"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

"In a series of long-term experiments, we have now determined the complete dose response for the tumor incidence induced by repeated beta irradiation of the backs of mice.
"Figure 1 shows data obtained in the present experiments together with data obtained previously (Ootsuyama and Tanooka 1988; Ootsuyama and Tanooka 1991). In the present experiment, none of the 50 mice irradiated with 0.5 Gy three times weekly throughout life developed tumors."

                              Figure 1

"The total data indicated that repeated beta irradiation resulted in 100% tumor incidences at 1 to 11.8 Gy per exposure. With 2.5 to 11.8 Gy, tumor emergence followed the same time course (saturation effect). An abrupt delay of tumor emergence occurred when the dose was reduced to 1.5 Gy, and with 0.75 Gy tumors began to appear only at the end of the life span of the mice. With 0.5 Gy per exposure employed in the present experiment, no tumor appeared within the life span of the mice."