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Farmus L, Till C, Green R, Hornung R, Martinez-Mier EA, Ayotte P, Muckle G, Lanphear B, Flora D. Critical windows of fluoride neurotoxicity in Canadian children by Farmus and colleagues - In reply to Guichon et al. (2022). ENVIRONMENTAL RESEARCH 2024; 254:115201. [PMID: 36709871 DOI: 10.1016/j.envres.2022.115201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 12/30/2022] [Indexed: 06/18/2023]
Affiliation(s)
- Linda Farmus
- Department of Psychology, York University, Toronto, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, Canada
| | - Rivka Green
- Department of Psychology, York University, Toronto, Canada
| | - Richard Hornung
- Consultant to Psychology Department, York University, Toronto, ON, Canada
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada
| | - Gina Muckle
- Centre de Recherche Du CHU de Québec, Université Laval, School of Psychology, Université Laval, Québec, QC, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
| | - David Flora
- Department of Psychology, York University, Toronto, Canada
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Yang S, Yu S, Du Y, Feng Z, Jiao X, Li Q, Wu J, Sun L, Zuo J, Fu X, Li Z, Huang H, Zhou G, Yu F, Ba Y. Correlations between bone metabolism biomarkers and fluoride exposure in adults and children. J Trace Elem Med Biol 2024; 84:127419. [PMID: 38461620 DOI: 10.1016/j.jtemb.2024.127419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/14/2024] [Accepted: 02/24/2024] [Indexed: 03/12/2024]
Abstract
Increased exposure to fluoride, which notably affects bone metabolism, is a global concern. However, the correlations and sensitivity of bone metabolism to fluoride remain controversial. In this cross-sectional study, 549 children (aged 7-12 years) and 504 adults (≥ 18 years old) were recruited in the high-fluoride areas of the Henan Province. Urinary fluoride (UF) level was determined using a fluoride electrode. Fasting venous blood serum was collected to measure bone metabolism biomarkers. The selected bone metabolism biomarkers for children included bone alkaline phosphatase (BALP), serum alkaline phosphatase (ALP), osteocalcin (OCN), calcitonin (CT), parathyroid hormone (PTH), phosphorus (P5+), and calcium (Ca2+). For adults, the biomarkers included ALP, CT, PTH, β-CrossLaps (β-CTX), P5+, and Ca2+. The correlations between UF and bone metabolism biomarkers were analyzed using binary logistic regression, a trend test, a generalized additive model, and threshold effect analysis. Regression analysis indicated a significant correlation between serum OCN, PTH, and UF levels in children aged 7-9 years. Serum OCN, PTH, and BALP contents were significantly correlated with UF in boys (P < 0.05). Furthermore, the interaction between age and UF affected serum P5+ and PTH (P < 0.05). The generalized additive model revealed nonlinear dose-response relationships between P5+, BALP, and UF contents in children (P < 0.05). Serum OCN level was linearly correlated with the UF concentration (P < 0.05). Similarly, a significant correlation was observed between β-CTX and UF levels in adults. In addition, significant correlations were observed between UF-age and serum Ca2+, β-CTX, and PTH contents. There was a non-linear correlation between serum Ca2+, P5+, and β- CTX and UF levels (P < 0.05). Overall, serum OCN, BALP, and P5+ levels can serve as sensitive bone metabolism biomarkers in children, while β-CTX, P5+, and Ca2+ can be considered fluoride-sensitive bone metabolism biomarkers in adults.
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Affiliation(s)
- Shuo Yang
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Shuiyuan Yu
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Yuhui Du
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Zichen Feng
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Xuecheng Jiao
- Department of Endemic Disease, Puyang Center for Disease Control and Prevention, Puyang, Henan 457000, China
| | - Qinyang Li
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Jingjing Wu
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Lei Sun
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Juan Zuo
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Xiaoli Fu
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Zhiyuan Li
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Hui Huang
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Guoyu Zhou
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Fangfang Yu
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China.
| | - Yue Ba
- Department of Environmental Health, School of Public Health, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China.
