Mean Radium Equivalent Activity Research Articles

Assessment of radioactivity level and associated radiological hazard in riverbed samples within industrial areas

ABSTRACT Terrestrial gamma radiation is one of the major outdoor radiation exposures to the general public that varies substantially based on the type and geological properties of the soil. The objective of this study is to evaluate the naturally occurring radioactive materials (NORMs) distribution and assess the hazard parameters in the riverbank soil within various industrial zones in the densely populated Dhaka and Chattogram cities of Bangladesh. The mean activities of 226Ra (37 ± 3), 232Th (58 ± 4), and 40K (1129 ± 18) Bqkg−1 in the assessed soil samples were found to be slightly higher than the world average values 32, 35, and 420 Bqkg−1, respectively. The mean radium equivalent activity (207.49 Bqkg−1) and the external and internal hazard indices were within the recommended limits of 370 Bqkg−1 and <1, respectively. The mean absorbed dose rate (99.47 nGyhr−1), annual effective dose (0.12 mSva−1), ELCR (4.27 × 10−4), and gamma level index (1.58) exceeded the world average values 59 nGyhr−1, 0.07 mSva−1, 2.9 × 10−4, and 1 respectively. However, the studied areas are safe from a radiological viewpoint with no radiation health hazard to the people. The results of this study can be utilized to produce factual baseline data for future studies.

Determination of natural and artificial radioactivity levels and radiation hazard indices for soil samples in Kırşehir

Abstract The aim of this study is to create a radiological map of Kırşehir province in Turkey by analyzing the radioactivity levels of soil samples and environmental radiation measurements. 226Ra, 232Th, 40K and 137Cs radionuclides were analysed in soil samples collected from 47 locations using gamma spectrometry with an HPGe detector. According to the results obtained, gamma radioactivity concentration ranges and mean values for 226Ra, 232Th, 40K and 137Cs were determined as 133 ± 15–1515 ± 128 Bq/kg (599.40 Bq/kg), 0.3 ± 0.09–21.1 ± 1.7 Bq/kg (4.61 Bq/kg), 8.7 ± 0.9–128.5 ± 8.5 Bq/kg (29.66 Bq/kg) and 11.6 ± 8.6–273.8 ± 19.9 Bq/kg (48.80 Bq/kg) respectively. Average radioactivity levels for 40K and 232Th are above the world average. The mean radium equivalent activity (Raeq), gamma dose rate (D), annual effective dose equivalent (AEDE), external hazard index (H ex ), and the excess lifetime cancer risk (ELCR) were calculated as 145.45 Bq/kg, 122.13 nGy/h, 0.15 mSv/h, 0.39 and 0.29 × 10−3 respectively.

Evaluation of natural radioactivity in the soil surrounding Bhabha Atomic Research Centre, Visakhapatnam, Andhra Pradesh, India

Abstract Activity concentrations of naturally occurring radionuclides in soil samples collected during 2013–2018 from different 53 locations around Bhabha Atomic Research Centre (BARC), Visakhapatnam, Andhra Pradesh, India, were determined using high-purity germanium gamma-ray spectrometry. An R and D center of BARC is upcoming at Visakhapatnam, North coastal Andhra Pradesh. The annual effective dose (AED) and the radiation indices from the soil activity were evaluated to generate the baseline data for this area. The average activity concentrations of the naturally occurring radionuclides 238U, 226Ra, 232Th, and 40K in the soil samples studied are 29 ± 8 Bq/kg, 31 ± 1 Bq/kg, 188 ± 2 Bq/kg, and 471 ± 10 Bq/kg, respectively. The concentration of 226Ra and 40K in the collected samples is comparable with the world average concentrations of 33 Bq/kg and 420 Bq/kg, however, 232Th is observed to be higher than the world average of 45 Bq/kg. AED due to external terrestrial radiation from the region studied is in the range the range 0.37 to 2.5 mSv/y with an average of 0.9 mSv/y. The mean radium equivalent activity values for around 70% of the studied samples are lower than the permitted levels of 370 Bq/kg. The mean external exposure index has been determined to be around the safe criterion limit of unity. The mean value of the representative level index Iϒ is 2.4. Higher values in some locations are due to thorium in monazite deposits. This report will be useful as preoperational study to evaluate the impact on the environment due to ongoing and future man-made developments.

