External dose estimates of laboratory rats and mice during exposure to dispersed neutron-activated Mn-56 powder

Estimates of external absorbed dose in experimental animals exposed to sprayed neutron-activated Mn-56 powder are necessary for comparison with internal absorbed doses estimated under the same exposure conditions, which is required for a correct interpretation of the observed biological effects. It has been established that the measured dose of external absorbed dose as a result of gamma irradiation range 1-15 mGy, which is order of magnitude less than the maximal dose of internal gamma and beta irradiation of the whole body of the same experimental animals irradiated under the same conditions: according to the available literature data, the maximal values of absorbed dose of internal gamma-beta irradiation of the whole body are in the range of 330 mGy-1200 mGy for mice and 100 mGy-150 mGy for rats. It is concluded that under the conditions of experiments with dispersed neutron-activated powder (MnO2)-Mn-56, internal gamma-beta irradiation of experimental animals is the main factor of radiation exposure compared to external gamma irradiation.