Soil mineral analysis and environmental radioactivity in Ghizer, Eastern Hindukush, Pakistan

Distribution of natural and anthropogenic radionuclides (226Ra, 232Th, 137Cs and 40K) was determined in 32 samples from Ghizer, an Eastern Hindukush district at an altitude of 2286 m in Pakistan using high resolution gamma-ray spectrometry. Mineralogical analysis by X-ray diffractometry identified quartz, calcite, albite and anorthite as major phases whereas actinolite, chlorite serpentine and kaolinite as minor phases. The activity concentrations for 226Ra, 232Th, 137Cs and 40K varied from 25.2 ± 1.7 to 145.3 ± 10.1 Bq kg−1, 24.9 ± 1.1 to 197 ± 9 Bq kg−1, 2.03 ± 0.21 to 16.7 ± 1.1 and 252 ± 6 to 1433 ± 35 Bq kg−1, respectively. The samples yielded average radium equivalent activity as 178.4 ± 23.3 Bq kg−1. The majority of the samples revealed external hazard index and representative level index less than one. The average air absorbed dose rate was 91.2 ± 13.6 nGy h−1 corresponding to the annual effective dose rate 111.8 ± 17.4 μSv y−1. These values were higher than the world averages for air absorbed dose rate and outdoor annual effective dose rate. Principal component analysis was applied to obtain distribution pattern within the samples and among the radionuclides.

Measurement of Specific Activity of Natural Radioactive Materials and Cs-137 in Soil Samples for Some Areas in Al-Doura City in Baghdad Governorate

In the present work, radium (226Ra), thorium (232Th), potassium (40 K), and cesium (137Cs) (Bq/kg) was measured for 24 soil samples of some districts of Al-Doura city in Baghdad governorate. The gamma spectrometry method with NaI (Tl) detector was used for radiometric measurements. The average values of specific activity for 226Ra, 232Th, 40K and 137Cs in soil samples were 38.03, 42.48, 16.34 and 2.76 Bq/kg, respectively. The radiation indicators were measured and the average values recorded were 100 Bq/kg, 44.6 nGy/h, 0.27 Bq/kg, 0.373 Bq/kg, 0.219 mSv/y, 0.055 mSv/y and 0.689 Bq/kg for the parameters of radium equivalent activity (Raeq), the absorbed dose rate (D), the external hazard index (Hex), the internal risk index (Hin), and the annual effective equivalent dose for the indoor (In Eff.), outdoor annual effective dose equivalent (Out Eff.) and representative gamma index (Iγr), respectively. All the health hazard indices were well below their recommended limits, except in one soil sampling site (AL-Eskan site) which were found to be 0.495 Hex and 0.668 Hin.

Fertility Cancer and Hereditary Risks in Soil Sample of Nasarawa, Nasarawa State, Nigeria

A survey of Fertility Cancer and Hereditary Risks in Soil Sample of Nasarawa was carried out. This study assessed the level of Fertility Cancer and Hereditary Risks in some part of Nasarawa using the gamma-ray spectrometry. The mean concentration for 40K was 645.29 ± 07.32 Bq/kg, for 226Ra was 28.43 ± 4.8422 Bq/Kg and for 232Th was 66.84 ± 2.0201 Bq/Kg. The average effective dose due to the ingestion was 0.36±0.1µSv/y which was approximately 1000 times lower than the world average effective dose. Radium equivalent activity Raeq (Bq/kg), alpha index and total cancer risk were found to be 161.44±8.08 Bq/kg, 0.142±0.02 and (0.21±0.05) ×10-5 respectively. UNSCEAR/ USEPA stipulated that; radium equivalent activity, alpha index, effective dose and total cancer risk should not exceed the limit of 370 Bq/kg, unity, 300 µSv/y and 1 ×10-4 respectively. Hence the values obtained in this work were within the acceptable limits. This implies that the ingestion or inhalation of soil is not associated with any radiological risk of concern.

Measurement of Natural Radionuclides and Radon Gas Concentration in Surface Soil samples within Jalingo Metropolis, North East Nigeria

Activity concentrations of radionuclides (226Ra, 232Th, 40K) and radon gas in soil samples collected within Jalingo Metropolis were assessed by gamma spectrometric techniques using Na (TI) scintillation detector. The result showed an average activity concentration of 226Ra, 232Th and 40K to be 18.626±7.31 Bq/kg, 16.709±10.96 Bq/kg and,167.935±389.33 Bq/kg. The concentrations of 226Ra, 232Th were lower than the world average value while 40K was far higher that the recommended value.Most people in the study area use soil for building construction therefore, it was necessary to asses if there are any radiological hazards associated with the soil. This was achieved by determining Radium equivalent activity (Raeq), internal hazard index (Hin) and Annual effective dose rate. The result indicates that the indices are within normal limit. The Radon concentration in soil varies 11.126±1.315 kBq/kg to 30.374±3.331 kBq/kg with a mean value of 17.881±7.019 kBq/kg which is within the safety limits. Generally, the result showed that the soil in the study area might not pose major hazard to the members of the public

Measurement of NORM in Building Materials to Assess Radiological Hazards to Human Health and Develop the Standard Guidelines for Residents in Thailand: Case Study in Sand Samples Collected from Seven Northeastern Thailand Provinces

A total of 223 sand samples collected from seven provinces in Northeastern Thailand were analyzed for their gamma radioactivity from naturally occurring radioactive materials (NORMs), and the data were used to calculate the concentrations of Ra-226, Th-232, and K-40. Radiological safety indicators such as the indoor external dose rates (Din), the annual indoor effective dose (Ein), the activity concentration index (I), the radium equivalent activity (Raeq), the external hazard index (Hex), the internal haphazard index (Hin), and the excess lifetime cancer risk (ELCR) were calculated. The activity concentrations were found to be 36 ± 10 Bq/kg for Ra-226, 2.64 ± 0.58 Bq/kg for Th-232, and 323 ± 168 Bq/kg for K-40. Din is 62 ± 23 nGy/h. The Ein is 0.30 ± 0.11 mSv/y. The activity concentrations and other indicators were reported by each province and compared with the safety standards and are found to be within the safe limits in this study. The results can be used to develop the standard guideline levels for choosing building materials in Thailand.

