Annual Gonadal Dose Equivalent Research Articles

Determination of Radionuclides Concentrations in Surface Soil Samples in the District of Bandirma, Balıkesir

Determination of the environmental radioactivity concentration value is very important as it directly effects human health. Natural and artificial radionuclide concentration levels have been determined by looking 226Ra, 232Th, 40K, and 137Cs radionuclides. In this study, natural and artificial continental radionuclide concentrations were measured in the Bandirma district of Balikesir. 226Ra, 232Th, 40K, and 137Cs radioactivity concentrations were detected with the aid of a high-purity germanium (HpGe) detector. Soil samples used in the study were selected from 30 different locations sampling points located in Bandirma. The radiological hazard indices such as absorbed gamma dose rate (D), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AED), excess lifetime cancer risk (ELCR), internal hazard index (Hin), external hazard index (Hex) and gamma representative level (GRL) were determined. The mean values of 226Ra, 232Th, 40K, and 137Cs concentrations in this study were 15.81 ± 1.35 Bq kg−1, 28.86 ± 1.07 Bq kg−1, 276.86 ± 11.69 Bq kg−1, and 1.98 ± 0.31 Bq kg−1 respectively. The calculated radiological hazard parameters were compared with the world averages. The obtained radioactivity concentration values were measured to be below the world average.

Assessment of natural radioactivity and radiological hazards of soil collected from rabia town in nineveh governorate (North Iraq)

The effects of the environment on human exposure to radiation from naturally occurring radioactive elements have been investigated around the world. In the group of natural radionuclides under examination, the study’s objective is to ascertain the distribution, potential anthropogenic origins, and activity of the radionuclides 226Ra, 232Th, 40K and their radiological risk parameters in twelve soil samples taken from Rabia town in Nineveh Governorate, North Iraq using NaI (Tl) detector. For the examined region, the activity concentrations of 238U, 232Th, and 40K ranged from 4.79 ± 0.211 to 21.77 ± 0.675 Bq kg−1, 11.21 ± 0.942 to 33.57 ± 2.185 Bq kg−1, and 112.8 ± 32.074 to 312.2 ± 95.463 Bq kg−1, respectively. The estimated radiological hazard parameters for the examined samples included the absorbed dose rate (Dair), annual effective dose equivalent (AED), gamma-ray hazard index (I), and annual gonadal dose equivalent. Furthermore, the current work revealed the distribution of radionuclides and their relationships with the mineralogical composition. Based on obtained results, this soil is safe for the population living in the study area and can be used as a building material or for other human activities without posing any radiological danger.

Radiological assessment in beach sediment of coastline, Ghana

The natural and artificial radioactivity in beach sediment sampled from the coastline of Ghana were analyzed using High Purity Germanium gamma ray detector. The overall average activity concentrations of 226Ra, 232Th, 40K and 137Cs were estimated to be 43 ± 6, 22 ± 1, 393 ± 74 and 8.4 ± 0.5 Bqkg−1, respectively. Apart from 226Ra the mean activity concentrations of the measured radionuclides were below the world averages of 32, 45, 412 and 18.2 Bqkg−1 respectively. High 137Cs mean concentration of 109.8 Bqkg−1 was observed for one of the locations, which might be due to the occurrence of a nuclear incidence or other factors. The evaluated radiological parameters also had values below world averages, except for some coastal areas which recorded Annual Gonadal Dose Equivalent (AGDE) values higher than the reference level of 300 μSvy−1. There was no significant risk associated with the radionuclide activities evaluated along the coast of Ghana. The correlation between the radionuclides and the radiological parameters were analyzed with the Pearson correlation matrix, cluster and PCA analysis, and they all showed similar outcomes. Spatial distribution maps were also created using ArcGIS software for a pictorial view of the distribution of radionuclides along the study area.

Human health risk assessment due to consumption of dried fish in Chennai, Tamil Nadu, India: a baseline report.