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Ba Y, Feng Z, Fu X, Chen R, Jiao X, Du Y, Liu X, Huang H, Yu F, Zhou G. Mediation of mitochondrial DNA copy number and oxidative stress in fluoride-related bone mineral density alteration in Chinese farmers. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:184. [PMID: 38695941 DOI: 10.1007/s10653-024-01970-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/25/2024] [Indexed: 06/17/2024]
Abstract
Excessive fluoride can adversely affect bone mineral density (BMD). Oxidative stress and mitochondrial dysfunction are crucial mechanisms of health damage induced by fluoride. Here, a cross-sectional survey involving 907 Chinese farmers (aged 18-60) was carried out in Tongxu County in 2017, aiming to investigate the significance of mitochondrial DNA copy number (mtDNAcn) and oxidative stress in fluoride-related BMD change. Concentrations of urinary fluoride (UF), serum oxidative stress biomarkers, including total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA), as well as relative mtDNAcn in peripheral blood were determined. The multivariable linear model and mediation analysis were performed to assess associations between UF, oxidative stress, and relative mtDNAcn with BMD. Results showed that GSH-Px levels increased by 6.98 U/mL [95% confidence interval (CI) 3.41-10.56)] with each 1.0 mg/L increment of UF. After stratification, the T-AOC, relative mtDNAcn, and BMD decreased by 0.04 mmol/L (-0.08 ~ -0.01), 0.29-unit (-0.55 ~ -0.04), and 0.18-unit (-0.33 ~ -0.03) with every 1.0 mg/L elevation of UF in the excessive fluoride group (EFG, adults with UF > 1.6 mg/L), respectively. Furthermore, T-AOC and relative mtDNAcn were favorably related to the BMD in the EFG (β = 0.82, 95%CI 0.16-1.48 for T-AOC; β = 0.11, 95%CI 0.02-0.19 for relative mtDNAcn). Mediation analysis showed that relative mtDNAcn and T-AOC mediated 15.4% and 17.1% of the connection between excessive fluoride and reduced BMD, respectively. Findings suggested that excessive fluoride was related to lower BMD in adults, and the decrement of T-AOC and relative mtDNAcn partially mediate this relationship.
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Affiliation(s)
- Yue Ba
- Department of Occupational and Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
- Yellow River Institute for Ecological Protection & Regional Coordinated Development, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Zichen Feng
- Department of Occupational and Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Xiaoli Fu
- Department of Health Management, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Ruiqin Chen
- Department of Epidemiology, Jinshui District Center for Disease Control and Prevention, Zhengzhou, 450053, Henan, China
| | - Xuecheng Jiao
- Department of Epidemic Prevention and Control, Puyang Center for Disease Control and Prevention, Puyang, 457001, Henan, China
| | - Yuhui Du
- Department of Occupational and Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Xiaoxue Liu
- Department of Occupational and Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Hui Huang
- Department of Occupational and Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Fangfang Yu
- Department of Occupational and Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
- Yellow River Institute for Ecological Protection & Regional Coordinated Development, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Guoyu Zhou
- Department of Occupational and Environmental Health, School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China.
- Yellow River Institute for Ecological Protection & Regional Coordinated Development, Zhengzhou University, Zhengzhou, 450001, Henan, China.
