Bq Kg-1 For 238U Research Articles

Radioactivity determination in depth distribution of stone samples of Kalaburagi District, Karnataka, India.

The activity concentrations of 238U, 232Th and 40K were found using high-resolution gamma-ray spectrometry on depth profile samples collected from the Kalaburagi districts. This study aims to ascertain the radioactivity Changes concerning the depth profile. With values of 51.64±0.50 Bqkg-1 for 238U, 58.77±0.23 for 232Th and 313.92±3.57 for 40K, respectively, the depth profile samples of Jayanagar in the Kalaburagi region exhibit significant activity concentrations among the measured values. Moreover, estimates of the K/Th and K/U ratios have been made, based on surface-level collected samples, which may have values that differ from the samples under study.

Assessment of Radionuclides Contents in Soil and Food Samples Due to Civil War in Enugu State, South-Eastern, Nigeria and Its Radiological Hazards

Human activities may influence the distribution of naturally occurring radioactive materials in the environment. This therefore, cause for concern radiological, as human are exposed to these radioactive materials without their consent. This study hereby evaluate the radionuclide contents from natural and artificially occurring radionuclides in soil samples and farm produce in Enugu. Gamma-ray spectroscopy was used to determine the radioactivity concentration level of the environmental radionuclides such as 238U, 232Th, and 40K and manmade radionuclides in soil, cassava, and bitter leaf samples within studied locations in Enugu State, Nigeria. The mean activity concentration of the radionuclides detected in the samples were 1136.74±27.07, 1118.53±4.85, 196.104±0.02 Bqkg-1 for 40K, 41.66±0.04, 22.99±0.38, Bqkg-1 for 238U and 36.44±0.04, 15.89±0.07, 7.69±0.02 Bqkg-1for 232Th. 137Cs ranged from 3.07 ± 0.01 – 7.81 ± 0.03 Bqkg-1. The radioactivity levels and estimated radiological indices were higher than the recommended limits. The values confirmed the reports of different fora on the radiological hazards due to exposure to high radiation in the region assayed.

Evaluation of Radioactivity Contents and Excess Lifetime Cancer Risk Due to Ingestion from Natural Radionuclides in Maize Samples from Some Selected Maize Farms in Ekiti State, Nigeria

The study was carried out to evaluate the radioactivity concentrations of 40K, 232Th and 238U in five maize samples collected from maize farms within Ekiti State, Nigeria. The activity concentration measurements were determined using n – type co-axial HPGe detectors for the state. The activity concentrations were found to vary from 994.67 – 2457.01 Bq Kg-1 for 40K, 32.84 – 91.88 Bq kg-1 for 232Th and 43.21 – 97.77 Bq kg-1 for 238U respectively. The annual effective dose to individuals from the consumption of the Maize was estimated on the basis of the measured radionuclides content in the food crop which ranged between 0.41 and 1.51 m Svy-1 respectively. The value1.04 m Svy-1 were obtained for the state as the mean total annual effective dose. The mean excess life time cancer risk was also calculated to be 2.06x10-9 . The value was compared with the internationally acceptable limits and found to be far less to the maximum permissible dose of 1.0 x10-3 recommended for the public by the United Nations Scientific Committee on the Effects of Atomic Radiation. Hence, the maize was found to be safe for human consumption.

ANNUAL EFFECTIVE DOSE ESTIMATION DUE TO THE NATURAL RADIOACTIVITY IN YAM TUBERS (Dioscorea rotundata) CULTIVATED IN NORTHCENTRAL NIGERIA

Yam tubers (Dioscorea rotundata) and soil from commercially cultivated farmland in northcentral Nigeria were collected and investigated for their natural radioactivity content using a 3” × 3” NaI(Tl) gamma detector. Average activities of 238U, 232Th and 40K in the investigated farm soil were 38.13±3.76 Bq kg-1, 15.06±0.99 Bq kg-1 and 381.80±15.50 Bq kg-1, respectively. The results agree with the world’s acceptable levels of safety. Activities measured in the yam tubers were in the range from BDL -76.68±9.73 Bq kg-1 for 238U, BDL - 19.77±1.30 Bq kg-1 for 232Th and 312.50±20.73 - 627.94±38.37 Bq kg-1 for 40K, with average values of 29.23±4.0, 13.10±0.72 and 445.10±27.20 Bq kg-1, respectively. The total effective dose from radionuclide intake from yam ingestion fluctuated between 272.12 μSv y-1 and 935.97 μSv y-1. Correlation analysis identified 238U and 232Th as the leading contributors to the total effective dose from ingesting yam tubers cultivated in northcentral Nigeria.

