Determination of gamma-emitting radionuclides in the inter-tidal sediments off Balochistan (Pakistan) Coast, Arabian Sea

Assessment of radiological indices and physiochemical characterization of sediments in Chashma Lake, Pakistan

Twenty surface sediment samples were gathered from Chasma Lake, deciding the radionuclides 137Cs, 226Ra, 228Ra, 232Th, and 40K and their associated hazard indices. The deliberate radionuclide activities of present research have been contrasted with earlier research, and acquired outcomes in the present study are found below the results in the world. The radiation hazard indices following the presence of natural radionuclides in sediment samples were estimated, and the results assigned the values of all the determined radiological indices found inside the worldwide suggested limits. It was concluded from the current review that the sediment of Chashma Lake is safe for construction and agriculture and does not make radiation dangerous to the nearby local area of the lake.

Assessment of radioactivity levels in shore sediments along the coastline of the Orange River, Oranjemund, Namibia

The objective of present study was to evaluate the activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K and radiological hazards due to gamma exposure of shore sediment along the coastline of the Orange River, Oranjemund, Namibia. A total of 20 shore sediment samples were collected along the coastline of the Orange River. Shore sediment samples were analyzed using a Canberra Gamma Spectrometric detector inter phased with a multichannel analyzer (MCA) that was well calibrated for energy and efficiency respectively. The mean activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K for the shore sediment samples were 63.46 ± 9.83 Bqkg⁻¹, 54.88 ± 5.03 Bqkg⁻¹ and 416.99 ± 57.85 Bqkg⁻¹ respectively. The mean activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K in the shore sediment samples were slightly higher than world reference levels. Also, the radiological hazards parameters of absorbed dose rates, annual effective dose equivalent (outdoor) and the excess lifetime cancer risk for the Orange River shore sediment samples were calculated. The mean values calculated for absorbed dose rates (63.98 nGy/h), annual effective dose equivalent (outdoor) (0.78 mSv/y) and excess lifetime cancer risk (2.73) were higher than the recommended limits, therefore long term radiation exposure of the local population along the coastline of the Orange River may pose significant health threat from radiological point of view.

Radiological risk assessment in sediment of Namal Lake, Mianwali, Pakistan

This study is concentrated on the radiological risk assessment of sixteen surface sediment samples recovered from Namal Lake, District Mianwali, Punjab, Pakistan. The activity of ¹³⁷Cs, ⁴⁰ K, ²²⁶Ra, ²²⁸Ra, and ²³²Th was carried out with the help of a high purity germanium detector (HPGe) in the sediment, varied in the ranges of > 0.02-3.73 ± 1.31, 98.32 ± 21.45-341.02 ± 58.67, 18.34 ± 2.16-34.23 ± 4.34, 1.62 ± .30-2.34 ± .52, and 0.14 ± 0.10-2.34 ± 0.59 Bq kg^-1 with average values 0.74 ± 0.29, 237.26 ± 37.97, 25.06 ± 4.74, 1.97 ± 0.39, and 1.73 ± 0.33 Bq kg^-1, respectively. The measured concentrations in the current study have been compared with other earlier studies in the world. The data was also used for determining the other useful parameters like radium equivalent activity, absorbed dose rate, annual effective dose rate, and external and internal hazards index to assess the radiological risk assessment for the environment around the study area. The ERICA Tool software was also applied for radiological risk assessment for lake fish due to the radioactivity present in the lake sediments. It was concluded from the results of ERICA tool that the risk quotient in this study is less than one indicating that no toxic effects of radioactivity for Namal Lake fish.

An overview of radioactivity measurement studies in Pakistan

In our environment, various naturally occurring radionuclides are present (both underground and overground) in several places, which results in lifelong human exposure. The radiation dose received by human beings from the radiation emitted by these naturally occurring radionuclides is approximately 87%. Exposure to radiation poses radiological health hazards. To assess the human health hazards from radiation, the concentration of these naturally occurring radionuclides are measured in soil (used for cultivation), building materials (soil, bricks, sand, marble, etc.), water and dietary items, worldwide. The available literature revealed that numerous studies related to the subject have been carried out in Pakistan. Most of these studies measured the radioactivity concentrations of primordial [uranium (238U), thorium (232Th), radium (226Ra) and potassium (40K)] and anthropogenic [cesium (137Cs)] radionuclide in soil samples (used for cultivation), fertilizers, building materials (i.e. bricks, rocks, sand, soil, marble, etc.), as well as water and dietary items, using a sodium iodide detector or high purity germanium. An effort was made in 2008 to compile these studies as a review article. However, since then, considerable studies have been undertaken and reported in the literature. Therefore, the main objective of the present article is to provide a countrywide baseline data on radionuclide levels, by overviewing and compiling the relevant studies carried out in Pakistan.

