Effect of sodium and potassium supplementation on accumulation and excretion of radiocaesium in reindeer

We tested the effect of sodium and potassium supplementation on radiocaesium excretion and accumulation in reindeer eating lichens (winter diet). Nine reindeer were divided into 3 groups of 3 animals. One group was daily given 0.35 M KC1, one was given 0.35 M NaCl (both dissolved in 1 1 water), and one group was kept as a control with no mineral supplement. The animals were contaminated with 137Cs from radioactive pasture. During 3 weeks before the experiment the 137Cs concentrations were maintained by daily supplementation of 157Cs sprayed on lichens. From the start of the experimental period the animals received identical large daily doses of I34CsCl. Animals which were given KCl supplementation showed a lower accumulation of 134Cs in red blood cells (RBC) and a faster decrease of 137Cs in RBC than control animals. Sodiumchloride supplementation had no clear effects on radiocaesium concentrations in RBC. Mineral supplements did not affect excretion of radiocaesium via faeces. Supplement of KCl or NaCl increased urine production and the amount of radiocaesium excreted via the urine. It is concluded that increased K intake decreases the radiocaesium concentration in the animals more than is explained by increased urine production alone. This supports the theory that increased K concentration in the diet may contribute to a fast elimination of radiocaesium in reindeer during spring.