Activity Level of 238U, 232Th, 40K and Resultant Dose Rates in Soil and Some Commonly Cultivated Vegetables

This present study aims to determine the level of natural radionuclides of 40K, 238U and 232Th in soil samples and (Potato, Solanum tuberosum and Carrot, Daucus carota) samples and vegetables (Tomato, Solanum hycopersicum and Eggplant Solanum melongena) in Al- Mada'in district 30 km south east of Baghdad, Iraq. High purity germanium (HPGe) detector was used for measurement. The transfer factors, annual absorbed dose rate and the annual effective dose in the samples collected were determined. The results showed that the mean level of measured natural radionuclides were 362.6 ± 41.6 Bqkg-1, 184.7 ± 17.4 Bqkg-1, 191.9 ± 13.5 Bqkg-1, 120.3 ± 10.6 Bqkg-1 and 126.1 ± 11.7 Bqkg-1 for 40K; 19.67 ± 2.00 Bqkg-1, 4.70 ± 0.609 Bqkg-1, 5.43 ± 0.977 Bqkg-1, 3.30 ± 0.460 Bqkg-1 and 2.40 ± 0.701 Bqkg-1 for 238U and 12.34 ± 4.12 Bqkg-1, 3.77 ± 0.904 Bqkg-1, 4.54 ± 0.709 Bqkg-1, 3.51 ± 0.721 and 3.81 ± 0.796 Bqkg-1 for 232Th to soil, tomato, eggplant, potato and carrot samples respectively. The soil-to-tomato transfer factors were found to be 0.512, 0.242 and 0.344 for 40K, 238U and 232Th and soil-to-eggplant transfer factors were found to be 0.534, 0.279 and 0.408 for 40K, 238U and 232Th respectively. The soil-to-potato transfer factors were found to be 0.336, 0.170 and 0.320 for 40K, 238U and 232Th while the soil-to-carrot transfer factors were found to be 0.348, 0.122 and 0.309 for 40K, 238U and 232Th respectively. The mean absorbed dose rate was 30.0 ± 0.57 nGyh-1 and the mean annual outdoor effective dose was 55.2 mSvy-1. This present study's annual effective dose report was 91.6% of the world average value of 70.0 msvy-1 and 87.3% of Thi-Qar government, south Iraq state value of 39.9 msvy-1.

ACTIVITY LEVEL OF 238U, 232TH, 40K AND RESULTANT DOSE RATES IN SOIL AND SOME COMMON CULTIVATED VEGETABLES

The aim of this present study is to determine the level of natural radionuclides of 40K, 238U and 232Th in soil samples and in (Potato, Solanum tuberosum and Carrot, Daucus carota) samples and vegetables (Tomato, Solanum hycopersicum and Eggplant Solanum melongena) in Al- Mada’in district 30 km southeast of Baghdad, Iraq. High purity germanium (HPGe) detector was used for measurement. The transfer factors, annual absorbed dose rate and the annual effective dose in the samples collected were determined. The results showed that the mean level of measured natural radionuclides were 362.6 ± 41.6 Bqkg-1, 184.7 ± 17.4 Bqkg-1, 191.9 ± 13.5 Bqkg-1, 120.3 ± 10.6 Bqkg-1 and 126.1 ± 11.7 Bqkg-1 for 40K; 19.67 ± 2.00 Bqkg-1, 4.70 ± 0.609 Bqkg-1, 5.43 ± 0.977 Bqkg-1, 3.30 ± 0.460 Bqkg-1 and 2.40 ± 0.701 Bqkg-1 for 238U and 12.34 ± 4.12 Bqkg-1, 3.77 ± 0.904 Bqkg-1, 4.54 ± 0.709 Bqkg-1, 3.51 ± 0.721 and 3.81 ± 0.796 Bqkg-1 for 232Th for soil, tomato, eggplant, potato and carrot samples respectively. The soil-to-tomato transfer factors were found to be 0.512, 0.242 and 0.344 for 40K, 238U and 232Th and soil-to-eggplant transfer factors were found to be 0.534, 0.279 and 0.408 for 40K, 238U and 232Th respectively. The soil-to-potato transfer factors were found to be 0.336, 0.170 and 0.320 for 40K, 238U and 232Th while the soil-to-carrot transfer factors were found to be 0.348, 0.122 and 0.309 for 40K, 238U and 232Th respectively. The mean absorbed dose rate was 30.0 ± 0.57 nGyh-1 and the mean annual outdoor effective dose was 55.2 mSvy-1. The annual effective dose report for this present study 91.6% of the world average value of 70.00 msvy-1 and 87.3% of Thi-Qar government, south Iraq state value of 39.9 msvy-1.

