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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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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] [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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Hall M, Hornung R, Chevrier J, Ayotte P, Lanphear B, Till C. Fluoride exposure and thyroid hormone levels in pregnancy: The MIREC cohort. ENVIRONMENT INTERNATIONAL 2024; 184:108442. [PMID: 38237505 PMCID: PMC10973885 DOI: 10.1016/j.envint.2024.108442] [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: 08/18/2023] [Revised: 01/03/2024] [Accepted: 01/10/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND Fluoride exposure may increase the risk of hypothyroidism, but results from previous studies are inconsistent at low-level fluoride exposure (i.e., ≤0.7 mg/L). Human studies of fluoride and thyroid hormone levels in pregnancy are scarce. OBJECTIVES We examined associations between fluoride exposure and maternal thyroid hormone levels in a Canadian pregnancy cohort, with consideration for fetal sex-specific effects. METHODS We measured fluoride concentrations in drinking water and spot urine samples collected during each trimester from 1876 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. We also measured maternal thyroid stimulating hormone (TSH), free thyroxine (FT4), and total thyroxine (TT4) levels during the first trimester of pregnancy. We used linear and non-linear regression models to estimate associations between fluoride exposure and levels of TSH, FT4, and TT4. We explored effect modification by fetal sex and considered maternal iodine status as a potential confounder. RESULTS A 1 mg/L increase in urinary fluoride was associated with a 0.30 (95 %CI: 0.08, 0.51) logarithmic unit (i.e., 35.0 %) increase in TSH among women pregnant with females, but not males (B = 0.02; 95 %CI: -0.16, 0.19). Relative to women with urinary fluoride concentrations in the first quartile (0.05-0.32 mg/L), those with levels in the third quartile (0.49-0.75 mg/L) had higher FT4 and TT4 (i.e., inverted J-shaped associations), but the association was not statistically significant after adjustment for covariates (p = 0.06). Water fluoride concentration showed a U-shaped association with maternal FT4, whereby women with water fluoride concentrations in the second (0.13-0.52 mg/L) and third (0.52-0.62 mg/L) quartiles had significantly lower FT4 compared to those with levels in the first quartile (0.04-0.13 mg/L). Adjustment for maternal iodine status did not change the results. DISCUSSION Fluoride exposure was associated with alterations in maternal thyroid hormone levels, the magnitude of which appeared to vary by fetal sex. Given the importance of maternal thyroid hormones for fetal neurodevelopment, replication of findings is warranted.
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Affiliation(s)
- Meaghan Hall
- Psychology Department, York University, Toronto, ON, Canada.
| | - Rick Hornung
- Retired, Consultant to Psychology Department, York University, Toronto, ON, Canada.
| | - Jonathan Chevrier
- School of Population and Global Health, McGill University, Montreal, QC, Canada.
| | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada.
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
| | - Christine Till
- Psychology Department, York University, Toronto, ON, Canada.
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India Aldana S, Colicino E, Cantoral Preciado A, Tolentino M, Baccarelli AA, Wright RO, Téllez Rojo MM, Valvi D. Longitudinal associations between early-life fluoride exposures and cardiometabolic outcomes in school-aged children. ENVIRONMENT INTERNATIONAL 2024; 183:108375. [PMID: 38128386 PMCID: PMC10842303 DOI: 10.1016/j.envint.2023.108375] [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: 07/12/2023] [Revised: 11/06/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND/AIM Fluoride is a natural mineral present in food, water, and dental products, constituting ubiquitous long-term exposure in early childhood and across the lifespan. Experimental evidence shows fluoride-induced lipid disturbances with potential implications for cardiometabolic health. However, epidemiological studies are scarce. For the first time, we evaluated associations between repeated fluoride measures and cardiometabolic outcomes in children. METHODS We studied ∼ 500 Mexican children from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort with measurements on urinary fluoride at age 4, and dietary fluoride at ages 4, 6, and 8 years approximately. We used covariate-adjusted linear mixed-effects and linear regression models to assess fluoride associations with multiple cardiometabolic outcomes (ages 4-8): lipids (total cholesterol, HDL, LDL, and triglycerides), glucose, HbA1c, adipokines (leptin and adiponectin), body fat, and age- and sex-specific z-scores of body mass index (zBMI), waist circumference, and blood pressure. RESULTS Dietary fluoride intake at age 4 was associated with annual increases in triglycerides [β per-fluoride-doubling = 2.02 (95 % CI: 0.37, 3.69)], cholesterol [β = 1.46 (95 % CI: 0.52, 2.39)], HDL [β = 0.39 (95 % CI: 0.02, 0.76)], LDL [β = 0.87 (95 % CI: 0.02, 1.71)], and HbA1c [β = 0.76 (95 % CI: 0.28, 1.24)], and decreased leptin [β = -3.58 (95 % CI: -6.34, -0.75)] between the ages 4 and 8. In cross-sectional analyses at age 8, higher tertiles of fluoride exposure were associated with increases in zBMI, triglycerides, glucose, and leptin (p-tertile trend < 0.05). Stronger associations were observed in boys at year 8 and in girls prior to year 8 (p-sex interaction < 0.05). Fewer but consistent associations were observed for urinary fluoride at age 4, indicating increased annual changes in HDL and HbA1c with higher fluoride levels. CONCLUSION Dietary fluoride exposures in early- and mid-childhood were associated with adverse cardiometabolic outcomes in school-aged children. Further research is needed to elucidate whether these associations persist at later ages.
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Affiliation(s)
- Sandra India Aldana
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Elena Colicino
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Maricruz Tolentino
- Department of Nutrition, National Institute of Perinatology, Mexico City, Mexico
| | - Andrea A Baccarelli
- Departments of Environmental Health Sciences and Epidemiology, Columbia University Mailman School of Public Health, 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
| | - Martha María Téllez Rojo
- Center for Nutrition and Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Damaskini Valvi
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Krzeczkowski JE, Hall M, Saint-Amour D, Oulhote Y, McGuckin T, Goodman CV, Green R, Muckle G, Lanphear B, Till C. Prenatal fluoride exposure, offspring visual acuity and autonomic nervous system function in 6-month-old infants. ENVIRONMENT INTERNATIONAL 2024; 183:108336. [PMID: 38064923 PMCID: PMC10981044 DOI: 10.1016/j.envint.2023.108336] [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: 06/15/2023] [Revised: 11/10/2023] [Accepted: 11/17/2023] [Indexed: 01/25/2024]
Abstract
BACKGROUND Prenatal fluoride exposure can have adverse effects on children's development; however, associations with visual and cardiac autonomic nervous system functioning are unknown. We examined associations between prenatal fluoride exposure and visual acuity and heart rate variability (HRV) in 6-month-old infants. METHODS We used data from Canadian mother-infant pairs participating in the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort. We estimated prenatal fluoride exposure using: i) fluoride concentration in drinking water (mg/L), ii) maternal urinary fluoride adjusted for specific gravity (MUFSG; mg/L) and averaged across pregnancy, and iii) maternal fluoride intake (µg/kg/day) from consumption of water, tea, and coffee, adjusted for maternal body weight (kg). We used multivariable linear regression to examine associations between each measure of fluoride exposure and Teller Acuity Card visual acuity scores (n = 435) and assessed HRV (n = 400) using two measures: root mean square of successive differences (RMSSD) and the standard deviation of N-N intervals (SDNN) measured at 6-months of age. RESULTS Median (IQR) values for water fluoride, MUFSG, and daily fluoride intake were 0.20 (IQR: 0.13-0.56) mg/L; 0.44 (0.28-0.70) mg/L and 4.82 (2.58-10.83) µg/kg/day, respectively. After adjustment for confounding variables, water fluoride concentration was associated with poorer infant visual acuity (B = -1.51; 95 % CI: -2.14,-0.88) and HRV as indicated by lower RMSSD (B = -1.60; 95 % CI: -2.74,-0.46) but not SDNN. Maternal fluoride intake was also associated with poorer visual acuity (B = -0.82; 95 % CI: -1.35,-0.29) and lower RMSSD (B = -1.22; 95 % CI: -2.15,-0.30). No significant associations were observed between MUFSG and visual acuity or HRV. CONCLUSION Fluoride in drinking water was associated with reduced visual acuity and alterations in cardiac autonomic function in infancy, adding to the growing body of evidence suggesting fluoride's developmental neurotoxicity.