The current study sought to determine the levels of radioactivity and heavy metal contamination in 22 dried fish samples collected in Chennai, Tamil Nadu. The study found that there were substantial heavy metals concentrations for Pb, Mn, Cr, Co, and Cd. The concentration of heavy metal Pb being alarmingly high (32.85 to 42.09mg/kg), followed by Cd (2.18mg/kg to 3.51mg/kg) than the permissible limit of WHO (2.17mg/kg) for Pb and (0.05mg/kg) for Cd. In terms of radioactivity, the gross alpha activity in the dried fish samples ranged 6.25 ± 0.12 to 48.21 ± 0.11 Bg/kg with an average of 20.35 Bg/kg and with a gross beta activity from 6.48 ± 0.02 to 479.47 ± 0.65 Bg/kg, for an average of 136.83 Bg/kg. The study found that the internal radiation dose that people receive upon consuming the fish species Sphyraena obtusata, Rachycentron canadum, Lepidocephalichthys thermalis, Synodontidae, Carangoides malabaricus, Sardina pilchardus, Scomberomorus commerson, Sillago sihama, Gerres subfasciatus, and Amblypharyngodon mola is above the ICRP-recommended limit of less than 1mSv/year. Annual gonadal dose equivalent (AGDE) and total excessive lifetime cancer risk (ELCR) ranged 0.488 µSv year-1 and 0.004 µSv year-1 respectively, the values of AGDE being higher than the global average value. The findings of the study indicate that the analyzed dried fish samples are contaminated with Pb and Cd, which shall pose cancer risk to the consumers as a result.

Evaluation of radiological risk associated with local building materials commonly used in Northwestern Nigeria

In this study, potential radiological risk due to the activity concentrations of primordial radionuclides (226Ra, 232Th, and 40K) in commonly used local building materials (sand, clay, kaolin and gypsum) in Northwestern Nigeria were assessed using NaI (Tl) detector. The measured activity concentrations ranged from 47 to 63 Bq kg−1 for 226Ra, 24–32 Bq kg−1 for 232Th, and 219–257 Bq kg−1 for 40K respectively. The mean values of 232Th, and 40K for all samples were below the respective world averages of 45 and 420 Bq kg−1 with that of 226Ra for all the samples higher than the world average value of 32 Bq kg−1. The potential radiological risks were assessed by determining radium equivalent activity (Raeq), internal and external hazard indices (Hin and Hex), absorbed gamma dose rates (DR), internal annual effective dose rates (IAED), and annual gonadal dose equivalent (AGDE) and activity utilization index (AUI). The assessed parameters were found to range between 104 and 125 Bq kg−1, 0.99 to 1.15, 0.28 to 0.34, 48 to 58 nGyh−1, 0.76 to 0.86 mSvy−1, and 0.78 to 0.96 respectively. The Raeq and DR for all the analyzed samples were found to be within International recommended limits of 370 Bq kg−1 and 59 nGy h−1 as recommended by UNSCEAR.

Radiation Risk Among Children due to Natural Radioactivity in Breakfast Cereals

Breakfast cereal is one of the common foods for children’s nutrition. It is made from sugar, barley, calcium carbonate, salt, maize, peanuts, molasses, and honey. Therefore, assessing the levels of radioactivity in breakfast cereal is essential for children’s health. Gamma-ray spectrometry NaI(Tl) was used to measure the radiation hazard in ten samples collected from the Iraqi market. The corresponding radiation dose quantities and hazard indices were also calculated. The average concentrations of 226Ra, 232Th, and 40K were found to be 18.195, 20.965, and 796.500 (Bq.kg-1). The annual effective dose equivalent (AEDEin), annual ingestion dose (AID), and the risk of cancer incidence (ELCR) were all seen to be within the accepted levels, except the annual gonadal equivalent dose (AGED). Radiation hazard index values (i.e., Iγ, Iα, and Hin) were noticed to be lower than unity, except Iγ was much higher than the internationally permissible limits for the samples of BGF5, BGF6, and BGF7 recommended by UNSCER2000. Therefore, the study findings reveal that this type of cereal can be considered a safe feeding material for children’s health.