RADIOLOGICAL ASSESSMENT OF GRAINS, VEGETABLES, FRUITS AND TUBER CROPS CULTIVATED IN OKEMESI TOWNSHIP, EKITI STATE, NIGERIA

Exposure to radiation is a natural phenomenon in the human environment. This is received from naturally occurring radionuclides in water, air, soil and food. Ingestion is one of the two major pathways through which these nuclides enter the human systems. Radiological assessment of fruits, vegetables, grains and tuber crops cultivated and consumed in Okemesi township, Ekiti State has been carried out using a 76mm by 76mm lead-shielded Sodium Iodide detector (NaI(Tl)) located at the Centre for Energy, Research and Development (CERD), Obafemi Awolowo University, Ile-Ife, Nigeria. The mean activity concentration of the radionuclides in the food samples was 155.76 ± 14.22 Bqkg-1 for 40K, 8.00 ± 0.24 Bqkg-1 for 238U and 7.39 ± 0.21 Bqkg-1for 232Th.The value obtained for Annual Effective Dose due to intake of the food crops (Ding) ranged from 104.32 to 687 µSv yr-1 while values for Excess Lifetime Cancer Risks (ECLR) ranged from 0.365 t0 2.407. Although the radioactivity levels in the food crops were lower than the world-wide limits, some values obtained for the AED and the ELCR were significantly higher than the recommended limits of UNSCEAR 2000. The rank order of Ding and ELCR in the food types was tubers ? fruits ? vegetables ? grains. Consumption of food cultivated in the area over a long period of time may induce a degree of health risks which should not be overlooked.

Assessment of Radionuclide Concentration in Surface Soil and Human Health Risk Associated with Exposure in Two Higher Institutions of Esan land, Edo State, Nigeria

The aim of this study is to assess the activity concentration of radionuclides and the possible health risk associated with exposure to radiation from the soil samples collected from two higher institutions in Esan land of Edo State, Nigeria. The gamma spectrometry system was used to determine the activity concentrations of radionuclides 238U, 232Th and 40K in the surface soil samples. The activity concentration of radionuclides ranged from 7.16 ± 0.63 to 102.37 ± 2.37 BqKg-1for 40K, from 0.75 ± 0.05 to 3.13 ± 0.11 BqKg-1 for 238U and from 2.25 ± 0.20 to 9.02 ± 0.40 BqKg-1for 232Th. The measured mean activity concentration of radionuclides for 40K, 238U and 232Th from the examined topsoil of Samuel Adegboyega University were 57.80 ± 1.7 BqKg-1; 2.07 ± 0.09 BqKg-1 and 6.89 ± 0.34 BqKg-1 respectively. At the neighbouring higher institution; College of Education, Igueben, the mean activity concentration of 40K, 238U and 232Th in its surface soil were 30.19 ± 1.22 BqKg-1, 1.41 ± 0.07 BqKg-1 and 4.85 ± 0.28 BqKg-1 respectively. The total mean values for radiation dose estimation for Radium Equivalent Activity, Absorbed Dose, Excess Lifetime Cancer Risk, Outdoor and Indoor Annual Effective Dose Equivalent are 13.20 BqKg-1, 6.03 nGy/ℎ, 0.026, 7.40 µSτ/γ and 29.60 µSτ/γ respectively. These values were found to be lower than the global average values. Hence, there is no radiation induced health threat to the students and members of staff in the study area.Keywords: Soil, exposure, health risk, activity concentrations

RADIOACTIVE DISEQUILIBRIUM AND DYNAMIC OF NATURAL RADIONUCLIDES IN SOILS IN THE STATE OF PERNAMBUCO-BRAZIL.