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Goin DE, Padula AM, Woodruff TJ, Sherris A, Charbonneau K, Morello-Frosch R. Water Fluoridation and Birth Outcomes in California. ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:57004. [PMID: 38752991 PMCID: PMC11098007 DOI: 10.1289/ehp13732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 05/18/2024]
Abstract
BACKGROUND There is a lack of research on the relationship between water fluoridation and pregnancy outcomes. OBJECTIVES We assessed whether hypothetical interventions to reduce fluoride levels would improve birth outcomes in California. METHODS We linked California birth records from 2000 to 2018 to annual average fluoride levels by community water system. Fluoride levels were collected from consumer confidence reports using publicly available data and public record requests. We estimated the effects of a hypothetical intervention reducing water fluoride levels to 0.7 ppm (the current level recommended by the US Department of Health and Human Services) and 0.5 ppm (below the current recommendation) on birth weight, birth-weight-for-gestational age z-scores, gestational age, preterm birth, small-for-gestational age, large-for-gestational age, and macrosomia using linear regression with natural cubic splines and G-computation. Inference was calculated using a clustered bootstrap with Wald-type confidence intervals. We evaluated race/ethnicity, health insurance type, fetal sex, and arsenic levels as potential effect modifiers. RESULTS Fluoride levels ranged from 0 to 2.5 ppm , with a median of 0.51 ppm . There was a small negative association on birth weight with the hypothetical intervention to reduce fluoride levels to 0.7 ppm [- 2.2 g ; 95% confidence interval (CI): - 4.4 , 0.0] and to 0.5 ppm (- 5.8 g ; 95% CI: - 10.0 , - 1.6 ). There were small negative associations with birth-weight-for-gestational-age z-scores for both hypothetical interventions (0.7 ppm : - 0.004 ; 95% CI: - 0.007 , 0.000 and 0.5 ppm : - 0.006 ; 95% CI: - 0.013 , 0.000). We also observed small negative associations for risk of large-for-gestational age for both the hypothetical interventions to 0.7 ppm [risk difference ( RD ) = - 0.001 ; 95% CI: - 0.002 , 0.000 and 0.5 ppm (- 0.001 ; 95% CI: - 0.003 , 0.000)]. We did not observe any associations with preterm birth or with being small for gestational age for either hypothetical intervention. We did not observe any associations with risk of preterm birth or small-for-gestational age for either hypothetical intervention. CONCLUSION We estimated that a reduction in water fluoride levels would modestly decrease birth weight and birth-weight-for-gestational-age z-scores in California. https://doi.org/10.1289/EHP13732.
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Affiliation(s)
- Dana E. Goin
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Amy M. Padula
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Tracey J. Woodruff
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Allison Sherris
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Palo Alto, California, USA
| | - Kiley Charbonneau
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Rachel Morello-Frosch
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, California, USA
- School of Public Health, University of California, Berkeley, Berkeley, California, USA
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Malin AJ, Eckel SP, Hu H, Martinez-Mier EA, Hernandez-Castro I, Yang T, Farzan SF, Habre R, Breton CV, Bastain TM. Maternal Urinary Fluoride and Child Neurobehavior at Age 36 Months. JAMA Netw Open 2024; 7:e2411987. [PMID: 38767917 PMCID: PMC11107298 DOI: 10.1001/jamanetworkopen.2024.11987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/18/2024] [Indexed: 05/22/2024] Open
Abstract
Importance Recent studies in Canadian and Mexican populations suggest an association of higher prenatal fluoride exposure with poorer neurobehavioral development, but whether this association holds for US-based populations is unknown. Objective To examine associations of third trimester maternal urinary fluoride (MUF) with child neurobehavior at age 3 years in the US. Design, Setting, and Participants This prospective cohort study utilized urine samples archived from 2017 to 2020 and neurobehavioral data assessed from 2020 to 2023 from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) pregnancy cohort, which consisted of predominately Hispanic women residing in Los Angeles, California. Cohort eligibility criteria at recruitment included being 18 years of age or older, less than 30 weeks' gestation, and a fluent English or Spanish speaker. Exclusion criteria included having a disability preventing participation or provision of informed consent, being HIV positive or incarcerated, and having a multiple gestation pregnancy. There were 263 mother-child pairs who completed the 3-year study visit. In this analysis, women who reported prenatal smoking were excluded. Data analysis was conducted from October 2022 to March 2024. Exposure Specific gravity-adjusted MUF (MUFSG), a biomarker of prenatal fluoride exposure. Main Outcomes and Measures Neurobehavior was quantified using the Preschool Child Behavior Checklist (CBCL), which included composite scores for Total Problems, Internalizing Problems, and Externalizing Problems. CBCL