Aspects of the geographical variations of naturally occurring 210Pb/210Po in permanent teeth of juveniles in the UK.

Purpose: To study geographical variations in the level of naturally occurring 210Pb-supported 210Po in permanent teeth of juveniles in the UK.

Materials And Methods: Permanent teeth extracted from 278 juveniles for orthodontic purposes were obtained from 48 counties in the UK. 210Po activity concentration was measured on the outer enamel surface using TASTRAK alpha-particle-sensitive plastic track detectors.

Morphological features of the microdistribution of naturally occurring 10Pb/2l0Po and 226Ra in the teeth of children and juveniles.

Purpose: 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.

Materials And 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.

Corona ions from powerlines and increased exposure to pollutant aerosols.

Purpose: To investigate corona ions emitted from high-voltage powerlines and assess their effects on exposure to environmental pollutant aerosols.

Materials And Methods: The charge density of ions in air required to produce a given change in the observed DC field at ground level was calculated. A DC field mill meter was used to map the DC fields near 132, 275 and 400 kV powerlines.

Increased exposure to pollutant aerosols under high voltage power lines.

Purpose: To assess increased exposure to airborne pollutants near power lines by investigating theoretically and experimentally the behaviour of 222Rn decay product marker aerosols in the 50 Hz electric field under power lines.

Materials And Methods: The behaviour of aerosols in outdoor air including those carrying 222Rn decay products was modelled theoretically in the presence of an AC field. TASTRAK alpha-particle spectroscopy was used to characterize 218Po and 214Po aerosols outdoors.

Fat cells in red bone marrow of human rib: their size and spatial distribution with respect to the radon-derived dose to the haemopoietic tissue.

Samples of human rib were collected at autopsy and 20 were selected for marrow fat cell measurement, representing an age range of 16-96 years. The mean diameter of fat cells in red bone marrow of human rib was found to increase from around 48 microns at ages 16-29 years to around 65 microns at ages 82-96 years. There was a greater number of fat cells of smaller size range in younger ages compared with that in older ones.

Spatial Distribution of Naturally Occurring Po and Ra in Children's Teeth.

Deciduous and permanent teeth extracted from juveniles for orthodontic purposes have been analysed using α-sensitive plastic track detectors for the spatial distribution of total α-activity and naturally occurring Pb-supported Po and Ra. The distribution of these radionuclides is nonuniform, with Po being primarily associated with outer enamel and Ra with the pulp. The observations suggest that Pb/Po concentrates at the interface of enamel with saliva or blood, by means of unidirectional ionic exchange with calcium.

Spatial distribution of naturally occurring 210Po and 226Ra in children's teeth.

Deciduous and permanent teeth extracted from juveniles for orthodontic purposes have been analysed using alpha-sensitive plastic track detectors for the spatial distribution of total alpha-activity and naturally occurring 210Pb-supported 210Po and 226Ra. The distribution of these radionuclides is non-uniform, with 210Po being primarily associated with outer enamel and 226Ra with the pulp. The observations suggest that 210Pb/210Po concentrates at the interface of enamel with saliva or blood, by means of unidirectional ionic exchange with calcium.

TASTRAK spectroscopy of polonium-210 alpha-particle activity at bone surfaces: evidence for a concentrated surface deposit less than 3 microns deep.

The technique of alpha-particle spectroscopy by CR-39 type TASTRAK plastic has been used to study the depth distribution of natural alpha-particle emitters at the surface of human bone. The predominant component of this alpha-particle activity was 210Po supported by 210Pb, although a smaller activity of 226Ra was also detected. Autopsy samples of human femur and cranium were obtained from subjects age 63 to 86.