Effectofhigh-fluoridewateronintelligenceinchildren.pdfVIP

74 Fluoride Vol. 33 No. 2 74-78 2000 Research Report EFFECT OF HIGH-FLUORIDE WATER ON INTELLIGENCE IN CHILDREN Y Lu,a ZR Sun,a LN Wu,a X Wang,a W Lu,a SS Liub Tianjin, China SUMMARY: The Intelligence Quotient (IQ) was measured in 118 children, aged 10-12 years, who were life-long residents in two villages of similar population size and social, educational and economic background but differing in the level of fluoride in drinking water. The children in the high-fluoride area (drinking water fluoride 3.15 ± 0.61 mg/L [ppm]) (mean ± S.D.) had higher uri- nary fluoride levels (4.99 ± 2.57 mg/L) than the children in the low-fluoride area (drinking water fluoride 0.37 ± 0.04 mg/L) (urinary fluoride 1.43 ± 0.64 mg/L). The IQ of the 60 children in the high-fluoride area was significantly lower, mean 92.27 ± 20.45, than that of the 58 children in the low-fluoride area, mean 103.05 ± 13.86. More children in the high-fluoride area, 21.6%, were in the re- tardation (70) or borderline (70-79) categories of IQ than children in the low fluoride area, 3.4%. An inverse relationship was also present between IQ and the urinary fluoride level. Exposure of children to high levels of fluoride may therefore carry the risk of impaired development of intelligence. Keywords: Fluoride and IQ, Fluoride excretion in urine, Fluoride in water, Intelligence and fluoride. INTRODUCTION In view of reports of increased fluoride levels in many foods and water sup- plies, it is urgent that further studies be conducted to examine whether there is a link in animals and humans between fluoride and disturbances of the devel- opment and function of the central nervous system. High-fluoride levels may occur in artesian well water when the water passes through strata with a high fluoride content, food may become contaminated when stored in contact with the smoke from a poorly ventila