Radiological Hazard Parameters Research Articles

Assessment of natural radioactivity in the Higher and Tethys Himalayan Rocks along Manali-Leh Highway, India.

The Higher and Tethys Himalayan region of NW-Himalaya is less explored from the natural radioactivity mapping assessment, though geologically and tectonically, this region is still active. The concentration of primordial radionuclides (226Ra, 232Th, and 40K) in rock samples of the Manali-Leh Highway region of the Himalayas is determined in the present study using the HPGe detector. The radiological hazard parameters are also estimated in terms of radium equivalent activity (Raeq), annual effective dose (Ein and Eout), hazard indices (Hin, Hex, Hα, and Hγ), and gamma absorbed dose rate. SEM-EDS analysis was used to understand the mineralogical composition of the rocks. The activity concentration of 226Ra, 232Th, and 40K radionuclides varies from 1.4 ± 0.9 to 25.3 ± 1.2, 0.7 ± 0.5 to 59.6 ± 1.6, and BDL (below detection limit) to 830.3 ± 45.7Bqkg-1, with an average value of 13.0 ± 1.0, 21.7 ± 1.0, and 243.7 ± 25.2Bqkg-1, respectively. The average of Raeq in the study region lies within the safe limit of 370Bqkg-1. The hazard indices have values < 1, indicating no radiological hazards to the population from the rocks. The annual effective dose also has values less than the global average value. This study revealed that the rocks of the Higher Himalayan region have a higher concentration of natural radioactivity, while the Tethys Himalayan rocks have lower concentrations of 226Ra, 232Th, and 40K radionuclides. The origin of rocks from different lithologies may be the reason for the natural radioactivity variation. The average concentrations of primordial radionuclides in the region are within the world average indicating that the rocks of the region are safe to be used for different purposes.

Assessment of radiological contamination due to gold mining in soil and food crops of Babban Tsauni, Gwagwalada, Nigeria.

This work assessed the activity concentrations of 238U(226Ra), 232Th, and 40K and their associated radiological risks due to exposure to soil and consumption of food crops in Babban Tsauni artisanal gold mine, Gwagwalada, Nigeria, using the gamma spectrometry technique. The mean activity concentrations of 226Ra, 232Th, and 40K in the mine soil were 60.2±9.9, 161.4±16.2, and 664.6±138.2, while they were 46.4±4.9, 79.9±39.3, 266.4±185.4 for tubers and 46.9±15.7, 100.5±35.8, 311.4±132.7 (Bq/kg) for grains, respectively. The results reveal that the activity concentrations of radionuclides in all samples exceeded the recommended values set by United Nations Scientific Committee on the Effects of Atomic Radiation (33, 45, and 420 Bq/kg) except 40K, which fell within the acceptable limit in all food crop sample types. Estimated results for radiological hazard parameters, radium equivalent, annual effective dose due to ingestion, and excess life cancer risk were within safe limits, while the annual effective dose due to external gamma radiation in soil and annual gonadal equivalent dose were significantly high in all investigated samples; these call for constant radiological monitoring.

Radiometric hazard assessment of soil and water samples adjacent to Bangladesh's first nuclear power plant before commissioning: Insights into human health and environmental radiological dynamics

The current study provides a comprehensive examination of both natural and anthropogenic activity concentrations found in soil and surface water samples near the Rooppur nuclear power plant (RNPP), the first of its kind under construction in Bangladesh. The investigation covers a range of activity concentrations including 226Ra, 232Th, and 40K in fifty soil and fifty water samples, revealing values ranging from 18 to 38, 18–51, and 310–560 Bqkg−1 for soil, and 2.1–6.1, 2.1–5.5, and 67–115 Bqkg−1 for water, respectively. Although outdoor absorbed dose rate, outdoor effective dose, and gamma representative level index values in some soil samples exceed global averages, other radiological hazard parameters such as radium equivalent activity, annual effective dose, external and internal hazard indices, and lifetime carcinogenic risk for both soil and water samples consistently remain below safety thresholds established by international organizations. These findings indicate that the soil and water samples collected from the vicinity of the RNPP do not pose significant radiological hazards to the nearby populations. This study's comprehensive dataset is anticipated to play a crucial role in facilitating the identification and evaluation of any changes in environmental radioactivity, thereby assisting in the effective management and regulation of nuclear power plant activities in the years to come.

