Howard Hu, M.D., Sc.D., Martha Telez-Rojo, Ph.D.
University of Michigan, University of Toronto
R01ES021446, R01ES007821, P01ES022844, P42ES05947, P30ES017885
NIEHS grantees discovered that higher levels of urinary fluoride during pregnancy were associated with increased incidence of attention deficit-hyperactivity disorder (ADHD)-like symptoms in school-aged children. ADHD is the most common psychiatric disorder diagnosed in childhood, affecting between five and nine percent of all school-aged children.
The study analyzed data from 213 mother-child pairs in Mexico City enrolled in a project that recruited pregnant women from 1994 to 2005 and has continued to follow the women and their children. The research team analyzed urine samples from pregnant mothers and their children between six and 12 years of age. The researchers then analyzed how levels of fluoride in urine, an indicator of exposure, were related to a child's performance on tests and questionnaires that measured inattention and hyperactivity, which provided scores related to ADHD.
These findings demonstrated that children with elevated prenatal fluoride exposure, as indicated by maternal urinary fluoride, were more likely to exhibit symptoms of ADHD. Prenatal fluoride exposure was also associated with inattentive behaviors, but not with hyperactivity or impulse control. According to the authors, these findings provided further evidence of the neurotoxic effects of prenatal fluoride exposure and warrant further investigation.
Citation: Bashash M, Marchand M, Hu H, Till C, Martinez-Mier EA, Sanchez BN, Basu N, Peterson KE, Green R, Schnaas L, Mercado-Garcia A, Hernandez-Avila M, Tellez-Rojo MM. 2018. Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6-12 years of age in Mexico City. Environ Int 121(Pt 1):658-666.