Geotechnical and environmental radioactivity investigations at Al Sādis Min Uktōber city, Cairo municipality (Egypt), for the high-speed railway construction

The present study aims to evaluate the possibility of constructing a new high-speed railway (HSR) at Al Sādis Min Uktōber city, Cairo (Egypt): geotechnical and environmental radiological hazards are estimated from several collected soil and water samples. A variety of laboratory geotechnical tests such as grain size, free swelling test, liquid and plastic limits, chemical analysis and uniaxial compression strength are applied to sixty-one drill holes. A geotechnical examination of the coarse-grained soil at the foundation level classified it as poorly graded soil. The results of the investigation of fine-grained soil at the foundation level shown that the liquid limit ranges from 22% to 55%, the plastic limit ranges from 12% to 28%, the plasticity index varies from 11% to 33%, free swelling varies from 51% to 71%. Mechanically, the uniaxial compressive strength values on rock samples range from 6.96 MPa to 142.39 MPa. The radioactive study is performed to detect the 226Ra, 232Th, and 40 K activity concentrations of the soil samples: their mean values are 34 ± 10 Bq·kg−1, 14 ± 5 Bq·kg−1 and 552 ± 20 Bq·kg−1, respectively. The values of radiological hazard indexes are not exceeded the permissible limits: e.g. the mean value of absorbed dose rate is 47 ± 6 nGy h−1; the annual gonadal dose equivalent is 0.3 ± 0.04 mSv·y−1; the lifetime cancer risk is 02 ± 0.2·10−3. Thus, the soil in the studied railway area is safe to use in building materials and infrastructure applications: the radiological hazards and the geotechnical studies confirmed the studied area is suitable to construct a new community having a HSR. According to the SWOT-PEST and environmental impact analyses, the construction of the HSR meets the criteria of the Kyoto Protocol, the EU Climate and Energy policy, and other international treaties.

Assessment of Background Radiation in Ojota Chemical Market, Lagos, Nigeria

The monitoring of radiation levels in human-inhabited environments is imperative to avoid public exposure. The activity concentration of primordial radionuclides at Ojota Chemical Market was measured to determine the in situ activity of 238U, 232Th, and 40K in ambient air using an RS-125 Super SPEC gamma spectrometry with global positioning system. The measured absorbed dose rates ranged from 28.35 to 106.55 nGy/h, giving an average value of 70.46 nGy/h. The estimated absorbed dose rate spanned from 22.25 to 101.03 nGy/h with a mean value of 65.50 nGy/h. The average concentrations of 40K, 238U, and 232Th were 458.55, 30.26, and 54.77 Bq/kg respectively. The outdoor and indoor absorbed doses averaged 80.39 and 132.55 µSv/y, respectively, and the mean value of excess lifetime cancer risk was 0.26 × 10−6 µSv/y. The external and internal hazard index averaged 0.39 and 0.47, respectively, and the mean annual gonadal dose equivalent was 465.14 µSv/y. The radium equivalent dose averaged 143.45 Bq/kg while the gamma representative index averaged 1.05. The absorbed dose rate, mean concentration of 40K and 232Th, the average values of excess lifetime cancer risk, the annual gonadal dose equivalent, and the gamma representative index were above the permissible limit as set by the radiation regulatory agencies. The study concluded that the human activities in Ojota Chemical Market might have increased the radiation burden of the community.

An In-Depth Examination of the Natural Radiation and Radioactive Dangers Associated with Regularly Used Medicinal Herbs.