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Affiliation(s)
- John E Krzeczkowski
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada.
| | - Meaghan Hall
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Dave Saint-Amour
- Faculté de médecine - Département d'ophtalmologie, Université de Montréal, Montréal, Québec, Canada
| | - Youssef Oulhote
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sina, New York, NY, USA
| | - Taylor McGuckin
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Carly V Goodman
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Rivka Green
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Gina Muckle
- Centre de recherche du CHU de Québec-Université Laval, Québec, Canada; École de Psychologie, Université Laval, Québec, Québec, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, Ontario, Canada
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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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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] [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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Hung M, Mohajeri A, Chiang J, Park J, Bautista B, Hardy C, Lipsky MS. Community Water Fluoridation in Focus: A Comprehensive Look at Fluoridation Levels across America. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:7100. [PMID: 38063530 PMCID: PMC10706776 DOI: 10.3390/ijerph20237100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023]
Abstract
Objective: This study reports on the number and percentage of community water systems (CWSs) meeting fluoride concentration standards set by the U.S. Department of Health and Human Services (DHHS). The study also explored changes in the population exposed to optimally fluoridated water in these systems between 2006 and 2020. Methods: This study analyzed U.S. Centers for Disease Control and Prevention data from 2006 to 2020, tabulating state-specific CWS fluoridation rates, ranking them, and calculating the percent change. Results: In 2020, 72.7% of the US population received CWS water, with 62.9% of those individuals served by a CWS system meeting DHHS fluoridation standards. This compares to 69.2% receiving CWS water in 2006 and 74.6% in 2012. The overall change in those receiving fluoridated water was 1.4%, from 61.5% in 2006 to 62.9% in 2020. State-specific percentages ranged from 8.5% in Hawaii to 100% in Washington DC in 2020 (median: 76.4%). Conclusions: Although endorsed by the American Dental Association, the percentage of individuals receiving fluoridated water did not increase substantially from 2006 to 2020, indicating that there has not been much progress toward meeting the Healthy People 2030 goal that 77.1% of Americans receive water with enough fluoride to prevent tooth decay.
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Affiliation(s)
- Man Hung
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UT 84095, USA
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA
- College of Social Work, University of Utah, Salt Lake City, UT 84112, USA
- Department of Veterans Affairs Medical Center, Salt Lake City, UT 84148, USA
| | - Amir Mohajeri
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UT 84095, USA
| | - Jody Chiang
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UT 84095, USA
| | - Jungweon Park
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UT 84095, USA
- College of Dentistry, Ohio State University, Columbus, OH 43210, USA
| | - Beatrice Bautista
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UT 84095, USA
| | - Chase Hardy
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UT 84095, USA
- College of Dentistry, University of Texas Health Sciences, San Antonio, TX 78253, USA
| | - Martin S. Lipsky
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UT 84095, USA
- Institute on Aging, Portland State University, Portland, OR 97201, USA
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10
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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] [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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11
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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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12
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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. ENVIRONMENTAL RESEARCH 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] [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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13
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Irigoyen-Camacho ME, Perez-Perez N, Zepeda-Zepeda MA, Velazquez-Alva MC, Castaño-Seiquer A, Barbero-Navarro I, Sanchez-Perez L. Relationships between dental fluorosis and fluoride concentrations in bottled water and groundwater in low-income children in Mexico. FRONTIERS IN ORAL HEALTH 2023; 4:1187463. [PMID: 37377524 PMCID: PMC10291056 DOI: 10.3389/froh.2023.1187463] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 05/17/2023] [Indexed: 06/29/2023] Open
Abstract
Introduction The aim of the current study was to investigate associations between dental fluorosis in children living in low socioeconomic areas in Mexico, and fluoride concentrations in tap water, fluoride concentrations and in bottled water, and body mass index (BMI). Methods A cross-sectional study involving 585 schoolchildren aged 8-12 years was conducted in communities in a southern state of Mexico with >0.7 parts per million (ppm) fluoride in the groundwater. The Thylstrup and Fejerskov index (TFI) was used to evaluate dental fluorosis, and the World Health Organization growth standards were used to calculate age-adjusted and sex-adjusted BMI Z-scores. A BMI Z-score ≤ -1 SD was used as the cut-off point for thinness, and multiple logistic regression models for dental fluorosis (TFI ≥ 4) were constructed. Results The mean fluoride concentration in tap water was 1.39 ppm (SD 0.66), and the mean fluoride concentration in bottled water was 0.32 ppm (SD 0.23). Eighty-four children (14.39%) had a BMI Z-score ≤ -1 SD. More than half (56.1%) of the children presented with dental fluorosis in TFI categories ≥ 4. Children living in areas with higher fluoride concentrations in the tap water [odds ratio (OR) 1.57, p = 0.002] and bottled water (OR 3.03, p < .001) were more likely to have dental fluorosis in the severe categories (TFI ≥ 4). BMI Z-score was associated with the probability of dental fluorosis (TFI ≥ 4; OR 2.11, p < 0.001), and the effect size was 29.3%. Discussion A low BMI Z-score was associated with a higher prevalence of dental fluorosis in the severe category. Awareness of the fluoride concentrations in bottled water may help prevent dental fluorosis, particularly in children exposed to several high fluoride content sources. Children with a low BMI may be more vulnerable to dental fluorosis.