composite T scores range from 28 to 100. T scores from 60 to 63 are in the borderline clinical range, whereas scores above 63 are in the clinical range. Linear and logistic regression models adjusted for covariates were conducted. Results A total of 229 mother-child pairs (mean [SD] maternal age, 29.45 [5.67] years; 116 female children [50.7%] and 113 male children [49.3%]) who had MUFSG measured were included in the study. Median (IQR) MUFSG was 0.76 (0.51-1.19) mg/L, and 32 participants (14.0%) had a Total Problems T score in the borderline clinical or clinical range. A 1-IQR (0.68 mg/L) increase in MUFSG was associated with nearly double the odds of the Total Problems T score being in the borderline clinical or clinical range (odds ratio, 1.83; 95% CI, 1.17-2.86; P = .008), as well as with a 2.29-point increase in T score for the Internalizing Problems composite (B = 2.29; 95% CI, 0.47-4.11; P = .01) and a 2.14-point increase in T score for the Total Problems composite (B = 2.14; 95% CI, 0.29-3.98; P = .02). Conclusions and Relevance In this prospective cohort study of mother-child pairs in Los Angeles, California, prenatal fluoride exposure was associated with increased neurobehavioral problems. These findings suggest that there may be a need to establish recommendations for limiting fluoride exposure during the prenatal period.
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Affiliation(s)
- Ashley J. Malin
- Department of Epidemiology, College of Public Health and Health Professions University of Florida, Gainesville
- College of Medicine, University of Florida, Gainesville
| | - Sandrah P. Eckel
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - E. Angeles Martinez-Mier
- Department of Dental Public Health and Dental Informatics, School of Dentistry, Indiana University, Indianapolis
| | - Ixel Hernandez-Castro
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Tingyu Yang
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Shohreh F. Farzan
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Rima Habre
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Carrie V. Breton
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Theresa M. Bastain
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
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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. RESEARCH SQUARE 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] [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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Hefferon R, Goin DE, Sarnat JA, Nigra AE. Regional and racial/ethnic inequalities in public drinking water fluoride concentrations across the US. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 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] [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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8
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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] [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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Veneri F, Vinceti M, Generali L, Giannone ME, Mazzoleni E, Birnbaum LS, Consolo U, Filippini T. Fluoride exposure and cognitive neurodevelopment: Systematic review and dose-response meta-analysis. ENVIRONMENTAL RESEARCH 2023; 221:115239. [PMID: 36639015 DOI: 10.1016/j.envres.2023.115239] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Many uncertainties still surround the possible harmful effect of fluoride exposure on cognitive neurodevelopment in children. The aim of this systematic review and meta-analysis was to characterize this relation through a dose-response approach, by comparing the intelligence quotient (IQ) scores in the highest versus the lowest fluoride exposure category with a random-effects model, within a one-stage dose-response meta-analysis based on a cubic spline random-effects model. Out of 1996 potentially relevant literature records, 33 studies were eligible for this review, 30 of which were also suitable for meta-analysis. The summary mean difference of IQ score, comparing highest versus lowest fluoride categories and considering all types of exposure, was -4.68 (95% confidence interval-CI -6.45; -2.92), with a value of -5.60 (95% CI -7.76; -3.44) for drinking water fluoride and -3.84 (95% CI -7.93; 0.24) for urinary fluoride. Dose-response analysis showed a substantially linear IQ decrease for increasing water fluoride above 1 mg/L, with -3.05 (95% CI -4.06; -2.04) IQ points per 1 mg/L up to 2 mg/L, becoming steeper above such level. A weaker and substantially linear decrease of -2.15 (95% CI -4.48; 0.18) IQ points with increasing urinary fluoride emerged above 0.28 mg/L (approximately reflecting a water fluoride content of 0.7 mg/L). The inverse association between fluoride exposure and IQ was particularly strong in the studies at high risk of bias, while no adverse effect emerged in the only study judged at low risk of bias. Overall, most studies suggested an adverse effect of fluoride exposure on children's IQ, starting at low levels of exposure. However, a major role of residual confounding could not be ruled out, thus indicating the need of additional prospective studies at low risk of bias to conclusively assess the relation between fluoride exposure and cognitive neurodevelopment.
