Revision 1
March 19, 1998
by Radiation, Science, and Health, Inc.,
Edited by J. Muckerheide

1.4
Biology, Genetics & Cancer Research

"In mammals, radiation hormesis enhances defense reactions against neoplastic and infectious diseases, increases longevity and improves fertility. ..in an experiment with mice the incidence of leukemia, cancers, and sarcomas was lower in animals irradiated with cesium-137 gamma radiation doses of 2.5 to 20 mSy than it was in nonirradiated controls. The number of all malignant neoplasms in animals exposed to a single dose of 10 mSv was more than 30% lower than in nonirradiated controls. In several experiments, small initial radiation doses have been shown to improve the survival of animals subsequently irradiated with large, near lethal doses. In other experiments, an increased life span was found in animals irradiated with doses between 250 and 3000 mSv. ....a group of French studies started in the early 1960’s, indicate that protozoa and bacteria exposed to artificially lowered levels of natural radiation demonstrate deficiency symptoms expressed as dramatically decreased proliferations. This indicates that ionizing radiation may be essential for life."

"In 1943, during the early stages of the Manhattan Project, it was found that the animals exposed to inhalation of uranium dust at levels that were expected to be fatal actually lived longer, appeared healthier, and had more offspring than the noncontaminated control animals. For years, these results were treated as an anomaly but later studies produced similar results (Brucer 1989). The first UNSCEAR report to the General Assembly of the United Nations presented the results of experiments showing longer survival times of mice and guinea pigs exposed to small doses of gamma radiation (UNSCEAR 1958)."