Effect of fluoride exposure on the intelligence of school children in Madhya Pradesh, India

Abstract

Objective:To assess the relationship between exposure to different drinking water fluoride levels and children's intelligence in Madhya Pradesh state, India.Materials and Methods:This cross-sectional study was conducted among 12-year-old school children of Madhya Pradesh state, India. The children were selected from low (< 1.5 parts per million) and high (≥1.5 parts per million) fluoride areas. A questionnaire was used to collect information on the children's personal characteristics, residential history, medical history, educational level of the head of the family, and socioeconomic status of the family. Levels of lead, arsenic, and iodine in the urine and the levels of fluoride in the water and urine were analyzed. The children's intelligence was measured using Raven's Standard Progressive Matrices. Data analysis was done using the chi-square, one way analysis of variance, simple linear regression, and multiple linear regression tests. P value <0.05 was considered statistically significant.Results:Differences in participant's sociodemographic characteristics, urinary iodine, urinary lead, and urinary arsenic levels were statistically not significant (P>0.05). However, a statistically significant difference was observed in the urinary fluoride levels (P 0.000). Reduction in intelligence was observed with an increased water fluoride level (P 0.000). The urinary fluoride level was a significant predictor for intelligence (P 0.000).Conclusion:Children in endemic areas of fluorosis are at risk for impaired development of intelligence.

Fluoride exposure and reported learning disability diagnosis among Canadian children: Implications for community water fluoridation

“…12 However, most of the 27 cross-sectional studies were conducted in areas of rural China that have high levels of naturally occurring fluoride in the water ranging from 2 to 11 ppm, which is approximately 3-16 times higher than optimal fluoride concentrations in Canada. 12 Not included in the aforementioned meta-analysis, eight additional cross-sectional studies performed in India (n = 4), [13][14][15][16] Iran (n = 1), 17 Mexico (n = 1) 18 and China (n = 2) 19,20 found that children classified as having "high" fluoride exposure (defined in various ways) scored lower on some or all components of metrics used to assess intelligence or cognition. In contrast, a prospective cohort study by Broadbent et al found no significant differences in IQ scores between New Zealand children living in fluoridated versus those living in non-fluoridated communities, adjusting for several potential confounders.…”

Effect of Fluoride Exposure Through Drinking Water on the Oral Health Status and Intelligence Profile of School Children of District Una, Himachal Pradesh: An Interim Analysis

“…17 Saxena et al and Shivaprakash et al in their study have also demonstrated that intellectual capacity of children decreases with increase in the fluorosis grade. 6,19 Data from previous studies support to the hypothesis that interaction between fluoride, lead, and arsenic could worsen the children's intelligence grades, 20 and thus, indicate a need for further investigation. Guan et al demonstrated that the contents of phospholipids and ubiquinone are altered in the brain of rats affected by chronic fluorosis, and therefore changes in membrane lipids could be a cause of this disorder.…”

“…Data from previous studies could lend support to the hypothesis that interaction between fluoride, lead and arsenic could worsen the children's intelligence grade and thus indicate a need for further investigation. 6 There is limited evidence on fluoride levels in water level across the country and so its association with dental fluorosis and intelligence of children. In addition, the fluoride levels in water bodies differ from region to region and are not uniform.…”

Activation of the AGE/RAGE system in the brains of rats and in SH-SY5Y cells exposed to high level of fluoride might connect to oxidative stress

“…Liu et al, 2010a;Y.J. Liu et al, 2010b), and the reduced intelligence quotient of children living in areas with endemic fluorosis (Rocha-Amador et al, 2007;Saxena et al, 2012;Tang et al, 2008) are particularly noteworthy. Earlier, we proposed that oxidative stress is an important factor in the multiple systemic damage associated with chronic fluorosis (Gao et al, 2008;Guan et al, 2000) and several studies support this hypothesis (Bharti and Srivastava, 2009;Wang et al, 2000Wang et al, , 2011.…”