The specific activity of U-238 and Th-232, as well as K-40 radionuclides, in twenty-nine investigated medicinal herbs used in Egypt has been measured using a high-purity germanium (HP Ge) detector. The measured values ranged from the BDL to 20.71 ± 1.52 with a mean of 7.25 ± 0.54 (Bq kg−1) for uranium-238, from the BDL to 29.35 ± 1.33 with a mean of 7.78 ± 0.633 (Bq kg−1) for thorium-232, and from 172 ± 5.85 to 1181.2 ± 25.5 with a mean of 471.4 ± 11.33 (Bq kg−1) for potassium-40. Individual herbs with the highest activity levels were found to be 20.71 ± 1.52 (Bq kg−1) for uranium-238 (H4, Thyme herb), 29.35 ± 1.33 (Bq kg−1) for thorium-232 (H20, Cinnamon), and 1181.2 ± 25.5 (Bq kg−1) for potassium-40 (H24, Worm-wood). (AACED) Ingestion-related effective doses over the course of a year of uranium-238 and thorium-232, as well as potassium-40 estimated from measured activity concentrations, are 0.002304 ± 0.00009 (minimum), 0.50869 ± 0.0002 (maximum), and 0.0373 ± 0.0004 (average)(mSv/yr). Radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), absorbed gamma dose rate (Doutdoor, Dindoor), gamma representative level index (I), annual effective dose (AEDtotal), external and internal hazard index (Hex, Hin), and excess lifetime cancer risk were determined in medicinal plants (ELCR). The radiological hazards assessment revealed that the investigated plant species have natural radioactivity levels that are well within the internationally recommended limit. This is the first time that the natural radioactivity of therapeutic plants has been measured in Egypt. In addition, no artificial radionuclide (for example, 137Cs) was discovered in any of the samples. Therefore, the current findings are intended to serve as the foundation for establishing a standard safety and guideline for using these therapeutic plants in Egypt.

Cancer risk (ELCR) and annual gonadotropin equivalent dose (AGED) in macaroni

Natural radioactivity has attracted a lot of attention in the world due to its crucial role in human safety. macaroni (Macaroni) is a dry, hollow pastry, made from cereals such as wheat, rice and barley. Macaroni is one of the basic and important for human beings, as well as its proven usefulness to the general health of human beings. Therefore, the measurement of natural radioactivity is a critical because of its direct impact on human safety. In this research, quantification has been made of natural radionuclide concentrations using NaI(Tl) gamma-ray spectrometry. The analyses of samples reveal the mean activity concentrations of 226Ra, 232Th, 40K% are found to 4.5E-01±0.071, 4.46±0.163 and 2.14±0.021, respectively. RLI,AUI,IC and Iα were also calculated the values ​​were less than one also estimated annual gonadal equivalent dose (AGED) resulting with an average 302.98±07.59 mSv.y-1 where was higher than globally limits. Consumption of macaroni for adult was found (0.035±0.0015) mSv.y-1 which less than global studies , while the average value of cancer risk ( 1.21E-04±0.000005*10-3 mSv.y-1 Below the international permissible limits. The study can be considered as a basis for future studies on this basic substance in food.

Natural radionuclide concentration and associated health hazard indices in coal samples from Okobo Coal Mine, Nigeria

Background: Mining activities of coal have the capacity to raise the level of natural radionuclide concentration in our environment. This exposes human population to ionizing radiations with their associated health hazards. This study was aimed at measuring natural radionuclide concentration of 226Ra, 232Th and 40K, and their associated health hazard indices in coal samples from Okobo coal mine. Materials and Methods: The survey design adopted for this study was the cross sectional type. Coal samples totaling ten (10) in number, were randomly collected from the coal mine. The sampled coal was analyzed at the University of Ibadan, in the laboratory of the National Institute of Radiation Protection and Research (NIRPR), using high resolution spectrometry technique, with high purity germanium (HPGe) detectors. Results: The obtained results revealed that the radionucide concentration of 226Ra in the sampled coal recorded slightly higher value (21.34±7.94 Bq/kg) than global average of 20 Bq/Kg. However, the recorded values for 232Th (13.61±5.08 Bq/kg) and 40K (20.91±15.77 Bq/kg) fall below the global average value of 20 and 50 Bq/Kg respectively. All calculated radiological hazard parameters recorded lower values than the global permissible value but for annual gonadal dose equivalent (AGDE) which recorded significantly higher value (407.74 mSv/yr) than the world acceptable limit of 300 mSv/yr. Conclusion: The activity concentration of 226Ra for Okobo coal sample recorded a unit mean value higher than the global average, however the recorded values for 232Th and 40K fall below global permissible values. All radiological health hazards recorded lower values than the precautionary safe limit but for annual gonadal equivalent dose which recorded significantly higher value than the global permissible limit. This implies that both staff and residents of the community could be exposed to radiological threat, which might affect the functionality of their sensitive organs if prolonged and cumulative exposure is not avoided.

