The Ra 226 , Po 210 , and Th 228 in Bovine Bone and Teeth

Abstract

The assay of the naturally occurring Ra226, Pb210, and Th228 content of man has been of concern for more than a decade. The importance of these studies in the evaluation of the possible hazards associated with low chronic levels of radiation either from fallout or from variations in the concentration of naturally occurring radioelements has been cited by Marinelli (1). The relative importance of both food and drinking water as sources of natural radioelements has been emphasized in a review by Stehney (2). Although Lucas (3) has shown a good correlation between the radium content of human bone and teeth from residents of a single city (3), direct information on the uptake of radium relative to other naturally occurring radioelements by bone and teeth in the same individual is not readily obtained. In contrast, animal bone and teeth samples are readily available. For this study, twenty-five bovine mandibles with teeth intact were obtained from fourteen states through the interest and cooperation of Brig. Gen. E. W. Young, United States Army Veterinary Service. Since milk is an important food source for the young growing human subject and contains significant concentrations of radium (4), these samples provide an additional opportunity to evaluate the variability of human exposure to the naturally occurring radioelements. Horse, porcine, and deer specimens were obtained for comparison. The various bovine teeth erupt at relatively fixed intervals over a period of more than 5 years (5). If we assume that the radium concentration observed in the tooth is related to that in the blood at the time of its formation, then each tooth, when compared to any other tooth, should be an accurate index of the relative blood radium levels.