| Literature DB >> 29997651 |
Rasha S Ahmed1, Raghad S Mohammed2, Rana O Abdaljalil2.
Abstract
Clay soil samples (0, 30, and 60 cm depths) were collected from two districts (Abu Al Khasib and Ad Dayr) in Basrah governorate in southern Iraq for gamma-ray spectroscopy. The activity concentrations for natural existing radionuclides in 18 soil samples were measured using high-purity germanium detector HPGe. From the obtained results of γ-ray spectroscopy, the 238U activity concentrations were found to be ranging from 2.4 to 5.6 ppm with an average of 3.5 ppm in Abu Al Khasib and ranging from 2.1 to 4.5 ppm with an average of 2.9 ppm in Ad Dayr. 232Th concentrations were ranging from 3.6 to 7.5 ppm with an average of 4.7 ppm in Abu Al Khasib and ranging from 3.7 to 7.9 ppm with an average of 5.0 ppm in Ad Dayr. 40K concentration was ranging from 0.1% to 2.0% with an average of 1.2% in Abu Al Khasib and ranging from 0.9% to 1.8% with an average of 1.3% in Ad Dayr. High 238U and 226Ra concentration levels were recorded in both study regions. The concentrations of 232Th are within the normal limits in both regions. High levels of 40K were recorded in some locations. Generally, in most locations, 40K activity was within normal ranges. The radium equivalent activity, the external hazard index, the internal hazard index, and the radioactivity level index were calculated to estimate the radiation hazard in Basrah. The estimated radiation hazard indices were within normal limits, except the radioactivity level index, which shows elevated values. The obtained results were compared with other countries and with the worldwide median certified values.Entities:
Year: 2018 PMID: 29997651 PMCID: PMC5994571 DOI: 10.1155/2018/2541020
Source DB: PubMed Journal: Int J Anal Chem ISSN: 1687-8760 Impact factor: 1.885
Figure 1Map of the surveyed area conducted using geomapapp [7].
Samples regions, depths, and codes indices [7].
| Abu Al Khasib | |||||||||
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| |||||||||
| Samples number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| Samples codes | A-S-1 | A-30-2 | A-60-3 | A-S-4 | A-30-5 | A-60-6 | A-S-7 | A-30-8 | A-60-9 |
| Depth of samples (cm) | 0 | 30 | 60 | 0 | 30 | 60 | 0 | 30 | 60 |
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| Ad Dayer | |||||||||
|
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| Samples number | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| Samples codes | D-S-1 | D-30-2 | D-60-3 | D-S-4 | D-30-5 | D-60-6 | D-S-7 | D-30-8 | D-60-9 |
| Depth of samples (cm) | 0 | 30 | 60 | 0 | 30 | 60 | 0 | 30 | 60 |
Mixed gamma source radionuclides used in HPGe detector and its standard properties.
| Radionuclide | 241Am | 109Cd | 57Co | 57Co | 139Ce | 113Sn | 137Cs | 88Y | 60Co | 60Co | 85Sr |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Energy keV | 60 | 88 | 122.5 | 136.9 | 165.7 | 392 | 661.6 | 898 | 1173.7 | 1132.8 | 513.9 |
| Activity kBq | 1.605 | 0.311 | 0.240 | 0.030 | 0.066 | 0.145 | 2.019 | 0.220 | 2.272 | 2.272 | 0.038 |
Figure 2(a) The linear scale of the efficiency calibration curve for HPGe detector (order of the polynomial is 4 with R2 = 0.709). (b) The energy calibration curve for HPGe detector.
Figure 3The number of counts as a function of energy of the radionuclides in samples 1 and 2, obtained by HPGe detector, and analyzed through Genie 2k Canberra software.
Figure 4Same as Figure 3 for samples 3 and 4.
Figure 5Same as Figure 3 for samples 5 and 6.
238U, 232Th, 40K activities in Bq/kg [7] and the estimated values in ppm using γ-ray spectroscopy.