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Affiliation(s)
| | - Nora Perez-Perez
- School of Dentistry, Regional University of the Southeast, Oaxaca de Juárez, Mexico
| | | | | | | | | | - Leonor Sanchez-Perez
- Health Care Department, Metropolitan Autonomous University-Xochimilco, Mexico City, Mexico
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Morales-Arredondo JI, Armienta-Hernández MA, Lugo-Dorantes AE, Barrera-Arrazola AP, Flores-Ocampo IZ, Flores-Vargas R. Fluoride presence in drinking water along the southeastern part of El Bajío Guanajuatense, Guanajuato, Mexico: sources and health effects. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:3715-3742. [PMID: 36484881 DOI: 10.1007/s10653-022-01426-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 10/25/2022] [Indexed: 06/01/2023]
Abstract
Drinking water with a high natural concentration of fluoride (F-) has serious consequences for the health of the rural population in the state of Guanajuato, Mexico, where the water contains levels of F- that are not allowed by national and international regulations (1.5 mg/L). This health problem is very common in multiple states throughout Mexico where drinking water is generally extracted from aquifers that are hosted in fractured volcanic rocks of the Tertiary. These aquifers show similar geological characteristics: deep basins that formed as a result of felsic eruptive events and the extensional deformation of the Basin and Range and are now filled with unconsolidated sediments. In this study, we assessed the occurrence of F in volcanic rocks collected at 11 sampling sites along the Sierra de Codornices in Guanajuato (ranging between 0.01299 and 0.146 wt%, average 0.039 wt%, and SD = 0.039 wt%; n = 10), a region where both rural and urban communities consume drinking water with a high F- content (up to 7.1 (mg/L). The F content is dispersed in volcanic rocks, and the highest levels are present in felsic rocks. The statistical and hydrogeochemical results of a sampling campaign of 32 wells in the Juventino Rosas (JR) and Villagran (Vill) municipalities in 2019 suggest that F- mobilization in groundwater is the product of silicate weathering and the dissolution of volcanic glass, alkaline desorption in the surfaces of F-containing minerals, and possibly ion exchange of minerals and clays or deep fluids enriched with F-, in addition to the precipitation of carbonates that decrease the Ca2+ concentration in groundwater. All of these processes can be accelerated by groundwater geothermal characteristics within the study area. The hydrogeochemical, fluoride exposure risk, and fluoride pollution index (FPI) results, as well as the epidemiological survey, indicate that teenagers and older adults from Praderas de la Venta are at risk of exposure to F- due to the high concentrations ingested over a long period, the toxicity of the element, and its ability to accumulate in the bones. Extended exposure to elevated levels increases the risk. This work allows us to observe how the populations of JR and Vill can be exposed to high F- contents in drinking water due to the geological characteristics of the region.
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Affiliation(s)
- Jose Ivan Morales-Arredondo
- Departamento de Recursos Naturales, Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria No. 3000, Col. Copilco Universidad, 04360, Delegación Coyoacán, CDMX, Mexico.
| | - Maria Aurora Armienta-Hernández
- Departamento de Recursos Naturales, Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria No. 3000, Col. Copilco Universidad, 04360, Delegación Coyoacán, CDMX, Mexico
| | - Angel Eduardo Lugo-Dorantes
- Universidad Nacional Autónoma de México, Ciudad Universitaria No. 3000, Col. Copilco Universidad, 04510, Delegación Coyoacán, CDMX, Mexico
| | - Andrea Pamela Barrera-Arrazola
- Universidad Nacional Autónoma de México, Ciudad Universitaria No. 3000, Col. Copilco Universidad, 04510, Delegación Coyoacán, CDMX, Mexico
| | - Itzamna Zaknite Flores-Ocampo
- Earth Sciences Postgraduate Program, Universidad Nacional Autónoma de México, Ciudad Universitaria No. 3000, Col. Copilco Universidad, 04510, Delegación Coyoacán, CDMX, Mexico
| | - Ricardo Flores-Vargas
- Earth Sciences Postgraduate Program, Universidad Nacional Autónoma de México, Ciudad Universitaria No. 3000, Col. Copilco Universidad, 04510, Delegación Coyoacán, CDMX, Mexico
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15
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Lin YY, Hsu WY, Yen CE, Hu SW. Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren. CHILDREN (BASEL, SWITZERLAND) 2023; 10:987. [PMID: 37371219 DOI: 10.3390/children10060987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023]
Abstract
Fluoride is present naturally in water and has been used worldwide for the prevention of caries. Several studies conducted in high water fluoride or endemic fluorosis areas reported that fluoride adversely affected children's cognitive function, but some studies had negative findings. This study aimed to assess the relationship between urinary fluoride, dental fluorosis, and intelligence among schoolchildren living in communities with non-fluoridated drinking water. This cross-sectional study was conducted on 562 children aged 6-12 years in Taichung, Taiwan. Each child's urinary fluoride level was determined by a fluoride-ion-selective electrode, and the dental fluorosis condition was evaluated according to the criteria of Dean's Index. The Raven's Colored Progressive Matrices-Parallel and Standard Progressive Matrices-Parallel were used to assess children's intelligence. The results showed that the mean (±standard deviation) urinary fluoride concentrations were 0.40 ± 0.27 mg/L (0.43 ± 0.23 mg/g creatinine) among participants. The prevalence of dental fluorosis was 23.67%. After extensive evaluation of potential confounders, dental fluorosis and urinary fluoride were not associated with intelligence quotient (IQ) scores or grades in the regression models. In conclusion, dental fluorosis and urinary fluoride levels were not significantly related to the IQ of schoolchildren living in areas with low drinking water fluoride.
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Affiliation(s)
- Yuh-Yih Lin
- Institute of Oral Sciences, Chung Shan Medical University, Taichung 40201, Taiwan
| | - Wen-Yu Hsu
- Department of Psychology, Chung Shan Medical University, Taichung 40201, Taiwan
| | - Chin-En Yen
- Department of Early Childhood Development and Education, Chaoyang University of Technology, Taichung 41349, Taiwan
| | - Suh-Woan Hu
- Institute of Oral Sciences, Chung Shan Medical University, Taichung 40201, Taiwan
- Department of Dentistry, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
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16
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Rocha-Amador DO, González-Martell AD, Pérez-Vázquez FJ, Cilia López VG. Health Risk Assessment in Mexican Children Exposed to Fluoride from Sweetened Beverages. Biol Trace Elem Res 2023; 201:2250-2257. [PMID: 35854170 DOI: 10.1007/s12011-022-03350-z] [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: 03/30/2022] [Accepted: 07/01/2022] [Indexed: 12/07/2022]
Abstract
The primary source of fluoride exposure is groundwater, but evidence suggests that beverages and food are additional fluoride sources. Intake of these products at an early age affects the optimal functioning of soft organs. An increase in sweetened beverage consumption by the pediatric population has been reported, suggesting an increase in fluoride exposure. The objectives of this study were to determine the fluoride concentrations in beverages and analyze the risk to human health from fluoride exposure to sweetened beverages consumed by children. Eighty-two sugar-sweetened beverages produced in different Mexican states were analyzed. The fluoride determination was carried out with an ion-selective electrode. The highest fluoride concentration was 1.92 mg/L; 73.2% of beverages showed fluoride values above permitted limits. Low-cost beverages had the highest fluoride values, suggesting that the water used for their production does not comply with fluorine regulations. According to the risk assessment in children from 3 to 6 years, the daily consumption of juices and sodas with concentrations that exceeded the normative of 0.7 mg/L could represent a risk to dental fluorosis development. It is crucial to control fluoride and regulate its concentrations in beverages for children to ensure food safety, especially in areas of endemic hydrofluorosis.
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Affiliation(s)
- Diana Olivia Rocha-Amador
- Departamento de Farmacia, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
- Facultad de Medicina-CIACYT, Universidad Autónoma de San Luis Potosí, San Luis Potosi, Mexico
| | - Andrea Daniela González-Martell
- Programa Multidisciplinario de Posgrado en Ciencias Ambientales (PMPCA), Universidad Autónoma de San Luis Potosí, San Luis Potosi, Mexico
- Facultad de Medicina-CIACYT, Universidad Autónoma de San Luis Potosí, San Luis Potosi, Mexico
| | - Francisco Javier Pérez-Vázquez
- CONACYT Research Fellow, Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología (CIACYT), Universidad Autónoma de San Luis Potosí, San Luis Potosi, Mexico
| | - Virginia Gabriela Cilia López
- CONACYT Research Fellow, Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología (CIACYT), Universidad Autónoma de San Luis Potosí, San Luis Potosi, Mexico.