Environmental radioactivity studies have been allowed establishing radiometric patterns in several area of the earth's crust. The work was conducted through radiometric analyses of regions with high levels of radionuclides and others with no history of anomalies. The research allowed establishing the radiometric profile of soils in the state of Pernambuco, Brazil, using a gamma spectrometry system. The specific activities ranged from 16.5 to 287.5 Bq kg-1 for 238U, 2.0 to 191.7 Bq kg-1 for 226Ra, 1.3 to 281.4 Bq kg-1 for 232Th and from 5.0 to 2600.9 Bq kg-1 for 40K. The results showed areas with low levels of ionizing radiation. However, for 40K some points presented high values, although non-representative of the number of samples investigated. The 226Ra/238U and 232Th/238U ratios allowed to determine the radioactive imbalance condition and to obtain information about aspects of soil availability providing an assessment of the dynamics of these radionuclides.

Measurement of (40K, 238U and 232Th) and Associated Dose Rates in Soil and Commonly Consumed Foods (Vegetables and Tubers) at Okitipupa, Ondo State, Southwestern Nigeria


 
 
 
 The aim of this present study is to collect soil samples and some commonly consumed food materials in Ondo State, Nigeria such as tubers (cassava, Manihot esculent and yam, Dioscorea alata) samples and vegetables (waterleaf, Talinium triangulare and bitter leaf, Vernonia amygdalina) samples at some selected locations in Okitipupa, Ondo state, Southwestern, Nigeria in order to determine the following natural radionuclides (40K, 238U and 232Th) levels using a well calibrated NaI(TI) which is well shielded with a detector coupled to a computer resident quantum MCA2100R Multichannel. The transfer factors, annual absorbed dose rate and the annual effective dose in the samples collected were estimated.
 The results showed that the measured natural radionuclides were present in the mean concentrations of 323.79 ± 12.45 Bqkg-1, 81.87 ± 45.30 Bqkg-1 and 57.62 ± 18.04 Bqkg-1 for 40K; 11.76 ± 36.03 Bqkg-1, 4.67 ± 10.12 Bqkg-1 and 3.45 ± 2.10 Bqkg-1 for 238U and 9.66 ± 0.89 Bqkg-1, 3.07 ± 2.45 Bqkg-1 and 2.45 ± 0.92 Bqkg-1 for 232Th for soil, yam and cassava samples respectively. The results also showed that the radionuclides were present in the concentrations of 11.76 ± 36.03 Bqkg-1 and 9.66 ± 0.89 Bqkg-1 for 40K; 9.67 ± 8.53 Bqkg-1 and 7.87 ± 1.89 Bqkg-1 for 238U and 8.63 ± 6.08 Bqkg-1 and 6.58 ± 0.76 Bqkg-1 for 232Th for waterleaf and bitter leaf samples respectively. The soil-to-yam transfer factors were found to be 0.26, 0.40 and 0.32 for 40K, 238U and 232Th and soil-to-cassava yam transfer factors were found to be 0.18, 0.29 and 0.25 for 40K, 238U and 232Th respectively. The soil-to-waterleaf transfer factors were found to be 0.37, 0.82 and 0.82 for 40K, 238U and 232Th while the soil-to-bitter leaf transfer factors were found to be 0.32, 0.74 and 0.68 for 40K, 238U and 232Th respectively.
 The mean absorbed dose rate was 25.08 ± 0.57 and the mean annual outdoor effective dose was 46.17 . The annual effective dose reported for this present study area represents 65.95% of the world average value of 70.00 and 47.11% of Nigeria value of 98.00 mSvy-1
 
 
 
 

Measurements of radioactivity levels in part of Ota Southwestern Nigeria: Implications for radiological hazards indices and excess lifetime cancer-risks

