DISTRIBUTION OF NATURAL RADIONUCLIDES ON COASTS OF BUSHEHR, PERSIAN GULF, IRAN

Document Type: Regular Paper

Authors

1 Department of Physics, University of Isfahan, Isfahan, 81747-73441, I. R. of Iran

2 2Department of Chemistry, University of Isfahan, Isfahan, 81747-73441, I. R. of Iran,

3 Central Laboratory, University of Isfahan, Isfahan, 81747-73441, I. R. of Iran

Abstract

A reconnaissance study has been made on the distribution of 238U, 232Th, 40K, 137Cs and
geochemical features in soil and sediment samples at various locations on the coast of Bushehr in the Persian
Gulf. In this study a gamma-ray spectrometer based on a High Purity Germanium detector and a PC based
MCA and X-ray fluorescence (XRF) method were used. Estimation of the measured radionuclide content
have been made for the absorbed dose rate of gamma radiation. The Activity concentration (A), the equivalent
radium (Req), and the external hazard index (Hex) which resulted from the natural radionuclides in soil and
sediment are also calculated. The base-line data of radionuclides and heavy metals in view of the
commissioning of nuclear and non-nuclear industries for the coast of Bushehr, which does not yet exist, was
obtained.
Activity concentration levels due to radionuclides were measured in 50 soil and sediment samples
collected from this region. The measurement was performed with respect to their gamma radioactivity for a
counting time of 24 hour intervals. From the accumulated spectra, activity concentration were determined for
40K (range from 108 to 520 Bq Kg-1), 137Cs (from 6 to 40 Bq Kg-1), 238U (from 12 to 75 Bq Kg-1) and 232Th
(from 8 to 33 Bq Kg-1) with the lowest limit detection (LLD) of, respectively, 68, 3.2, 4.3 and 4.3 Bq Kg-1.
The dose rate from ambient air at the soil ranges was between 14 to 44 nGy h-1 with an average of 30.56±
7.86 nGy h-1.

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