fusion, effectively restoring autophagic flux and reducing apoptosis. Notably, bafilomycin A1, a lysosomal lumen alkalizer, unsurprisingly exacerbated the NaF-induced increase in lysosomal pH and decreased lysosomal degradability, as well as enhanced apoptosis of SH-SY5Y cells. In conclusion, our results suggest that NaF exposure initiates excessive lysosomal stress response, resulting in elevated lysosomal pH, decreased lysosomal degradation, and blocked autophagic flux, which leads to neuronal apoptosis. Thus, the lysosomal stress response may be a promising target for the prevention and treatment of fluoride-induced developmental neurotoxicity.
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Affiliation(s)
- Wanjing Xu
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory of Preventive Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases (First Affiliated Hospital, School of Medicine, Shihezi University), Shihezi, China
| | - Zeyu Hu
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory of Preventive Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases (First Affiliated Hospital, School of Medicine, Shihezi University), Shihezi, China
| | - Yanling Tang
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory of Preventive Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases (First Affiliated Hospital, School of Medicine, Shihezi University), Shihezi, China
| | - Jingjing Zhang
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory of Preventive Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases (First Affiliated Hospital, School of Medicine, Shihezi University), Shihezi, China
| | - Shangzhi Xu
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China.
- Key Laboratory of Preventive Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases (First Affiliated Hospital, School of Medicine, Shihezi University), Shihezi, China.
| | - Qiang Niu
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China.
- Key Laboratory of Preventive Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases (First Affiliated Hospital, School of Medicine, Shihezi University), Shihezi, China.
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17
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Zhao Q, Pan W, Li J, Yu S, Liu Y, Zhang X, Qu R, Zhang Q, Li B, Yan X, Ren X, Qiu Y. Effects of neuron autophagy induced by arsenic and fluoride on spatial learning and memory in offspring rats. Chemosphere 2022; 308:136341. [PMID: 36087721 DOI: 10.1016/j.chemosphere.2022.136341] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 08/25/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
There are numerous studies showing that exposure to arsenic (As) or fluoride (F) damages the nervous system, but there is no literature investigating the effects of combined As and F exposure to induce autophagy on neurotoxicity in the offspring. In this study, we developed a rat model of As and/or F exposure through drinking water from before pregnancy to 90 days postnatal. The offspring rats were randomly divided into nine groups. Sodium arsenite (NaAsO2) (0, 35, 70 mg/L) and Sodium fluoride (NaF) (0, 50, 100 mg/L) were designed according to 3 × 3 factorial design. Our results suggested that the presence of F might antagonize the excretion of total As in urine, and As-F co-exposure led to severe pathological damage in brain tissue and reduced spatial learning and memory ability. At the same time, the experiments showed that As and F increased Beclin1 expression and LC3B ratio to activate autophagy; both P62 and Lamp2 expression were increased, suggesting that autophagy lysosomal degradation was blocked; SYN and JIP1 expression were significantly decreased, disrupting synaptic structure and function. Axonal autophagosome reverse transport regulation might be affected by combined As-F exposure, exacerbating neuronal synaptic damage and inducing neurotoxicity. Further analysis showed that there was an interaction between As and F exposure-induced changes in autolysosome-related proteins in the hippocampus, which showed antagonism, and the antagonism of the high As combined exposure groups were stronger than that of the low As combined exposure groups. In conclusion, our study showed that combined As and F exposure might induce reverse transport impairment of autophagy on axons, leading to autophagy defects, which in turn led to disruption of synaptic morphology and function, induced neurotoxicity, and there was an interaction between As and F, the type of its combined effect was antagonism.
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Affiliation(s)
- Qiuyi Zhao
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Weizhe Pan
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Jia Li
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Shengnan Yu
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Yan Liu
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Xiaoli Zhang
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China; Department of Microbiology Laboratory, Linfen Central Hospital, Linfen, China.
| | - Ruodi Qu
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Qian Zhang
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Ben Li
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Xiaoyan Yan
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
| | - Xuefeng Ren
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA; Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA.
| | - Yulan Qiu
- Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China.
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Ferreira MKM, Souza-Monteiro D, Bittencourt LO, Matos-Sousa JM, Chemelo VS, Santos VRN, Nunes PBO, Balbinot GDS, Prado AF, Collares FM, Ager FJ, Ortega-Feliu I, Respaldiza MA, Pessanha S, Lima RR. Fluoride exposure duringintrauterine and lactation periods promotes changes in the offspring rats' alveolar bone. Chemosphere 2022; 307:136053. [PMID: 35977563 DOI: 10.1016/j.chemosphere.2022.136053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/27/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
The importance of fluoride (F) for oral health is well established in the literature. However, evidence suggests that excessive exposure to this mineral is associated with adverse effects at different life stages and may affect many biological systems, especially mineralized tissues. The purpose of this study was to investigate the effects of F exposure during pregnancy and breastfeeding on the alveolar bone of the offspring since the alveolar bone is one of the supporting components of the dental elements. For this, the progeny rats were divided into three groups: control, 10 mg F/L, and 50 mg F/L for 42 (gestational and lactation periods). Analysis of the quantification of F levels in the alveolar bone by particle-induced gamma emission; Raman spectroscopy to investigate the physicochemical aspects and mineral components; computed microtomography to evaluate the alveolar bone microstructure and analyses were performed to evaluate osteocyte density and collagen quantification using polarized light microscopy. The results showed an increase in F levels in the alveolar bone, promoted changes in the chemical components in the bone of the 50 mg F/L animals (p < 0.001), and had repercussions on the microstructure of the alveolar bone, evidenced in the 10 mg F/L and 50 mg F/L groups (p < 0.001). Furthermore, F was able to modulate the content of organic bone matrix, mainly collagen; thus, this damage possibly reduced the amount of bone tissue and consequently increased the root exposure area of the exposed groups in comparison to a control group (p < 0.001). Our findings reveal that Fcan modulate the physicochemical and microstructural dimensions and reduction of alveolar bone height, increasing the exposed root region of the offspring during the prenatal and postnatal period. These findings suggest that F can modulate alveolar bone mechanical strength and force dissipation functionality.
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Affiliation(s)
- Maria Karolina Martins Ferreira
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Deiweson Souza-Monteiro
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - José Mário Matos-Sousa
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Victória Santos Chemelo
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Vinicius Ruan Neves Santos
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Paula Beatriz Oliveira Nunes
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Gabriela de Souza Balbinot
- Department of Dental Materials, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Alejandro Ferraz Prado
- Cardiovascular System Pharmacology and Toxicology Laboratory, Institute of Biological Sciences, Federal University of Pará, Belem, Brazil
| | - Fabricio Mezzomo Collares
- Department of Dental Materials, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Francisco José Ager
- National Accelerator Center (CNA), Cartuja Science and Technology Park, Calle Thomas Alva Edison 7 Sevilla, 41092, Sevilla, Spain
| | - Inés Ortega-Feliu
- National Accelerator Center (CNA), Cartuja Science and Technology Park, Calle Thomas Alva Edison 7 Sevilla, 41092, Sevilla, Spain
| | - Miguel Angel Respaldiza
- National Accelerator Center (CNA), Cartuja Science and Technology Park, Calle Thomas Alva Edison 7 Sevilla, 41092, Sevilla, Spain
| | - Sofia Pessanha
- Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics, NOVA School of Sciences and Technology, Campus Caparica, 2829-516, Caparica, Portugal
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil.
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19
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Kampouri M, Gustin K, Stråvik M, Barman M, Levi M, Daraki V, Jacobsson B, Sandin A, Sandberg AS, Wold AE, Vahter M, Kippler M. Association of maternal urinary fluoride concentrations during pregnancy with size at birth and the potential mediation effect by maternal thyroid hormones: The Swedish NICE birth cohort. Environ Res 2022; 214:114129. [PMID: 35998692 DOI: 10.1016/j.envres.2022.114129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/26/2022] [Accepted: 08/14/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Observational studies have indicated that elevated maternal fluoride exposure during pregnancy may impair child neurodevelopment but a potential impact on birth outcomes is understudied. OBJECTIVES To evaluate the impact of gestational fluoride exposure on birth outcomes (birth size and gestational age at birth) and to assess the potential mediating role of maternal thyroid hormones. METHODS We studied 583 mother-child dyads in the NICE cohort in northern Sweden. Maternal fluoride exposure was assessed by measuring urinary concentrations at late pregnancy (median: 29th gestational week) using an ion selective electrode. Plasma levels of free and total thyroxine (fT4, tT4) and triiodothyronine (fT3, tT3), and thyroid stimulating hormone (TSH) were measured with electrochemiluminescence immunoassays. The infant's weight, length, head circumference, and gestational age at birth were extracted from hospital records. RESULTS Median urinary fluoride concentration was 0.71 mg/L (5th-95th percentile 0.31-1.9 mg/L; specific gravity adjusted). In multivariable-adjusted regression models, every 1 mg/L increase of maternal urinary fluoride was associated with a mean increase in birth weight by 84 g (95%CI: 30, 138), length by 0.41 cm (95%CI: 0.18, 0.65), head circumference by 0.3 cm (95%CI: 0.1, 0.4), and with increased odds of being born large for gestational age (OR = 1.39, 95%CI: 1.03, 1.89). Every 1 mg/L increase of maternal urinary fluoride was also associated with a mean increase of the plasma fT3:fT4 ratio (B = 0.007, 95%CI: 0.000, 0.014), but not with the hormones or TSH. In mediation analyses, the maternal fT3:fT4 ratio did not explain the urinary fluoride-birth size relationships. DISCUSSION Gestational urinary fluoride concentrations were associated with increased size at birth and even with increased odds of being born large for gestational age. The fluoride-related associations with increased size at birth were not explained by changes in maternal thyroid hormone levels.