| Activity concentrations | ||||||
|---|---|---|---|---|---|---|
| Samples codes | 238U | 232Th | 40K | |||
| Bq/kg | ppm | Bq/kg | ppm | Bq/kg | ppm | |
| 1 | 58.6 | 4.7 | 26.9 | 6.6 | 522.1 | 2.0 |
| 2 | 57.3 | 4.6 | 18.9 | 4.6 | 408.1 | 1.6 |
| 3 | 40 | 3.2 | 18.5 | 4.5 | 296.6 | 1.1 |
| 4 | 31.7 | 2.6 | 15.4 | 3.8 | 298.4 | 1.2 |
| 5 | 38.3 | 3.1 | 17.2 | 4.2 | 240 | 0.9 |
| 6 | 69 | 5.6 | 30.8 | 7.5 | 528.2 | 2.0 |
| 7 | 31.3 | 2.5 | 16.8 | 4.1 | 303.4 | 1.2 |
| 8 | 36.3 | 2.9 | 15.2 | 3.7 | 273.2 | 1.1 |
| 9 | 29.5 | 2.4 | 14.7 | 3.6 | 25.8 | 0.1 |
| max. | 69.0 | 5.6 | 30.8 | 7.5 | 528.2 | 2.0 |
| min. | 29.5 | 2.4 | 14.7 | 3.6 | 25.8 | 0.1 |
| ave. | 43.6 | 3.5 | 19.4 | 4.7 | 321.8 | 1.2 |
| stdev. | 20.6 | 1.6 | 8.6 | 2.1 | 350.9 | 1.3 |
| med. | 38.3 | 3.1 | 17.2 | 4.2 | 298.4 | 1.2 |
| med. abs. div. | 7 | 0.6 | 1.8 | 0.4 | 58.4 | 0.3 |
| 10 | 32.5 | 2.6 | 21.4 | 5.2 | 341.8 | 1.3 |
| 11 | 27 | 2.2 | 17.3 | 4.2 | 300 | 1.2 |
| 12 | 34.2 | 2.8 | 18.3 | 4.5 | 322 | 1.2 |
| 13 | 28.9 | 2.3 | 17.3 | 4.2 | 241.8 | 0.9 |
| 14 | 56.1 | 4.5 | 32.2 | 7.9 | 461.4 | 1.8 |
| 15 | 30.6 | 2.5 | 15.3 | 3.7 | 321.4 | 1.2 |
| 16 | 32 | 2.6 | 20.8 | 5.1 | 309.8 | 1.2 |
| 17 | 52 | 4.2 | 24.1 | 5.9 | 450.2 | 1.7 |
| 18 | 26.5 | 2.1 | 16.3 | 4.0 | 284.8 | 1.1 |
| max. | 56.1 | 4.5 | 32.2 | 7.9 | 461.4 | 1.8 |
| min. | 26.5 | 2.1 | 15.3 | 3.7 | 241.8 | 0.9 |
| ave. | 35.5 | 2.9 | 20.3 | 5.0 | 337.0 | 1.3 |
| stdev. | 4.2 | 0.4 | 3.6 | 0.8 | 40.3 | 0.1 |
| med. | 32 | 2.6 | 18.3 | 4.5 | 321.4 | 1.2 |
| med. abs. div. | 3.1 | 0.3 | 2.5 | 0.6 | 21.4 | 0.1 |
The half-lives, atomic masses, and the calculated radioactivity conversion factors from Bq/kg to ppm for 238U, 232Th, 40K radionuclides.
| radionuclide | Half-life (years) | Atomic mass (u) |
|
|---|---|---|---|
|
238
| 4.5 × 109 | 238.05 | 0.080901 |
|
232
| 1.405 × 1010 | 232.03 | 0.246225 |
|
40
| 1.277 × 109 | 39.96 | 3.8585 × 10−3 |
The average activity concentrations of 238U, 232Th, 226Ra, and 40K radionuclides in Bq/kg evaluated by R. S. Mohammed and R. S. Ahmed [7], compared with different countries and worldwide average.
| Country | The average activity concentrations (Bq/kg) | ||||
|---|---|---|---|---|---|
| 238U | 232Th | 226Ra | 40K | reference | |
| Abu Al Khasib | 44 | 19 | 58 | 322 | [ |
| Ad Dayr | 36 | 20 | 46 | 337 | [ |
| Italy | – | 39 | 323 | 1,046 | [ |
| Turkey | 29 | 18 | – | 580 | [ |
| Spain | 33 | 49 | 45 | 650 | [ |
| Japan | 29 | 28 | 68 | 310 | [ |
| Belgium | – | 28 | 28 | 390 | [ |
| Mexico | 23 | 19 | – | 530 | [ |
| India | 26 | 51 | – | 5.6 | [ |
| Oman | 30 | 16 | – | 225 | [ |
| Algeria | – | – | 80 | 408 | [ |
| France | 37 | 38 | 38 | 599 | [ |
| Taiwan | 18 | 28 | – | 479 | [ |
| Jordan | 49 | 27 | – | 291 | [ |
| Egypt | 37 | 18 | – | 320 | [ |
| Qatar | 23 | 4.5 | – | 127 | [ |
| Thailand | 35 | 30 | – | 400 | [ |
| USA | 35 | 35 | – | 370 | [ |
| The Netherlands | – | 50 | – | 495 | [ |
| World | 35 | 30 | 35 | 400 | [ |
A comparison of the mass concentrations of 238U, 232Th, and 40K in clay soil samples evaluated in the present study with other locations around the world.