Super SPEC RS-125 radiation detector with large 2.0 x 2.0 NaI crystal and linear energy ranging from 0.80 MeV to 1.2 MeV was used to measure the activities of primordial nuclides and the radiation dose exposures rate in Iyana-Iyesi, Ota, southwestern Nigeria. The measured activities vary from 17±0.02 Bqkg-1 to 30.49 ±0.01 Bqkg-1, 50.01 ±0.16 Bqkg-1 to 158.49±0.17 Bqkg-1, and 406.9±0.42 Bqkg-1 to 1275.48±0.82 Bqkg-1 for238U,232Th and40K respectively. The acquired gamma radiation dose rate range from 138.696 ±2.06 (nGyh-1) to 350.103±7.21 (nGyh-1) with mean value of 148.22 (nGyh-1), almost three times higher than the recommended safe limit of 55 (nGyh-1). The measured activities and radiation dose rate were engaged to estimate the annual outdoor effective dose, gamma index, excess lifetime cancer risks and annual gonadal dose equivalent. It was observed from all the estimated parameters, those values in the study area are well above the recommended safe limit for normal background radiation. This suggest that the dwellers and those using the excavated geomaterials from this area for construction purposes are exposed to very high radiation from natural radionuclides. Further research to evaluate the mineralogy and geochemistry of the clay deposits in the area is highly recommended.

Radiation hazard in soil from Ajaokuta North-central Nigeria

Background: Measurement of the radiation dose distribution is important in assessing the health risk a population and serve as reference in documenting changes to environmental radioactivity in soil due to man-made activities. Materials and Methods: The activity concentration of 238U, 232Th and 40K in soil samples obtained from different locations in Ajaokuta Local Government area was measured using Hyper Pure germanium Detection System (HPGe). Results: The calculated average concentration of the radionuclides ranged from 12 ± 1 Bqkg-1 to 59 ± 2 Bqkg-1 for 238U, 14 ± 1 Bqkg-1 to 78 ± 5 Bqkg-1 for 232Th and 49 ± 2 Bqkg-1 to 1272 ± 23 Bqkg-1 for 40K. In order to evaluate the radiological hazards due to natural radionuclides within Ajaokuta, the absorbed dose rate, gamma index, radium equivalent and excess lifetime cancer risk were estimated. According to measured data from the top soil (0-10 cm), the estimated radium equivalent (Raeq) ranges from 55.7 Bqkg-1 at Steel Complex to 253.3 Bqkg-1 obtained from Forest samples. Conclusion: The mean absorbed dose rate, annual effective dose and gamma radiation index evaluated were 66.2 nGyh-1, 81.2 µSvy-1 and 1.05 respectively which are higher than the recommended limit for normal background radiation. Thus, we conclude that people living in these locations may be exposed to higher radiation.

Radioactivity concentrations and dose characteristics of granite stones

We obtained the radionuclide concentrations of 238U, 232Th, and 40K in various samples of the granite stones by measuring with a high efficiency NaI(Tl) (10.16 cm x 10.16 cm) scintillation detector. The activities of 238U, 232Th, and 40K were recorded and determined by a full-spectrum analysis. The concentrations of radionuclides were found to be in ranges of 32.3-92.6 Bqkg-1, 23.9-52.2 Bqkg-1, and 796.5-2018.4 Bqkg-1 for 238U, 232Th, and 40K, respectively. The radiological dose rates and the hazard indices were also calculated in this analysis.

