Soil depth profile of 137Cs, 210Pb and 40K in Algeria

Abstract

ABSTRACTThree soil depth profiles of 210Pb, 137Cs and 40K at different areas of Algeria were studied. The soil sampling areas are near the location where the French nuclear tests took place at 1960–1966. The two depth soil profiles were collected at Ghardaia region and the third one at Reggane region. The vertical distributions of radionuclides at the two soil depth profiles from Ghardaia region are different, probably due to the different soil composition. The soil depth profile from sandy soil show uniformity in the distribution of radionuclides without a clear maximum (peak). The soil depth profile that characterised by silty sand show a clear peak at 20–50 cm depth for all studied radioactive nuclides, while the observed activities are two times higher than the corresponding values in sandy soil samples. More specifically in Ghardaia region the 210Pb, 137Cs, 40K activity concentrations ranged between 27 and 50 Bq kg−1, 0.2 and 3 Bq kg−1 and 75 and 90 Bq kg−1 respectively in sandy soil type and between 37 and 75 Bq kg−1, 4 and 6 Bq kg−1 and 140 and 180 Bq kg−1 respectively in silty sand soil type. Finally, the third depth soil profile collected from Reggane site presents a completely different distribution of the studied radionuclides. The activity concentrations of 210Pb, 137Cs, 40K ranged between 37 and 51 Bq kg−1, 0.16 and 0.39 Bq kg−1 and 120 and 309 Bq kg−1 respectively. Three peaks in the 137Cs distribution revealed, were most probably, Chernobyl related 137Cs accounts for the surface peak, while the deeper peaks are connected to the weapons fallout.