In this new R01, we will capitalize on the unique resources of our Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) program, a molecular environmental epidemiology birth cohort study that won the 1999 NIEHS Progress and Achievement Award, to conduct a rigorous study of the potential impact of population-wide levels of exposure to fluoride on neurodevelopment. This effort addresses a 2007 US National Research Council report which concluded that more research is needed to address the possibility that population-wide levels of fluoride exposure may pose a significant threat to neurobehavior. The exceptional data and resources of ELEMENT has allowed our team to publish over 40 papers related to the impact of prenatal and childhood exposure to lead and other toxicants on neurobehavioral and physical development. Using levels of fluoride measured in our archived urine, fasting plasma and toenail specimens, validated measures widely recognized as being the best available biomarkers of fluoride exposure, we propose to study the impact of prenatal and childhood fluoride exposures on widely used and validated measures of neurobehavior at 2 to 14 years of age utilizing 3 of the 4 cohorts of ELEMENT. Our pilot research on archived urine and plasma samples from 40 randomly chosen mother-offspring pairs using rigorous and cross-validated laboratory methods indicates that our ELEMENT subjects have a distribution of fluoride levels that will enable us to pursue our specific aims. Further, our pilot data shows evidence of an inverse relationship between prenatal biomarkers of fluoride exposure and general cognitive function at 2 years (Bayley Scales of Mental Development), 4 years (McCarthy Scales of Children's Abilities) and 7-14 years (Wechsler Abbreviated Scales of Intelligence). Our overall goals will be to conduct a full investigation to () address hypotheses on the potential impact of pre- and postnatal exposures to fluoride on measures of overall neurobehavioral function; (B) explore the potential impacts of fluoride exposure on specific domains of neurobehavioral function, the shape of the dose-response relationships, differential susceptibility in relation to time windows of exposure (prenatal v. childhood), and, using archived data, potential interactions with lead exposure, another widely- distributed neurotoxicant; and (C) conduct a study of offspring to examine the drinking water, dietary, dentifrice, lifestyle, and other determinants of current urinary and toenail fluoride leves. Given the power of our archived resources and sample sizes, we will be able to accomplish this research at a small fraction of the cost and time required of a new study.

Public Health Relevance

This research will directly address the issue as to whether population-wide levels of prenatal and/or childhood fluoride exposure is a significant risk factor for some forms of adverse neurobehavioral performance. Given the widespread nature of fluoride use and exposure and the lack of rigorous epidemiologic research on this topic of the current base of evidence, this research promises to make a major contribution to fluoride risk assessment and policy decision-making.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES021446-05
Application #
9022477
Study Section
Behavioral Genetics and Epidemiology Study Section (BGES)
Program Officer
Gray, Kimberly A
Project Start
2012-06-01
Project End
2017-02-28
Budget Start
2016-03-01
Budget End
2017-02-28
Support Year
5
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Toronto
Department
Type
DUNS #
259999779
City
Toronto
State
ON
Country
Canada
Zip Code
M5 1S8
Lewis, Ryan C; Meeker, John D; Basu, Niladri et al. (2018) Urinary metal concentrations among mothers and children in a Mexico City birth cohort study. Int J Hyg Environ Health 221:609-615
Bashash, Morteza; Thomas, Deena; Hu, Howard et al. (2017) Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6-12 Years of Age in Mexico. Environ Health Perspect 125:097017
Chavarro, Jorge E; Watkins, Deborah J; Afeiche, Myriam C et al. (2017) Validity of Self-Assessed Sexual Maturation Against Physician Assessments and Hormone Levels. J Pediatr 186:172-178.e3
Somers, Emily C; Monrad, Seetha U; Warren, Jeffrey S et al. (2017) Antinuclear antibody prevalence in a general pediatric cohort from Mexico City: discordance between immunofluorescence and multiplex assays. Clin Epidemiol 9:1-8
Moynihan, Meghan; Peterson, Karen E; Cantoral, Alejandra et al. (2017) Dietary predictors of urinary cadmium among pregnant women and children. Sci Total Environ 575:1255-1262
Watkins, Deborah J; Fortenberry, Gamola Z; Sánchez, Brisa N et al. (2016) Urinary 3-phenoxybenzoic acid (3-PBA) levels among pregnant women in Mexico City: Distribution and relationships with child neurodevelopment. Environ Res 147:307-13
Huang, Siying; Hu, Howard; Sánchez, Brisa N et al. (2016) Childhood Blood Lead Levels and Symptoms of Attention Deficit Hyperactivity Disorder (ADHD): A Cross-Sectional Study of Mexican Children. Environ Health Perspect 124:868-74
Cantoral, A; Téllez-Rojo, M M; Ettinger, A S et al. (2016) Early introduction and cumulative consumption of sugar-sweetened beverages during the pre-school period and risk of obesity at 8-14 years of age. Pediatr Obes 11:68-74
Thomas, Deena B; Basu, Niladri; Martinez-Mier, E Angeles et al. (2016) Urinary and plasma fluoride levels in pregnant women from Mexico City. Environ Res 150:489-495
Xu, Jian; Hu, Howard; Wright, Rosalind et al. (2015) Prenatal Lead Exposure Modifies the Impact of Maternal Self-Esteem on Children's Inattention Behavior. J Pediatr 167:435-41

Showing the most recent 10 out of 18 publications