Migration of 137Cs in soils and its transfer to mushrooms and vascular plants in mixed forest

Migration of 137Cs in the podsol soil and transfer of 137Cs, 134Cs and potassium from the soil to mushrooms and vascular plants in the mixed forest at the Kampinos National Park near Warsaw, Poland, was studied in 1994 at locations lying about 6 km apart. In the soil at both locations, up to about 40% of 137Cs was present in the Of horizon and slightly less in the mixed organic/mineral OhAh horizon. The data indicate a slow vertical migration of radiocesium. Total content of 137Cs in the soils was ∼ 3000 Bq m−2. The enrichment of the Of horizon in 137Cs from the decomposing mushroom fruitbodies was evaluated and it was shown that it can significantly contribute to the horizontal displacement of radiocesium. Transfer factors (TF) for mushrooms and Calluna were calculated using the concentrations of 137Cs in the Of horizons, whereas for grass, Vaccinium myrtillus and Polypodium vulgare TF were calculated using a weighted mean concentration of 137Cs in the nutritive horizons with organic matter as a weight.