What the research found
The authors examined age-specific and gender-specific effects of fluoride level in drinking water and the incidence of osteosarcoma using a matched case–control study design. The study was conducted through 11 hospitals in the United States that included a complete residential history for each patient and type of drinking water (public, private well, bottled) used at each address. Their exploratory analysis, based on 103 cases under the age of 20 and 215 matched controls, plotted the impact of different assessments of exposure for the cases and controls. This method showed that by using fluoride level at each of the ages 4 to 12 years as the exposure definition, there was an increased adjusted odds ratio for males in the higher fluoride exposure group. The adjusted odds ratio was highest for males when exposure to fluoride at age 7 was used. This exploratory approach did not find a similar pattern among females. The authors concluded that their analysis found an association between fluoride exposure in drinking water during childhood and the incidence of osteosarcoma among males but not among females. The authors urged further research to confirm or refute this observation.