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Affiliation(s)
- Mariza Kampouri
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Klara Gustin
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Mia Stråvik
- Food and Nutrition Science, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Malin Barman
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Food and Nutrition Science, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Michael Levi
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Vasiliki Daraki
- Department of Endocrinology, University Hospital of Heraklion, Heraklion, Greece
| | - Bo Jacobsson
- Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Institute of Clinical Sciences, Department of Obstetrics and Gynecology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Anna Sandin
- Department of Clinical Science, Pediatrics, Sunderby Research Unit, Umeå University, Sweden
| | - Ann-Sofie Sandberg
- Food and Nutrition Science, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Agnes E Wold
- Institute of Biomedicine, Department of Infectious Diseases, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Marie Vahter
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Maria Kippler
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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20
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Ortíz-García SG, Torres-Sánchez LE, Muñoz-Rocha TV, Mercado-García A, Peterson KE, Hu H, Osorio-Yáñez C, Téllez-Rojo MM. Maternal urinary fluoride during pregnancy and birth weight and length: Results from ELEMENT cohort study. Sci Total Environ 2022; 838:156459. [PMID: 35660617 DOI: 10.1016/j.scitotenv.2022.156459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/27/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Epidemiological studies assessing prenatal fluoride exposure and anthropometry at birth are scarce, inconsistent and with methodological limitations. The aim of this study was to evaluate associations between maternal urinary fluoride (MUF) at each trimester of pregnancy and birth weight and length in 536 mother-child pairs in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort study. MUF (mg/L) was measured using microdiffusion/fluoride-specific electrode from at least one trimester of pregnancy. Non-linear associations were assessed through segmented regression models (MUF and birth weight Z-score) and we used linear regression models for MUF and birth length Z-score. Models were adjusted for potential confounders including urinary creatinine concentrations as a covariate. Non-creatinine adjusted MUF levels at each trimester of pregnancy were 0.81, 0.86, and 0.82 mg/L, mean concentrations for first, second and third trimester, respectively. For birth weight, we identified a MUF breakpoint at 0.99, 0.68 and 0.58 mg/L, for first, second and third trimester of pregnancy, respectively. In the first trimester, an increase of 1 mg/L in MUF concentrations ≥0.99 mg/L was associated with an increase in weight Z-score at birth (β = 0.79; 95% CI: 0.10, 1.48; p = 0.02). Second trimester MUF (≥0.68 mg/L) was marginally associated with birth weight decrease (β = -0.25; 95% CI: -0.55, 0.04; p = 0.09) and third trimester MUF (≥0.58 mg/L) was significantly associated with birth weight decrease (β = -0.33; 95% CI: -0.63, -0.03; p = 0.03). We observed a linear and significant association between MUF and Z-score of length at birth only for the first trimester of pregnancy (β = 0.55; 95% CI: 0.07, 1.04; p < 0.02). Prenatal fluoride exposure was associated with birthweight z-score with different susceptibility windows. Our findings reinforce the hypothesis that maternal fluoride exposure may affect birth anthropometry.
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Affiliation(s)
| | | | | | | | - Karen E Peterson
- Department of Nutritional Sciences, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Howard Hu
- University of Washington, School of Public Health, Seattle, WA, USA
| | - Citlalli Osorio-Yáñez
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, Apartado Postal 70228, Ciudad de México 04510, Mexico; Laboratorio de Fisiología Cardiovascular y Trasplante Renal, Unidad de Investigación UNAM-INCICH, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de Mexico, Mexico.
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21
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Avila-Rojas SH, Aparicio-Trejo OE, Sanchez-Guerra MA, Barbier OC. Effects of fluoride exposure on mitochondrial function: Energy metabolism, dynamics, biogenesis and mitophagy. Environ Toxicol Pharmacol 2022; 94:103916. [PMID: 35738460 DOI: 10.1016/j.etap.2022.103916] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 06/09/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
Fluoride is ubiquitous in the environment. Furthermore, drinking water represents the main source of exposure to fluoride for humans. Interestingly, low fluoride concentrations have beneficial effects on bone and teeth development; however, chronic fluoride exposure has harmful effects on human health. Besides, preclinical studies associate fluoride toxicity with oxidative stress, inflammation, and apoptosis. On the other hand, it is well-known that mitochondria play a key role in reactive oxygen species production. By contrast, fluoride's effect on processes such as mitochondrial dynamics, biogenesis and mitophagy are little known. These processes modulate the size, content, and distribution of mitochondria and their depuration help to counter the reactive oxygen species production and cytochrome c release, thereby allowing cell survival. However, a maladaptive response could enhance fluoride-induced toxicity. The present review gives a brief account of fluoride-induced mitochondrial alterations on soft and hard tissues, including liver, reproductive organs, heart, brain, lung, kidney, bone, and tooth.
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Affiliation(s)
- Sabino Hazael Avila-Rojas
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Departamento de Toxicología (CINVESTAV-IPN), Av. IPN No. 2508 Col., San Pedro Zacatenco, México CP 07360, Mexico.
| | | | - Marco Antonio Sanchez-Guerra
- Department of Developmental Neurobiology, National Institute of Perinatology, Montes Urales 800, Lomas Virreyes, Mexico 1100, Mexico.
| | - Olivier Christophe Barbier
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Departamento de Toxicología (CINVESTAV-IPN), Av. IPN No. 2508 Col., San Pedro Zacatenco, México CP 07360, Mexico.
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22
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Castiblanco-Rubio GA, Muñoz-Rocha TV, Téllez-Rojo MM, Ettinger AS, Mercado-García A, Peterson KE, Hu H, Cantoral A, Martínez-Mier EA. Dietary Influences on Urinary Fluoride over the Course of Pregnancy and at One-Year Postpartum. Biol Trace Elem Res 2022; 200:1568-1579. [PMID: 34176079 DOI: 10.1007/s12011-021-02799-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
Dietary factors are known to influence urinary fluoride (UF) levels in nonpregnant people. Maternal UF is used as a biomarker of fluoride exposure; however, dietary influences on UF during pregnancy are unknown. We compared UF levels and assessed the associations between UF and five select dietary influences in pregnancy vs. one-year postpartum: dietary fluoride (F), calcium intake from diet (Ca-diet), calcium intake from supplements (Ca-sup), dietary acid load (AL), and table salt use (TS) in 421 women exposed to fluoridated salt in the Mexican diet. Spot UF (mg/L) was measured by microdiffusion/fluoride-specific electrode and dilution-corrected with specific gravity (SG). Dietary variables were estimated from a validated Food Frequency Questionnaire. Comparisons among UF in pregnancy vs. one-year postpartum were performed with non-parametric tests. Associations between dietary variables and UF were assessed using random effect models (for pregnancy) and linear regression (for one-year postpartum). SG-corrected UF (median, range) during pregnancy (0.77, 0.01-4.73 mg/L) did not significantly differ from one-year postpartum (0.75, 0.15-2.62 mg/L) but did increase every 10 gestational weeks, β = 0.05 (CI: 0.00-0.10). Different dietary influences on UF were identified at each state. Although Ca-diet and AL were not associated with UF in either state, Ca-sup decreased UF only during pregnancy, β = - 0.012 mg/L (CI: - 0.023-0.00). Reporting TS use was associated with 12% increase in UF only at one-year postpartum (p = 0.026). These results suggest different dietary influences on UF in the pregnant state, which need consideration when using UF as a biomarker of fluoride exposure.
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Affiliation(s)
- Gina A Castiblanco-Rubio
- Department of Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, 415 Lansing St, Indianapolis, IN, 46202, USA.
| | - Teresa V Muñoz-Rocha
- Center for Nutrition and Health Research, Instituto Nacional de Salud Pública de México (INSP), Cuernavaca, Morelos, México
| | - Martha M Téllez-Rojo
- Center for Nutrition and Health Research, Instituto Nacional de Salud Pública de México (INSP), Cuernavaca, Morelos, México
| | - Adrienne S Ettinger
- Rutgers Biomedical and Health Sciences, Rutgers University, New Brunswick, NJ, USA
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Adriana Mercado-García
- Center for Nutrition and Health Research, Instituto Nacional de Salud Pública de México (INSP), Cuernavaca, Morelos, México
| | - Karen E Peterson
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Howard Hu
- Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - E Angeles Martínez-Mier
- Department of Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, 415 Lansing St, Indianapolis, IN, 46202, USA
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23
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Adkins EA, Yolton K, Strawn JR, Lippert F, Ryan PH, Brunst KJ. Fluoride exposure during early adolescence and its association with internalizing symptoms. Environ Res 2022; 204:112296. [PMID: 34755609 PMCID: PMC8725192 DOI: 10.1016/j.envres.2021.112296] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/19/2021] [Accepted: 10/25/2021] [Indexed: 05/14/2023]
Abstract
BACKGROUND Early, chronic, low-level fluoride exposure has been linked to attention-deficit hyperactivity disorder (ADHD) and learning deficits in children. Rodent studies suggest a link between fluoride exposure and internalizing behaviors. No human studies have examined the impact of fluoride on internalizing behaviors during adolescence. OBJECTIVE Evaluate the relationship between urinary fluoride and early adolescent internalizing symptoms in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS). METHODS Participants in CCAAPS provided non-fasting spot urine samples at age 12 years (n = 286). Urine samples were analyzed using a microdiffusion method to determine childhood urinary fluoride (CUF) concentrations and were log-transformed for analyses. Caregivers of CCAAPS participants completed the Behavior Assessment System for Children-2 (BASC-2) at the age 12 study visit to assess internalizing symptoms (e.g., anxiety, depression, somatization), and a composite score of the three domains; T-scores ≥ 60 were used to identify adolescents in a clinically "at-risk" range. Race, age of the adolescent, household income, maternal age at birth, caregiver depression, caregiver-child relationships, and age 12-year serum cotinine concentrations were considered covariates in regression models. Sex-specific effects of fluoride exposures were investigated through the inclusion of interaction terms. RESULTS Higher CUF concentrations were significantly associated with increased somatization (β = 3.64, 95% CI 0.49, 6.81) and internalizing composite T-scores in a clinically "at-risk" range (OR = 2.9, 95% CI 1.24, 6.9). Compared to females, males with higher CUF concentrations had more internalizing (pinteraction = 0.04) and somatization symptoms (pinteraction = 0.02) and were nearly seven times more likely to exhibit "at-risk" internalizing symptomology. CUF concentrations were not significantly associated with depression or anxiety symptoms. CONCLUSIONS This is the first study to link fluoride exposure and internalizing symptoms, specifically somatization. Somatization represents an interface of physical and psychological health. Continued follow-up will help shed light on the sex-specific relationship between fluoride and mental health and the role of somatization.