Assessment of Environmental Radioactivity in Soil Samples from Kathmandu Valley, Nepal

This study was conducted to determine the amount of naturally occurring radioactivity in the soil of Nepal's Kathmandu valley. The activity of naturally occurring radionuclides was determined in these soil samples using a sodium iodide detector. Activity concentrations of 238U, 232Th, and 40K were found in the range: 32.00-111.38 Bq kg-1, 33.52-130.04 Bq kg-1, and 342.50-897.71 Bq kg-1, respectively. These values are well within the permissible range as recommended by UNSCEAR. The soil samples with the highest activity concentrations were primarily found in the valley's northern region. The activity concentrations were also used to calculate the radiation hazard indices: the mean value obtained were 96.63 nGy hr-1 for Absorbed Gamma Dose Rate in Air, 200.04 Bq kg-1 for Radium Equivalent Activity, the 0.12 mSv yr-1 for Annual Effective Dose, and 0.55 for External Hazard Index. These calculated hazard indices were used to estimate the potential radiological health risk from the soil, and the dose rates associated with it were significantly less than their permissible limit. The overall findings indicate no radiological threat to the population's health in the study area. Additionally, the findings of this study provide baseline information on potential radionuclides that contribute mostly for radiation exposure from natural sources.

Assessment the Natural Radioactivity of Radionuclides ( 226Ra, 232Th, 40K, and 137Cs) in Wheat Grain

This paper investigates the activity concentration of radionuclides (226Ra, 232Th, 40K and 137Cs) in the wheat grain samples using a high-purity germanium detector. Thirty-six wheat grain samples were collected from different locations of Koya City, Iraqi Kurdistan region. Average activity concentrations of 226Ra, 232Th and 40K in wheat grain are found to be 0.407 ± 0.097 Bq.kg-1 for 226Ra, 0.36 ± 0.14 Bq.kg-1 for 232Th and 109.25± 2.214 Bq.kg-1 for 40K, respectively. The measured activity concentrations for the radionuclides are compared with the reported data from other countries. In addition, the fallout radionuclide of 137Cs has no detection of in the wheat grain samples. The radium equivalent activity Raeq, internal and external hazard indices Hin and Hex, and annual gonadal dose equivalent are calculated for the measured samples. The total ingestion dose is 113.19 µSv.y-1, which is below the world average value of 290 µSv.y-1.

Determination the Natural Radioactivity Levels at Selected Regions in Al-Najaf Governorate

The natural radioactivity levels for radium(226Ra), thorium (232Th) and potassium (40K) have been determined in soil samples selected from different regions in Najaf governorate in Iraq. The samples were collected from the ground surface. Eight samples were measured by gamma ray spectroscopy using high purity germanium detector. The levelsof radionuclides concentrations in selected samples 232Th, 226Ra and 40K were in the range of (2.5±0.29 to 7.7±0.52) Bq/kg (6.3±0.43 to 16.4±1.9) Bq/kg and (31.5±3.4 to 204.1±11.9) Bq/kg for, respectively. The mean Radium Equivalent Activity, External and Internal Hazard Indices, the Absorbed Dose Rate in Air and the Annual Effective Doses Equivalent were studied and found these parameter are less than the reported values. Therefore, the radioactivity in the studied area in Najaf does not pose any radiological hazard to the general public.

Assessment of natural radioactivity and radiation hazards of building materials in Kinondoni District, Dar es Salaam, Tanzania

Natural radionuclides from building materials are one of the potential sources of external as well as internal radiation exposure to the human body. Currently, this exposure has been increasing since people spend more than 80% of their time indoors (ICRP 1991). Commonly used building materials from Kinondoni District were investigated using γ-spectrometry; their activity concentrations of 226Ra, 232Th and 40K in Bq/kg were measured. The results showed that average values of activity concentrations of 226Ra, 232Th and 40K were 15.62, 21.51 and 237.99 Bq/kg, respectively. All the activity concentrations in the studied samples were lower than the world average values of 35 Bq/kg for 226Ra, 30 Bq/kg for 232Th and 400 Bq/kg for 40K. The radium equivalent activity ( 𝑅𝑎𝑒𝑞), external ( 𝐻𝑒𝑥), internal hazard index ( 𝐻𝑖𝑛) and gamma activity concentration index (𝐼𝛾) were calculated to assess the radiological hazards due to presence of natural radionuclides in the building materials. The results showed that the average values of Raeq, Hex, and Iγ were 64.7 Bq/kg, 0.17, 0.21 and 0.24, respectively. These values were lower than the world criteria values 370 for Raeq, ≤ 1 for Hex, ≤ 1 for Hin and ≤ 1 for Iγ, respectively. The obtained results indicated that all the investigated building materials were safe for inhabitants. Keywords: Building materials, Natural radionuclides, Radiation hazards, Gamma ray spectrometry, Activity concentration