Anna L Choi1, Ying Zhang2, Guifan Sun3, David C Bellinger4, Kanglin Wang5, Xiao Jing Yang6, Jin Shu Li6, Quanmei Zheng3, Yuanli Fu7, Philippe Grandjean8. 1. Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA. Electronic address: achoi@hsph.harvard.edu. 2. School of Stomatology, China Medical University, Shenyang, China. 3. School of Public Health, China Medical University, Shenyang, China. 4. Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA; Department of Neurology, Children's Hospital, Boston, USA. 5. Mianning Center for Disease Control and Prevention, Xichang, Sichuan, China. 6. Sichuan Center for Disease Control and Prevention, Chengdu, Sichuan, China. 7. Center for Disease Control and Prevention of Liangshan Perfecture, Xichang, Sichuan, China. 8. Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA; Institute of Public Health, University of Southern Denmark, Odense, Denmark.
Abstract
BACKGROUND: A systematic review and meta-analysis of published studies on developmental fluoride neurotoxicity support the hypothesis that exposure to elevated concentrations of fluoride in water is neurotoxic during development. METHODS: We carried out a pilot study of 51 first-grade children in southern Sichuan, China, using the fluoride concentration in morning urine after an exposure-free night; fluoride in well-water source; and dental fluorosis status as indices of past fluoride exposure. We administered a battery of age-appropriate, relatively culture-independent tests that reflect different functional domains: the Wide Range Assessment of Memory and Learning (WRAML), Wechsler Intelligence Scale for Children-Revised (WISC-IV) digit span and block design; finger tapping and grooved pegboard. Confounder-adjusted associations between exposure indicators and test scores were assessed using multiple regression models. RESULTS: Dental fluorosis score was the exposure indicator that had the strongest association with the outcome deficits, and the WISC-IV digit span subtest appeared to be the most sensitive outcome, where moderate and severe fluorosis was associated with a digit span total score difference of -4.28 (95% CI -8.22, -0.33) and backward score with -2.13 (95% CI -4.24, -0.02). CONCLUSIONS: This pilot study in a community with stable lifetime fluoride exposures supports the notion that fluoride in drinking water may produce developmental neurotoxicity, and that the dose-dependence underlying this relationship needs to be characterized in detail.
BACKGROUND: A systematic review and meta-analysis of published studies on developmental fluorideneurotoxicity support the hypothesis that exposure to elevated concentrations of fluoride in water is neurotoxic during development. METHODS: We carried out a pilot study of 51 first-grade children in southern Sichuan, China, using the fluoride concentration in morning urine after an exposure-free night; fluoride in well-water source; and dental fluorosis status as indices of past fluoride exposure. We administered a battery of age-appropriate, relatively culture-independent tests that reflect different functional domains: the Wide Range Assessment of Memory and Learning (WRAML), Wechsler Intelligence Scale for Children-Revised (WISC-IV) digit span and block design; finger tapping and grooved pegboard. Confounder-adjusted associations between exposure indicators and test scores were assessed using multiple regression models. RESULTS:Dental fluorosis score was the exposure indicator that had the strongest association with the outcome deficits, and the WISC-IV digit span subtest appeared to be the most sensitive outcome, where moderate and severe fluorosis was associated with a digit span total score difference of -4.28 (95% CI -8.22, -0.33) and backward score with -2.13 (95% CI -4.24, -0.02). CONCLUSIONS: This pilot study in a community with stable lifetime fluoride exposures supports the notion that fluoride in drinking water may produce developmental neurotoxicity, and that the dose-dependence underlying this relationship needs to be characterized in detail.
Authors: Morteza Bashash; Deena Thomas; Howard Hu; E Angeles Martinez-Mier; Brisa N Sanchez; Niladri Basu; Karen E Peterson; Adrienne S Ettinger; Robert Wright; Zhenzhen Zhang; Yun Liu; Lourdes Schnaas; Adriana Mercado-García; Martha María Téllez-Rojo; Mauricio Hernández-Avila Journal: Environ Health Perspect Date: 2017-09-19 Impact factor: 9.031
Authors: Sabine Guth; Stephanie Hüser; Angelika Roth; Gisela Degen; Patrick Diel; Karolina Edlund; Gerhard Eisenbrand; Karl-Heinz Engel; Bernd Epe; Tilman Grune; Volker Heinz; Thomas Henle; Hans-Ulrich Humpf; Henry Jäger; Hans-Georg Joost; Sabine E Kulling; Alfonso Lampen; Angela Mally; Rosemarie Marchan; Doris Marko; Eva Mühle; Michael A Nitsche; Elke Röhrdanz; Richard Stadler; Christoph van Thriel; Stefan Vieths; Rudi F Vogel; Edmund Wascher; Carsten Watzl; Ute Nöthlings; Jan G Hengstler Journal: Arch Toxicol Date: 2020-05-08 Impact factor: 5.153