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17
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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] [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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18
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Hall M, Lanphear B, Chevrier J, Hornung R, Green R, Goodman C, Ayotte P, Martinez-Mier EA, Zoeller RT, Till C. Fluoride exposure and hypothyroidism in a Canadian pregnancy cohort. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161149. [PMID: 36764861 PMCID: PMC9992168 DOI: 10.1016/j.scitotenv.2022.161149] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/19/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
BACKGROUND While fluoride can have thyroid-disrupting effects, associations between low-level fluoride exposure and thyroid conditions remain unclear, especially during pregnancy when insufficient thyroid hormones can adversely impact offspring development. OBJECTIVES We evaluated associations between fluoride exposure and hypothyroidism in a Canadian pregnancy cohort. METHODS We measured fluoride concentrations in drinking water and three dilution-corrected urine samples and estimated fluoride intake based on self-reported beverage consumption. We classified women enrolled in the Maternal-Infant Research on Environmental Chemicals Study as euthyroid (n = 1301), subclinical hypothyroid (n = 100) or primary hypothyroid (n = 107) based on their thyroid hormone levels in trimester one. We used multinomial logistic regression to estimate the association between fluoride exposure and classification of either subclinical or primary hypothyroidism and considered maternal thyroid peroxidase antibody (TPOAb) status, a marker of autoimmune hypothyroidism, as an effect modifier. In a subsample of 466 mother-child pairs, we used linear regression to explore the association between maternal hypothyroidism and child Full-Scale IQ (FSIQ) at ages 3-to-4 years and tested for effect modification by child sex. RESULTS A 0.5 mg/L increase in drinking water fluoride concentration was associated with a 1.65 (95 % confidence interval [CI]: 1.04, 2.60) increased odds of primary hypothyroidism. In contrast, we did not find a significant association between urinary fluoride (adjusted odds ratio [aOR]: 1.00; 95%CI: 0.73, 1.39) or fluoride intake (aOR: 1.25; 95%CI: 0.99, 1.57) and hypothyroidism. Among women with normal TPOAb levels, the risk of primary hypothyroidism increased with both increasing water fluoride and fluoride intake (aOR water fluoride concentration: 2.85; 95%CI: 1.25, 6.50; aOR fluoride intake: 1.75; 95%CI: 1.27, 2.41). Children born to women with primary hypothyroidism had lower FSIQ scores compared to children of euthyroid women, especially among boys (B coefficient: -8.42; 95 % CI: -15.33, -1.50). DISCUSSION Fluoride in drinking water was associated with increased risk of hypothyroidism in pregnant women. Thyroid disruption may contribute to developmental neurotoxicity of fluoride.
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Affiliation(s)
- Meaghan Hall
- Psychology Department, York University, Toronto, ON, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Jonathan Chevrier
- School of Population and Global Health, McGill University, Montreal, QC, Canada
| | - Rick Hornung
- Retired; Consultant to Psychology Department, York University, Toronto, ON, Canada
| | - Rivka Green
- Psychology Department, York University, Toronto, ON, Canada
| | - Carly Goodman
- Psychology Department, York University, Toronto, ON, Canada
| | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada
| | | | - R Thomas Zoeller
- Biology Department, The University of Massachusetts Amherst, Amherst, MA, United States
| | - Christine Till
- Psychology Department, York University, Toronto, ON, Canada.
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Tang Y, Zhang J, Hu Z, Xu W, Xu P, Ma Y, Xing H, Niu Q. PRKAA1 induces aberrant mitophagy in a PINK1/Parkin-dependent manner, contributing to fluoride-induced developmental neurotoxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 255:114772. [PMID: 36924562 DOI: 10.1016/j.ecoenv.2023.114772] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 03/02/2023] [Accepted: 03/11/2023] [Indexed: 06/18/2023]
Abstract
Chronic fluoride exposure can cause developmental neurotoxicity, however the precise mechanisms remain unclear. To explore the mechanism of mitophagy in fluoride-induced developmental neurotoxicity, specifically focusing on PRKAA1 in regulating the PINK1/Parkin pathway, we established a Sprage Dawley rat model with continuous sodium fluoride (NaF) exposure and an NaF-treated SH-SY5Y cell model. We found that NaF exposure increased the levels of LC3-Ⅱ and p62, impaired autophagic degradation, and subsequently blocked autophagic flux. Additionally, NaF exposure increased the expression of PINK1, Parkin, TOMM-20, and Cyt C and cleaved PARP in vivo and in vitro, indicating NaF promotes mitophagy and neuronal apoptosis. Meanwhile, phosphoproteomics and western blot analysis showed that NaF treatment enhanced PRKAA1 phosphorylation. Remarkably, the application of both 3-methyladenosine (3-MA; autophagy inhibitor) and dorsomorphin (DM; AMPK inhibitor) suppressed NaF-induced neuronal apoptosis by restoring aberrant mitophagy. In addition, 3-MA attenuated an increase in p62 protein levels and NaF-induced autophagic degradation. Collectively, our findings indicated that NaF causes aberrant mitophagy via PRKAA1 in a PINK1/Parkin-dependent manner, which triggers neuronal apoptosis. Thus, regulating PRKAA1-activated PINK1/Parkin-dependent mitophagy may be a potential treatment for NaF-induced developmental neurotoxicity.
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Affiliation(s)
- 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
| | - 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
| | - 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
| | - 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
| | - 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
| | - 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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20
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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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21
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Enax J, Amaechi BT, Farah R, Liu JA, Schulze zur Wiesche E, Meyer F. Remineralization Strategies for Teeth with Molar Incisor Hypomineralization (MIH): A Literature Review. Dent J (Basel) 2023; 11:dj11030080. [PMID: 36975577 PMCID: PMC10047667 DOI: 10.3390/dj11030080] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/01/2023] [Accepted: 03/07/2023] [Indexed: 03/16/2023] Open
Abstract
Molar incisor hypomineralization (MIH) is a highly prevalent dental developmental disorder with a significant health burden for patients and high treatment needs, yet no comprehensive review article on all remineralization systems as a non-invasive treatment approach for MIH has been published. Typical characteristics of MIH-affected teeth are a lower mineral density and lower hardness compared to healthy teeth leading to sensitivity and loss of function. Thus, the use of formulations with calcium phosphates to remineralize MIH-affected teeth is reasonable. This review presents an up-to-date overview of remineralization studies focusing on active ingredients investigated for remineralization of MIH, i.e., casein phosphopeptide amorphous calcium phosphate (CPP-ACP), casein phosphopeptide amorphous calcium fluoride phosphate (CPP-ACFP), hydroxyapatite, calcium glycerophosphate, self-assembling peptide, and fluoride. Overall, 19 studies (in vitro, in situ, and in vivo) were found. Furthermore, an additional search for studies focusing on using toothpaste/dentifrices for MIH management resulted in six studies, where three studies were on remineralization and three on reduction of sensitivity. Overall, the studies analyzed in this review showed that MIH-affected teeth could be remineralized using calcium phosphate-based approaches. In conclusion, calcium phosphates like CPP-ACP, calcium glycerophosphate, and hydroxyapatite can be used to remineralize MIH-affected teeth. In addition to MIH-remineralization, CPP-ACP and hydroxyapatite also offer relief from MIH-associated tooth sensitivity.
