Transfer of radiocaesium from soil and plants to reindeer in Iceland

Abstract

The Icelandic reindeer (Rangifer tarandus), which were brought from Norway over 200 years ago, show very different levels of 137Cs concentration compared to other Nordic reindeer, even if pre-Chernobyl data are used. Average values of 0.6–22 Bq/kg were observed during the hunting seasons in 1990–1992, whereas winter values of about 300 Bq/kg were reported for Norway, Sweden, and Finland prior to the Chernobyl accident. This low concentration is due to the low average 137Cs concentration in the reindeer's diet, which contains no significant amounts of high-activity lichens or mushrooms. The most important lichen in the reindeer's diet is Cetraria islandica with a 137Cs concentration that is much lower than is commonly found in lichens, 15 Bq/kg dry wt. This study indicates that the concentration in reindeer meat shows no significant seasonal variation. Some similarities can be found in a survey carried out in many areas of Russia during the winter of 1964–1965, where the lowest concentration in reindeer meat was found in the northern part of the Yakut region of Siberia. No seasonal variation was seen there and the most important lichen in the reindeer's diet was Cetraria islandica.