Radiological assessment of natural radioactivity in river sediments along the Kaligandaki River at Jomsom Area, Nepal.

Background: The Kaligandaki River from Kushma to Galeshwor is considered a high natural background radiation area, requiring baseline assessment of naturally occurring radionuclides for radiation protection.Materials and Methods: A portable gamma-ray spectrometer (PGIS-2) equipped with a NaI(Tl) scintillator detector was employed. Radiological hazard parameters, including radium equivalent activity, absorbed gamma dose rates in air, annual effective dose rate, external hazard index, and internal hazard index, were determined.Results and Discussion: The mean activities of radionuclides <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K, were found to exceed global average values. Radium equivalent activity ranged from 141.48 Bq·kg<sup>−1</sup> to 313.24 Bq·kg<sup>−1</sup>, with a mean value 204.91 Bq·kg<sup>−1</sup> for the Kushma–Galeshwor region. The annual effective dose rates were 0.12 mSv· yr<sup>−1</sup> and 0.47 mSv· yr<sup>−1</sup> for outdoors and indoors, respectively.Conclusion: Although these values exceed global averages, they remain within established safety limits. The findings highlight the importance of continuous monitoring to ensure environmental and public safety in regions with naturally occurring radioactive materials. Therefore, from a radiation protection perspective, the region is considered safe.

Assessment of gamma radiation and associated radiation hazards in coastal sediments of south east coast of Tamilnadu, India with statistical approach

In the present study, we present results of radiometric and petrographic analyses of sediment samples collected from the river banks of Jhelum, Neelum, and Kunhar confluencing in the district Muzaffarabad. Gamma activity concentrations due to 226Ra, 232Th, and 40K were determined using high-purity germanium detector (HPGe). For a total of thirty sediment samples collected from three rivers, the activity concentrations of 226Ra, 232Th and 40K varied from 03.32 ± 0.40 to 100.45 ± 2.08 Bq Kg−1, 02.17 ± 1.35 to 298.42 ± 4.50 Bq Kg−1 and 37.88 ± 11.66 to 1386.32 ± 30.17 Bq Kg−1 with mean values of 36.91 ± 1.12, 61.57 ± 2.81 and 557.33 ± 19.81 Bq Kg−1, respectively. The overall value of Raeq for all the investigated sediment samples was found to be in the range from 9.34 ± 3.23 to 633.53 ± 10.14 Bq Kg−1 with mean value of 167.88 ± 6.66 Bq Kg−1. The values estimated for hazard indices, viz., external hazard index (Hex), internal hazard index (Hin), representative index (Ir), gamma index (I) and alpha index (Iα) for all sediment samples were found to be in the range from 0.02 ± 0.008 to 1.71 ± 0.03, 0.034 ± 0.009 to 1.98 ± 0.03, 0.07 ± 0.02 to 4.57 ± 0.07, 0.03 ± 0.01 to 2.29 ± 0.03 and 0.02 ± 0.002 to 0.50 ± 0.010 with mean values of 0.45 ± 0.02, 0.55 ± 0.02, 1.23 ± 0.04, 0.62 ± 0.02 and 0.18 ± 0.010, respectively. The activity concentrations were subsequently used to estimate the terrestrial gamma ray absorbed dose rate in air at 1 m above the ground and annual effective dose. For all the samples, the values of gamma absorbed dose rate and annual effective dose ranged from 4.42 ± 1.49 to 284.24 ± 4.64 nGyh−1 and 0.027 ± 0.009 to 1.74 ± 0.03 mSv year−1 with mean values of 77.49 ± 3.04 nGyh−1 and 0.48 ± 0.02 mSv year−1, respectively. Mean gamma absorbed dose rate computed in the present study is higher than that reported for world average (59 nGy h−1) and it also exceeds the UNSCEAR proposed safe limit of 55 nGyh−1. The resulting annual effective dose is also higher than the worldwide average value of 0.07 mSv year−1, however, it is less than the safe limit of 1 mSv year−1. From the present study, it is concluded that there is a possibility of high radiation risk from the sediments of the surveyed rivers due to elevated activity concentrations and doses when used as building materials. The building codes need to be revisited taking into account the effects of radiation exposure and absorbed dose on the inhabitants.