Investigation of Radiological and Chemical Contents of Bauxite Ore Extracted in Turkey.

In this study, which consists of two parts, the radiological and chemical content of bauxite ore was investigated. Gamma-ray spectrometry was used in the first part of the study to determine the activity concentrations of natural radionuclides in samples taken from bauxite deposits in Turkey. The measured activity concentrations of 226Ra, 232Th, and 40K varied from 12.1 ± 2.5 to 132.6 ± 11.4 Bq kg-1 with a mean of 78.4 ± 8.3 Bq kg-1, 6.5 ± 0.5 to 97.3 ± 9.9 Bq kg-1 with a mean of 64.5 ± 5.9 Bq kg-1, and 5.1 ± 0.0 to 356.4 ± 40.1 Bq kg-1 with a mean of 52.6 ± 5 Bq kg-1, respectively. The calculated mean radium equivalent activity value is 177.4 Bq kg-1, the mean gamma dose rate absorbed in the air is 78.8 nGy h-1, the mean corresponding annual effective dose value is 96.6 μSv y-1, and the mean lifetime risk of cancer is 3.85 × 10-4. The chemical content of the bauxite samples was determined in the second part of the study using X-ray fluorescence spectrometry (XRF). For which sectors in the industry the existing bauxite deposits in Turkey can be used was investigated based on this information.

Assessment of naturally occurred radiation hazards in chemical and organic fertilizers used in Chattogram area, Bangladesh

ABSTRACT The present work deals with identifying and determining the activity levels of naturally occurring radionuclides 226Ra and 232Th series, their decay products and 40K in chemical and organic fertilisers used in the Chattogram area, Bangladesh. A total of 39 samples collected from retail markets were investigated, out of which 28 are chemical fertilisers and the others are organic fertilisers. The average activity concentration of 226Ra and 232Th found in TSP fertiliser are 304.57 ± 36.0 and 19.1 ± 6.8 Bq kg−1 respectively and the average activity concentration of 40K in MOP fertiliser is found as 10,311.11 ± 1168 Bq kg−1. In the organic fertiliser samples, the mean concentration of 226Ra, 232Th and 40K are 17.35 ± 3.11, 7.20 ± 1.74 and 437.14 ± 42.58 Bq kg−1, respectively. The mean absorbed dose rates were measured after the end of our experiment, and the value was found to be 91.39 nGy h−1. The combined (indoor + outdoor) annual effective dose equivalent was also estimated as 0.322 mSv year−1. The mean radium equivalent activity found to be 190.15 ± 26.74 Bq kg−1 is well below the recommended level of 370 Bq kg1. The internal hazard index, external hazard index, and radioactivity level index of the investigated fertiliser samples were found as 0.56 ± 0.034, 0.54 ± 0.08 and 0.69 ± 0.10, respectively. From the calculated hazard parameters, the excess lifetime cancer risk (ELCR) was found to be higher than the world average in most of the chemical fertilisers except in DAP and BOR, while the organic fertilisers show lower than the world average. The obtained results reveal that there are no significant radiation hazards due to natural radionuclides of the fertiliser samples in the studied area, but the higher concentration of 40K in MOP suggests strengthening the regulatory work. Overall, this study highly recommends the use of organic fertilisers, as these kinds have hazard parameters lower than the recommended levels.

Assessment of Natural Radioactivity in Cements Used as Building Materials in Poland.