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Affiliation(s)
- Emily A Adkins
- Department of Environmental and Public Health Sciences, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH, 45267, USA
| | - Kimberly Yolton
- Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, 3333 Burnet Avenue, MLC, 5041, Cincinnati, OH, 45229, USA
| | - Jeffrey R Strawn
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, 260 Stetson Street, Cincinnati, OH, 45219, USA
| | - Frank Lippert
- Department of Cariology, Operative Dentistry, and Dental Public Health, Oral Health Research Institute, Indiana University School of Dentistry, 415 Lansing Street, Indianapolis, IN, 46202, USA
| | - Patrick H Ryan
- Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - Kelly J Brunst
- Department of Environmental and Public Health Sciences, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH, 45267, USA.
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24
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Grandjean P, Hu H, Till C, Green R, Bashash M, Flora D, Tellez-Rojo MM, Song PX, Lanphear B, Budtz-Jørgensen E. A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children. Risk Anal 2022; 42:439-449. [PMID: 34101876 PMCID: PMC9831700 DOI: 10.1111/risa.13767] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/30/2021] [Accepted: 05/22/2021] [Indexed: 05/11/2023]
Abstract
As a guide to establishing a safe exposure level for fluoride exposure in pregnancy, we applied benchmark dose modeling to data from two prospective birth cohort studies. We included mother-child pairs from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort in Mexico and the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort in Canada. Maternal urinary fluoride concentrations (U-F, in mg/L, creatinine-adjusted) were measured in urine samples obtained during pregnancy. Children were assessed for intelligence quotient (IQ) at age 4 (n = 211) and between six and 12 years (n = 287) in the ELEMENT cohort, and three to four years (n = 407) in the MIREC cohort. We calculated covariate-adjusted regression coefficients and their standard errors to assess the association of maternal U-F concentrations with children's IQ measures. Assuming a benchmark response of 1 IQ point, we derived benchmark concentrations (BMCs) and benchmark concentration levels (BMCLs). No deviation from linearity was detected in the dose-response relationships, but boys showed lower BMC values than girls. Using a linear slope for the joint cohort data, the BMC for maternal U-F associated with a 1-point decrease in IQ scores was 0.31 mg/L (BMCL, 0.19 mg/L) for the youngest boys and girls in the two cohorts, and 0.33 mg/L (BMCL, 0.20 mg/L) for the MIREC cohort and the older ELEMENT children. Thus, the joint data show a BMCL in terms of the adjusted U-F concentrations in the pregnant women of approximately 0.2 mg/L. These results can be used to guide decisions on preventing excess fluoride exposure in pregnant women.
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Affiliation(s)
- Philippe Grandjean
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Public Health, University of Southern Denmark, Odense, Denmark
- Address correspondence to Philippe Grandjean, Environmental Medicine, University of Southern Denmark, J.B. Winslows vej 17A, 5000 Odense C, Denmark; tel: +45 6550 3769; fax: +45 6591 1458;
| | - Howard Hu
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - Morteza Bashash
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Martha Maria Tellez-Rojo
- Centro de Investigacion en Salud Poblacional, Instituto Nacional de Salud Publica, Cuernavaca, Morelos, Mexico
| | - Peter X.K. Song
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada
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25
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Regan SL, Williams MT, Vorhees CV. Review of rodent models of attention deficit hyperactivity disorder. Neurosci Biobehav Rev 2022; 132:621-637. [PMID: 34848247 PMCID: PMC8816876 DOI: 10.1016/j.neubiorev.2021.11.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023]
Abstract
Attention deficit hyperactivity disorder (ADHD) is a polygenic neurodevelopmental disorder that affects 8-12 % of children and >4 % of adults. Environmental factors are believed to interact with genetic predispositions to increase susceptibility to ADHD. No existing rodent model captures all aspects of ADHD, but several show promise. The main genetic models are the spontaneous hypertensive rat, dopamine transporter knock-out (KO) mice, dopamine receptor subtype KO mice, Snap-25 KO mice, guanylyl cyclase-c KO mice, and latrophilin-3 KO mice and rats. Environmental factors thought to contribute to ADHD include ethanol, nicotine, PCBs, lead (Pb), ionizing irradiation, 6-hydroxydopamine, neonatal hypoxia, some pesticides, and organic pollutants. Model validation criteria are outlined, and current genetic models evaluated against these criteria. Future research should explore induced multiple gene KOs given that ADHD is polygenic and epigenetic contributions. Furthermore, genetic models should be combined with environmental agents to test for interactions.
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Affiliation(s)
- Samantha L. Regan
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45229
| | - Michael T. Williams
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Charles V. Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229,Corresponding author: Charles V. Vorhees, Ph.D., Div. of Neurology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, USA:
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26
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Schillinger D, Banava S, Gansky SA. Integrating Oral, Physical, and Mental Health Via Public Health Literacy. Health Lit Res Pract 2022; 6:e17-e24. [PMID: 35133945 PMCID: PMC8823462 DOI: 10.3928/24748307-20220105-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/24/2021] [Indexed: 11/20/2022] Open
Affiliation(s)
- Dean Schillinger
- Address correspondence to Dean Schillinger, MD, University of California San Francisco, 533 Parnassus Avenue, San Francisco, CA, 94143;
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27
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Wang A, Duan L, Huang H, Ma J, Zhang Y, Ma Q, Guo Y, Li Z, Cheng X, Zhu J, Zhou G, Ba Y. Association between fluoride exposure and behavioural outcomes of school-age children: a pilot study in China. Int J Environ Health Res 2022; 32:232-241. [PMID: 32281876 DOI: 10.1080/09603123.2020.1747601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 03/20/2020] [Indexed: 06/11/2023]
Abstract
To assess the association between fluoride exposure and children's behavioural outcomes, we recruited 325 resident school-age children (7-13 years old) lived in Tongxu County of Henan Province in China. We measured urinary fluoride (UF) concentrations using the ion-selective electrode method. Children's behavioural outcomes were assessed by Conners' Parent Rating Scale-Revised, including conduct problems, learning problems, psychosomatic problems, impulsive-hyperactive, anxiety, and ADHD index. It turned out that each 1.0 mg/L increment in UF concentration corresponded with an elevation in the psychosomatic problem score of 4.01 (95% CI: 2.74, 5.28) and a 97% (OR = 1.97, 95% CI: 1.19, 3.27) increase in the prevalence of psychosomatic problems after adjusting for potential influencing factors. The sensitivity analysis results were consistent with those observed in our preliminary analysis. Our study suggests that fluoride exposure is positively related to the behavioural problem in school-age children, psychosomatic problem in particular.
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Affiliation(s)
- Anqi Wang
- Department of Environment Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
- Environment and Health Innovation Team, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Leizhen Duan
- Department of Medical Services, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Hui Huang
- Department of Environment Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
- Environment and Health Innovation Team, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Jun Ma
- Department of Endemic Disease, Kaifeng Center for Disease Control and Prevention, Kaifeng, Henan, P. R. China
| | - Yawei Zhang
- Department of Environmental Health Sciences, Yale University School of Public Health, New Haven, CT, USA
| | - Qiang Ma
- Teaching and Research Office, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Yao Guo
- Nursing College of Henan University of Chinese Medicine, Zhengzhou, Henan, P. R. China
| | - Zhiyuan Li
- Department of Environment Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
- Environment and Health Innovation Team, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Xuemin Cheng
- Department of Environment Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
- Environment and Health Innovation Team, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Jingyuan Zhu
- Department of Environment Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Guoyu Zhou
- Department of Environment Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
- Environment and Health Innovation Team, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
| | - Yue Ba
- Department of Environment Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
- Environment and Health Innovation Team, School of Public Health, Zhengzhou University, Zhengzhou, Henan, P. R. China
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Adkins EA, Brunst KJ. Impacts of Fluoride Neurotoxicity and Mitochondrial Dysfunction on Cognition and Mental Health: A Literature Review. Int J Environ Res Public Health 2021; 18:12884. [PMID: 34948493 DOI: 10.3390/ijerph182412884] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022]
Abstract
This review focuses on the synthesis of current experimental and observational data regarding the effect of fluoride exposure on childhood mental health and the role of mitochondrial function as a mechanism of action. We aggregated data on the relationships between fluoride neurotoxicity, mitochondrial function, and cognitive and mental health using PubMed. Current animal and human research suggest that prenatal and perinatal fluoride exposure might have neurotoxic effects. These studies observed physical changes (fur loss and delayed reflex development in animals), intelligence loss, increased hyperactivity, and irregular moods associated with fluoride exposure. Two gaps in the literature were identified: (1) there is limited research on the mental and emotional impacts of fluoride exposure compared to research on cognitive outcomes, and (2) human studies primarily focus on prenatal and perinatal exposure, with little research conducted at other time points (e.g., adolescence). Furthermore, there is no agreed-upon mechanism for the neurotoxic effects of fluoride; however, fluoride can induce mitochondrial damage, including decreasing circulating mitochondrial DNA content, dysregulating biogenesis, and circular structure loss. Additionally, many neurodevelopmental conditions have mitochondrial underpinnings. More work is needed to elucidate the impact and timing of fluoride exposure on mental health and the role of mitochondrial function as a biological mechanism
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Thygesen M, Schullehner J, Hansen B, Sigsgaard T, Voutchkova DD, Kristiansen SM, Pedersen CB, Dalsgaard S. Trace elements in drinking water and the incidence of attention-deficit hyperactivity disorder. J Trace Elem Med Biol 2021; 68:126828. [PMID: 34391071 DOI: 10.1016/j.jtemb.2021.126828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/13/2021] [Accepted: 07/30/2021] [Indexed: 01/18/2023]
Abstract
BACKGROUND Trace elements have been suggested to have neurotoxic effects and increase the risk of neurodevelopmental disorders, but studies of a potential role of trace elements in relation to Attention-Deficit/Hyperactivity Disorder (ADHD) are very limited. The objective of this study was to conduct an exploratory analysis investigating the associations between 17 geogenic trace elements (Ba, Co, Eu, I, Li, Mo, Rb, Re, Rh, Sb, Sc, Se, Si, Sr, Ti, U and Y) found in Danish drinking water and the risk of developing ADHD. METHODS In this cohort study, 284,309 individuals, born 1994-2007, were followed for incidence of ADHD from the age of five until the end of study, December 31, 2016. We conducted survival analyses, using Poisson regression to estimate incidence rate ratios (IRRs) with 95 % confidence intervals (CI) in three different confounder adjustment scenarios. RESULTS In a model including adjustments for age, sex, calendar year, parental socio-economic status, neighborhood level socio-economic status and parental psychiatric illness, we found that six of the 17 trace elements (Sr, Rb, Rh, Ti, Sb and Re) were associated with an increased risk of ADHD, whereas two (Ba and I) were inversely associated with ADHD. However, when including region as a covariate in the model, most trace elements were no longer associated with ADHD or the association changed direction. Four trace elements (I, Li, Rb, and Y) remained significantly associated with ADHD but in an inverse direction and for three of these (I, Li and Y), we found significant interactions with region in their association with ADHD. CONCLUSION The trace elements under investigation, at levels found in Danish drinking water, do not seem to contribute to the development of ADHD and our findings highlight the importance of examining consistency of associations across geographic areas.
