Persistence of super(137)Cs in the litter layers of forest soil horizons of Mount IDA/Kazdagi, Turkey

In 2010-2012, an extensive study was performed in forest sites of Mount IDA (Kazdagi)/Edremit 26 years after the Chernobyl accident. The super(137)Cs activity concentrations were determined by gamma-ray spectrometry in the forest soil layers (O sub(L), O sub(F) + O sub(H) and A horizons) separately. Based on 341 surface soil samples and 118 soil profiles, activity concentrations of super(137)Cs in O sub(L) horizons varied between 0.25 plus or minus 0.14 and 70 plus or minus 1 Bq kg super(-1), while the ranges of super(137)Cs activity concentrations in O sub(F) + O sub(H) and A horizons were 13 plus or minus 1-555 plus or minus 3 Bq kg super(-1) and 2 plus or minus 1-253 plus or minus 2 Bq kg super(-1), respectively. Cesium-137 deposition in the study area was estimated to be in the range of 1-39 kBq m super(-2) and a linear relationship between the deposition of super(137)Cs and the altitude was observed. The distributions of super(137)Cs activities in O sub(L), O sub(F) + O sub(H) and A horizons throughout the region were mapped in detail. The highest super(137)Cs activities were found in O sub(F) + O sub(H) horizons, with markedly lower super(137)Cs activity in mineral horizons of soil profiles. It is observed that super(137)Cs content of humus layer increases with the thickness of the humus layer for coniferous forest sites. The super(137)Cs activity concentrations were higher than the recommended screening limits (150 Bq kg super(-1)) at some of the investigated areas. The current activity concentration of top soil layers indicates that over many years since the initial deposition, super(137)Cs activity is keeping still high in the organic horizons.