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

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±1.4mg/L; As 5.8±1.3μg/L); Salitral (F 5.3±0.9mg/L; As 169±0.9μg/L) and 5 de Febrero (F 9.4±0.9mg/L; As 194±1.3μg/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 (β values = -13, -15.6, -16.9, respectively). Similar results were observed for F in drinking water (β values = -6.7, -11.2, -10.2, respectively) and As in drinking water (β 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 (β = -5.72, p = 0.003). These data suggest that children exposed to either F or As have increased risks of reduced IQ scores.