Induction of sister chromatid exchanges by extremely low doses of alpha-particles.
The induction of sister chromatid exchanges (SCE) was examined in Chinese hamster ovary cells irradiated in the G1 phase of the cell cycle with alpha-particles from a plutonium-238 source. A significant increase in the frequency of SCE occurred with doses as low as 0.31 mGy (31 millirads). Although 30% of the cells showed an increased frequency of SCE at this dose, less than 1% of cell nuclei were actually traversed by an alpha-particle. A dose of approximately 2.0 Gy was necessary to produce a similar increase in SCE by X-rays. These results indicate that genetic damage may be induced by low doses of alpha-radiation in cell nuclei not actually traversed by an alpha-particle. This phenomenon may have important implications in the estimation of risks of such exposures.
Nagasawa
H
H
Department of Cancer Biology, Harvard School of Public Health, Boston, Massachusetts 02115.
Little
J B
JB
D000512:Alpha Particles / Q000009:adverse effects*; D000818:Animals; D016466:CHO Cells / Q000528:radiation effects; D002467:Cell Nucleus / Q000528:radiation effects; D006224:Cricetinae; D004307:Dose-Response Relationship, Radiation; D016193:G1 Phase; D011005:Plutonium / Q000009:adverse effects; D012854:Sister Chromatid Exchange / Q000528:radiation effects*; D013997:Time Factors
D011005:Plutonium