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Affiliation(s)
- Joachim Enax
- Research Department, Dr. Kurt Wolff GmbH & Co. KG, Johanneswerkstr. 34-36, 33611 Bielefeld, Germany
- Correspondence: (J.E.); (B.T.A.); (F.M.)
| | - Bennett T. Amaechi
- Department of Comprehensive Dentistry, School of Dentistry, University of Texas Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
- Correspondence: (J.E.); (B.T.A.); (F.M.)
| | - Rayane Farah
- Department of Comprehensive Dentistry, School of Dentistry, University of Texas Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
| | - Jungyi Alexis Liu
- Department of Developmental Dentistry, School of Dentistry, University of Texas Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
| | - Erik Schulze zur Wiesche
- Research Department, Dr. Kurt Wolff GmbH & Co. KG, Johanneswerkstr. 34-36, 33611 Bielefeld, Germany
| | - Frederic Meyer
- Research Department, Dr. Kurt Wolff GmbH & Co. KG, Johanneswerkstr. 34-36, 33611 Bielefeld, Germany
- Correspondence: (J.E.); (B.T.A.); (F.M.)
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22
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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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23
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Colorimetric sensing of fluoride ion by a Chlorophosphonazo III -based Al3+ complex in aqueous media via indicator displacement approach. Tetrahedron Lett 2023. [DOI: 10.1016/j.tetlet.2023.154405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Fluoride in the Central Nervous System and Its Potential Influence on the Development and Invasiveness of Brain Tumours-A Research Hypothesis. Int J Mol Sci 2023; 24:ijms24021558. [PMID: 36675073 PMCID: PMC9866357 DOI: 10.3390/ijms24021558] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
The purpose of this review is to attempt to outline the potential role of fluoride in the pathogenesis of brain tumours, including glioblastoma (GBM). In this paper, we show for the first time that fluoride can potentially affect the generally accepted signalling pathways implicated in the formation and clinical course of GBM. Fluorine compounds easily cross the blood-brain barrier. Enhanced oxidative stress, disruption of multiple cellular pathways, and microglial activation are just a few examples of recent reports on the role of fluoride in the central nervous system (CNS). We sought to present the key mechanisms underlying the development and invasiveness of GBM, as well as evidence on the current state of knowledge about the pleiotropic, direct, or indirect involvement of fluoride in the regulation of these mechanisms in various tissues, including neural and tumour tissue. The effects of fluoride on the human body are still a matter of controversy. However, given the growing incidence of brain tumours, especially in children, and numerous reports on the effects of fluoride on the CNS, it is worth taking a closer look at these mechanisms in the context of brain tumours, including gliomas.
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25
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Do LG, Spencer AJ, Sawyer A, Jones A, Leary S, Roberts R, Ha DH. Early Childhood Exposures to Fluorides and Child Behavioral Development and Executive Function: A Population-Based Longitudinal Study. J Dent Res 2023; 102:28-36. [PMID: 36214232 DOI: 10.1177/00220345221119431] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
It is important to both protect the healthy development and maintain the oral health of the child population. The study examined the effect of early childhood exposures to water fluoridation on measures of school-age executive functioning and emotional and behavioral development in a population-based sample. This longitudinal follow-up study used information from Australia's National Child Oral Health Study 2012-14. Children aged 5 to 10 y at baseline were contacted again after 7 to 8 y, before they had turned 18 y of age. Percent lifetime exposed to fluoridated water (%LEFW) from birth to the age 5 y was estimated from residential history and postcode-level fluoride levels in public tap water. Measures of children's emotional and behavioral development were assessed by the Strength and Difficulties Questionnaire (SDQ), and executive functioning was measured by the Behavior Rating Inventory of Executive Function (BRIEF). Multivariable regression models were generated to compare the associations between the exposure and the primary outcomes and controlled for covariates. An equivalence test was also conducted to compare the primary outcomes of those who had 100% LEFW against those with 0% LEFW. Sensitivity analysis was also conducted. A total of 2,682 children completed the SDQ and BRIEF, with mean scores of 7.0 (95% confidence interval, 6.6-7.4) and 45.3 (44.7-45.8), respectively. Those with lower %LEFW tended to have poorer scores of the SDQ and BRIEF. Multivariable regression models reported no association between exposure to fluoridated water and the SDQ and BRIEF scores. Low household income, identifying as Indigenous, and having a neurodevelopmental diagnosis were associated with poorer SDQ/BRIEF scores. An equivalence test confirmed that the SDQ/BRIEF scores among those with 100% LEFW were equivalent to that of those who had 0% LEFW. Exposure to fluoridated water during the first 5 y of life was not associated with altered measures of child emotional and behavioral development and executive functioning.
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Affiliation(s)
- L G Do
- School of Dentistry, Faculty of Health and Behavioural Sciences, The University of Queensland, Herston, Queensland, Australia
| | - A J Spencer
- Australian Research Centre for Population Oral Health, Adelaide Dental School, The University of Adelaide, Adelaide, Australia
| | - A Sawyer
- School of Psychology, The University of Adelaide, Adelaide, Australia
| | - A Jones
- School of Population and Global Health, Population and Public Health, The University of Western Australia, WA, Australia
| | - S Leary
- Bristol Dental School, University of Bristol, Bristol, UK
| | - R Roberts
- School of Psychology, The University of Adelaide, Adelaide, Australia
| | - D H Ha
- School of Dentistry, Faculty of Health and Behavioural Sciences, The University of Queensland, Herston, Queensland, Australia
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26
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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. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND 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] [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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27
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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] [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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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] [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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The association between fluoride in water and blood pressure in children and adolescents. Pediatr Res 2022; 92:1767-1772. [PMID: 35190682 DOI: 10.1038/s41390-022-01982-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 01/10/2022] [Accepted: 01/16/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND The objective of this study was to determine the association between water and plasma fluoride and blood pressure (BP) among children and adolescents. METHODS Our study population was individuals of 8-18 years in the 2013-2016 National Health and Nutrition Examination Survey. We performed a multivariable linear and logistic regression analysis to examine the relationship between fluoride and BP. RESULTS In a linear regression analysis for systolic BP (SBP) (mm Hg) adjusting for age, sex, race, and poverty, fluoride in water (mg/L) was significant with a coefficient of -0.44 (p = 0.046) among adolescents (12-18 years). Additional adjustments for race, poverty, serum levels of cotinine, and BMI remained significant. While an inverse relationship was found in children (8-11 years), none were significant. Fluoride in plasma was not significant across all ages. The odds ratio of high BP for an increase in water fluoride also was not significant. CONCLUSIONS Higher concentrations of fluoride in water were associated with low SBP only among adolescents. Fluoride alone cannot be responsible for BP as several biological metabolic processes may influence its physiological effects. Fluoride consumption should be considered in conjunction with these processes. IMPACT The high fluoride in drinking water was statistically significantly associated with low systolic BP in children and adolescents. The odds ratio of high BP for an increase in fluoride in drinking water was not significant. Our study contributes to the existing literature by providing individualized data and results on an individual level.