Terrestrial Radiation Doses from Selected Towns of Southwestern Nigeria

The activity concentrations of natural gamma-emitting radionuclides 238U, 232Th and 40K in soils from 7 sampling sites each in Ondo and Lagos States, southwestern Nigeria have been measured by using a well calibrated Hyper Pure Germanium Detector (HPGe). The mean activity concentration values of 39.24±1.12, 52.86±1.40 and 445.02±12.24 Bq kg-1 for 238U, 232Th and 40K respectively were obtained for . Activity concentration values of 23.21±0.92, 22.84 ± 0.78 and 204.02±7.00 Bq kg-1 were recorded for 238U, 232Th and 40K respectively for . The results obtained were used to estimate the absorbed dose rates in outdoor air which was found to be in the range of 12.35±179.59 nGy h-1 for Ondo State and 5.91±83.29 nGy h-1 for Lagos State with an overall mean values of 67.50±1.86 nGy h-1 and 33.83±1.17 nGy h-1 respectively for the two States. The corresponding outdoor annual effective dose rates were estimated to be between 22.7 and 330.6 μSv y-1 for and between 7.3 and 102.2 μSv y-1 for assuming 30% and 20% occupancy factors for the two states respectively. The average outdoor annual effective dose rate for towns in Ondo State is 64.85 μSv y-1 representing 92.64% of the world average value (70 μSv y-1) given by UNSCEAR. However, the cities in have an average outdoor effective dose of 41.52 μSv y-1 which is less than 60% of the world average value. The values of the collective effective dose as calculated from the outdoor annual effective dose rates were found to be 540858 and 273296 person-Sv for Ondo and Lagos States respectively.

Assessment Of Natural Radioactivity Level And Radiation Hazard Parameters In The Terrestrial Environment Of Eloor Island, Kerala

The present study is aimed at measuring the concentration of primordial radionuclides in the soil samples of Eloor Island, an industrial area in Ernakulum District and evaluating the radiation exposure to the local population. The ambient radiation exposure rate was measured using portable scintillometer survey meter and the activity concentration of 232Th, 238U and 40K in the soil samples were analyzed using (5×4)” NaI(Tl) gamma spectrometer. The exposure rate measured using survey meter varied from 63 nGyh-1 to 374 nGyh-1. The activity concentration of 232Th, 238U and 40K in soil samples ranged from 44.8 Bq kg-1 to 792.8 Bqkg-1 for 232Th, 8 Bqkg-1 to 445.5 Bqkg-1 for 238U and 129 Bqkg-1 to 1160.5 Bqkg-1 for 40K. Hence the absorbed gamma dose and radiation hazard indices due to natural environmental radiation was done. The study showed no significant impact due to the NORM Industries in the Eloor Industrial region.

Radiological Monitoring of Borehole in Dei-Dei, Abuja, North Central Nigeria

Inhabitants in Dei-Dei area of Abuja consume groundwater that recharges from different lithologic units of subsurface structures due to inadequate public water supply.The water is consumed untreated and during drilling, it cuts across so many rock formations, to extents constitute radioactive elements which are to be evaluated. Vertical Electric Sounding and Shuttle Radar Topography mission was used to determine the structure of electric conductivity and map lineaments.Hydrogeologically motivated borehole with geophysical log data was drilled. Activity concentrations were analysed using high resolution co-axial HPGe gamma spectrometer system. The activity concentrations ranges from 45± 2 to 98 ± 6 Bq kg-1 for 232Th, 18 ± 2 to 37 ± 4 Bq kg-1 for 238U and 236 ± 32 Bq kg-1 to 1195±151 Bq kg-1 for 40K. Structurally, fractured interconnectivity attributed to low levels in some layers. Activity levels are within the limits, requires research within groundwater activity levels and rock geochemistry.

Studies of the Terrestrial outdoor Gamma Dose Rate Levels in Ogun-Osun River Basins Development Authority Headquarters, Abeokuta, Nigeria

Problem statement: The natural radioactivity levels in the soils of Ogun-Osun River Basins Development Authority Headquarters, (O-ORBDA HQ) Abeokuta, South-Western part of Nigeria were measured. Approach: (O-ORBDA HQ) is a parastatal of Federal Ministry of Water Resources and Rural Development in Nigeria charged with the responsibility for the development and management of the water resources in its area of coverage. The area of the site was divided into fifteen segments and soil samples were collected at a depth of about 10cm at the intersection of these lines. Results: Global Positioning System (GPS) was used to obtain the geographical position of each sample point. NaI (Tl) scintillation detector coupled with a Canberra series 100 plus MCA was used as the detecting device for the gamma scintillation spectroscopy. The average activity concentrations obtained for the three radionuclides were 896.12± 274.48 Bq kg-1 for 40K, 13.93±2.36 Bq kg-1 for 238U and 18.67±5.06 Bq kg-1 for 232Th. The average values of the absorbed dose rates in air of each radionuclide were found to be 37.64±11.53 nGy h-1 for 40K, 5.98±1.10 nGy h-1 for 238U and 12.44±3.37 nGy h-1 for 232Th. Conclusion/Recommendations: The baseline average outdoor annual effective dose equivalent in O-ORBDA HQ due to the radioactivity concentrations was found to be 68.74±19.51 μSv year-1. This value is less than the world average of 70 μSv year-1 specified by UNSCEAR for an outdoor effective dose. Hence the probability of occurence of any of the health effects of radiation is low. Since no artificial radionuclides was detected, this represents the baseline value of natural radioactivity.