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Affiliation(s)
- Malene Thygesen
- National Centre for Register-based Research, Department of Economics and Business, School of Business and Social Sciences, Aarhus University, Aarhus, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus and Copenhagen, Denmark; Centre for Integrated Register Based Research, CIRRAU, Aarhus University, Aarhus, Denmark.
| | - Jörg Schullehner
- Department of Public Health, Section of Environment, Occupation and Health, Aarhus University, Aarhus, Denmark; Geological Survey of Denmark and Greenland, GEUS, Denmark; Big Data Centre for Environment and Health, BERTHA, Aarhus University, Aarhus, Denmark
| | | | - Torben Sigsgaard
- Centre for Integrated Register Based Research, CIRRAU, Aarhus University, Aarhus, Denmark; Department of Public Health, Section of Environment, Occupation and Health, Aarhus University, Aarhus, Denmark; Big Data Centre for Environment and Health, BERTHA, Aarhus University, Aarhus, Denmark
| | | | | | - Carsten B Pedersen
- National Centre for Register-based Research, Department of Economics and Business, School of Business and Social Sciences, Aarhus University, Aarhus, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus and Copenhagen, Denmark; Centre for Integrated Register Based Research, CIRRAU, Aarhus University, Aarhus, Denmark; Big Data Centre for Environment and Health, BERTHA, Aarhus University, Aarhus, Denmark
| | - Søren Dalsgaard
- National Centre for Register-based Research, Department of Economics and Business, School of Business and Social Sciences, Aarhus University, Aarhus, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus and Copenhagen, Denmark; Centre for Integrated Register Based Research, CIRRAU, Aarhus University, Aarhus, Denmark
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Cantoral A, Téllez-Rojo MM, Malin AJ, Schnaas L, Osorio-Valencia E, Mercado A, Martínez-Mier EÁ, Wright RO, Till C. Dietary fluoride intake during pregnancy and neurodevelopment in toddlers: A prospective study in the progress cohort. Neurotoxicology 2021; 87:86-93. [PMID: 34478773 DOI: 10.1016/j.neuro.2021.08.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 05/03/2021] [Accepted: 08/28/2021] [Indexed: 12/21/2022]
Abstract
Foods and beverages provide a source of fluoride exposure in Mexico. While high fluoride concentrations are neurotoxic, recent research suggests that exposures within the optimal range may also pose a risk to the developing brain. This prospective study examined whether dietary fluoride intake during pregnancy is associated with toddlers' neurodevelopment in 103 mother-child pairs from the PROGRESS cohort in Mexico City. Food and beverage fluoride intake was assessed in trimesters 2 and 3 using a food frequency questionnaire and Mexican tables of fluoride content. We used the Bayley-III to evaluate cognitive, motor, and language outcomes at 12 and 24 months of age. Adjusted linear regression models were generated for each neurodevelopment assessment time point (12 and 24 months). Mixed-effects models were used to consider a repeated measurement approach. Interactions between maternal fluoride intake and child sex on neurodevelopmental outcomes were tested. Median (IQR) dietary fluoride intake during pregnancy was 1.01 mg/d (0.73, 1.32). Maternal fluoride intake was not associated with cognitive, language, or motor outcomes collapsing across boys and girls. However, child sex modified the association between maternal fluoride intake and cognitive outcome (p interaction term = 0.06). A 0.5 mg/day increase in overall dietary fluoride intake was associated with a 3.50-point lower cognitive outcome in 24-month old boys (95 % CI: -6.58, -0.42); there was no statistical association with girls (β = 0.07, 95 % CI: -2.37, 2.51), nor on the cognitive outcome at 12-months of age. Averaging across the 12- and 24-month cognitive outcomes using mixed-effects models revealed a similar association: a 0.5 mg/day increase in overall dietary fluoride intake was associated with a 3.46-point lower cognitive outcome in boys (95 % CI: -6.23, -0.70). These findings suggest that the development of nonverbal abilities in males may be more vulnerable to prenatal fluoride exposure than language or motor abilities, even at levels within the recommended intake range.
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Zhou G, Hu Y, Wang A, Guo M, Du Y, Gong Y, Ding L, Feng Z, Hou X, Xu K, Yu F, Li Z, Ba Y. Fluoride Stimulates Anxiety- and Depression-like Behaviors Associated with SIK2-CRTC1 Signaling Dysfunction. J Agric Food Chem 2021; 69:13618-13627. [PMID: 34735150 DOI: 10.1021/acs.jafc.1c04907] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Using Sprague-Dawley rats and rat PC12 cells treated with sodium fluoride (NaF), we investigated the effects of SIK2-CRTC1 signaling on the neurobehavioral toxicity induced by fluoride. The in vivo results demonstrated that NaF treatment induced anxiety- and depression-like behaviors in juvenile rats, resulting in histological and ultrastructural abnormalities in the rat hippocampus and medial prefrontal cortex. Moreover, NaF exposure induced neuronal loss and excessive apoptosis. We also found that NaF elevated the expression of SIK2 and reduced the expression of CRTC1, brain-derived neurotrophic factor (BDNF), and VGF. The in vitro results showed that NaF suppressed cell viability, induced SIK2-CRTC1 signaling dysfunction, and caused excessive apoptosis in PC12 cells. Notably, targeted knockout of SIK2 with SIK2-siRNA or blocking of SIK2-CRTC1 signaling with 7,8-dihydroxyflavone (7,8-DHF) (as well as venlafaxine) can reduce apoptosis and increase cell viability in vitro. These findings suggest that neuronal death resulting from abnormal SIK2-CRTC1 signaling contributes to neurobehavioral toxicity induced by fluoride.
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Affiliation(s)
- Guoyu Zhou
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Yue Hu
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Anqi Wang
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Meng Guo
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Yuhui Du
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Yongxiang Gong
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Limin Ding
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Zichen Feng
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Xiangbo Hou
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Kaihong Xu
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Fangfang Yu
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Zhiyuan Li
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Yue Ba
- Department of Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
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32
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Till C, Green R. Controversy: The evolving science of fluoride: when new evidence doesn't conform with existing beliefs. Pediatr Res 2021; 90:1093-1095. [PMID: 32443137 PMCID: PMC9922476 DOI: 10.1038/s41390-020-0973-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/11/2020] [Indexed: 02/02/2023]
Abstract
Over the past 75 years, health authorities have declared that community water fluoridation-a practice that reaches over 400 million worldwide-is safe. Yet, studies conducted in North America examining the safety of fluoride exposure in pregnancy were nonexistent. When a Canadian study reported that higher fluoride exposure in pregnant women was associated with lower IQ scores in young children, critics attacked the methodology of the study and discounted the significance of the results. Health authorities continued to conclude that fluoride is unequivocally safe, despite four well-conducted studies over the last 3 years consistently linking fluoride exposure in pregnancy with adverse neurodevelopmental effects in offspring. We describe the challenges of conducting fluoride research and the overt cognitive biases we have witnessed in the polarized fluoride debate. The tendency to ignore new evidence that does not conform to widespread beliefs impedes the response to early warnings about fluoride as a potential developmental neurotoxin. Evolving evidence should inspire scientists and health authorities to re-evaluate claims about the safety of fluoride, especially for the fetus and infant for whom there is no benefit.