Dose Measurement and Cancer Risk from Natural Radioactivity in Cleaning Powders at Kurdistan Markets, Iraq

Abstract: The Kurdistan region of Iraq has seen a rise in the use of cleaning powders due to their favorable effects on health. However, various levels of radioactive isotopes, including 238U, 232Th, and 40K, can be found in the ore used to make some cleaning powders. Therefore, washing powder is regarded as one of the environmental sources of radionuclides and radioactivity. In this study, 25 samples of ordinary cleaning powder were analyzed to estimate the specific activities of 238U, 232Th, and 40K using a gamma-ray sodium iodide NaI(Tl) detector. The mean activity concentrations of 238U, 232Th, and 40K were found to be 0.27±0.027, 1.881±0.149, and 19.213±0.899 Bq.kg-1, respectively, which are well below the recommended values set by UNSCEAR 2000: 32, 45, and 400 Bq/kg for 238U, 232Th, and 40K, respectively. The radiological hazard parameters determined for each sample of detergent were also found to be lower than the maximum allowable values recommended by international organizations. Therefore, cleaning powders sold in the Kurdistan region markets pose no radioactive risk to users. Keywords: Cancer risk, NaI(Tl) detector, Detergent, Radioactivity, Primordial radionuclide.

Assessment of Natural Radioactivity in Cements (Local and Imported) in Mali

&amp;lt;i&amp;gt;Background&amp;lt;/i&amp;gt;: In this article, the radioactivity concentrations of U-238, Th-232 and K-40 (NORM) and radiological hazard parameters in different types of cements commonly used in Mali and available on the Malian market have been analyzed. The obtained values of NORM concentrations and radiological hazards in seven (07) cements samples will permit to the AMARAP to estimate the exposure (gamma rays) from the buildings and dwellings made by these cements. It will permit also to determine any over exposure (determinist effects which are an immediate tissue reaction due to the high exposition of ionizing radiation) and minimize as well the associated risk due to low doses (stochastic effects). &amp;lt;i&amp;gt;Materials and Methods&amp;lt;/i&amp;gt;: The health impact due to the exposure of radionuclides from these cements was evaluated by the determination of specific activity of radionuclides U-238, Th-232 and K-40 using gamma spectrometry analysis. The radiological hazards such as Absorbed Dose Rate (Ḋ) Annual Effective Dose (Ė) Internal and External Dose indexes (H&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt; and H&amp;lt;sub&amp;gt;ex&amp;lt;/sub&amp;gt;) were evaluated in these cements samples. &amp;lt;i&amp;gt;Results&amp;lt;/i&amp;gt;: The range of specific activities for U-238 vary from 21.77 ± 1.50 to 145.31 ± 7.70 Bq/kg, for Th-232 from 8.85 ± 0.52 to 73.56 ± 3.82 Bq/kg and for K-40 from 104.27 ± 5.63 to 351.97 ± 18.08 Bq/kg. The peak of U-238 wasn’t detected only in one (01) sample (CIM04). The highest value of specific activity was reported in sample CIM07 (DANGOTE). The values of radiological hazard such as Ḋ, Ė, H&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt; and H&amp;lt;sub&amp;gt;ex&amp;lt;/sub&amp;gt; from this work were within the dose criteria limits given by international organizations (ICRP and UNSCEAR) and national standards. &amp;lt;i&amp;gt;Conclusion&amp;lt;/i&amp;gt;: This study shows the analyzed cements do not pose any significant source of radiation hazard and are safe for use in the construction of dwellings even if the risk (stochastic effect) associated with low dose exists. Special attention and more analyzes must be done on them for more protection of public health.

A baseline monitoring of radiological sediment quality and associated risk assessment in coastal ecosystems of the Republic of Congo.

This study presents the first data on levels of natural radioactive elements in sediments from coastal ecosystems of the Republic of Congo. Sediment samples from five coastal sites were collected and analyzed by high-resolution gamma spectrometry for determination of activities of long-lived gamma-emitting radionuclides (234Th, 238U, 226Ra, 210Pb, 228Th, 228Ra, and 40K). The specific activities were of the same order of magnitude as those measured in sediments of most countries neighboring the Republic of Congo. However, variations in activities were observed from one site to another and also from one sampling point to another within the same site without exceeding the global average reference values. It can be assumed, therefore, that no significant anthropogenic impact is perceptible in the study area. The most commonly used radiological hazard parameters, based mainly on 238U, 232Th, and 40K activities, were assessed and the ERICA tool was applied to quantify the radiation exposure burden to human and biota resulting from radionuclides in sediments. Besides being useful for future monitoring efforts, the data produced in this work could be important for the worldwide database on radioactivity in the oceans and seas (MARIS) since no data are available in the Congolese marine environment.

