Concentrations of alkali and alkaline earth elements in mushrooms and plants collected in a Japanese pine forest, and their relationship with 137Cs

137Cs and stable Na, K, Rb, Cs, Mg, Ca, Sr, Ba and Al were determined in 29 mushrooms and 8 plants collected from a Japanese pine forest. Concentrations of 137Cs, Cs and Rb in mushrooms were one order of magnitude higher than those in plants growing in the same forest. On the other hand, concentrations of Ca and Sr in mushrooms were obviously lower than those in plants. A good correlation (r=0•99, p<0•01) between 137Cs and stable Cs concentrations was observed for mushrooms. The 137Cs/Cs ratios were almost constant (137Cs/Cs=134±36 Bq mg-1 in 1990) and were significantly higher than that in the surface soil (27 Bq mg-1). The ratios for plants were almost the same as those for mushrooms. In plant samples, good correlations were observed among the concentrations of K, Rb, Cs and Mg. Correlation between those of Ca and Sr was also good. In contrast, Cs was not correlated with K in mushrooms, indicating that the mechanism of Cs uptake was different from that for K. Rb showed a correlation with Cs (r=0•82).