Long-term effects of low-dose radiation and hormesis

This paper reports on hormesis, a term to describe a stimulatory as well as a beneficiary effect at low dose of an agent known to be toxic at a higher dose. The authors reviewed our long-term data on C 57 Black/6 mice following neutron or gamma irradiation in an attempt to detect any hormetic action associated with the carcinogenic effect or/and shortening of life span. A total of 7,109 mice of either sex were either sham-, neutron-, or cobalt-irradiated at the age of 33 days ± 3. The dose ranged from 3.2 to 47.2 cGy for neutrons and from 18.0 to 141.0 cGy for cobalt rays. quantitative dose-response relationships for tumor incidence were obtained within equal time intervals throughout the entire life span