In this study, natural and artificial radionuclide concentrations were determined and radiological dose values of nine different medicinal plants {Sweet marjoram (Origanum majorana), Rosemary (Rosmarinus officinalis) Lavender (Lavandula x intermedia), Thyme (Thymus vulgaris), Sage (Salvia officinalis), Peppermint (Mentha piperita), Holy basil (Ocimum Sanctum), Bush basil (Ocimum minimum) and Lemon balm (Melissa officinalis)} used in Balikesir province from Turkey were evaluated. Gamma-ray spectrometry was used to determine the natural and artificial radionuclide concentrations of these medicinal plants. To evaluate radiological dose values, absorbed gamma dose rate (D), radium equivalent activity (Raeq) annual gonadal dose equivalent (AGDE), exposure dose (ER), annual effective dose (AED), excess lifetime cancer risk (ELCR), internal hazard index (Hin), external hazard index (Hex) and gamma representative level (GRL) were determined. Mean values of 226Ra and 232Th activity concentrations are lower than the world average values, whereas mean values of 40K activity concentrations are higher than the world average values for present medicinal plants. Lavandula x intermedia has the highest 137Cs concentration, whilst Thymus vulgaris L. has the lowest 137Cs activity concentration. D, Raeq, AGDE, ER, AED and ECLR values are the highest for Lavandula x intermedia, whilst they are the smallest for Rosmarinus officinalis L. among the studied medicinal plants. Average values of Hin and Hex are lower than the permissible value of 1, whilst the average value of GRL is higher than permissible limit value of 1.

The objective of this study were to analyze the specific activity of the natural radioactive nuclide of 226Ra, 232Th and 40K and to calculate the Radium equivalent activity (Raeq), the Internal hazard index (Hin), the External hazard index (Hex), the Gamma-absorbed dose rate (D) and the Annual external effective dose rate (E) in the 20 soil samples from Koh Phangan District, Surat Thani Province by using gamma-ray spectrometer with a high purity germanium detector (HPGe). The results show that the specific activity of radioactive nuclides in many samples were higher than Thailand and the global average values. In addition, the Radium equivalent activity (Raeq), the Internal hazard index (Hin), the external hazard index (Hex) and the gamma-absorbed dose rate (D) were higher than the UNSCEAR criterion (2000). The present study found that the radioactivity may affect the health of people living in that area.

This work aims to evaluate radioactivity levels of 238U (226Ra), 232Th(228Ra), and 40K and the associated radiological hazard indices, as well as to assess the current status and concentrations of heavy metals along the coastline of the Gulf of Suez, in order to identify potential sources of contamination and to construct radioactivity baseline for this area. Measurements of the activity concentrations of 238U(226Ra), 232Th(228Ra), and 40K in Bqkg-1 of the collected samples were carried out using high-purity germanium (HPGe) detector. Heavy metals in seawater, shore sediment, and algae samples were determined using ICP-OES. The average activity concentrations of 238U(226Ra), 232Th(228Ra), and 40K were found to be 13.79 ± 0.75, 14.57 ± 1.15, and 128.9 ± 4.15Bqkg-1, respectively. The radiological hazard indices of absorbed dose rate in nGyh-1 (D), annual effective dose rate in mSvy-1, AED, radium equivalent activity in Bq (Raeq), external and internal hazard indices (Hex, Hin), and cancer risk factor were calculated and compared with the worldwide averages. The distribution patterns of annual effective dose (AED) at the Suez Gulf showed that the south east of the Gulf is characterized by higher AED. Water quality parameters (water temperature, salinity, pH, DO, and Eh) reveal that Suez Gulf was undoubtedly affected by the rate of the human activities. Heavy metal concentrations in shore sediments showed some variation within the study area and followed the following order: Fe > Mn > Zn > Al > B > Co > Ni > Pb > V > Cr > Mo > Cu > Cd. Furthermore, heavy metal concentrations indicated that northern part of the Gulf contains the highest levels of these metals compared to the southern one.

Evaluation of radiological hazards in the sediments of Ogun river, South-Western Nigeria

In this paper, we attempt to determine the activity concentration of natural and artificial radionuclides in 37 sand samples from the Mediterranean coast of Antalya in Turkey by using a high purity Germanium (HpGe) detector. 238 U, 232 Th, 40 K and 137 Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard index of sand samples are determined res-pectively. The average values are 13.43 ± 0.21 Bq/kg, 6.96 ± 0.06 Bq/kg and, 122.46 ± 18.58 Bq/kg, for 238 U, 232 Th and 40 K respectively. Most of the activity concentration values are less than below minimum detection limit for 137 Cs. The average values of the absorbed dose rate D (nGy/h), annual effective dose equivalent AEDE(μSv/y), radium equivalent activity Ra eq (Bq/kg), external hazard index H ex and internal hazard index H in are 15.52 nGy/h, 19.03 μSv/y, 32.81 Bq/kg, 0.09 and 0.12 respectively. It is observed that 238 U, 232 Th, 40 K and 137 Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity are in the limit of the published values, external and internal hazard index values are less than unity.

