"Low Level
Radiation Health Effects: Compiling  the Data"

Revision 2
March 19, 1999

by Radiation, Science, and Health, Inc.,
Edited by J. Muckerheide

1.3
Animal & Plant
Biology

1.3.1
Mammals

References

"An observed 'beneficial' effect from low doses of radiation is described. When mature sperm of rainbow trout were exposed to 25 and 50 rad, the ratios of eggs with embryos to eggs without embryos were significantly increased by approximately 35 and 40%, respectively, as compared with the control. With the higher dose of 400 rad to the sperm the effect was unconditionally 'harmful' and the yield of embryos was greatly reduced.
"It is suggested that the beneficial effect may be due to changes in the protein of the sperm and the harmful effect to changes in the DNA."

"Four independent replicate experiments were carried out. Each involved five radiation doses ranging in two-fold steps from 25 to 400 rads. Radiation from a cobalt-60 source of about 3.9 Ci was delivered at a rate of 64 rad/min. Thus the exposure times ranged from about 0.4 min to just under 7 min."

"A simple computation of relative frequencies, based on pooling the data from the four experiments, indicates substantial increases in the proportions of eggs with embryos to eggs without embryos as a result of exposure of sperm to doses of 25 and 50 rad (Table II). A considerable effect in the opposite direction resulted from exposure to the higher doses."
                               Table 2