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Affiliation(s)
- Christine Till
- Department of Psychology, York University, 4700 Keele St., Toronto, ON, Canada.
| | - Rivka Green
- Department of Psychology, York University, 4700 Keele St., Toronto, ON, Canada
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33
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Han J, Kiss L, Mei H, Remete AM, Ponikvar-Svet M, Sedgwick DM, Roman R, Fustero S, Moriwaki H, Soloshonok VA. Chemical Aspects of Human and Environmental Overload with Fluorine. Chem Rev 2021; 121:4678-4742. [PMID: 33723999 PMCID: PMC8945431 DOI: 10.1021/acs.chemrev.0c01263] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Indexed: 12/24/2022]
Abstract
Over the last 100-120 years, due to the ever-increasing importance of fluorine-containing compounds in modern technology and daily life, the explosive development of the fluorochemical industry led to an enormous increase of emission of fluoride ions into the biosphere. This made it more and more important to understand the biological activities, metabolism, degradation, and possible environmental hazards of such substances. This comprehensive and critical review focuses on the effects of fluoride ions and organofluorine compounds (mainly pharmaceuticals and agrochemicals) on human health and the environment. To give a better overview, various connected topics are also discussed: reasons and trends of the advance of fluorine-containing pharmaceuticals and agrochemicals, metabolism of fluorinated drugs, withdrawn fluorinated drugs, natural sources of organic and inorganic fluorine compounds in the environment (including the biosphere), sources of fluoride intake, and finally biomarkers of fluoride exposure.
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Affiliation(s)
- Jianlin Han
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Loránd Kiss
- University
of Szeged, Institute of Pharmaceutical Chemistry
and Interdisciplinary Excellence Centre, Eötvös u. 6, 6720 Szeged, Hungary
| | - Haibo Mei
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Attila Márió Remete
- University
of Szeged, Institute of Pharmaceutical Chemistry
and Interdisciplinary Excellence Centre, Eötvös u. 6, 6720 Szeged, Hungary
| | - Maja Ponikvar-Svet
- Department
of Inorganic Chemistry and Technology, Jožef
Stefan Institute, Jamova
cesta 39, 1000 Ljubljana, Slovenia
| | - Daniel Mark Sedgwick
- Departamento
de Química Orgánica, Universidad
de Valencia, 46100 Burjassot, Valencia Spain
| | - Raquel Roman
- Departamento
de Química Orgánica, Universidad
de Valencia, 46100 Burjassot, Valencia Spain
| | - Santos Fustero
- Departamento
de Química Orgánica, Universidad
de Valencia, 46100 Burjassot, Valencia Spain
| | - Hiroki Moriwaki
- Hamari
Chemicals Ltd., 1-19-40, Nankokita, Suminoe-ku, Osaka 559-0034, Japan
| | - Vadim A. Soloshonok
- Department
of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU, 20018 San Sebastian, Spain
- IKERBASQUE,
Basque Foundation for Science, 48011 Bilbao, Spain
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Castiblanco-Rubio GA, Muñoz-Rocha TV, Cantoral A, Téllez-Rojo MM, Ettinger AS, Mercado-García A, Peterson KE, Hu H, Martínez-Mier EA. Dietary fluoride intake over the course of pregnancy in Mexican women. Public Health Nutr 2021; 24:2388-96. [PMID: 33602354 DOI: 10.1017/S1368980021000781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To estimate dietary fluoride intake (F) over the course of pregnancy and the overall adjusted difference in dietary F intake by pregnancy stages and levels of compliance with dietary recommendations. DESIGN Secondary data analysis from a longitudinal pregnancy cohort study in a population exposed to fluoridated salt. Women were followed during the early, middle and late stages of their pregnancy (n 568). The dietary intake of recommended prenatal nutrients according to Mexican dietary guidelines and F intake (mg/d) was estimated with a validated FFQ. Data were summarised with descriptive statistics. Levels of F intake were compared with the USA's Institute of Medicine adequate intake (AI) of 3 mg/d for pregnancy. Adjusted differences in F intake by pregnancy stages and levels of compliance with recommendations were estimated using random effects models. SETTING Mexico City. PARTICIPANTS Women participating in the Early Life Exposures in Mexico to ENvironmental Toxicants (ELEMENT) project, from 2001 to 2003. RESULTS Median dietary F intake throughout pregnancy ranged from 0·64 (interquartile range (IQR) 0·38) in the early to 0·70 (IQR 0·42) in the middle, and 0·72 (IQR 0·44) mg/d in the late stage (0·01 mg F/kg per d). Corresponding adjusted intakes of F were 0·72 (95 % CI 0·70, 0·74), 0·76 (95 % CI 0·74, 0·77) and 0·80 (95 % CI 0·78, 0·82) mg/d. Women who were moderately and highly compliant with Mexican dietary recommendations ingested, on average, 0·04 and 0·14 mg F/d more than non-compliant women (P < 0·005). CONCLUSIONS Dietary F intake was below current AI, was greater with the progression of pregnancy and in women who were moderately and highly compliant with dietary recommendations.
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Zhao L, Yu C, Lv J, Cui Y, Wang Y, Hou C, Yu J, Guo B, Liu H, Li L. Fluoride exposure, dopamine relative gene polymorphism and intelligence: A cross-sectional study in China. Ecotoxicol Environ Saf 2021; 209:111826. [PMID: 33360592 DOI: 10.1016/j.ecoenv.2020.111826] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Excessive fluoride exposure is related to adverse health outcomes, but whether dopamine (DA) relative genes are involved in the health effect of low-moderate fluoride exposure on children's intelligence remain unclear. OBJECTIVES We conducted a cross-sectional study to explore the role of DA relative genes in the health effect of low-moderate fluoride exposure in drinking water. METHODS We recruited 567 resident children, aged 6-11 years old, randomly from endemic and non-endemic fluorosis areas in Tianjin, China. Spot urine samples were tested for urinary fluoride concentration, combined Raven`s test was used for intelligence quotient test. Fasting venous blood were collected to analyze ANKK1 Taq1A (rs1800497), COMT Val158Met (rs4680), DAT1 40 bp VNTR and MAOA uVNTR. Multivariable linear regression models were used to assess associations between fluoride exposure and IQ scores. We applied multiplicative and additive models to appraise single gene-environment interaction. Generalized multifactor dimensionality reduction (GMDR) was used to evaluate high-dimensional interactions of gene-gene and gene-environment. RESULTS In adjusted model, fluoride exposure was inversely associated with IQ scores (β = -5.957, 95% CI: -9.712, -2.202). The mean IQ scores of children with high-activity MAOA genotype was significantly lower than IQ scores of those with low-activity (P = 0.006) or female heterozygote (P = 0.016) genotype. We detected effect modification by four DA relative genes (ANKK1, COMT, DAT1 and MAOA) on the association between UF and IQ scores. We also found a high-dimensional gene-environment interaction among UF, ANKK1, COMT and MAOA on the effect of IQ (testing balanced accuracy = 0.5302, CV consistency: 10/10, P = 0.0107). CONCLUSIONS Our study suggests DA relative genes may modify the association between fluoride and intelligence, and a potential interaction among fluoride exposure and DA relative genes on IQ.
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Affiliation(s)
- Liang Zhao
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing 100191, PR China; Institute of Environment and Health, Tianjin Centers for Disease Control and Prevention, Tianjin 300011, PR China
| | - Canqing Yu
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing 100191, PR China
| | - Jun Lv
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing 100191, PR China; Key Laboratory of Molecular Cardiovascular Sciences (Peking University), Ministry of Education, Beijing 100191, PR China; Peking University Institute of Environmental Medicine, Beijing 100191, PR China
| | - Yushan Cui
- Institute of Environment and Health, Tianjin Centers for Disease Control and Prevention, Tianjin 300011, PR China
| | - Yang Wang
- Institute of Environment and Health, Tianjin Centers for Disease Control and Prevention, Tianjin 300011, PR China
| | - Changchun Hou
- Institute of Environment and Health, Tianjin Centers for Disease Control and Prevention, Tianjin 300011, PR China
| | - Jingwen Yu
- School of public health, Tianjin Medical University, Tianjin 300070, PR China
| | - Baihui Guo
- School of public health, Tianjin Medical University, Tianjin 300070, PR China
| | - Hongliang Liu
- School of public health, Tianjin Medical University, Tianjin 300070, PR China; Tianjin Municipal Bureau of Health Inspection, Tianjin 300070, PR China
| | - Liming Li
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing 100191, PR China.
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Ferreira MKM, Aragão WAB, Bittencourt LO, Puty B, Dionizio A, Souza MPCD, Buzalaf MAR, de Oliveira EH, Crespo-Lopez ME, Lima RR. Fluoride exposure during pregnancy and lactation triggers oxidative stress and molecular changes in hippocampus of offspring rats. Ecotoxicol Environ Saf 2021; 208:111437. [PMID: 33096359 DOI: 10.1016/j.ecoenv.2020.111437] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 05/28/2023]
Abstract
Long-term exposure to high concentrations of fluoride (F) can damage mineralized and soft tissues such as bones, liver, kidney, intestine, and nervous system of adult rats. The high permeability of the blood-brain barrier and placenta to F during pregnancy and lactation may be critical to neurological development. Therefore, this study aimed to investigate the effects of F exposure during pregnancy and lactation on molecular processes and oxidative biochemistry of offspring rats' hippocampus. Pregnant Wistar rats were randomly assigned into 3 groups in accordance with the drinking water received: G1 - deionized water (control); G2 - 10 mg/L of F and G3 - 50 mg/L of F. The exposure to fluoridated water began on the first day of pregnancy and lasted until the 21st day of breastfeeding (when the offspring rats were weaned). Blood plasma samples of the offspring rats were collected to determine F levels. Hippocampi samples were collected for oxidative biochemistry analyses through antioxidant capacity against peroxyl (ACAP), lipid peroxidation (LPO), and nitrite (NO2-) levels. Also, brain-derived neurotrophic factor (BDNF) gene expression (RT-qPCR) and proteomic profile analyses were performed. The results showed that exposure to both F concentrations during pregnancy and lactation increased the F bioavailability, triggered redox imbalance featured by a decrease of ACAP, increase of LPO and NO2- levels, BDNF overexpression and changes in the hippocampus proteome. These findings raise novel questions regarding potential repercussions on the hippocampus structure and functioning in the different cognitive domains.
