Mushrooms: An important route of radiocaesium transfer from soil to grazing reindeer

Abstract

In the late summer and fall of 1988 mushrooms were precent i n abundance i n Scandinavia and concomitant ly increased levels of radiocaesium were observed i n both domestic and w i l d grazing animals. Subsequent studies revealed high concentrations of radiocaesium i n several species of mushrooms highly sought by reindeer and other ruminants. In August the intake of radiocaesium by oesophageally fistulated reindeer grazing i b i rch forest amounted to as much as 1.9-5.7 k B q per feeding bout of 10 m i n . A major component of the ingesta was mushrooms. In sacco studies was showed a rapid release of radiocaesium from mushroom tissue into the rumen. Feeding trials w i t h contaminated mushrooms to goats also showed that radiocaesium was easily available and behaved s imilar ly to oral doses of ionic Cs . Radiocaesium f rom mushrooms was rapidly transfered to m i l k . It can be assumed that the higher activity found in reindeer calves than i n females partly can be explained by intake of m i l k and partly by larger intake of food per unit of body weight than in adult animals. Recent studies have shown that o ld bomb test fallout of radiocaesium can be mobi l i zed into the food chain by mushrooms. A l t h o u g h the general level of radiocaesium in reindeer forages decrease s lowly , radiocaesium f rom the Chernob y l accident can, when there is a large mushroo m crop, probably cause serious problems to the reindeer industry in the years to come. Rangifer, Special Issue No . 4,1990 37