Radioactive risk assessment of beach sand along the coastline of Mediterranean Sea at El-Arish area, North Sinai, Egypt

Beach sand includes various levels of natural radioactivity, which can cause health effects. The natural radioactivity was measured in the beach sand along the coastline of the Mediterranean Sea at the east of the El-Arish area, Egypt. Using the HPGe spectrometer, the contribution of radionuclides 226Ra, 232Th and 40K in the gamma emitted radiation illustrated that the 226Ra, 232Th and 40K activity concentrations are 8.8 ± 3.9, 30.8 ± 12.2 and 106.9 ± 46.8 Bq kg−1, respectively, which is lower than the reported worldwide limit 33, 45 and 412 Bq kg−1. The radioactive hazards associated with the beach sand along the coastline of the Mediterranean Sea at the east of the El-Arish area were investigated. The obtained results among the radiological hazard parameters, the radium equivalent content (Raeq), the absorbed dose rate (Dair), annual effective dose (AED), external (Hex) and internal (Hin) hazard indices were estimated. Moreover, the excess lifetime cancer risk (ELCR) and the annual gonadal dose equivalent (AGDE) were also computed and illustrated their values less than the recommended levels. Multivariate statistical approaches like Pearson correlation, the principal component analysis (PCA) and the hierarchical cluster analysis (HCA) were applied to investigate the correlation between the radionuclides and the corresponding radiological hazard variables. Based on the statistical analysis, the 226Ra and 232Th mainly contribute to the radioactive risk of beach sand. Finally, no significant risk of the public associated with utilizing beach sand in building materials.

Evaluation of background radiation of Maryland School complex, Lagos, Nigeria

The background radiation of Maryland School Complex was taken using RS-125 hand-held gamma spectrometer. The average concentration of the measured radionuclides were 19.16, 46.14, 165.00 Bq/kg for 238U, 232Thand 40K, respectively. The average value of measured dose rate and the estimated dose rate were 44.93 and 43.55Bq/kg. The mean values of the estimated radiological parameter were 53.45, 213.78μSv/y for indoor and outdoor annual effective dose. The excess lifetime cancer risk averaged 0.17, the hazard indices were 0.26 and 0.32 for external and internal respectively. The annual gonadal dose and radium equivalent were 303.90 μSv/y and 97.85 Bq/kg, while the gamma representative index was 0.69. The mean concentration of radionuclides measured and the estimated radiological parameter were within the recommended values. This therefore follows that the risk of exposure to ionizing radiation for both the staff and the students of the community is within acceptable limits.

Estimation of Utilization Index and Excess Lifetime Cancer Risk in Soil Samples Using Gamma Ray Spectrometry in Ibolo-Oraifite, Anambra State, Nigeria