It has been analyzed in this article the radioactivity concentrations of 226Ra, 232Th, 40K and radiological hazard parameters in different types of cements commonly used in Poland and available on the Polish market. The radiological hazard parameters are, in particular, absorbed gamma dose rate, annual effective dose, radium equivalent activity, the external hazard index, and the gamma and alpha indices. The radionuclide activities of the most important radionuclides 226Ra, 232Th, 40K have been determined by gamma-ray spectrometry with the use of two kinds of spectrometers of different operational parameters. One performed also measurements on 30-day and 45-day aged samples as to verify if there is a statistically significant difference in radioactivity concentration for shorter and longer aging time. The radioactivity concentrations in the cement samples ranged from 21.7–75.7 Bq·kg−1 for 226Ra, 12.3–47.3 Bq·kg−1 for 232Th to 123–430 Bq·kg−1 for 40K. The radiological parameters in cement samples were calculated as follows: mean radium equivalent activity Raeq = 127 Bq·kg−1, mean absorbed gamma dose rate D = 115 nGy·h−1, mean annual effective dose E = 570 µSv·y−1, external hazard index Hex = 0.32, internal hazard index Hin = 0.51, mean activity concentration index Iγ = 0.47 and mean alpha index Iα = 0.28. The results were compared with the reported data from other countries and the international standard values given by European Commission (EC) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2000). Finally, thorough statistical analysis has been performed.

Evaluation of environmental radioactivity in soils around a coal burning power plant and a coal mining area in Barapukuria, Bangladesh: Radiological risks assessment

To study the distributions and potential dispersions of naturally occurring radioactive materials (NORMs: 226Ra, 232Th, and 40K) from coal-based activities (Barapukuria, Bangladesh), we studied a suite of systematically collected surface and sub-surface soil samples by X-ray fluorescence and high purity germanium detector based γ-spectroscopy. The average (range) radioactivities of 226Ra, 232Th, and 40K in the studied soil samples were 80.6 (33.0–118.0), 104.4 (43.0–182.0), and 508.1 (318.3–743.4) Bq.kg−1, respectively, which are significantly higher than the corresponding world average value. No significant fractionations of NORMs were observed between the surface and sub-surface soils, except for 232Th. Along with the anthropogenic origin, several geochemical processes (e.g., weathering, mineralogical dissolution/precipitation, alteration, leaching, differential solubility mediated geochemical mobility etc.) play significant role in NORM distributions. Major-oxide abundances, indices-based calculations, and correlation studies on the measured parameters revealed the natural processes (e.g., geochemical mobility, mineralogical distributions, water logging based differential solubility) responsible for NORM distributions. In terms of mean radium equivalent activity, internal hazard index, and total annual effective dose values, the studied area possesses trivial radiological risks, whereas the values of internal absorbed gamma dose and excess lifetime cancer risk demonstrate significant health hazards. Considering the adverse radiological risks originating from coal-based industrial activities and the long half-lives of NORMs, the present scenario will potentially be deteriorated.

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.

Transfer Factors from Soil to Plant of Natural Radionuclides at Abu-Ghraib City, Iraq Using Gamma Ray Spectroscopy

Activity concentrations of natural radionuclides, artificial radio-cesium, and soil-to-plant transfer factor in common different plants species grown at Abu-Ghraib city in the capital Baghdad have been evaluated using NaI(Tl) gamma spectroscopy. Five species of plants have been selected, namely green pepper, cucumber, celery, basil, and mint. The measurements were made on four parts of each plant sample which were included soil, roots, stalk, and leave for knowledge and evaluation the transfer factors. The maximum mean specific activity concentration of U-238 and Th-232 was 9.853±10.904 Bq/kg, 6.005±2.729Bq/kg in celery, while the maximum mean specific activity concentration of K-40 was 141.172±71.703 Bg/kg in cucumber, respectively. The results showed that the uranium, thorium, potassium and cesium concentration not exceeded the permissible limit. The mean Radium equivalent activity was 35.553 Bq\\kg lower than 370 Bq\\kg recommended by UNSCEAR. The maximum absorbed dose rate in root-mint samples was 30.290 nGy/h which is lower than 84 nGy/h, while the mean annual outdoor effective dose equivalent in root samples was 148.597 mSv/y which is lower than 290 mSv/y recommended by UNSCEAR, respectively. The maximum H hazard index was 0.097 in root samples which is less than ≤1 recommended by UNSCEAR. The excess lifetime cancer risk (ECLR) ranged from 5.441×10 −3 to 520.081×10 −3. This value is higher than recommended limit 0.29 ×10 −3 and 1.16 ×10 −3 reported by UNSCEAR. The ELCR is a function of environmental geology and K-40 has very high soil-to-plant transfer factor compared to other radionuclides in the samples. Therefore, there is a risk of their administration. The maximum of radioactivity level index was 0.265 Bq/kg which is less than ≤1.