Radiation protection for Gabes phosphate area residents: Assessing natural radioactivity in soil and potable water samples

Phosphate mining activities are recognized to be one of various industrial processes generating enhanced Naturally Occurring Radioactive Materials (NORM) by introducing natural radionuclides into the surrounding soils and water bodies, posing a risk to human health.This study was carried out to assess the level of natural radionuclides in soils and potable waters collected from the phosphate area of Gabes city, located in southeastern Tunisia, and to evaluate radiation protection measures by estimating radiological health hazard parameters. Gamma spectrometry system employing an HPGe detector was used in this study to assess 40K, 232Th and 226Ra activity concentration in soils. The average values were found to be 163.7, 14.5, and 7.7 Bq kg−1, respectively, which were lower than worldwide average values. The radiological hazard parameters assessed in this study were radium equivalent activity (Ra-eq), external hazard index (Hex), external gamma absorbed rate (GDR), external annual effective dose (Deff) and excess lifetime cancer risk (ELCR). The calculated average values of the above-mentioned parameters were of 41 Bq kg−1, 0.1, 20.2 nGy h−1, 24.8 μSv y−1 and 8.7 × 10−5 all of which were found to be below their permissible standards.For potable water samples, the activity concentrations of radium were analyzed using an HPGe detector and those of uranium were determined by alpha spectrometry. The average activity concentrations of uranium and radium isotopes in underground water samples were found to be higher than those obtained in tap water samples. For both types of water, the average values for all radionuclides were found to be below their respective reference limits.The annual ingestion effective doses were also estimated in this study. The estimated average values for infant and children for underground water samples were higher than the permissible limit of 100 μSv y−1 set by WHO. The 226Ra was the main contributor to the effective doses for different age categories, followed by 228Ra.

Assessment of radionuclides in the soil of Bonny Local Government Area Of Rivers State, Nigeria and evaluation of radiological risk

Twenty Samples each of soil from Bonny LGA, Rivers State, Nigeria were analyzed using NaI(IT) gamma detector to estimate radiation hazard due to the anthropogenic sources. The activity concentration of 232Th was found to be in the range 18.78 – 397.13 BqKg-1, 40K in the range 43.72 – 390.62 BqKg-1 and 226Ra in the range 10.77 – 57.84 BqKg-1 all in soil. These results were used to calculate the radiological hazard parameters including the Annual Gonadal Equivalent Dose. The calculated gamma exposure rates ranged between 10.00 – 270.79 nGyh-1 while the average value of the Excess Lifetime Cancer Risk (ELCR) was found to be 0.38 x 10-3 for soil which is higher than the world average of 0.29 x 10-3.

Assessment of radiation exposure in the phosphate mining area of Gafsa (Southeastern Tunisia)

ABSTRACT This study investigates the radiological health implications of sixty-three (63) samples of soil, food, and drinking water collected from the phosphate mining area of Gafsa in Southeastern Tunisia. Additionally, it assesses the exposure to radon concentrations in houses located around the phosphate mining sites. The activity concentrations in soil samples were found to be 382.1, 36.1 and 16.3 Bq kg−1 respectively for 40K, 232Th and 226Ra. The average activity of 232Th was higher than worldwide average value of 30 Bq kg−1. Eleven (11) radiological hazard parameters were computed based on various exposure scenarios including external gamma dose rate (GDR), annual effective dose (AED) and risk assessment (RA). The calculated GDR values were of 3.2 nGy h−1 in food and 45.4 nGy h−1 in soil samples, while the average AED values were of 3.9 µSv y−1 in food and 83.5 µSv y−1 in soil samples. Internal AED due to ingestion of radionuclides was found to have a mean value of 0.1 µSv y−1 in soil, 264.4 µSv y−1 in food and 10 µSv y−1 in drinking water samples. The AED values due to inhalation of soil-dust and radon were assessed to be 2.1 and 1.2 µSv y−1, respectively. The RA average values in food and drinking water samples were found to be 3 × 10−5 and 2.4 × 10−4, respectively. Based on the exposure pathway, inhalation of radioactivity through soil and radon resulted in highest total AED values, which remained below the reference limit. This was followed by internal exposure, with total AED values of 274.5 µSv y−1.