Ionizing radiations emanating from human natural environment could have serious negative effects at certain exposure level. Therefore the evaluation of radioisotopes of natural origin becomes very important in order to achieve specific objective to quantifying the radiological parameters and their respective health implications. Hence the estimation of Activity Utlization Index (AUI) and Excess Lifetime Cancer Risk (ELCR) has been done using gamma spectroscopy method. The results showed that the mean activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K from which the AUI and ELCR were computed were 22.19, 9.70 and 543.80 Bqkg^-1respectively. Activity Utilization Index ranged from 0.24 to 0.55 and Excess Lifetime Cancer Risk ranged from 0.07 to 0.17 x 10-3. The average value of AUI was 0.38 whereas that of ELCR was found to be 0.12×10^-3 which implied that 0.38 < 2, 0.17 < 0.29, standard permissible limits. Mean values of Dose, Igamma, annual effective dose equivalent (AEDE), H_in, H_ex and annual gonadal equivalent dose (AGED) were 38.95nGh^-1, 0.61, 0.05, 0.27, 0.21 and 279.87µSvy^-1 respectively. In conclusion, the empirical values of activity utilization index showed good air quality. Also, the computed values of the excess lifetime cancer risks indicated very low chances of potential carcinogenicity effect for a specific exposure to ionizing radiation in this environment.

Radiological Investigation on Sediments: A Case Study of Wadi Rod Elsayalla the Southeastern Desert of Egypt

The presence of heavy radioactive minerals in the studied granitoids from which the Wadi sediments leads to the study of the exposure to emitted gamma rays from the terrestrial radionuclides, such as 238U, 232Th, and 40K. The geological study revealed that the Wadi sediments derived from the surrounding granitoids, such as syenogranite, alkali feldspar granite, and quartz syenite. The mineral analysis confirmed that the granitoids were enriched with radioactive minerals, such as uranothorite as well as monazite, zircon, yttrocolumbite, and allanite. The mean activity of the 238U, 232Th, and 40K concentrations are 62.2 ± 20.8, 84.2 ± 23.3, and 949.4 ± 172.5 Bq kg−1, respectively, for the investigated Wadi sediments, exceeding the reported limit of 33, 45 and 412 Bq kg−1, respectively. Public exposure to emitted gamma radiation is detected by estimating many radiological hazard indices, such as the radium equivalent content (Raeq), external and internal hazard indices (Hex and Hin), annual effective dose (AED), annual gonadal dose equivalent (AGDE), and excess lifetime cancer (ELCR). The obtained results of the radiological hazards parameters showed that public exposure to emitted gamma radiation can induce various dangerous health effects. Thus, the application of the investigated sediments in different building materials and infrastructures fields is not safe. A multivariate statistical analysis (MSA) was applied to detect radionuclide correlations with the radiological hazard parameters estimated in the granite samples.

Natural and artificial radionuclide activity concentrations and dose assessments of some medicinal plants in Balikesir, Turkey

ABSTRACT 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.

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.

Assessment of solid mineral to soil radioactivity contamination index in selected mining sites and their radiological risk indices to the public

ABSTRACT This study examined the radioactivity levels of soil samples within selected solid mining sites in Nigeria using high-purity germanium (HpGe) detector. Sixty soil samples in all were collected from the 10 solid mineral mining sites investigated and six samples were collected as control samples from non-mining environment for analyses. The results of the activity concentration values obtained for 40K, 226Ra and 232Th are 100.22 Bq kg−1, 33.15 Bq kg−1 and 77.31 Bq kg−1, respectively. The 226Ra and 40K activities were found to be within the United Nation Scientific Committee on the Effects of Atomic Radiation acceptable permissible limit, but the 232Th mean value was above the permissible limit of 30 Bq kg−1 for the public. In comparison, 40K, 226Ra and 232Th soil samples mean activity concentrations were higher than the control soil samples values by 48.6%, 43.7% and 62.3%, respectively. The results of estimated radiation hazard indices indicate average values of 150.72 Bq kg−1, 68.40 nGyh−1 , 83.65 µSvy−1 and 454.70 µSvy−1 for the Radium Equivalent (Ra eq ), Absorbed Dose Rate (D), Dose Equivalent (AEDE) and Annual Gonadal Equivalent Dose (AGED), respectively. The mean values for External Hazard Indices (Hex, Hin), Representative Gamma index () and Excess Life Cancer Risk (ELCR) were 0.41, 0.50, 1.06 and 0.29 × 10−3, respectively. The statistical analysis shows positive skewness.

