A Study on Percutaneous Absorption of Radioisotopes

Abstract

This study was carried out to investigate the percutaneous absorption of radioisotopes and the first aid procedure for skin contamination accidents.In the experiments of the percutaneous absorption, a small amount of carrier free 32P (pH 1) or 90Y (pH<1, =10) was pipetted on the normal and the injured skin of rats, and the absorption of these radionuclides was measured for about one hour using the outer counting method. Autoradiographs of the skin contaminated with 32P or radiocolloidal 198Au were made. Percentage of the absorption of 32P through the normal skin was 6.5% of the applied amount. With injury on the skin, the amounts absorbed ranged from 20 to 90%, depending on depth and bleeding state of the wound, but coagulated blood which covered the wound was found to be a good barrier against the absorption of the radioisotope just like as the normal skin. The absorption of 90Y was affected with the pH and radiocolloidal 90Y was difficult to be absorbed through the normal and the injured skin.To investigate the blocking means against the percutaneous absorption, the effects of washing and of administration of tannic acid and epirenamine-hydrochlor were examined. Epirenamine-hydrochlor was found to have, although for short time, strong blocking effect against the absorption into the body. From this result, the use of peripheral-angiotonics has been proposed as a first aid procedure for the skin contamination accident.