Decreased intelligence in children and exposure to fluoride and arsenic in drinking water

Cad Saude Publica. 2007;23 Suppl 4:S579-87. doi: 10.1590/s0102-311x2007001600018.

Abstract

Recent evidence suggests that fluoride (F) and arsenic (As) may adversely affect intelligence quotient (IQ) scores. We explore the association between exposure to F and As in drinking water and intelligence in children. Three rural communities in Mexico with contrasting levels of F and As in drinking water were studied: Moctezuma (F 0.8+/-1.4 mg/L; As 5.8+/-1.3 microg/L); Salitral (F 5.3+/-0.9 mg/L; As 169+/-0.9 microg/L) and 5 de Febrero (F 9.4+/-0.9 mg/L; As 194+/-1.3 microg/L). The final study sample consisted of 132 children from 6 to 10 years old. After controlling for confounders, an inverse association was observed between F in urine and Performance, Verbal, and Full IQ scores (beta values = -13, -15.6, -16.9, respectively). Similar results were observed for F in drinking water (beta values = -6.7, -11.2, -10.2, respectively) and As in drinking water (beta values= -4.30, -6.40, -6.15, respectively). The p-values for all cases were < 0.001. A significant association was observed between As in urine and Full IQ scores (beta = -5.72, p = 0.003). These data suggest that children exposed to either F or As have increased risks of reduced IQ scores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arsenic / toxicity*
  • Child
  • Environmental Exposure*
  • Epidemiologic Methods
  • Female
  • Fluorides / toxicity*
  • Humans
  • Intelligence / drug effects*
  • Lead / toxicity
  • Male
  • Mexico
  • Rural Population
  • Socioeconomic Factors
  • Water Pollution, Chemical / analysis*
  • Water Supply / analysis*

Substances

  • Lead
  • Arsenic
  • Fluorides