Investigation of natural and artificial radioactivity levels in travertines of the Cappadocia region in Turkey

This study determined natural and artificial radionuclide concentrations to evaluate natural radioactivity and health risk levels of nine travertines in the Yaprakhisar and Balkayası regions in Turkey. The samples coded B1-M, B2, B5, B7, B8, and B10 represent waste derived from the Yaprakhisar travertines, as well as samples T5-M, T12, and Z1 travertines derived from Balkayası. The levels of natural and artificial radionuclide concentrations (232Th, 40K, and 137Cs) were measured using a high-purity germanium (HpGe) detector system. The travertine activity ranged from 2.09 to 12.07 Bq kg−1 for 232Th, 4.21 to 13.41 Bq kg−1 for 40K, and 0.42–3.26 Bq kg−1 for 137Cs. The results showed that the activity concentration values for 232Th, 40K, and 137Cs were coherent with the travertine analysis results in the UNSCEAR, 2000; 2008 publications. The values obtained were lower than the average values in the UNSEAR reports. The radiological hazard parameters calculated in this study were absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AEDEtotal), excess lifetime cancer risk (ELCRtotal), gamma representative level (GRL), internal hazard index (Hin) and external hazard index (Hex).

Uranium concentrations and its isotopes in baby food of Iraq

Abstract This study determines uranium concentrations and isotopes (238U, 235U, and 234U) in baby food samples collected from Iraqi markets using solid-state nuclear track detector technical (CR-39). Also, some radiological hazard parameters such as annual committed effective dose (E U) and risk of an excess cancer fatality per million persons (RECFPMP) for the same study samples were calculated using theoretical equations. The samples in the present study were classified into three varieties: cereals and cereal products, vegetables and fruits, and biscuits. The results show that the average uranium concentration (mg/kg or ppm) values in cereals and cereal products, vegetables and fruits, and biscuits were 0.71 ± 0.01, 0.81 ± 0.04, and 0.72 ± 0.031, respectively. At the same time, the average values of 238U, 235U, and 234U in all samples of the present study were 9.08 ±0.17 Bq/kg, 0.42 ± 0.0081 Bq/kg, and 9.33 ± 0.18 Bq/kg, respectively. The total average of E U (mSv/y) due to all uranium isotopes (238U, 235U, and 234U) in cereals and cereal products, vegetables and fruits, and biscuits were 0.042 ± 0.0006, 0.039 ± 0.001, and 0.034 ± 0.001, respectively. Moreover, it was found that the average values of RECFPMP were 0.159 ± 0.002 in cereals and cereal products samples, 0.154 ± 0.007 in vegetables and fruits samples, and 0.130 ± 0.005 in biscuits samples. Uranium concentrations and the total annual committed effective dose in all baby food samples comply with the worldwide limits approved by UNSCEAR, which state safe limitations (1.7 mg/kg) and (0.32 mSv/y), respectively. So, one may conclude that there is no danger of uranium concentrations in the case of baby consumption.

Seasonal Variations of Radioactivity Concentrations in Soil and Sediment of Meriç River, Turkey

In this study, natural and artificial radioactivity levels were determined for spring, summer, autumn and winter in soil and sediment samples collected from different sites in the Meriç River using a HPGe detector. The mean radioactivity levels in this study were compared with other activity concentrations in various region’s soils and sediments and also with the world mean values. The mean activity concentrations of 40K were found to be higher than the world mean value in both soil and sediment samples. In addition, 137Cs radionuclide emitted into the atmosphere by the Chernobyl explosion is still present in both soil and sediment. In order to estimate the potential health risk in samples, radiological hazard parameters were calculated for samples and compared with the recommended values.

Radiological hazards assessment of building materials used in Swakopmund, Namibia

