title: Morphological features of the microdistribution of naturally occurring 10Pb/2l0Po and 226Ra in the teeth of children and juveniles.
abstract: OBJECTIVE
  To examine the microdistribution of natural alpha-radioactivity in deciduous teeth of children and the permanent teeth of juveniles extracted for orthodontic purpose from across the UK.
  
  
  METHODS
  The microdistribution of 210Pb-supported 210Po and 226Ra in 708 deciduous and permanent teeth and 32 foetal teeth was measured on 1442 TASTRAK alpha-particle track detectors.
  
  
  RESULTS
  Of the various findings, a number are of special interest. Around half of the 210Pb activity in the outer enamel of deciduous teeth appears to have been acquired in utero as a result of transplacental transfer. In deciduous and permanent teeth, 226Ra is concentrated mainly in the circumpulpal region, while the highest levels of 210Po are on the highly calcified outer enamel surface. Furthermore, activity concentrations recorded on this surface were In-normally distributed.
  
  
  CONCLUSIONS
  210Pb-supported 210Po activity on the outer enamel surface of permanent teeth constitutes an assay of cumulative environmental exposure with which to assess exposure in bone, both in utero and in childhood. Such assessment can be used to study geographical variations in the alpha-activity in teeth. More work is also required to determine the concentrations of both 210Po and 210Pb in the foetal skeleton.
authors.affiliation: H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK.
authors.forename: P R
authors.initials: PR
authors.lastname: James
authors.forename: J J
authors.initials: JJ
authors.lastname: Close
authors.forename: P A
authors.initials: PA
authors.lastname: Keitch
authors.forename: J E
authors.initials: JE
authors.lastname: Allen
authors.forename: A P
authors.initials: AP
authors.lastname: Fews
authors.forename: D L
authors.initials: DL
authors.lastname: Henshaw
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D019229:Dentition, Permanent; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007856:Lead Radioisotopes / Q000032:analysis; D008297:Male; D011059:Polonium / Q000032:analysis; D011830:Radiation Effects; D011883:Radium / Q000032:analysis; D014094:Tooth, Deciduous / Q000528:radiation effects*; D006113:United Kingdom
chemical_list: D007856:Lead Radioisotopes; D011059:Polonium; D011883:Radium