Measurement of natural radioactivity in sand samples collected along the bank of rivers Indus and Kabul in northern Pakistan

Assessment of radioactivity in sand samples from eastern Nepal in perspective of radiological hazards

This study was conducted to investigate the activity concentrations of 226Ra, 232Th and 40K in the sand samples and the health hazards associated with them utilizing a NaI (Tl) gamma spectrometer. The average activity concentrations of 226Ra, 232Th and 40K were found to be 24.8 ± 10.1, 39.8 ± 16.4 and 531.3 ± 52.8 Bq kg-1, respectively. The calculated radiological hazard parameters, including radium equivalent activity, absorbed gamma dose and effective dose rate, were found to be 122.7 ± 34.0 Bq kg-1, 57.7 ± 14.9 nGy h-1 and 0.3 ± 0.1 mSv y-1, respectively. Notably, these results were observed to be below the recommended thresholds. Other measured hazard indices were also lower than the prescribed values. From a radiological perspective, the present study concludes that the sand samples do not pose any threat to human health when utilized as a building material.

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 maps in beach sands along some coastal regions of Turkey

In the present research, the gamma-emitting radionuclides in beach sands along the coastal regions of the Ordu, Giresun and Trabzon provinces, Turkey have been determined. The natural and anthropogenic radionuclide concentrations of the samples have been measured employing a germanium (HPGe) detector with high resolution and purity. The activity for ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs of the samples were found to vary in the range from below detection limit (BDL) to 65Bq·kg^-1, from BDL to 28Bq·kg^-1, from 9 to 1936Bq·kg^-1 and from BDL to 22Bq·kg^-1, respectively. The activity concentrations were compared with those in the literature. The associated radiological hazard indices were estimated, and were compared to the internationally recommended values. The radiological map of beach sand in the surveyed area was imaged. The data presented in the study are crucial since they constitute a baseline for the radiological mapping of the region in the future.

Assessment of radiological hazards of Lawrencepur sand, Pakistan using gamma spectrometry

The Lawrencepur sand had remained refrigerated during a long period of glaciations in the study area. Owing to its derivation from the granitic rocks of the Himalayas and its preservation under glacial environment, the sand grains are still fresh and may contain high level of primordial radioactivity. For that reason, radiological hazards of Lawrencepur sand were assessed using a high-purity germanium gamma spectrometry technique. The average activity concentrations of (226)Ra, (232)Th and (40)K were found to be 15.97±3.05, 27.98±4.89 and 498.20±15.91 Bq kg(-1), respectively. These values are higher than those of the sands of many countries of the world but lower than those of some of the Pakistani, Indian and Egyptian sands. The outdoor and indoor hazard indices and annual effective doses of the Lawrencepur sand are higher than those of some of the sand deposits of European, African and American countries but lower than those of nearby Pakistani and Indian sands. However, the hazard indices and annual effective doses of the Lawrencepur sand are within the safe limits. Overall, the Lawrencepur sand does not pose any radiological health hazard as a building material.

Radiological risk assessment of natural radionuclides in sand collected from some beaches along the coastline of southwestern Nigeria

The activity concentrations of natural radionuclides in sand from three beaches in southwestern Nigeria had been determined employing the gamma-ray spectroscopy method. The mean activity concentrations of (226)Ra, (232)Th and (40)K, respectively, were 12.5 ± 3.3, 25.8 ± 4.7 and 153.9 ± 18.5 Bq kg(-1) for Suntan Beach, 13.1 ± 3.1, 23.9 ± 4.5 and 219.9 ± 33.9 Bq kg(-1) for Bar Beach. Lekki Beach had 13.2 ± 3.2, 26.3 ± 3.8 and 149.0 ± 19.8 Bq kg(-1), respectively. The absorbed dose rates were calculated as 27.8 ± 3.1, 29.7 ± 4.0, 28.2 ± 3.3 nGy h(-1), respectively. The corresponding annual effective doses are 0.034 ± 0.004, 0.036 ± 0.005, 0.035 ± 0.004 mSv y(-1), which are less than the limit of 1 mSv y(-1) recommended for the members of the public. The radiological hazard indices are within the maximum recommended limits, hence pose no significant radiological hazards for construction.