title: Effect of fluoridated water on intelligence in 10-12-year-old school children.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the relationship of drinking water fluoride levels with children's intelligence quotient (IQ).
  
  
  METHODS
  Water was collected from initially identified endemic fluoride regions according to the geological research of Government of India. Fluoride concentration of the water was assessed by utilizing fluoride ion selective electrode, Orion 9609BN, and categorized on the basis of fluoride concentration into low, medium, and high-fluoride regions, i.e., Virajpet (low fluoride level < 1.2 ppm), Banavara (Medium fluoride level 1.2-2 ppm), and Mastihalli (High fluoride levels > 3 ppm). Government school from all three villages were selected randomly and IQ levels were assessed by using Raven's Standard Progressive Matrices. This test was conducted on each child in the study sample.
  
  
  RESULTS
  A significant inverse relationship was found between the fluoride concentration in drinking water and IQ (rvalue = -0.204;P< 0.000). It was observed that IQ level was negatively correlated with fluoride concentration in drinking water.
  
  
  CONCLUSIONS
  It is concluded that IQ level was negatively correlated with fluoride level in drinking water. Factors that might affect children's IQ need to be considered, and it is necessary to devise solutions for preventing the harmful effects of excessive intake of fluoride ion to the body.
authors.affiliation: Department of Public Health Dentistry, Al Azhar Dental College, Thodupuzha, Kerala, India.
authors.forename: A
authors.initials: A
authors.lastname: Aravind
authors.affiliation: Department of Public Health Dentistry, P.S.M Dental College, Akkikavu, Thrissur, Kerala, India.
authors.forename: R S
authors.initials: RS
authors.lastname: Dhanya
authors.affiliation: Department of Pedodontics, Al Azhar Dental College, Thodupuzha, Kerala, India.
authors.forename: Ajay
authors.initials: A
authors.lastname: Narayan
authors.affiliation: Department of Preventive Dental Sciences, College of Dentistry, Prince Sattam bin Abdul Aziz University, Al kharj, Kingdom of Saudi Arabia.
authors.forename: George
authors.initials: G
authors.lastname: Sam
authors.affiliation: Department of Conservative Dentistry and Endodontics, Mahe Institute of Dental Sciences, Puducherry, India.
authors.forename: V J
authors.initials: VJ
authors.lastname: Adarsh
authors.affiliation: Department of Public Health Dentistry, St. Gregorios Dental College, Chelad, Kothamangalam, Ernakulam, Kerala, India.
authors.forename: M
authors.initials: M
authors.lastname: Kiran
keywords: Dental fluorosis; drinking water; fluoride; intelligence quotient