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Affiliation(s)
- Federica Veneri
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), Unit of Dentistry & Oral-Maxillo-Facial Surgery - University of Modena and Reggio Emilia, Modena, Italy; PhD Program in Clinical and Experimental Medicine, Department of Biomedical, Metabolic and Neural Sciences - University of Modena and Reggio Emilia, Modena, Italy
| | - Marco Vinceti
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy; Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.
| | - Luigi Generali
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), Unit of Dentistry & Oral-Maxillo-Facial Surgery - University of Modena and Reggio Emilia, Modena, Italy
| | - Maria Edvige Giannone
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy
| | - Elena Mazzoleni
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy
| | - Linda S Birnbaum
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Ugo Consolo
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), Unit of Dentistry & Oral-Maxillo-Facial Surgery - University of Modena and Reggio Emilia, Modena, Italy
| | - Tommaso Filippini
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy; School of Public Health, University of California Berkeley, Berkeley, CA, USA
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A Scoping Review of Iodine and Fluoride in Pregnancy in Relation to Maternal Thyroid Function and Offspring Neurodevelopment. Adv Nutr 2023; 14:317-338. [PMID: 36796438 DOI: 10.1016/j.advnut.2023.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [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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Zhang J, Tang Y, Hu Z, Xu W, Ma Y, Xu P, Xing H, Niu Q. The inhibition of TRPML1/TFEB leads to lysosomal biogenesis disorder, contributes to developmental fluoride neurotoxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 250:114511. [PMID: 36608573 DOI: 10.1016/j.ecoenv.2023.114511] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/29/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Fluoride is capable of inducing developmental neurotoxicity; regrettably, the mechanism is obscure. We aimed to probe the role of lysosomal biogenesis disorder in developmental fluoride neurotoxicity-specifically, the regulating effect of the transient receptor potential mucolipin 1 (TRPML1)/transcription factor EB (TFEB) signaling pathway on lysosomal biogenesis. Sprague-Dawley rats were given fluoridated water freely, during pregnancy to the parental rats to 2 months after delivery to the offspring. In addition, neuroblastoma SH-SY5Y cells were treated with sodium fluoride (NaF), with or without mucolipin synthetic agonist 1 (ML-SA1) or adenovirus TFEB (Ad-TFEB) intervention. Our findings revealed that NaF impaired learning and memory as well as memory retention capacities in rat offspring, induced lysosomal biogenesis disorder, and decreased lysosomal degradation capacity, autophagosome accumulation, autophagic flux blockade, apoptosis, and pyroptosis. These changes were evidenced by the decreased expression of TRPML1, nuclear TFEB, LAMP2, CTSB, and CTSD, as well as increased expression of LC3-II, p62, cleaved PARP, NLRP3, Caspase1, and IL-1β. Furthermore, TRPML1 activation and TFEB overexpression both restored TFEB nuclear protein expression and promoted lysosomal biogenesis while enhancing lysosomal degradation capacity, recovering autophagic flux, and attenuating NaF-induced apoptosis and pyroptosis. Taken together, these results show that NaF promotes the progression of developmental fluoride neurotoxicity by inhibiting TRPML1/TFEB expression and impeding lysosomal biogenesis. Notably, the activation of TRPML1/TFEB alleviated NaF-induced developmental neurotoxicity. Therefore, TRPML1/TFEB may be promising markers of developmental fluoride neurotoxicity.
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Affiliation(s)
- Jingjing Zhang
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China
| | - Yanling Tang
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China
| | - Zeyu Hu
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China
| | - Wanjing Xu
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China
| | - Yue Ma
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China
| | - Panpan Xu
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China
| | - Hengrui Xing
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China
| | - Qiang Niu
- Department of Preventive Medicine, School of Medicine, Shihezi University, Shihezi, Xinjiang, 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, People's Republic of China.