Assessment of natural radionuclides and its radiological hazards from tiles made in Nigeria

Activity concentrations of 226Ra, 232Th, 40K, and 137Cs in soil samples collected at Mount Rainier National Park and Satsop Nuclear Power Plant zone in State of Washington (USA) and Curonian Spit National Park and Ignalina Nuclear Power Plant zone in Lithuania have been measured by gamma spectrometry. The results have been compared with the worldwide measured average values reported by the UNSCEAR. Higher activity concentrations of 137Cs were found in Curonian Spit National Park due to Chernobyl accident fallout. The radium equivalent activity (Raeq), the external hazard index (Hex), the internal hazard index (Hin), the absorbed dose rate (D), and the annual effective dose rate (AEDR) were also calculated and compared with the international recommended values. These calculated hazard indices used to estimate the potential radiological health risk in soil and the dose rate associated with it are below their permissible limit.

The present work is the first systematic and large scale study on radioactive materials and heavy metals in surface soil around the Bayanwula prospective uranium mining area in China. In this work, both natural and anthropogenic radionuclides and heavy metals in 48 surface soil samples were analyzed using High Purity Germanium (HPGe) γ spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS). The obtained mean activity concentrations of 238U, 226Ra, 232Th, 40K, and 137Cs were 25.81 ± 9.58, 24.85 ± 2.77, 29.40 ± 3.14, 923.0 ± 47.2, and 5.64 ± 4.56 Bq/kg, respectively. The estimated average absorbed dose rate and annual effective dose rate were 76.7 ± 3.1 nGy/h and 83.1 ± 3.8 μSv, respectively. The radium equivalent activity, external hazard index, and internal hazard index were also calculated, and their mean values were within the acceptable limits. The estimated lifetime cancer risk was 3.2 × 10−4/Sv. The heavy metal contents of Cr, Ni, Cu, Zn, As, Cd, and Pb from the surface soil samples were measured and their health risks were then assessed. The concentrations of all heavy metals were much lower than the average backgrounds in China except for lead which was about three times higher than that of China’s mean. The non-cancer and cancer risks from the heavy metals were estimated, which are all within the acceptable ranges. In addition, the correlations between the radionuclides and the heavy metals in surface soil samples were determined by the Pearson linear coefficient. Strong positive correlations between radionuclides and the heavy metals at the 0.01 significance level were found. In conclusion, the contents of radionuclides and heavy metals in surface soil around the Bayanwula prospective uranium mining area are at a normal level.

Natural radioactivity concentrations and dose assessment in coastal sediments along the East Coast of Tamilnadu, India with statistical approach

Assessment of radioactive materials and heavy metals in the surface soil around uranium mining area of Tongliao, China

Natural radioactivity in some major rivers of coastal Karnataka on the southwest coast of India

226Ra, 232Th and 40K activity concentrations have been determined by gamma-ray spectrometry in different types of marble, granite and ceramic tiles that are commonly used for interior and exterior purposes in buildings in Riyadh, Saudi Arabia. Marble showed the lowest concentrations of the three measured radionuclides, while the highest 226Ra and 40K activities were found in granite and the highest 232Th concentration was found in ceramic samples. Activity measurements were used to calculate the elemental concentrations of uranium and thorium and to assess the associated radiation hazards by evaluating various radiological hazard indices, such as radium equivalent activity, external and internal hazard indices and gamma and alpha radiation indices. Moreover, the absorbed gamma dose rate in indoor air, annual effective dose equivalent and annual gonadal dose equivalent were also presented. In most cases, the calculated parameters showed levels below the permissible limits indicating the safe use of these materials for building constructions. The relative contribution of the natural radionuclides to the radiation dose in the studied materials as well as the hazard portion due to exhaled radon was also estimated. The lifetime risk assessment from exposure to gamma sources in the investigated samples showed values in the range of 10−4–10−3.