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Affiliation(s)
- Maria Karolina Martins Ferreira
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Walessa Alana Bragança Aragão
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Bruna Puty
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Aline Dionizio
- Department of Biological Sciences, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil
| | | | | | | | - Maria Elena Crespo-Lopez
- Laboratory of Molecular Pharmacology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil.
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Dórea JG. Exposure to environmental neurotoxic substances and neurodevelopment in children from Latin America and the Caribbean. Environ Res 2021; 192:110199. [PMID: 32941839 DOI: 10.1016/j.envres.2020.110199] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 05/24/2023]
Abstract
Environmental (and occupational) exposure to neurotoxic substances is a worldwide problem that can affect children's neurodevelopment (ND). In Latin American and Caribbean (LAC) countries there are over 300 million children living under the threat of neurodevelopmental delays due to toxic environmental exposure. Large industrial centers, intense mining and agricultural activities, along with changing complex ecosystems constitute a mosaic that drives contamination of air, water and the food chain. Neurotoxic contaminants such as pesticides (organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, and manganese fungicides), chemicals of industrial use (phthalates), and metals (Hg, Pb, Al, As, F, Cd, Mo, Mn) are at the center of environmental exposure studies. Exposure to neurotoxic substances singly or in combination with other compounds or socioeconomic stressors (maternal education, socio-economic and nutritional status) intertwined with occupational and para-occupational exposure can affect ND (motor, cognition, behavior) of children. Significant negative effects of pesticides and neurotoxic elements on ND were found in all studied countries, affecting especially the less-privileged children from laboring families. Studies showed that exposures to the neurotoxicants in human milk are secondary to their more lasting effects during prenatal exposure. This review integrates exposure (prenatal and breastfeeding), metabolism, and ND effects of neurotoxicants. It highlights the overwhelming evidence showing that current levels of exposures are hazardous and detrimental to children's ND in LAC countries. The evidence indicates that a reduction in neurotoxicant exposure is essential to protect children's ND. Therefore, it is urgent to adopt policies and actions that prevent and remediate region-specific children's ND issues.
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Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília, 70919-970, DF, Brazil.
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Green R, Rubenstein J, Popoli R, Capulong R, Till C. Sex-specific neurotoxic effects of early-life exposure to fluoride: A review of the epidemiologic and animal literature. CURR EPIDEMIOL REP 2020; 7:263-273. [PMID: 33816056 PMCID: PMC8011433 DOI: 10.1007/s40471-020-00246-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW A growing body of evidence suggests adverse neurodevelopmental effects of early-life exposure to fluoride that may differ depending on timing of exposure and sex of the exposed. We conducted a literature search to identify the animal and human epidemiologic studies that examined sex-specific neurodevelopmental differences in response to prenatal and postnatal exposure to fluoride. RECENT FINDINGS Six of 138 animal studies and 15 of 106 human epidemiologic studies tested for sex-specific effects. Prenatal exposure to fluoride was associated with a male susceptibility to adverse behavioural effects in four of six animal studies and lower IQ in one of three prospective cohort studies. The body of evidence examining sex-effects associated with postnatal fluoride exposure was scarce, and many animal and cross-sectional human studies were considered to have a high risk of bias. SUMMARY Compared to females, male offspring appear to be more sensitive to prenatal, but not postnatal, exposure to fluoride. We discuss several sex-specific mechanisms and emphasize the need for future research.
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Affiliation(s)
- R. Green
- York University, Department of Psychology, 4700 Keele St
| | - J. Rubenstein
- York University, Department of Psychology, 4700 Keele St
| | - R. Popoli
- York University, Department of Psychology, 4700 Keele St
| | - R. Capulong
- York University, Department of Psychology, 4700 Keele St
| | - C. Till
- York University, Department of Psychology, 4700 Keele St
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Rodríguez I, Burgos A, Rubio C, Gutiérrez AJ, Paz S, Rodrigues da Silva Júnior FM, Hardisson A, Revert C. Human exposure to fluoride from tea (Camellia sinensis) in a volcanic region-Canary Islands, Spain. Environ Sci Pollut Res Int 2020; 27:43917-43928. [PMID: 32740848 DOI: 10.1007/s11356-020-10319-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
Fluoride is highly present in the environment, especially in water and its derivatives. Excessive fluoride contribution to diet poses a health risk. Tea leaves accumulate fluoride and the consumption of tea (Camellia sinensis) could pose a risk to human by the excessive fluoride intake. Ninety tea samples were analyzed by potentiometry using a selective fluoride ion electrode. Mixed tea samples (2.82 ± 1.11 mg/L) and black tea samples (2.28 ± 0.79 mg/L) recorded the highest fluoride levels. The contribution of drinking water is important for increasing fluoride levels in teas. The daily consumption of two cups (250 mL per cup) of mixed and black teas prepared with La Laguna tap water does pose a health risk for children (4-8 years old) because of the high contribution percentages (74.4% and 63.6%, respectively) of the Tolerable Upper Intake Level set in 2.5 mg/day by the EFSA (European Food Safety Authority). A minor consumption in children (4-8 years old) and adults during pregnancy is advisable.
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Affiliation(s)
- Inmaculada Rodríguez
- Department of Legal Medicine, Universidad de La Laguna, 38071, La Laguna, Tenerife, Canary Islands, Spain
| | - Antonio Burgos
- Department of Preventive Medicine and Public Health, Universidad de La Laguna, 38071, La Laguna, Tenerife, Canary Islands, Spain
| | - Carmen Rubio
- Department of Toxicology, Universidad de La Laguna, 38071, La Laguna, Tenerife, Canary Islands, Spain
| | - Angel J Gutiérrez
- Department of Toxicology, Universidad de La Laguna, 38071, La Laguna, Tenerife, Canary Islands, Spain
| | - Soraya Paz
- Department of Toxicology, Universidad de La Laguna, 38071, La Laguna, Tenerife, Canary Islands, Spain.
| | | | - Arturo Hardisson
- Department of Toxicology, Universidad de La Laguna, 38071, La Laguna, Tenerife, Canary Islands, Spain
| | - Consuelo Revert
- Department for Physical Medicine and Pharmacology, Universidad de La Laguna, 38071, La Laguna, Tenerife, Canary Islands, Spain
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Green R, Till C, Cantoral A, Lanphear B, Martinez-Mier EA, Ayotte P, Wright RO, Tellez-Rojo MM, Malin AJ. Associations between Urinary, Dietary, and Water Fluoride Concentrations among Children in Mexico and Canada. Toxics 2020; 8:E110. [PMID: 33233802 PMCID: PMC7711675 DOI: 10.3390/toxics8040110] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/29/2020] [Accepted: 10/30/2020] [Indexed: 01/09/2023]
Abstract
Fluoride, which may be toxic to the developing brain, is added to salt in Mexico and drinking water in Canada to prevent dental caries. We compared childhood urinary fluoride (CUF) concentrations in Mexico City and Canada to characterize patterns of fluoride exposure in these two populations. We also examined associations of CUF with dietary and water fluoride levels in Mexico City and Canada respectively. We included 561 children (ages 4–6; mean age 4.8 years) from the Programming Research in Obesity, Growth, Environment, and Social Stress (PROGRESS) cohort in Mexico City, and 645 children (ages 2–6; mean age 3.7 years) from the Maternal–Infant Research on Environmental Chemicals (MIREC) cohort in Canada. We applied Spearman correlations, T-tests, ANOVA or covariate-adjusted linear regression to examine associations of CUF (mg/L; adjusted for specific gravity) with demographics and dietary or water fluoride concentrations. We used Welch equivalence testing to compare means across cohorts. Mean (SD) CUF was equivalent (t = 4.26, p < 0.001) in PROGRESS: 0.74 (0.42) and fluoridated Canadian communities: 0.66 (0.47), but lower in non-fluoridated Canadian communities: 0.42 (0.31) (t = −6.37, p < 0.001). Water fluoride concentrations were significantly associated with CUF after covariate adjustment for age and sex in MIREC (B = 0.44, 95% CI: 0.30, 0.59, p < 0.001). In contrast, daily food and beverage fluoride intake was not associated with CUF in PROGRESS (p = 0.82). We found that CUF levels are comparable among children in Mexico City and fluoridated Canadian communities, despite distinct sources of exposure. Community water fluoridation is a major source of fluoride exposure for Canadian children.
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Affiliation(s)
- Rivka Green
- Department of Psychology, York University, Toronto, ON M3J 1P3, Canada; (R.G.); (C.T.)
| | - Christine Till
- Department of Psychology, York University, Toronto, ON M3J 1P3, Canada; (R.G.); (C.T.)
| | - Alejandra Cantoral
- Departamento de Salud, Universidad Iberoamericana, Ciudad de México 01219, Mexico
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, BC V5A 1S6, Canada;
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Laval University, Quebec City, QC G1V 0A6, Canada;
| | - Robert O. Wright
- Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (R.O.W.); (A.J.M.)
| | - Martha M. Tellez-Rojo
- School of Public Health, Instituto Nacional de Salud Pública, Cuernavaca 62100, Mexico;
| | - Ashley J. Malin
- Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (R.O.W.); (A.J.M.)