Hazardous parameters associated with natural radioactivity exposure from black sand

Black sand samples collected from Baltim beaches (Kafr El-Sheikh governorate) in Egypt on the Mediterranean Sea shore were analyzed radiometrically and evaluated using a nondestructive gamma ray spectroscopic techniques. The natural radionuclides of ²²⁶Ra, ²³²Th and ⁴⁰K in the black sand samples were identified and quantified. It is found that the activity concentrations for ²²⁶Ra, ²³²Th and ⁴⁰K in different eleven sites (S1S11) were found within the ranges of 28-322, 91-308 and 81-339 Bq/kg, respectively. Moreover, different radiological hazardous parameters (absorbed dose rate, annual effective dose equivalent, radium activity, annual gonadal dose equivalent and excess lifetime cancer risk) were calculated. The results show that these values are greater than the permissible values due to increasing the activity concentrations of the primordial radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K. The dose rate for radiation emitted at 1 m from the surface of land was measured directly and the results shown that all sites emit radiation doses more than the international permissible value (57 nGy/h) especially at three sites which around 340 nGy/h. These values are important to establish baseline levels of this environmental radioactivity to detect any upcoming change for the local population and resorts people. The relatively high dose rate will be considered as a spa for the physical therapy such as treatment of some skin diseases and rheumatoid.

Radiological impact of natural radioactivity in Egyptian phosphate rocks, phosphogypsum and phosphate fertilizers

In this study, the activity concentrations of the natural radionuclides in phosphate rocks and its products were measured using a high- purity germanium detector (HPGe). The obtained activity results show remarkable wide variation in the radioactive contents for the different phosphate samples. The average activity concentration of ²³⁵U, ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K was found as (45, 1031, 786, 85 and 765Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897Bq/kg) for single super phosphate respectively. Based on the measured activities, the radiological parameters (activity concentration index, absorbed gamma dose rate in outdoor and indoor and the corresponding annual effective dose rates and total excess lifetime cancer risk) were estimated to assess the radiological hazards. The total excess lifetime cancer risk (ELCR) has been calculated and found to be high in all samples, which related to high radioactivity, representing radiological risk for the health of the population.

Natural radioactivity measurements of beach sands in Gran Canaria, Canary Islands (Spain)

Concentrations of natural radionuclides (226)Ra, (232)Th, (40)K and man-made (137)Cs in most important tourist Gran Canaria beaches have been determined using a high-purity Germanium detector to analyse their radiological hazard. Average values of the activity concentrations of (226)Ra, (232)Th and (40)K were 17.6±1.4, 21.3±1.8 and 480±22 Bq kg(-1), respectively. Observed activity concentration values of (137)Cs were practically negligible from a radiological protection point of view. The results of this paper were compared with others published in the bibliography for beaches and coastal sediments of different countries. The mean external air absorbed dose rate was 43.9±2.8 nGyh(-1), which resulted in an outdoor annual effective dose below the world average. Also, the radium equivalent and the external hazard index were calculated. Results from Gran Canaria beaches showed the low levels of radioactivity, indicating no significant radiological risk related to human activities in the area.

Radiation dose estimation of sand samples collected from different Egyptian beaches

A high pure germanium detector-based gamma-ray spectroscopy low-background counting system was used to determine the levels of natural radioactivity from beach sand samples on the Egyptian coast along the Mediterranean and Red Seas. The activity concentrations of (226)Ra, (232)Th and (40)K were found to lie in the range of 30±11 to 60±14 Bq kg(-1) with a mean of 39±15 Bq kg(-1), 12±3 to 30±14 Bq kg(-1) with a mean of 21±13 Bq kg(-1) and 392±22 to 413±22 Bq kg(-1) with a mean of 402±23 Bq kg(-1), respectively. Radiation hazard indices and annual effective doses were evaluated and compared with the international data. The results indicate that the values obtained fall below the internationally accepted maximum limits and do not pose any significant radiation hazard to individuals in the study area. From these results, a radiological baseline map of Egyptian beaches can be drawn and used as reference information to assess any future alterations in the radioactivity of beach sands due to any changes in the sea sediments.

Natural radioactivity measurements in Pakistan--an overview

Humans have always been exposed throughout their period of existence to naturally occurring ionising radiation. Specifically, naturally occurring radionuclides are present in variable amounts in our environment. To assess radiological health hazards, naturally occurring radionuclides are being measured in soil, sand, marble, bricks etc throughout the world. In this regard, extensive data have been reported for Pakistan, which have been compiled and reviewed in this article. The majority of the reported articles are about monitoring of the radiological health hazards of naturally occurring radionuclides. In a few articles, use of the radionuclides has been reported for the exploration of uranium and thorium deposits. Most of the reported data have been obtained using a high purity germanium detector or a sodium iodide detector.