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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] [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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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. ENVIRONMENTAL RESEARCH 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] [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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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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Avila-Rojas SH, Aparicio-Trejo OE, Sanchez-Guerra MA, Barbier OC. Effects of fluoride exposure on mitochondrial function: Energy metabolism, dynamics, biogenesis and mitophagy. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2022; 94:103916. [PMID: 35738460 DOI: 10.1016/j.etap.2022.103916] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [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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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: 1] [Impact Index Per Article: 0.5] [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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Goodman CV, Hall M, Green R, Chevrier J, Ayotte P, Martinez-Mier EA, McGuckin T, Krzeczkowski J, Flora D, Hornung R, Lanphear B, Till C. Iodine Status Modifies the Association between Fluoride Exposure in Pregnancy and Preschool Boys' Intelligence. Nutrients 2022; 14:2920. [PMID: 35889877 PMCID: PMC9319869 DOI: 10.3390/nu14142920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 12/07/2022] Open
Abstract
In animal studies, the combination of in utero fluoride exposure and low iodine has greater negative effects on offspring learning and memory than either alone, but this has not been studied in children. We evaluated whether the maternal urinary iodine concentration (MUIC) modifies the association between maternal urinary fluoride (MUF) and boys' and girls' intelligence. We used data from 366 mother-child dyads in the Maternal-Infant Research on Environmental Chemicals Study. We corrected trimester-specific MUF and MUIC for creatinine, and averaged them to yield our exposure variables (MUFCRE, mg/g; MUICCRE, µg/g). We assessed children's full-scale intelligence (FSIQ) at 3 to 4 years. Using multiple linear regression, we estimated a three-way interaction between MUFCRE, MUICCRE, and child sex on FSIQ, controlling for covariates. The MUICCRE by MUFCRE interaction was significant for boys (p = 0.042), but not girls (p = 0.190). For boys whose mothers had low iodine, a 0.5 mg/g increase in MUFCRE was associated with a 4.65-point lower FSIQ score (95% CI: -7.67, -1.62). For boys whose mothers had adequate iodine, a 0.5 mg/g increase in MUFCRE was associated with a 2.95-point lower FSIQ score (95% CI: -4.77, -1.13). These results suggest adequate iodine intake during pregnancy may minimize fluoride's neurotoxicity in boys.
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Affiliation(s)
- Carly V. Goodman
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Meaghan Hall
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Rivka Green
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Jonathan Chevrier
- Department of Epidemiology, Biostatistics, and Occupational Health, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC H3A 1G1, Canada;
| | - Pierre Ayotte
- Département de Médecine Sociale et Préventive, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada;
| | - Esperanza Angeles Martinez-Mier
- Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, Indianapolis, IN 46202, USA;
| | - Taylor McGuckin
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - John Krzeczkowski
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - David Flora
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada;
| | - Christine Till
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
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Knappett PSK, Farias P, Miller GR, Hoogesteger J, Li Y, Mendoza‐Sanchez I, Woodward RT, Hernandez H, Loza‐Aguirre I, Datta S, Huang Y, Carrillo G, Roh T, Terrell D. A Systems Approach to Remediating Human Exposure to Arsenic and Fluoride From Overexploited Aquifers. GEOHEALTH 2022; 6:e2022GH000592. [PMID: 35799913 PMCID: PMC9250112 DOI: 10.1029/2022gh000592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 05/14/2023]
Abstract
In semiarid agricultural regions, aquifers have watered widespread economic development. Falling water tables, however, drive up energy costs and can make the water toxic for human consumption. The study area is located in central Mexico, where arsenic and fluoride are widely present at toxic concentrations in well water. We simulated the holistic outcomes from three pumping scenarios over 100 years (2020-2120); (S1) pumping rates increase at a similar rate to the past 40 years, (S2) remain constant, or (S3) decrease. Under scenario S1, by 2120, the depth to water table increased to 426 m and energy consumption for irrigation increased to 4 × 109 kWh/yr. Arsenic and fluoride concentrations increased from 14 to 46 μg/L and 1.0 to 3.6 mg/L, respectively. The combined estimated IQ point decrements from drinking untreated well water lowered expected incomes in 2120 by 27% compared to what they would be with negligible exposure levels. We calculated the 100-year Net Present Value (NPV) of each scenario assuming the 2020 average crop value to water footprint ratio of 0.12 USD/m3. Without drinking water mitigation, S1 and S3 yielded relative NPVs of -5.96 × 109 and 1.51 × 109 USD, respectively, compared to the base case (S2). The relative NPV of providing blanket reverse osmosis treatment, while keeping pumping constant (S2), was 11.55 × 109 USD and this gain increased when combined with decreased pumping (S3). If a high value, low water footprint crop was substituted (broccoli, 1.51 USD/m3), the net gains from increasing pumping were similar in size to those of implementing blanket drinking water treatment.
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Affiliation(s)
| | - P. Farias
- Environmental HealthInstituto Nacional de Salud PúblicaCuernavacaMéxico
| | - G. R. Miller
- Civil & Environmental EngineeringTexas A&M UniversityCollege StationTXUSA
| | - J. Hoogesteger
- Water Resources ManagementWageningen UniversityWageningenThe Netherlands
| | - Y. Li
- Mines, Metallurgy and Geology EngineeringUniversity of GuanajuatoGuanajuatoMéxico
| | | | - R. T. Woodward
- Agricultural EconomicsTexas A&M UniversityCollege StationTXUSA
| | - H. Hernandez
- Geomatic and Hydraulic EngineeringUniversity of GuanajuatoGuanajuatoMéxico
| | - I. Loza‐Aguirre
- Mines, Metallurgy and Geology EngineeringUniversity of GuanajuatoGuanajuatoMéxico
| | - S. Datta
- Geological SciencesUniversity of Texas at San AntonioSan AntonioTXUSA
| | - Y. Huang
- Geology & GeophysicsTexas A&M UniversityCollege StationTXUSA
| | - G. Carrillo
- Public HealthTexas A&M UniversityCollege StationTXUSA
| | - T. Roh
- Public HealthTexas A&M UniversityCollege StationTXUSA
| | - D. Terrell
- Caminos de AguaSan Miguel de AllendeMéxico
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Meyer F, Enax J, Amaechi BT, Limeback H, Fabritius HO, Ganss B, Pawinska M, Paszynska E. Hydroxyapatite as Remineralization Agent for Children's Dental Care. FRONTIERS IN DENTAL MEDICINE 2022. [DOI: 10.3389/fdmed.2022.859560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Children are prone to develop dental caries. This is supported by epidemiological data confirming early childhood caries (ECC) as a highly prevalent disease affecting more than every second child worldwide. ECC is known to result from an imbalance between re- and demineralization where demineralization dominates due to frequent acid production by cariogenic bacteria present in oral biofilms. The application of oral care formulations containing remineralizing agents helps to prevent dental caries. As young children are sensitive and usually swallow (intended or unintended) a majority of toothpaste or other oral care products during daily dental care, all ingredients, especially the actives, should be non-toxic. Biomimetic hydroxyapatite [HAP; Ca5(PO4)3(OH)] is known to have favorable remineralizing properties combined with an excellent biocompatibility, i.e., it is safe if accidently swallowed. Several clinical trials as well as in situ and in vitro studies have shown that HAP remineralizes enamel and dentin. Remineralization occurs due to deposition of HAP particles on tooth surfaces forming mineral-mineral bridges with enamel crystals, but also indirectly through calcium and phosphate ions release as well as HAP's buffering properties in acidic environments (i.e., in plaque). HAP induces a homogenous remineralization throughout the subsurface enamel lesions. This review summarizes the current evidence showing HAP as an effective remineralizing agent in oral care products for children. Additional studies showing also further beneficial effects of HAP such as the reduction of biofilm formation and the relief of hypersensitivity in children with molar incisor hypomineralization (MIH). It can be concluded that HAP is an effective and safe remineralizing agent for child dental care.