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12
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Wen C, Zhang Q, Xie F, Jiang J. Brick tea consumption and its relationship with fluorosis in Tibetan areas. Front Nutr 2022; 9:1030344. [PMID: 36583212 PMCID: PMC9792988 DOI: 10.3389/fnut.2022.1030344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022] Open
Abstract
Brick tea-type fluorosis (BTF) due to a high intake of brick tea is possible in Tibetan populations, and dental fluorosis (DF) and skeletal fluorosis (SF) are its primary manifestations. To determine the prevalence of DF and SF and their relationships with brick tea intake in Tibetan populations, a literature review was conducted for studies published between 1994 and 2021. The available evidence revealed that brick tea may be produced from older stems and leaves of the tea plant and that the fluoride content of brick tea exceeds the national standard. The harsh environment of the plateau has led to limited food sources for the local Tibetan people who form the habit of drinking tea leaves as a satiation solution to digest greasy food and replenish vitamins, and regular consumption of brick tea leads to excessive exposure of Tibetan residents to fluoride. Studies in Tibet showed that the prevalence of DF in children was 14.06-75.93% in different districts, and the overall pooled prevalence of DF was 26.08%. The prevalence of SF in adults was 19.90-74.77% in different Tibetan districts, and the overall pooled prevalence of SF was 33.84%. The analysis of risk factors showed that the prevalence of BTF may be related to high-altitude and different working and living conditions, and BTF in children may be associated with fluoride intake during mothers' pregnancy and lactation. With the development of bioinformatics research, gene polymorphisms were suspected to be related to susceptibility to fluorosis in Tibetan populations. The study of BTF in Tibetan people needs to be further investigated and standardized, and additional studies evaluating the pathogenesis and preventive measures of BTF are warranted.
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Affiliation(s)
- Cai Wen
- Department of Oral Implantology, Affiliated Stomatological Hospital of Southwest Medical University, Luzhou, Sichuan, China,Department of VIP Dental Service, Affiliated Stomatological Hospital of Southwest Medical University, Luzhou, Sichuan, China,Luzhou Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Affiliated Stomatological Hospital of Southwest Medical University, Luzhou, Sichuan, China,*Correspondence: Cai Wen, ; orcid.org/0000-0002-3400-5382
| | - Qing Zhang
- Department of Nosocomial Infection Control, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Fei Xie
- Luzhou Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Affiliated Stomatological Hospital of Southwest Medical University, Luzhou, Sichuan, China,School of Stomatology, Southwest Medical University, Luzhou, Sichuan, China
| | - Jixin Jiang
- Luzhou Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Affiliated Stomatological Hospital of Southwest Medical University, Luzhou, Sichuan, China,School of Stomatology, Southwest Medical University, Luzhou, Sichuan, China
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13
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Den Besten P, Wells CR, Abduweli Uyghurturk D. Fluoride exposure and blood cell markers of inflammation in children and adolescents in the United States: NHANES, 2013-2016. Environ Health 2022; 21:102. [PMID: 36289513 PMCID: PMC9608888 DOI: 10.1186/s12940-022-00911-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Ingestion of fluoride in drinking water has been shown to result in increased cellular markers of inflammation in rodent models. However, the approximately 5-10 × increase in water fluoride concentrations required in rat and mouse models to obtain plasma fluoride concentrations similar to those found in humans has made relevant comparisons of animal to human studies difficult to assess. As an increased white blood cell count (WBC) is a marker of inflammation in humans, we used available NHANES survey data to assess the associations between plasma fluoride levels in the U.S. and blood cell counts children and adolescents. METHODS: Multiple linear regressions were done to determine the association of blood cell counts and plasma fluoride in publicly available NHANES survey data from the 2013-2014 and 2015-2016 cycles. Plasma fluoride concentration measurements were available only for children aged 6 to 19, inclusive, and therefore this subpopulation was used for all analyses. Covariate predictors along with plasma fluoride were age, ethnicity, gender, and Body Mass Index (BMI). RESULTS: Plasma fluoride was significantly positively associated with water fluoride, total WBC count, segmented neutrophils, and monocytes, and negatively associated with red blood cell count when adjusted for age, gender and BMI. CONCLUSION Our finding that neutrophils and monocytes are associated with higher plasma fluoride in U.S. children and adolescents is consistent with animal data showing fluoride related effects of increased inflammation. These findings suggest the importance of further studies to assess potential mechanisms that are involved in absorption and filtration of ingested fluoride, particularly in tissues and organs such as the small intestine, liver and kidney.