Health Risk Assessment of Natural Radioactivity in Wasteland Soils in Okakarara, Namibia..

Human activities such as waste disposal tend to impact negatively on the environment. Some waste products are associated with elevated levels of natural radioactivity. It was therefore, the aim of the study to investigate the health risk associated with natural radioactivity from Okakarara municipal waste dumpsite. In this study, gamma spectrometric analysis was used to determine the activity concentrations of 226Ra, 232Th and 40K in 18 soil samples. From these activity concentrations, some radiological parameters were calculated. The average activity concentrations of 226Ra, 232Th and 40K in (Bq.kg-1) were 15.45±0.47, 18.00±0.55, and 215.73±4.29, respectively. The average Raeq value was 57.80±0.98 Bq.kg-1. In all the samples, Raeq values were found to be lower than the worldwide value of 370 Bq.kg-1. The absorbed dose rate was found to be 27.00±0.44 nGy.h-1, whereas an average value of 0.03 mSv.y-1 for AEDE is noted, which is less than 0.48 mSv, the worldwide average. The Annual Gonadal Dose Equivalent (AGDE) was 190.89 μSv.y-1, a value less than the world average of 298 μSv.y-1. The average values of the Representative Level Index (RLI) and the External Hazard Index (Hex) was found to be 0.43 and 0.16., respectively. These indices were less than unity. The average value of the excess lifetime cancer risk (ECLR) was 1.16 x 10-4. This value was lower than the internationally acceptable limit of 2.9 x 10-4. From these results it can be concluded that natural radioactivity from the wasteland area of Okakarara was not an issue of health concern.

Multivariate statistical study of technologically enhanced naturally occurring radioactive materials and radiation hazards in crude oil and petroleum products of Ma’rib refinery, Yemen

Crude oil and oil products are among the significant sources of technologically enhanced naturally occurring radioactive materials (TENORMs). Thirty-one samples of eight types of crude oil and petroleum products were collected from the Ma’rib Refinery, located in the Ma’rib Governorate, central Yemen. These samples were analyzed using a gamma-ray spectroscopy system with a high purity germanium detector (HPGe). The specific radio-activities of 40K, 232Th, and 226Ra for crude oil samples ranged 5.943–32.252, 1.711–12.646, and 2.445–15.520 Bq L−1, respectively. Oil products ranged 8.333–40.355, 1.556–12.812, and 3.014–17.024 Bq L−1. Potential environmental and health risks were assessed by calculating radiation hazard indicators of radium equivalent activity (Raeq) Bq L−1, absorbed gamma dose rate (AGDR) nGy h−1, annual effective dose rate (AEDR) mSv, external hazard index (Hex), internal hazard index (Hin), annual gonadal dose equivalent (AGDE) mSv, activity utilization index (AUI), excess lifetime cancer risk (ELCR), activity concentration index (Iy), and alpha index (Iα) that ranged 5.614–33.291, 2.636–15.589, 0.003–0.019, 0.016–0.093, 0.022–0.135, 0.018–0.106, 0.045–0.285, 0.011–0.067, 0.041–0.239, and 0.012–0.078 for crude oil and 9.453–36.067, 4.475–16.837, 0.005–0.021, 0.026–0.101, 0.037–0.147, 0.031–0.114, 0.019–0.072, 0.076–0.314, 0.069–0.258, and 0.015–0.085 for oil products. The estimated average values of these indicators were compared with global averages and were below the recommended limits. The relationship between TENORMs and radiation hazard indicators and their maximum activity contributions were determined by applying multivariate statistical methods. This study is important to provide an overview of activity concentrations of natural radionuclides in the petroleum industry of Yemen. Therefore, the results are useful for assessing the radiological hazards of petroleum products in humans.