Excretion of Radiocesium (137Cs) in Sweat from Humans

Sweat from the whole body was collected in five healthy unacclimatized male students during two consecutive periods of profuse sweating in a climatic chamber with a hot humid environment. In each subject one sweat collection experiment was performed before and another experiment about two weeks after an oral dose of Cs (160 nCi). Before the intake of the Cs oral dose the volunteers had a “natural” body burden in the same range as other Oslo-residents, whereas their mean body burden rose by a factor of approximately six, measured five days after the intake of the dose. The mean concentration of Cs in whole body sweat after the intake of the oral dose was about 10 times higher than the initial values. After the oral dose of Cs, the amount excreted through sweating was about 30 pCi Cs per hour. Thus, the present data show that the elimination of Cs through sweating might be considerable during prolonged periods of profuse perspiration. Consequently, this excretory pathway should not be neglected under conditions where heat, humidity and physical exertion pertain. There was no decrease in the concentration of Cs in whole body sweat from the first to the second period of sweat collection. Thus, the results give no support to the hypothesis of an “internal” contamination of the sweat of the initial stages of secretion.