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Affiliation(s)
- Pamela Den Besten
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, CA USA
| | - Christine R. Wells
- Statistical Methods and Data Analytics, UCLA Office of Advanced Research Computing, Los Angeles, CA USA
| | - Dawud Abduweli Uyghurturk
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, CA USA
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14
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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. THE SCIENCE OF THE TOTAL ENVIRONMENT 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] [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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15
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Goodman CV, Bashash M, Green R, Song P, Peterson KE, Schnaas L, Mercado-García A, Martínez-Medina S, Hernández-Avila M, Martinez-Mier A, Téllez-Rojo MM, Hu H, Till C. Domain-specific effects of prenatal fluoride exposure on child IQ at 4, 5, and 6-12 years in the ELEMENT cohort. ENVIRONMENTAL RESEARCH 2022; 211:112993. [PMID: 35276192 PMCID: PMC9890727 DOI: 10.1016/j.envres.2022.112993] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 02/13/2022] [Accepted: 02/19/2022] [Indexed: 05/17/2023]
Abstract
OBJECTIVE Prenatal exposure to fluoride has been associated with adverse neurodevelopmental outcomes. However, the neuropsychological profile of fluoride's developmental neurotoxicity at low levels and the stability of this relationship across childhood has not been characterized. We investigated the longitudinal and domain specific effect of prenatal fluoride exposure on IQ among children ages 4, 5, and 6-12 years in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort. METHODS We measured the average of maternal urinary fluoride at each trimester of pregnancy adjusted for creatinine (MUFCRE). Children were administered the McCarthy Scales of Children's Abilities at ages 4 (N = 386) and 5 (N = 308), and the Wechsler Abbreviated Scale of Intelligence at age 6-12 (N = 278). We used generalized estimating equation (GEE) models to estimate the population averaged effect of MUFCRE concentration on longitudinal General Cognitive Index (GCI)/Full-Scale IQ (FSIQ), Verbal IQ (VIQ), and Performance IQ (PIQ) scores (N = 348). We tested for possible interactions between MUFCRE and child sex as well as for MUFCRE and time point on children's IQ. All models controlled for relevant available covariates. RESULTS The mean/median MUFCRE concentration was 0.90/0.83 mg/L (SD = 0.39; IQR, 0.64-1.11 mg/L). A 0.5 mg/L increase in MUFCRE predicted an average 2.12-point decrease in GCI/FSIQ (95% CI: -3.49, -0.75) and 2.63-point decrease in PIQ (95% CI: -3.87, -1.40). MUFCRE was marginally associated with VIQ across time (B = -1.29, 95% CI: -2.60, 0.01). No interactions between MUFCRE and child sex or MUFCRE and time were observed. CONCLUSION The negative association between prenatal fluoride exposure and longitudinal IQ was driven by decrements in non-verbal intelligence (i.e. PIQ), suggesting that visual-spatial and perceptual reasoning abilities may be more impacted by prenatal fluoride exposure as compared to verbal abilities.