A Canberra coaxial High Purity Germanium (HPGe) gamma-ray spectrometry detector was used to measure activity concentrations of radionuclides in commonly used building materials in Swakopmund, Namibia. The activity concentrations in, Bq.kg−1, for 226Ra, 232Th and 40K in all sample groups of building materials (cement, sand, cement bricks and roof tiles) were found to be in the range of 18.002–499.266, 14.069–132.508 and 162.794–1747.260, respectively. The average activity concentration of 40K was found to be two times higher than the critical level of 500 Bq.kg−1 in sand, cement bricks, clay bricks and roof tiles. The measured activity concentrations were used to estimate average dose rates and radiological hazard parameters. The absorbed dose rate (D) both due to indoor and outdoor exposure was higher than the international acceptable safe limits in all sample groups while the annual effective dose equivalent (AEDE) due to indoor exposure was higher in sand, cement bricks and clay brick samples. AEDE due to outdoor exposure was within acceptable safe limits for all sample groups. Radium equivalent (Raeq), external hazard (Hex) and gamma (Iγ) hazard indices were found to be higher than the acceptable safe limit only in clay bricks samples. The internal hazard (Hin) index was only higher than the acceptable safe limit in cement and clay bricks while the alpha (Iα) index was higher in sand, cement bricks and clay bricks. The Excess Lifetime Cancer Risk (ELCR) exceeded the acceptable safe limits in all sample groups. Our study showed that most of the computed radiological parameters were significantly higher than prescribed safe limits in most of the samples and therefore may pose a health risk to the inhabitants of Swakopmund.

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±52.8Bq 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±34.0Bq kg-1, 57.7±14.9 nGy h-1 and 0.3±0.1mSv 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.

Assessment of natural radioactivity levels and potential radiological risks of commonly used building materials in Uttara Kannada District, Karnataka, India.

The main goal of this study is to evaluate the natural radioactivity and potential radiological risks of frequently used building materials in Uttara Kannada district. Using an High purity Germanium Detector (HPGe) detector-based gamma-ray spectrometer, the activity concentration of 226Ra, 232Th and 40K was determined. The activity concentration of 226Ra, 232Th and 40K in the construction materials vary from 13.78±0.90 to 151.9±1.85, 14.21±0.80 to 207.72±2.9 and 55.26±1.20 to 1298.24±25Bqkg-1 with an average value of 40.57±1.37,60.13±1.70 and 425.38±4.75Bqkg-1 having a geometric mean of 33.07, 46.49 and 290.20Bqkg-1, respectively. The mean annual effective dose equivalent was found to be 0.68mSv y-1 and is less than the International Commission on Radiological Protection proposed acceptable limit of 1mSv y-1. The estimated radiological hazard parameters show that these building materials are safe to use in the construction of homes and do not offer a substantial source of radiation hazard.

Natural radioactivity level in graphite samples from the Cătălinul deposit, Parâng Mountains, Romania: sources identification and radiological risk assessment

Twenty graphite samples (amorphous and crystalline flake types of graphite) were collected from the ore storage of the Catalinul deposit and, the 238U, 232Th, 40K naturally occurring radionuclides have been investigated by gamma-ray spectrometry. The mineral contents of selected graphite samples were examined using a scanning electron microscope (SEM). The radiological hazard parameters: radium equivalent activity (Raeq), absorbed gamma dose rates in air (DR), and external hazard index (Hex) were calculated and compared with international safety limits. Radiometric data showed average specific activities for 238U, 232Th and, 40K of 80.40, 49.69 and, 124.21 Bq kg–1 for amorphous graphite respectively, 38.53, 76.25 and, 241.12 Bq kg–1 for flake graphite. Zircon, rutile, uraninite, coffinite, urano-thorite, and monazite are the main radioactive element bearing minerals. The mean of the radiological hazard parameters: Raeq – 262.22 (Bq kg–1), DR – 123.72 (nGy/h), and 0.7 – Hex do not exceed the recommended values by UNSCEAR.

Evaluation of natural radioactivity in soils of Konya (Turkey) and estimation of radiological health hazards.

Surface soil samples were collected from Konya, Turkey and natural activity concentrations were determined using the ɤ-ray spectroscopy system with HPGe detector. The activity concentrations of 226Ra, 232Th and 40K were found to vary from 14.07 ± 0.71 Bq kg-1 dw to 67.27 ± 1.62 Bq kg-1 dw, 10.19 ± 2.60 Bq kg-1 dw to 46.09 ± 0.76 Bq kg-1 dw and 107.87 ± 13.32 Bq kg-1 dw to 605.95 ± 11.34 Bq kg-1 dry weight (dw), respectively. The radiological hazard parameters such as Raeq, D, AEDE, ELCR, AGDE, Hex, Hin, and Iɤ evaluated the radiological risk for the public and environment. The mean values of D, AEDE and ELCR are lower than the world average value of 57 nGy h-1, 70 μSv y-1, 0.29 × 10-3 respectively. The activity concentration distribution maps of 226Ra, 232Th and 40K and the radiological maps of the radiological hazard parameters were plotted using the Surfer programme. Cluster analysis was carried out to indicate the similarity between the variables.