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Grandjean P, Hu H, Till C, Green R, Bashash M, Flora D, Tellez-Rojo MM, Song P, Lanphear B, Budtz-Jørgensen E. A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children. medRxiv 2020:2020.10.31.20221374. [PMID: 33173917 PMCID: PMC7654913 DOI: 10.1101/2020.10.31.20221374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
As a safe exposure level for fluoride in pregnancy has not been established, we used data from two prospective studies for benchmark dose modeling. We included mother-child pairs from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort in Mexico and the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort in Canada. Children were assessed for IQ at age 4 (n=211) and between 6 and 12 years (n=287) in the ELEMENT cohort and between ages 3 and 4 years (n=512) in the MIREC cohort. We calculated covariate-adjusted regression coefficients and their standard errors to explore the concentration-effect function for maternal urinary fluoride with children's IQ, including possible sex-dependence. Assuming a benchmark response of 1 IQ point, we derived benchmark concentrations (BMCs) of maternal urinary fluoride and benchmark concentration levels (BMCLs). No deviation from linearity was detected from the results of the two studies. Using a linear slope, the BMC for maternal urinary fluoride associated with a 1-point decrease in IQ scores of preschool-aged boys and girls was 0.29 mg/L (BMCL, 0.18 mg/L). The BMC was 0.30 mg/L (BMCL, 0.19 mg/L) when pooling the IQ scores from the older ELEMENT children and the MIREC cohort. Boys showed slightly lower BMC values compared with girls. Relying on two prospective studies, maternal urine-fluoride exposure at levels commonly occurring in the general population, the joint data showed BMCL results about 0.2 mg/L. These results can be used to guide decisions on preventing excess fluoride exposure in vulnerable populations.
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Affiliation(s)
- Philippe Grandjean
- Harvard T.H. Chan School of Public Health, Department of Environmental Health, Boston, MA 02115, USA
- Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Howard Hu
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - Morteza Bashash
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Martha Maria Tellez-Rojo
- Centro de Investigacion en Salud Poblacional, Instituto Nacional de Salud Publica, Cuernavaca, Morelos, Mexico
| | - Peter Song
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada
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Strunecka A, Strunecky O. Mechanisms of Fluoride Toxicity: From Enzymes to Underlying Integrative Networks. Applied Sciences 2020; 10:7100. [DOI: 10.3390/app10207100] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Fluoride has been employed in laboratory investigations since the early 20th century. These studies opened the understanding of fluoride interventions to fundamental biological processes. Millions of people living in endemic fluorosis areas suffer from various pathological disturbances. The practice of community water fluoridation used prophylactically against dental caries increased concern of adverse fluoride effects. We assessed the publications on fluoride toxicity until June 2020. We present evidence that fluoride is an enzymatic poison, inducing oxidative stress, hormonal disruptions, and neurotoxicity. Fluoride in synergy with aluminum acts as a false signal in G protein cascades of hormonal and neuronal regulations in much lower concentrations than fluoride acting alone. Our review shows the impact of fluoride on human health. We suggest focusing the research on fluoride toxicity to the underlying integrative networks. Ignorance of the pluripotent toxic effects of fluoride might contribute to unexpected epidemics in the future.
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Bashash M, Hu H. Ingestion of infant formula constituted from fluoridated water associated with IQ deficit. J Pediatr 2020; 222:253-7. [PMID: 32586530 DOI: 10.1016/j.jpeds.2020.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abduweli Uyghurturk D, Goin DE, Martinez-Mier EA, Woodruff TJ, DenBesten PK. Maternal and fetal exposures to fluoride during mid-gestation among pregnant women in northern California. Environ Health 2020; 19:38. [PMID: 32248806 PMCID: PMC7132865 DOI: 10.1186/s12940-020-00581-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 02/20/2020] [Indexed: 05/28/2023]
Abstract
BACKGROUND Previous studies have shown a correlation between fluoride concentrations in urine and community water fluoride concentrations. However, there are no studies of the relationship between community water fluoridation, urine, serum, and amniotic fluid fluoride concentrations in pregnant women in the US. The aim of this study was to determine the relationship between maternal urine fluoride (MUF), maternal urine fluoride adjusted for specific gravity (MUFSG), maternal serum fluoride (MSF), amniotic fluid fluoride (AFF) concentrations during pregnancy, and community water fluoridation in Northern California. METHODS Archived samples of urine, serum and amniotic fluid collected from second trimester pregnant women in Northern California from 47 different communities in Northern California and one from Montana (n = 48), were analyzed for fluoride using an ion specific electrode following acid microdiffusion. Women's addresses were matched to publicly reported water fluoride concentrations. We examined whether fluoride concentrations in biospecimens differed by fluoridation status of the community water, and determined the association between water fluoride concentrations and biospecimen fluoride concentrations using linear regression models adjusted for maternal age, smoking, Body Mass Index (BMI), race/ethnicity, and gestational age at sample collection. RESULTS Fluoride concentrations in the community water supplies ranged from 0.02 to 1.00 mg/L. MUF, MSF , and AFF concentrations were significantly higher in pregnant women living in communities adhering to the U.S. recommended water fluoride concentration (0.7 mg/L), as compared with communities with less than 0.7 mg/L fluoride in drinking water. When adjusted for maternal age, smoking status, BMI, race/ethnicity, and gestational age at sample collection, a 0.1 mg/L increase in community water fluoride concentration was positively associated with higher concentrations of MUF (B = 0.052, 95% CI:0.019,0.085), MUFSG (B = 0.028, 95% CI: -0.006, 0.062), MSF (B = 0.001, 95% CI: 0.000, 0.003) and AFF (B = 0.001, 95% CI: 0.000, 0.002). CONCLUSIONS We found universal exposure to fluoride in pregnant women and to the fetus via the amniotic fluid. Fluoride concentrations in urine, serum, and amniotic fluid from women were positively correlated to public records of community water fluoridation. Community water fluoridation remains a major source of fluoride exposure for pregnant women living in Northern California.
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Affiliation(s)
- Dawud Abduweli Uyghurturk
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, San Francisco, California USA
| | - Dana E. Goin
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, California USA
| | - Esperanza Angeles Martinez-Mier
- Department of Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, Indianapolis, Indiana USA
| | - Tracey J. Woodruff
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, California USA
| | - Pamela K. DenBesten
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, San Francisco, California USA
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Babajko S, Gayrard V, Houari S, Thu Bui A, Barouki R, Niederreither K, Fini JB, Dursun E, Coumoul X. [Oral cavity as a target and a marker of environmental exposures: developmental dental defects]. Med Sci (Paris) 2020; 36:225-230. [PMID: 32228840 DOI: 10.1051/medsci/2020024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The oral cavity is one of the main route for environmental contaminations associated to many chronic diseases (cancers, fertility and behavior disorders for example) via alimentation, medications and respiration. These environmental factors including, among others, endocrine disruptors and excessive fluoride can disrupt dental development and thus generate irreversible enamel defects. These defects are then treated with materials that may release molecules capable of generating these defects, leading to a vicious circle, particularly in pregnant women and young children. The present paper aims to review the state of knowledge, questions and controversies on common environmental factors in contact with the oral cavity. It also reviews their mechanisms of action and the mediators involved in enamel pathologies associated with environmental conditions. Dental tissues can not only be targeted by environmental factors but can also serve as early and easily accessible markers of exposure to these agents. Understanding and characterizing the environmental impact in the oral cavity will help to prevent multiple diseases, oral and distant, whose link with oral homeostasis is just being explored.
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Affiliation(s)
- Sylvie Babajko
- Centre de Recherche des Cordeliers, Inserm UMRS 1138, Université de Paris, Sorbonne Université, 15 rue de l'École de Médecine, 75006, Paris, France
| | | | - Sophia Houari
- Centre de Recherche des Cordeliers, Inserm UMRS 1138, Université de Paris, Sorbonne Université, 15 rue de l'École de Médecine, 75006, Paris, France
| | - Ai Thu Bui
- Centre de Recherche des Cordeliers, Inserm UMRS 1138, Université de Paris, Sorbonne Université, 15 rue de l'École de Médecine, 75006, Paris, France
| | - Robert Barouki
- Inserm UMRS 1124, Université de Paris, 75006 Paris, France
| | | | - Jean-Baptiste Fini
- Muséum National d'Histoire Naturelle, CNRS UMR 7221, 75006 Paris, France
| | - Elisabeth Dursun
- Unité de Recherche en Biomatériaux Innovants et Interfaces EA4462, Université Paris Descartes, Montrouge ; Hôpital Henri Mondor, AP-HP, 94010 Créteil, France
| | - Xavier Coumoul
- Inserm UMRS 1124, Université de Paris, 75006 Paris, France
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Wang M, Liu L, Li H, Li Y, Liu H, Hou C, Zeng Q, Li P, Zhao Q, Dong L, Zhou G, Yu X, Liu L, Guan Q, Zhang S, Wang A. Thyroid function, intelligence, and low-moderate fluoride exposure among Chinese school-age children. Environ Int 2020; 134:105229. [PMID: 31698198 DOI: 10.1016/j.envint.2019.105229] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 09/25/2019] [Accepted: 09/26/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Thyroid hormones (THs) are critical for brain development. Whether low-moderate fluoride exposure affects thyroid function and what the impact is on children's intelligence remain elusive. OBJECTIVES We conducted a cross-sectional study to examine the associations between low-moderate fluoride exposure and thyroid function in relation to children's intelligence. METHODS We recruited 571 resident children, aged 7-13 years, randomly from endemic and non-endemic fluorosis areas in Tianjin, China. We measured fluoride concentrations in drinking water and urine using the national standardized ion selective electrode method. Thyroid function was evaluated through the measurements of basal THs [(total triiodothyronine (TT3), total thyronine (TT4), free triiodothyronine (FT3), free thyronine (FT4)] and thyroid-stimulating hormone (TSH) levels in serum. Multivariable linear and logistical regression models were used to assess associations among fluoride exposure, thyroid function and IQ scores. RESULTS In adjusted models, every 1 mg/L increment of water fluoride was associated with 0.13 uIU/mL increase in TSH. Every 1 mg/L increment of urinary fluoride was associated with 0.09 ug/dL decrease in TT4, 0.009 ng/dL decrease in FT4 and 0.11 uIU/mL increase in TSH. Fluoride exposure was inversely related to IQ scores (B = -1.587; 95% CI: -2.607, -0.568 for water fluoride and B = -1.214; 95% CI: -1.987, -0.442 for urinary fluoride). Higher TT3, FT3 were related to the increased odds of children having high normal intelligence (OR = 3.407, 95% CI: 1.044, 11.120 for TT3; OR = 3.277, 95% CI: 1.621, 6.623 for FT3). We detected a significant modification effect by TSH on the association between urinary fluoride and IQ scores, without mediation by THs. CONCLUSIONS Our study suggests low-moderate fluoride exposure is associated with alterations in childhood thyroid function that may modify the association between fluoride and intelligence.
