Vertical distributions and gamma dose rates of 40K, 232Th, 238U and 137Cs in the selected forest soils in Izmir, Turkey

Abstract

This paper presents the results obtained from a radioecological study carried out in the selected forest sites of Izmir, Turkey. The levels of gamma-emitting radionuclides, 40K, 232Th, 238U and 137Cs, in soils were determined using gamma spectroscopy. The activity profile for 40K, 232Th and 238U exhibits a uniform distribution with respect to depth. The depth distribution of 137Cs activity was established by fitting the experimental points to an exponential or a Gaussian function. About 42-97% of the 137Cs deposition was found in the first 10 cm of soil even after 18 y from Chernobyl accident. The dose-rate and annual-effective dose received from external irradiation were quantified. It is indicated that 137Cs from the fallout plays a less role in external radiation exposures in forest sites of Izmir than in potential exposures from naturally occurring radionuclides accounted for by soil.

Establishment of control site baseline data for erosion studies using radionuclides: a case study in East Slovenia

“…The maximum mass activity of 40 K, 724 Bq kg À1 , was measured in the 30e40 cm soil increment. Generally, the vertical distribution of 40 K in soil is uniform (Karadeniz and Yaprak, 2008). However, our mass activity results suggest that potassium distribution in natural soils is not always homogenously distributed.…”

Edaphic factors affecting the vertical distribution of radionuclides in the different soil types of Belgrade, Serbia

“…40 The specific activities of 137 Cs were maximal at 10-15 cm depth, which is in accordance with numerous studies showing that 137 Cs deposition is mostly contained within the surface soil layer. [41][42][43] The 137 Cs specific activities in the surface soil layers showed a wide range of values (from 8.3 to 160 Bq kg À1 in the 0-5 cm layer and from 8.4 to 120 Bq kg À1 in the 5-10 cm layer), which could be attributed to non-homogeneous surface contamination after the Chernobyl accident. The 137 Cs inventories calculated according to eqn (1) were found to vary between 60 Bq m À2 for profile C and 320 Bq m À2 for profile E, which is in accordance with values reported for Belgrade area after the Chernobyl accident.…”

Spatial distribution and vertical migration of 137Cs in soils of Belgrade (Serbia) 25 years after the Chernobyl accident

“…Numerous studies following the Chernobyl accident have shown that soil is the main reservoir for radiocesium [1][2][3] and its spatial distribution in soil has been widely investigated. [4][5][6] It has been recognized that 137 Cs was mostly deposited in the surface soil layer (0-15 cm) [7][8][9] and that its concentration decreases slightly with depth. [10][11][12][13] The physicochemical characteristics of soil and other environmental conditions inuence the migratory behavior of cesium in soil.…”