Assessment of radioactivity levels and radiation hazards in building materials in Egypt

Different degrees of natural radioactivity found in quartz can have negative consequences on health. Quartz vein along the investigated Abu Ramad area, Egypt, had its natural radioactivity assessed. The HPGe spectrometer was used to determine the role played by the radionuclides 238U, 232Th, and 40K in the gamma radiation that was emitted, and the results showed that these concentrations are 484.64 ± 288.4, 36.8 ± 13.1 and 772.2 ± 134.6 Bq kg−1 were higher than the corresponding reported global limits of 33, 45, and 412 Bq kg−1 for each radionuclide (238U, 232Th, and 40K). Among the radiological hazard parameters, the excess lifetime cancer risk (ELCR) is estimated and it's mean value of ELCR (1.2) is higher than the permissible limit of 0.00029. The relationship between the radionuclides and the associated radiological hazard characteristics was investigated based on multivariate statistical methods including Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). According to statistical research, the radioactive risk of quartz is primarily caused by the 238U, 232Thand 40K. Finally, applying quartz to building materials would pose a significant risk to the public.

Measurement of radioactivity in soils of Karamjal and Harbaria mangrove forest of Sundarbans for establishment of radiological database.

This work presents the first in-depth study of soil radioactivity in the mangrove forest of Bangladesh part of the Sundarbans. It used HPGe gamma-ray spectrometry to measure the amount of natural radioactivity in soil samples from Karamjal and Harbaria sites of the world's largest mangrove forest. The activity concentrations of most of the 226Ra (14±2 Bqkg-1 to 35±4 Bqkg-1) and 232Th (30±5 Bqkg-1 to 50±9 Bqkg-1) lie within the world average values, but the 40K concentration (370± 44 Bqkg-1 to 660±72 Bqkg-1) was found to have exceeded the world average value. The evaluation of radiological hazard parameters revealed that the outdoor absorbed dose rate (maximum 73.25 nGyh-1) and outdoor annual effective dose (maximum 0.09 mSvy-1) for most samples exceeded the corresponding world average values. The elevated concentration of 40K is mainly due to the salinity intrusion, usage of fertilizers and agricultural runoff, and migration of waste effluents along the riverbanks. Being the pioneering comprehensive research on the Bangladesh side of the Sundarbans, this study forms a baseline radioactivity for the Sundarbans before the commissioning of the Rooppur Nuclear Power Plant in Bangladesh.

Natural Radionuclide Concentration in Kaolin Deposits and Dose Assessment Within Delta State, Nigeria

The assessment of natural radionuclide concentration in kaolin deposits and dose rate within Delta state, Nigeria has been carried out. Four kaolin mining sites within four Local Government Areas in the state were studied. Background Ionizing Radiation levels of each of the mining site was measured using a Gamma Scout handheld radiation meter and a GPS meter used to obtain the actual positions where the BIR levels were taken around each kaolin site. A total of twenty-five (25) samples were collected for Gamma spectrometry analysis at National Institute of Radiation Protection and Research, University of Ibadan. The mean BIR exposure rates for Ukwuani, Aniocha South, Ughelli North and Ughelli South LGAs were 0.01mRh -1 , 0.013mRh -1 , 0.013mRh -1 and 0.014mRh -1 respectively and were within the world’s recommended permissible limit of 0.013mRh -1 given by UNSCEAR. The mean activity concentrations of 238 U, 232 Th and 40 K in kaolin samples were estimated to be 137.028 ± 7.194, 13.532 ± 1.568 and 6.724 ± 0.396 Bqkg -1 respectively for Ukwuani; 425.494 ± 22.16, 18.63 ± 2.17 and 11.955 ± 0.71 Bqkg -1 respectively for Ughelli South; 596 ± 30.772, 18.728 ± 2.124 and 8.912 ± 0.526 Bqkg -1 respectively for Ughelli North and finally, 120.026 ± 6.235, 10.533 ± 1.182 and 15.024 ± 0.879 Bqkg -1 respectively for Aniocha South. These results compare quite well with the world’s average value of activity concentrations for natural radionuclides reported by UNSCEAR, except for 40 K which is higher than the world’s average at Ughelli North and South. The values of all the radiological hazard parameters for all the mining sites are less than the recommended limits. The calculated Excess Lifetime Cancer Risk also reveal that the values are all within the recommended limits, therefore, the risk of cancer inducement due to radiation exposure is within the acceptable limits for all the mining sites.