THE IMPACT OF INCREASED NATURAL BACKGROUND OF SOIL ON THE ANIMAL PRODUCTION OF RUMINANTS IN THE REGION LIVNO

In this paper, the impact of increased levels of uranium and radium in soil on the levels of activity and radiation-hygienic validity of animal products of ruminants was investigated.Region around Livno town is placed on coal layer with the in creased levels of uranium and radium compared with other coals used in Bosnia and Herzegovina. As a result of mixing between coal matrix and soil, in creased value of average absorbed dose rate at 1 m above the ground (144 nGy h-1) was measured. The highest average value of 238U and 226Ra in the samples of animal products of ruminants was measured in the samples of sheep cheese (0.070 Bq kg-1 for 238U and 0.207 Bq kg-1 for 226Ra). The levels of these two radionuclides in the rest of animal product of ruminants were aproximatelly similar and ranged 0.016–0.046 Bq kg-1 for 238U and 0.028–0.080 Bq kg-1 for 226Ra. Levels of 40K were in the range of average values for animal products (31.2–86.4 Bq kg-1). Calculated annual effective dose by ingestion of the animal products of ruminants were approximatelly 0.064 mSv with the highest dose contribution of 40K (96.4%). On the base of obtained results, animal products of ruminants produced in observed region, can be considered as valid for human consumption from radiation-hygienic aspect.

Assessment of Radiation Dose Rates in the High Terrestrial Gamma Radiation Area of Selama District, Perak, Malaysia

Survey of terrestrial gamma radiation (TGR) dose rates have been conducted in Selama district, Perak, Malaysia. Themean value of TGR dose rate outdoor in Selama is (273 ± 133) nGy h-1. For the habited land, the mean TGR dose ratesoutdoor and indoor are (205 ± 59) nGy h-1 and (212± 64) nGy h-1 respectively. They contribute fatal cancer risk of 6.4 x10-5 per year to an individual in the area. The activity concentrations of 238U, 232Th, and 40K in the soil samples wereanalysed using a high resolution co-axial HPGe gamma ray spectrometer system. The values obtained range from 57 Bqkg-1 to 364 Bq kg-1 with the mean value of (178±95) Bq kg-1 for 238U; 207 Bq kg-1 to 625 Bq kg-1 with the mean value of(353±143) Bq kg-1 for 232Th, and 26 Bq kg-1 to 601 Bq kg-1 with the mean values of (273±133) Bq kg-1 for 40K.

Comparison on in situ and laboratory gamma-ray spectroscopy of terrestrial gamma radiation in Ibadan, Southwestern Nigeria

In situ - ray spectroscopic method of measeruments, using the calibration factor by Zombori et al, and laboratory method for soil samples were carried out in Ibadan, SW Nigeria. The average specific activities of 40K, 238U and 232Th in the soil were 299.0 16.5 Bqkg-1, 40.0 5.8 Bqkg-1 and 95.0 7.8 Bqkg-1, respectively, by in situ measurements, while for the laboratory measurements, the specific activities were found to be 355.0 19.7 Bqkg-1 for 40K, 31.0 5.9 Bqkg-1 for 238U and 63.0 7.5 Bqkg-1 for 232Th. Statistical analysis using F- hypothesis test of microsoft excel 5.0 analysis toolpak gave F-values to be 0.32, 0.52 and 0.00, respectively, which indicated that the radionuclides were not site dependent. The comparison shows a correlation of 0.65, 0.59 and 0.63 respectively, for 40K, 238U and 232Th. Key words : gamma - ray; calibration; soil; activity; radionuclide (Global Journal of Pure and Applied Sciences: 2002 8(4): 507-512)