Neutron energy-dependent initial DNA damage and chromosomal exchange

Citation
K. Tanaka et al., Neutron energy-dependent initial DNA damage and chromosomal exchange, J RADIAT R, 40, 1999, pp. 36-44
Citations number
12
Categorie Soggetti
Experimental Biology
Journal title
JOURNAL OF RADIATION RESEARCH
ISSN journal
04493060 → ACNP
Volume
40
Year of publication
1999
Supplement
S
Pages
36 - 44
Database
ISI
SICI code
0449-3060(199912)40:<36:NEIDDA>2.0.ZU;2-Q
Abstract
This study was undertaken to investigate the biological effect of monoenerg etic neutrons on human lymphocyte DNA and chromosomes. Monoenergetic neutro ns of 2.3, 1.0, 0.79, 0.57, 0.37 and 0.186 MeV were generated, and Cf-252 n eutrons and Co-60 gamma-rays were also used for comparison. Biological effe ct was evaluated two ways. The RBE values with the comet assay were estimat ed as 6.3 and 5.4 at 0.37 MeV and 0.57 MeV relative to that of 60Co gamma-r ays, and chromosome aberration rates were also observed in these different levels of monoenergetic neutrons. The yield of chromosome aberrations per u nit dose was high at lower neutron energies with a gradual decline with 0.1 86 MeV neutron energy. The RBE was increased to 10.7 at 0.57 MeV from 3.9 a t Cf-252 neutrons and reached 16.4 as the highest RBE at 0.37 MeV, but the value decreased to 11.2 at 0.186 MeV. The response patterns of initial DNA damage and chromosome exchange were quite similar to that of LET. These res ults show that the intensity of DNA damage and chromosomal exchange is LET dependent. RBE of low energy neutrons is higher than that of fission neutro ns. Low energy neutrons containing Hiroshima atomic bomb radiation may have created a significantly higher incidence of biological effect in atomic bo mb survivors.