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Affiliation(s)
- Carly V Goodman
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Morteza Bashash
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Rivka Green
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Peter Song
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Karen E Peterson
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | | | | | | | | | | | | | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Christine Till
- Faculty of Health, York University, Toronto, Ontario, Canada
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Fluoride Metabolism in Pregnant Women: A Narrative Review of the Literature. Metabolites 2022; 12:metabo12040324. [PMID: 35448511 PMCID: PMC9032535 DOI: 10.3390/metabo12040324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 02/06/2023] Open
Abstract
Epidemiological studies use biomarkers of fluoride exposure in pregnant women as surrogate measures of fetal fluoride exposure; however, there is little understanding of how pregnancy affects fluoride metabolism and its biomarkers. This narrative review summarizes the changes of pregnancy that have the potential to impact fluoride’s absorption, distribution and excretion, and highlights the limited body of evidence on the topic. The physiologic systems that experience pregnancy-associated changes relevant to fluoride’s metabolism are the cardiovascular, renal, metabolic and gastrointestinal, as well bone and calcium metabolism and the body’s acid-base balance. The available evidence indicates that fluoride is found in the maternal plasma and urine, placenta, amniotic fluid and fetus. Although plasma and urinary fluoride vary across gestation, there is insufficient quality evidence to determine the direction or extent of such variation. Furthermore, there is no doubt that fluoride from maternal blood crosses the placenta and is absorbed and excreted by the fetus; however, the biological mechanisms behind this placental passage are unknown. Research on maternal and prenatal biomarkers of fluoride exposure would benefit from studies on how pregnancy-associated changes affect the metabolism of fluoride across gestation, the mechanisms for the intestinal absorption of fluoride in pregnant women, and the placental passage of fluoride.
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Farag MA, Hamouda S, Gomaa S, Agboluaje AA, Hariri MLM, Yousof SM. Dietary Micronutrients from Zygote to Senility: Updated Review of Minerals' Role and Orchestration in Human Nutrition throughout Life Cycle with Sex Differences. Nutrients 2021; 13:nu13113740. [PMID: 34835995 PMCID: PMC8625354 DOI: 10.3390/nu13113740] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 12/15/2022] Open
Abstract
Micronutrients such as selenium, fluoride, zinc, iron, and manganese are minerals that are crucial for many body homeostatic processes supplied at low levels. The importance of these micronutrients starts early in the human life cycle and continues across its different stages. Several studies have emphasized the critical role of a well-balanced micronutrient intake. However, the majority of studies looked into or examined such issues in relation to a specific element or life stage, with the majority merely reporting the effect of either excess or deficiency. Herein, in this review, we will look in depth at the orchestration of the main element requirements across the human life cycle beginning from fertility and pregnancy, passing through infancy, childhood, adolescence, and reaching adulthood and senility, with insight on the interactions among them and underlying action mechanisms. Emphasis is given towards approaches to the role of the different minerals in the life cycle, associated symptoms for under- or overdoses, and typical management for each element, with future perspectives. The effect of sex is also discussed for each micronutrient for each life stage as literature suffice to highlight the different daily requirements and or effects.
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Affiliation(s)
- Mohamed A. Farag
- Department of Pharmacognosy, College of Pharmacy, Cairo University, Cairo 11562, Egypt
- Department of Chemistry, School of Sciences & Engineering, the American University in Cairo, New Cairo 11835, Egypt; (S.H.); (S.G.); (A.A.A.); (M.L.M.H.)
- Correspondence: (M.A.F.); (S.M.Y.)
| | - Samia Hamouda
- Department of Chemistry, School of Sciences & Engineering, the American University in Cairo, New Cairo 11835, Egypt; (S.H.); (S.G.); (A.A.A.); (M.L.M.H.)
| | - Suzan Gomaa
- Department of Chemistry, School of Sciences & Engineering, the American University in Cairo, New Cairo 11835, Egypt; (S.H.); (S.G.); (A.A.A.); (M.L.M.H.)
| | - Aishat A. Agboluaje
- Department of Chemistry, School of Sciences & Engineering, the American University in Cairo, New Cairo 11835, Egypt; (S.H.); (S.G.); (A.A.A.); (M.L.M.H.)
| | - Mohamad Louai M. Hariri
- Department of Chemistry, School of Sciences & Engineering, the American University in Cairo, New Cairo 11835, Egypt; (S.H.); (S.G.); (A.A.A.); (M.L.M.H.)
| | - Shimaa Mohammad Yousof
- Department of Medical Physiology, Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Department of Medical Physiology, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt
- Correspondence: (M.A.F.); (S.M.Y.)
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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] [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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