Assessing the Intelligence Quotient of 5-10-year-old Children in Salem District, India with Varying Fluoride Levels:...

Prolonged exposure to excessive fluoride can cause fluorosis and affect the developing brain by crossing the placental and blood-brain barriers. Salem district, with an average groundwater fluoride concentration of 3.7 ppm, which exceeds the recommended levels, provides a setting to explore its impact on children's intelligence quotient (IQ). The aim of the study was to assess and correlate the IQ levels of children in the age group of 5-10 with fluoride levels in water using Raven's Colored Progressive Matrices (RCPM).

This study employed a cross-sectional design to study a cohort of 5-10-year-old children in Salem. Participants were selected based on groundwater fluoride levels (<1.0 ppm, 1.0 ppm, and ≥1.0 ppm). The study included children born and raised in Salem, whose mothers resided there during pregnancy. Children with a history of brain diseases were excluded. Parents completed a validated modified questionnaire by Makharia et al., and socioeconomic status was rated using the Updated Modified Kuppuswamy Scale (2021). Children's intellectual ability was assessed with the RCPM under a trained psychologist's supervision, and IQ scores were classified per the Current Wechsler classification. Data were analyzed using chi-square tests, regression analysis, and Spearman's correlation.

Among the five areas assessed, Ayothiyapattinam had the highest fluoride levels, and Attayampatti the lowest. Children in low-fluoride areas had a higher proportion in the superior IQ group (5.6%) than those in high-fluoride areas (1.5%).

Elevated fluoride levels were linked to lower IQ scores, with no significant association between socioeconomic status and IQ.

This study underscores the relatively underexplored effects of fluoride on neurodevelopment, demonstrating its potential to adversely impact children's IQ when exposure exceeds recommended limits. Maintaining optimal fluoride levels is essential to achieving a balance between its protective benefits for dental health and its implications for cognitive development.