| Location | 238U (ppm) | 232Th (ppm) | 40K (%) | references |
|---|---|---|---|---|
| Present study (Abu Al Khasib) | 2.4-5.6 | 3.6-7.5 | 0.1-2.0 | |
| Present study (Ad Dayr) | 2.1-4.5 | 3.7-7.9 | 0.9-1.8 | |
| Cyprus | 0.08-7.2 | 0.25-13.1 | 0.04-2.91 | [ |
| Italy | 0.16-5.6 | 0.25-16.8 | 0.03-5.14 | [ |
| Bulgaria | 0.64-15.2 | 1.73-39.5 | 0.05-3.75 | [ |
| Canada (Rock) | 0.8-16.4 | 1.1-41.0 | 1.0-6.2 | [ |
| Jordan | 1.76-8.32 | 5.18-25.4 | 0.45-1.96 | [ |
| USA | 0.32-11.2 | 0.98-32.1 | 0.32-2.28 | [ |
| Egypt | 0.48-9.6 | 0.49-23.7 | 0.09-2.12 | [ |
| Serbia and Montenegro | 1.2-6.24 | 4.45-21.0 | 0.88-2.99 | [ |
| Albania | 0.48-7.68 | 0.98-39.5 | 0.05-3.75 | [ |
| Australia | 1.6-3.8 | 6-19 | 0.7-1.9 | [ |
| World Average | 2.64 | 11.1 | 1.37 | [ |
The measured values for Ra [7], Hext, Hin hazard indices in (Bq/Kg) and the radioactivity level index I for 18 clay soil samples, in addition to its max., min., ave., stdev., med., and med. abs. div. values.
| Samples |
226
|
|
|
|
|
|---|---|---|---|---|---|
| 1 | 76.8 | 155.50 | 0.42 | 0.63 | 1.13 |
| 2 | 78.4 | 136.90 | 0.37 | 0.58 | 0.98 |
| 3 | 58 | 107.29 | 0.29 | 0.45 | 0.77 |
| 4 | 42.8 | 87.80 | 0.24 | 0.35 | 0.64 |
| 5 | 44.8 | 87.88 | 0.24 | 0.36 | 0.63 |
| 6 | 99.6 | 184.32 | 0.50 | 0.77 | 1.32 |
| 7 | 37.4 | 84.79 | 0.23 | 0.33 | 0.62 |
| 8 | 50.8 | 93.57 | 0.25 | 0.39 | 0.67 |
| 9 | 37.4 | 60.41 | 0.16 | 0.26 | 0.41 |
| max. | 99.60 | 184.32 | 0.50 | 0.77 | 1.32 |
| min. | 37.40 | 60.46 | 0.16 | 0.26 | 0.41 |
| ave. | 58.44 | 110.94 | 0.30 | 0.46 | 0.80 |
| stdev. | 27.86 | 67.24 | 0.18 | 0.26 | 0.51 |
| med. | 50.8 | 93.57 | 0.25 | 0.39 | 0.67 |
| med. abs. div. | 13.4 | 13.72 | 0.04 | 0.06 | 0.1 |
| 10 | 39.2 | 96.12 | 0.26 | 0.37 | 0.70 |
| 11 | 33.8 | 81.64 | 0.22 | 0.31 | 0.60 |
| 12 | 48.4 | 99.36 | 0.27 | 0.40 | 0.72 |
| 13 | 36.6 | 79.96 | 0.22 | 0.32 | 0.58 |
| 14 | 75.4 | 156.97 | 0.42 | 0.63 | 1.13 |
| 15 | 41.8 | 88.43 | 0.24 | 0.35 | 0.65 |
| 16 | 41.6 | 95.20 | 0.26 | 0.37 | 0.69 |
| 17 | 62.6 | 131.73 | 0.36 | 0.53 | 0.96 |
| 18 | 32 | 77.24 | 0.21 | 0.29 | 0.57 |
| max. | 75.40 | 156.97 | 0.42 | 0.63 | 1.13 |
| min. | 32.00 | 77.24 | 0.21 | 0.29 | 0.57 |
| ave. | 45.71 | 100.74 | 0.27 | 0.40 | 0.73 |
| stdev. | 5.09 | 13.35 | 0.04 | 0.06 | 0.09 |
| med. | 41.6 | 95.2 | 0.26 | 0.37 | 0.69 |
| med. abs. div. | 6.8 | 13.56 | 0.04 | 0.05 | 0.09 |