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Goodman C, Hall M, Green R, Hornung R, Martinez-Mier EA, Lanphear B, Till C. Maternal fluoride exposure, fertility and birth outcomes: The MIREC cohort. ENVIRONMENTAL ADVANCES 2022; 7:100135. [PMID: 36644332 PMCID: PMC9837859 DOI: 10.1016/j.envadv.2021.100135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
OBJECTIVE Fluoride exposure >1.5 mg/L from water has been associated with adverse pregnancy and birth outcomes. Little is known, however, about the effect of fluoride at levels consistent with water fluoridation (i.e., 0.7 mg/L) on pregnancy and birth outcomes. We examined the relationship between maternal fluoride exposure, fertility, and birth outcomes in a Canadian pregnancy cohort living in areas where municipal drinking water fluoride concentrations ranged from 0.04 to 0.87 mg/L. METHODS Using data from the Maternal-Infant Research on Environmental Chemicals (MIREC) study, we estimated fluoride exposure during pregnancy using three different metrics: (1) maternal urinary fluoride concentrations standardized for specific gravity (MUFSG) and averaged across all three trimesters (N = 1566), (2) water fluoride concentration (N = 1370), and (3) fluoride intake based on self-reported consumption of water, coffee, and tea, adjusted for body weight (N = 1192). Data on fertility, birth weight, gestational age, preterm birth, and small-for-gestational age (SGA) were assessed. We used multiple linear regression to examine associations between fluoride exposure, birth weight and gestational age, and logistic regression to examine associations with fertility, preterm birth, and SGA, adjusted for relevant covariates. RESULTS Median (IQR) MUFSG was 0.50 (0.33-0.76) mg/L, median water fluoride was 0.52 (0.17-0.64) mg/L, and median fluoride intake was 0.008 (0.003-0.013) mg/kg/day. MUFSG, water fluoride concentrations, and fluoride intake were not significantly associated with fertility, birth weight, gestational age, preterm birth, or SGA. Fetal sex did not modify any of the associations. CONCLUSION Fluoride exposure during pregnancy was not associated with fertility or birth outcomes in this Canadian cohort.
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Affiliation(s)
- Carly Goodman
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
| | - Meaghan Hall
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
| | - Rivka Green
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | | | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Christine Till
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
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Neuromodulatory effects of hesperidin against sodium fluoride-induced neurotoxicity in rats: Involvement of neuroinflammation, endoplasmic reticulum stress, apoptosis and autophagy. Neurotoxicology 2022; 90:197-204. [DOI: 10.1016/j.neuro.2022.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 04/04/2022] [Accepted: 04/07/2022] [Indexed: 12/19/2022]
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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. ENVIRONMENTAL RESEARCH 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] [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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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 ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 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] [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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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. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 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] [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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Impacts of Fluoride Neurotoxicity and Mitochondrial Dysfunction on Cognition and Mental Health: A Literature Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182412884. [PMID: 34948493 PMCID: PMC8700808 DOI: 10.3390/ijerph182412884] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [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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Dietary fluoride intake during pregnancy and neurodevelopment in toddlers: A prospective study in the progress cohort. Neurotoxicology 2021; 87:86-93. [PMID: 34478773 PMCID: PMC8595627 DOI: 10.1016/j.neuro.2021.08.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [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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Wang S, Zhao Q, Li G, Wang M, Liu H, Yu X, Chen J, Li P, Dong L, Zhou G, Cui Y, Wang M, Liu L, Wang A. The cholinergic system, intelligence, and dental fluorosis in school-aged children with low-to-moderate fluoride exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 228:112959. [PMID: 34808511 DOI: 10.1016/j.ecoenv.2021.112959] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 10/27/2021] [Accepted: 10/31/2021] [Indexed: 06/13/2023]
Abstract
Disruption of cholinergic neurotransmission can affect cognition, but little is known about whether low-to-moderate fluoride exposure affects cholinergic system and its effect on the prevalence of dental fluorosis (DF) and intelligence quotient (IQ). A cross-sectional study was conducted to explore the associations of moderate fluoride exposure and cholinergic system in relation to children's DF and IQ. We recruited 709 resident children in Tianjin, China. Ion selective electrode method was used to detect fluoride concentrations in water and urine. Cholinergic system was assessed by the detection of choline acetyltransferase (ChAT), acetylcholinesterase (AChE) and acetylcholine (ACh) levels in serum. Compared with children in the first quartile, those in fourth quartile the risk of either developing DF or IQ < 120 increased by 19% and 20% for water and urinary fluoride. The risk of having both increased by 58% and 62% in third and fourth quartile for water fluoride, 52% and 65% for urinary fluoride. Water fluoride concentrations were positively associated with AChE and negatively associated with ChAT and ACh, trends were same for urinary fluoride except for ACh. The risk of either developing DF or having non-high intelligence rose by 22% (95%CI: 1.07%, 1.38%) for the fourth quartile than those in the first quartile of AChE, for having the both, the risk was 1.27 (95%CI: 1.07, 1.50), 1.37 (95%CI: 1.17, 1.62) and 1.44 (95%CI: 1.23, 1.68) in second, third and fourth quartiles. The mediation proportion by AChE between water fluoride and either developing DF or IQ < 120 was 15.7%. For both to exist, the proportion was 6.7% and 7.2% for water and urinary fluoride. Our findings suggest low-to-moderate fluoride exposure was associated with dysfunction of cholinergic system for children. AChE may partly mediate the prevalence of DF and lower probability of having superior and above intelligence.
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Affiliation(s)
- Sumei 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; School of Public Health, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Gaochun 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Hongliang Liu
- Tianjin Centers for Disease Control and Prevention, Tianjin, 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
| | - Jingwen Chen
- 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yushan Cui
- Tianjin Centers for Disease Control and Prevention, Tianjin, PR China
| | - Mengru 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), 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.
| | - 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; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
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Effects of SNPs in SOD2 and SOD3 interacted with fluoride exposure on the susceptibility of dental fluorosis. Int J Hyg Environ Health 2021; 239:113879. [PMID: 34758947 DOI: 10.1016/j.ijheh.2021.113879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/11/2021] [Accepted: 10/28/2021] [Indexed: 11/21/2022]
Abstract
A total of 649 children aged 7-13 years of age were recruited in a cross-sectional study in Tongxu County, China (2017) to assess the effects of interaction between single nucleotide polymorphisms (SNPs) in SOD2 and SOD3 gene and fluoride exposure on dental fluorosis (DF) status. Associations between biomarkers and DF status were evaluated. Logistic regression suggested that the risk of DF in children with rs10370 GG genotype and rs5746136 TT genotype was 1.89-fold and 1.72-fold than that in children with TT/CC genotype, respectively. Increased T-SOD activity was associated with a lower risk of DF (OR = 0.99). The rs2855262*rs10370*UF model was regarded as the optimal interaction model in generalized multifactor dimensionality reduction analyses. Our findings suggested that rs4880 and rs10370 might be useful genetic markers for DF, and there might be interactions among rs10370 in SOD2, rs2855262 in SOD3, and fluoride exposure on DF status.
