Initial damage in human interphase chromosomes from alpha particles with linear energy transfers relevant to radon exposure

Bradford Loucas, C. R. Geard

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

To determine the efficiency at which α particles at LETs chosen to simulate exposure to radon progeny break chromosomes, the premature chromosome condensation technique was used to measure breaks soon after irradiation. Noncycling human fibroblasts were irradiated with graded doses of monoenergetic α particles accelerated to produce LETs of 90, 120, 150, 180 and 200 keV/μm at the midpoint of the cell nuclei. Premature chromosome condensation was initiated immediately after irradiation and cells were scored for the total number of prematurely condensed chromosomes and fragments per cell. Similar experiments were conducted with 250 kVp X rays for comparison. Irradiation with α particles produced 8.6 to 13.1 excess fragments per gray, while X rays produced 5.8 excess fragments, resulting in RBEs around 2. Calculations of the number of breaks produced on average by a single particle traversal of a cell nucleus indicated that at the LETs tested more than one break (1.5-2.8) was produced by each traversal, the maximum being that produced by 180 keV/μm α particles. When chromosome aberrations are scored at metaphase after high-LET irradiation, RBEs considerably greater than those recorded here (~2) have been reported. These results showing relatively small differences in initial break levels for α particles in the LET range of the radon progeny relative to X rays indicate that the greater aberration frequencies are not due principally to an increase in breakage efficiency, but interactions between breaks along the same particle track are important.

Original languageEnglish (US)
Pages (from-to)9-14
Number of pages6
JournalRadiation Research
Volume139
Issue number1
DOIs
StatePublished - 1994
Externally publishedYes

Fingerprint

Alpha Particles
radon
Linear Energy Transfer
Radon
linear energy transfer (LET)
chromosomes
Interphase
Human Chromosomes
energy transfer
interphase
alpha particles
damage
Chromosomes
irradiation
X-Rays
progeny
Cell Nucleus
fragments
X-radiation
cell nucleus

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Radiology Nuclear Medicine and imaging
  • Biophysics
  • Radiation

Cite this

Initial damage in human interphase chromosomes from alpha particles with linear energy transfers relevant to radon exposure. / Loucas, Bradford; Geard, C. R.

In: Radiation Research, Vol. 139, No. 1, 1994, p. 9-14.

Research output: Contribution to journalArticle

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