title: Determining the optimal concentration of fluoride in drinking water in Pakistan.
abstract: OBJECTIVE
  This study was designed to determine the optimal concentrations of fluoride for drinking water in Pakistan. Clinical dental examination of 1020 school children aged 12 years was carried out in 19 cities of Pakistan. Correlation between concentrations of water fluoride, caries and fluorosis was investigated by analyzing the data on fluoride concentrations in drinking water in the sampled population for which the caries and the fluorosis levels were also measured.
  
  
  METHODS
  The optimal level of fluoride in drinking water is universally calculated by applying the equation of Galagan and Vermillion, which permits the calculation of water intake as a function of temperature. The annual mean maximum temperatures (AMMT) recorded during the last 5 years were collected from the meteorological centres of the 28 divisional headquarter stations. The average AMMT of Pakistan is 29 degrees C at which the optimal fluoride in drinking water of Pakistan was calculated to be 0.7 ppm. As drinking habits differ in various parts of the world, determination of optimal concentration of fluoride for drinking water in Pakistan was performed using a modified Galagan and Vermillion equation, which applies a correction factor of 0.56 to the equation. The optimal fluoride in drinking water in Pakistan using this modified equation was determined to be 0.39 ppm.
  
  
  RESULTS
  Observation of the correlation showed that a fluoride concentration of 0.35 ppm in drinking water was associated with maximum reduction in dental caries and a 10% prevalence of fluorosis.
  
  
  CONCLUSIONS
  Determining the most appropriate concentrations of fluoride in drinking water is crucial for communities. It is imperative that each country calculates its own optimal level of fluoride in drinking water based on the dose-response relationship of fluoride in drinking water with the levels of caries and fluorosis. Climatic conditions, dietary habits of the population and other possible fluoride exposures need to be considered in formulating these recommendations.
authors.affiliation: Shaikh Zayed Federal Postgraduate Medical Institute, Shaikh Zayed Medical Complex, Lahore 54600, Pakistan. ayyazk@brain.net.pk
authors.forename: Ayyaz Ali
authors.initials: AA
authors.lastname: Khan
authors.forename: Helen
authors.initials: H
authors.lastname: Whelton
authors.forename: Denis
authors.initials: D
authors.lastname: O'Mullane
mesh_terms: D002327:Cariostatic Agents / Q000032:analysis*; D002648:Child; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005459:Fluorides / Q000032:analysis*; D009050:Fluorosis, Dental / Q000453:epidemiology*; D017408:Guidelines as Topic; D006801:Humans; D008297:Male; D010154:Pakistan / Q000453:epidemiology; D015995:Prevalence; D013696:Temperature; D014881:Water Supply / Q000032:analysis*
chemical_list: D002327:Cariostatic Agents; D005459:Fluorides