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Naidu R, Biswas B, Willett IR, Cribb J, Kumar Singh B, Paul Nathanail C, Coulon F, Semple KT, Jones KC, Barclay A, Aitken RJ. Chemical pollution: A growing peril and potential catastrophic risk to humanity. ENVIRONMENT INTERNATIONAL 2021; 156:106616. [PMID: 33989840 DOI: 10.1016/j.envint.2021.106616] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 04/26/2021] [Accepted: 05/02/2021] [Indexed: 05/14/2023]
Abstract
Anthropogenic chemical pollution has the potential to pose one of the largest environmental threats to humanity, but global understanding of the issue remains fragmented. This article presents a comprehensive perspective of the threat of chemical pollution to humanity, emphasising male fertility, cognitive health and food security. There are serious gaps in our understanding of the scale of the threat and the risks posed by the dispersal, mixture and recombination of chemicals in the wider environment. Although some pollution control measures exist they are often not being adopted at the rate needed to avoid chronic and acute effects on human health now and in coming decades. There is an urgent need for enhanced global awareness and scientific scrutiny of the overall scale of risk posed by chemical usage, dispersal and disposal.
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Affiliation(s)
- Ravi Naidu
- Global Centre for Environmental Remediation (GCER), The University of Newcastle, ATC Building, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Bhabananda Biswas
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia; Future Industries Institute, UniSA STEM, University of South Australia, Mawson Lakes, SA 5095, Australia
| | - Ian R Willett
- School of Agriculture & Food Systems, The University of Melbourne, VIC 3052, Australia
| | - Julian Cribb
- Australian National Centre for the Public Awareness of Science (as an adjunct), Australian National University, Canberra 0200, Australia
| | - Brajesh Kumar Singh
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2753, Australia
| | | | - Frederic Coulon
- Cranfield University, School of Water, Energy and Environment, Cranfield MK43 0AL, United Kingdom
| | - Kirk T Semple
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Kevin C Jones
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Adam Barclay
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Robert John Aitken
- Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW 2308, Australia; Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW 2308, Australia
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Farías P, Estevez-García JA, Onofre-Pardo EN, Pérez-Humara ML, Rojas-Lima E, Álamo-Hernández U, Rocha-Amador DO. Fluoride Exposure through Different Drinking Water Sources in a Contaminated Basin in Guanajuato, Mexico: A Deterministic Human Health Risk Assessment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182111490. [PMID: 34770007 PMCID: PMC8583120 DOI: 10.3390/ijerph182111490] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/06/2021] [Accepted: 10/13/2021] [Indexed: 01/18/2023]
Abstract
Water fluoride levels above the World Health Organization’s guideline (1.5 mg/L), common in overexploited aquifers, represent a health hazard. Our objective was to assess the health risks posed by exposure to fluoride in different drinking water sources in a contaminated basin in Mexico. Fluoride was measured in mutual drinking water sources and in the urine of 39 children and women. Risks were estimated through hazard quotient (HQ) by drinking water source. Dental fluorosis was assessed in the children. Mean fluoride water concentrations (mg/L) were: well, 4.2; waterhole, 2.7; bottled, 2.1; rainwater, 0.4. The mean urinary fluoride concentrations (specific gravity adjusted) were 2.1 mg/L and 3.2 mg/L in children and women, respectively. Our multiple linear regression model showed children’s urinary fluoride concentrations increased 0.96 mg/L for every 1 mg/L increase in water fluoride (p < 0.001). Dental fluorosis was diagnosed in 82% of the children, and their HQ according to drinking water source was: well, 1.5; waterhole, 1.1; bottled, 0.8; harvested rainwater, 0.3. The pervasive dental fluorosis indicates a toxic past fluoride exposure; urinary fluoride levels and HQs indicate high exposure and current health risks for most children. Drinking harvested rainwater will likely prevent most of the local fluoride exposure.
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Affiliation(s)
- Paulina Farías
- Instituto Nacional de Salud Pública, Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca 62100, Mexico; (J.A.E.-G.); (E.N.O.-P.); (M.L.P.-H.); (E.R.-L.); (U.Á.-H.)
- Correspondence:
| | - Jesús Alejandro Estevez-García
- Instituto Nacional de Salud Pública, Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca 62100, Mexico; (J.A.E.-G.); (E.N.O.-P.); (M.L.P.-H.); (E.R.-L.); (U.Á.-H.)
| | - Erika Noelia Onofre-Pardo
- Instituto Nacional de Salud Pública, Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca 62100, Mexico; (J.A.E.-G.); (E.N.O.-P.); (M.L.P.-H.); (E.R.-L.); (U.Á.-H.)
| | - María Luisa Pérez-Humara
- Instituto Nacional de Salud Pública, Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca 62100, Mexico; (J.A.E.-G.); (E.N.O.-P.); (M.L.P.-H.); (E.R.-L.); (U.Á.-H.)
| | - Elodia Rojas-Lima
- Instituto Nacional de Salud Pública, Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca 62100, Mexico; (J.A.E.-G.); (E.N.O.-P.); (M.L.P.-H.); (E.R.-L.); (U.Á.-H.)
| | - Urinda Álamo-Hernández
- Instituto Nacional de Salud Pública, Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca 62100, Mexico; (J.A.E.-G.); (E.N.O.-P.); (M.L.P.-H.); (E.R.-L.); (U.Á.-H.)
| | - Diana Olivia Rocha-Amador
- Departamento de Farmacia, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato 36050, Mexico;
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50
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Ning H, Li C, Yin Z, Hu D, Ge Y, Chen L. Fluoride exposure decreased neurite formation on cerebral cortical neurons of SD rats in vitro. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:50975-50982. [PMID: 33977427 DOI: 10.1007/s11356-021-13950-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
Fluoride, a geochemical element, can damage the brain and result in dysfunction of the central nervous system. In recent years, fluoride-induced neurotoxicity has become one of research focuses of environmental toxicology. Our previous study showed that fluoride could induce the structural damages of the cerebral cortex and reduce the learning and memory abilities of mice offspring. However, the underlying mechanisms of these effects remain unclear. In this study, primary neurons were isolated from the cerebral cortices of postnatal 1-day SD rats. The primary cultured cerebral cortical neurons were adherent and the cellular network was obvious. Neurons were identified by Nissl's staining and were used for experiments. Different concentrations of sodium fluoride (0.5, 1.0, 1.5, 2.0 and 2.5 mM) were chosen to explore its toxic effects on neuron of SD rats in vitro. Results showed that neuronal morphology was obviously damaged in 2.0 and 2.5 mM, but was not adversely affected in 0.5 and 1 mM. Further studies revealed that the neurites of neuron were shrunken and even became fractured with the increase in NaF dose, which have been detected by scanning electron microscopy (SEM). Meanwhile, TEM showed marginated chromatin, widened nuclear gaps, damaged nuclei and swollen or even absent mitochondria in 1.5, 2 and 2.5 mM group. The cytoskeletal staining was consistent with the above results. The number of neurites of cerebral cortical neuron significantly decreased after fluoride exposure by immunofluorescent assay. In summary, high fluoride (1.5, 2 and 2.5 mM) concentrations exerted a significant toxic effect on the cellular morphologies and neural formation of primary cultured cortical neurons. These findings provide new insights into the roles of NaF in neuronal damage and can contribute to an improved understanding of fluoride-induced neurotoxicity.
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Affiliation(s)
- Hongmei Ning
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Chong Li
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Zhihong Yin
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Dongfang Hu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Yaming Ge
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China.
| | - Lingli Chen
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China.
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