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Affiliation(s)
- Mengwei Wang
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Ling Liu
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Huijun Li
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yonggang Li
- Tianjin Baodi District Centers for Disease Control and Prevention, Tianjin, PR China
| | - Hongliang Liu
- Tianjin Centers for Disease Control and Prevention, Tianjin, PR China
| | - Changchun Hou
- Tianjin Centers for Disease Control and Prevention, Tianjin, PR China
| | - Qiang Zeng
- Tianjin Centers for Disease Control and Prevention, Tianjin, PR China
| | - Pei Li
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Qian Zhao
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Lixin Dong
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Guoyu Zhou
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Xingchen Yu
- Department of Epidemiology and Biostatistics, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Li Liu
- Department of Epidemiology and Biostatistics, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Qing Guan
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
| | - Shun Zhang
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
| | - Aiguo Wang
- Department of Occupational and Environmental Health, Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
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Till C, Green R, Flora D, Hornung R, Martinez-Mier EA, Blazer M, Farmus L, Ayotte P, Muckle G, Lanphear B. Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Environ Int 2020; 134:105315. [PMID: 31743803 PMCID: PMC6913880 DOI: 10.1016/j.envint.2019.105315] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/24/2019] [Accepted: 11/05/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Infant consumption of formula reconstituted with fluoridated water can lead to excessive fluoride intake. We examined the association between fluoride exposure in infancy and intellectual ability in children who lived in fluoridated or non-fluoridated cities in Canada. METHODS We examined 398 mother-child dyads in the Maternal-Infant Research on Environmental Chemicals cohort who reported drinking tap water. We estimated water fluoride concentration using municipal water reports. We used linear regression to analyze the association between fluoride exposure and IQ scores, measured by the Wechsler Primary and Preschool Scale of Intelligence-III at 3-4 years. We examined whether feeding status (breast-fed versus formula-fed) modified the impact of water fluoride and if fluoride exposure during fetal development attenuated this effect. A second model estimated the association between fluoride intake from formula and child IQ. RESULTS Thirty-eight percent of mother-child dyads lived in fluoridated communities. An increase of 0.5 mg/L in water fluoride concentration (approximately equaling the difference between fluoridated and non-fluoridated regions) corresponded to a 9.3- and 6.2-point decrement in Performance IQ among formula-fed (95% CI: -13.77, -4.76) and breast-fed children (95% CI: -10.45, -1.94). The association between water fluoride concentration and Performance IQ remained significant after controlling for fetal fluoride exposure among formula-fed (B = -7.93, 95% CI: -12.84, -3.01) and breastfed children (B = -6.30, 95% CI: -10.92, -1.68). A 0.5 mg increase in fluoride intake from infant formula corresponded to an 8.8-point decrement in Performance IQ (95% CI: -14.18, -3.34) and this association remained significant after controlling for fetal fluoride exposure (B = -7.62, 95% CI: -13.64, -1.60). CONCLUSIONS Exposure to increasing levels of fluoride in tap water was associated with diminished non-verbal intellectual abilities; the effect was more pronounced among formula-fed children.
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Affiliation(s)
| | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center, OH, USA
| | | | - Maddy Blazer
- Faculty of Health, York University, Ontario, Canada
| | - Linda Farmus
- Faculty of Health, York University, Ontario, Canada
| | - Pierre Ayotte
- Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada; Department of Social and Preventive Medicine, Laval University, Quebec, Canada
| | - Gina Muckle
- Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada; School of Psychology, Laval University, Quebec, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada; Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Canada
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48
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Lacson CFZ, Lu MC, Huang YH. Fluoride network and circular economy as potential model for sustainable development-A review. Chemosphere 2020; 239:124662. [PMID: 31499305 DOI: 10.1016/j.chemosphere.2019.124662] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/13/2019] [Accepted: 08/23/2019] [Indexed: 06/10/2023]
Abstract
Fluorine is the most reactive elements among the halogen group and commonly and ubiquitously occurs as fluoride in nature. The industrial processes produce fluoride by-products causing the increase of unwanted environmental levels and consequently posing risk on human and environmental health worldwide. This review gives a fundamental understanding of fluoride networks in the industrial processes, in the geological and hydrological transport, and in the biological sphere. Numerous biological pathways of fluoride also increase the risk of exposure. Literature shows that various environmental levels of fluoride due to its chemical characteristics cause bioaccumulation resulting in health deterioration among organisms. These problems are aggravated by emitted fluoride in the air and wastewater streams. Moreover, the current waste disposal dependent on incineration and landfilling superpose to the problem. In our analysis, the fluoride material flow model still follows a linear economy and reuse economy to some extent. This flow model spoils resources with high economic potential and worsens environmental problems. Thus, we intend a shift from the conventional linear economy to a circular economy with the revival of three-dimensional objectives of sustainable development. Linkages between key dimensions of the circular economy to stimulate momentum for perpetual sustainable development are proposed to gain economic, environmental and social benefits.
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Affiliation(s)
- Carl Francis Z Lacson
- Department of Chemical Engineering, Sustainable Environment Research Center, National Cheng Kung University, Tainan, 701, Taiwan
| | - Ming-Chun Lu
- Department of Environmental Resources Management, Chia Nan University of Pharmacy and Science, Tainan, 71710, Taiwan.
| | - Yao-Hui Huang
- Department of Chemical Engineering, Sustainable Environment Research Center, National Cheng Kung University, Tainan, 701, Taiwan.
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49
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Abstract
BACKGROUND After the discovery of fluoride as a caries-preventing agent in the mid-twentieth century, fluoridation of community water has become a widespread intervention, sometimes hailed as a mainstay of modern public health. However, this practice results in elevated fluoride intake and has become controversial for two reasons. First, topical fluoride application in the oral cavity appears to be a more direct and appropriate means of preventing caries. Second, systemic fluoride uptake is suspected of causing adverse effects, in particular neurotoxicity during early development. The latter is supported by experimental neurotoxicity findings and toxicokinetic evidence of fluoride passing into the brain. METHOD An integrated literature review was conducted on fluoride exposure and intellectual disability, with a main focus on studies on children published subsequent to a meta-analysis from 2012. RESULTS Fourteen recent cross-sectional studies from endemic areas with naturally high fluoride concentrations in groundwater supported the previous findings of cognitive deficits in children with elevated fluoride exposures. Three recent prospective studies from Mexico and Canada with individual exposure data showed that early-life exposures were negatively associated with children's performance on cognitive tests. Neurotoxicity appeared to be dose-dependent, and tentative benchmark dose calculations suggest that safe exposures are likely to be below currently accepted or recommended fluoride concentrations in drinking water. CONCLUSION The recent epidemiological results support the notion that elevated fluoride intake during early development can result in IQ deficits that may be considerable. Recognition of neurotoxic risks is necessary when determining the safety of fluoride-contaminated drinking water and fluoride uses for preventive dentistry purposes.
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Affiliation(s)
- Philippe Grandjean
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
- Department of Public Health, University of Southern Denmark, Odense, Denmark.
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50
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Malin AJ, Bose S, Busgang SA, Gennings C, Thorpy M, Wright RO, Wright RJ, Arora M. Fluoride exposure and sleep patterns among older adolescents in the United States: a cross-sectional study of NHANES 2015-2016. Environ Health 2019; 18:106. [PMID: 31818308 PMCID: PMC6902325 DOI: 10.1186/s12940-019-0546-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/15/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND Fluoride from environmental sources accumulates preferentially in the pineal gland which produces melatonin, the hormone that regulates the sleep-wake cycle. However, the effects of fluoride on sleep regulation remain unknown. This population-based study examined whether chronic low-level fluoride exposure is associated with sleep patterns and daytime sleepiness among older adolescents in the United States (US). METHOD This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (2015-2016). We analyzed data from adolescents who had plasma fluoride (n = 473) and water fluoride (n = 419) measures and were not prescribed medication for sleep disorders. Relationships between fluoride exposure and self-reported sleep patterns or daytime sleepiness were examined using survey-weighted linear, binomial logistic or multinomial logistic regression after covariate adjustment. A Holm-Bonferroni correction accounted for multiple comparisons. RESULTS The average age of adolescents was 17 years (range = 16-19). Median (IQR) water and plasma fluoride concentrations were 0.27 (0.52) mg/L and 0.29 (0.19) μmol/L respectively. An IQR increase in water fluoride was associated with 1.97 times higher odds of reporting symptoms suggestive of sleep apnea (95% CI: 1.27, 3.05; p = 0.02), a 24 min later bedtime (B = 0.40, 95% CI: 0.10, 0.70; p = 0.05), a 26 min later morning wake time (B = 0.43, 95% CI: 0.13, 0.73; p = 0.04), and among males, a 38% reduction in the odds of reporting snoring (95% CI: 0.45, 0.87, p = 0.03). CONCLUSIONS Fluoride exposure may contribute to changes in sleep cycle regulation and sleep behaviors among older adolescents in the US. Additional prospective studies are warranted to examine the effects of fluoride on sleep patterns and determine critical windows of vulnerability for potential effects.
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Affiliation(s)
- Ashley J Malin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Sonali Bose
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Division of Pulmonary, Critical Care and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stefanie A Busgang
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chris Gennings
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Michael Thorpy
- The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, New York, NY, USA
| | - Robert O Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Rosalind J Wright
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Manish Arora
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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