Investigation of Radiological Hazards in the Soil of Mazandaran Province, Iran

Introduction: This paper aimed to outline the procedure for determining the activity concentrations of naturally occurring radionuclides (i.e., 226Ra, 232Th, and 40K) in surface soil samples collected from Mazandaran province, Iran. Material and Methods: In total, 61 samples were collected between longitude 50˚ 34′ and 54˚ 10′ east and latitude 35˚ 47′ and 36˚ 35′ north from uncultivated locations of Mazandaran province, Iran. The measurements were performed by the gamma spectrometry system using a High Purity Germanium detector. Results: The mean levels of 226Ra, 232Th, and 40K were found to be 20 Bqkg-1 (without considering high-level areas), 33 Bqkg-1, and 421 Bqkg-1, respectively. The results were compared with those of different countries across the world. The radiological hazard to the natural radioactivity was assessed by calculating the absorbed dose rate, the radium equivalent activity, the external and internal hazard indices, and the outdoor and indoor annual effective dose rate. The mean radium equivalent without considering three high-level areas was estimated at 100.8 Bqkg-1. Conclusion: Results indicated that no radiological risk may threat the residents of the areas under study, except for regions near the hot spring in Sadat Shahr and Lavich, Iran. Without considering high-level areas, the mean radium equivalent activity was 100.8 Bqkg-1 that was about 73% lower than the permissible maximum. Moreover, internal and external hazard indices were less than the unit. The mean absorbed dose rate, as well as the outdoor and indoor annual effective dose rates were 48.56 nGyh-1, 238.4 µSv y-1, and 292.6 µSv y-1, respectively.

Spatial distribution of natural and artificial radioactivity concentrations in soil samples and statistical approach, Nevşehir, Turkey

Abstract The concentrations of 226Ra, 232Th, 40K and 137Cs radionuclides in soil samples collected from 323 different regions of Nevşehir province were determined by using a gamma spectrometer with an HPGe detector. The mean gamma activity concentrations (ranges) of 226Ra, 232Th, 40K and 137Cs for districts were determined as 49.45 (7.40–193.90), 54.08 (&lt;2.8–122.50), 698.43 (37.67–1370.20) and 8.26 (0.10–52.60) Bq kg−1, respectively. The mean activity concentrations of 226Ra, 232Th and 40K were higher than the world mean value. According to Kolmogorov–Smirnov test, distributions of 226Ra, 232Th and 137Cs show log-normal distributions. Whereas, 40K shows normal distribution. The mean radium equivalent activity was 181.68 Bq kg−1 which is lower than the recommended maximum value of 370 Bq kg−1. The mean external terrestrial gamma dose rate was found to be 85.12 nGy h−1. The calculated external hazard value was 0.49 and within the acceptable limit which is less than unity (Hex ≤ 1). Thermo Scientific RadEye NBR detector was used to determine environmental gamma dose rates. The gamma dose rates were measured at 445 points at a height of 1 m from land surface. The mean outdoor gamma dose rate (range) was found as 150.13 (50–480) nGy h−1. This mean value was found higher than world mean value. The fact that most of the Nevşehir province is based on volcanic rocks explains why the gamma dose rates are high.

Assessment of gamma radiation levels of beach sands in Bitlis region of Lake Van

Natural gamma radioisotope activity concentration levels in beach sands in the Bitlis region of Lake Van, in eastern Turkey, were determined using an HPGe detector. A total of 15 different beach sand samples were collected from Ahlat, Adilcevaz, and Tatvan shoreline regions, and then 226Ra, 232Th, 40K, and 137Cs radioisotope activity concentrations were measured. Mean values of gamma emissions for each radioisotope were determined as 58.78, 65.89, 1590.25, and 4.84 Bq kg−1 for 226Ra, 232Th, 40K, and 137Cs, respectively. Mean radium equivalent activity, absorbed gamma dose rate, annual effective dose, and external hazard index values were calculated as 275.45 Bq kg−1, 135.41 nGy h−1, 0.17 mSv year−1, and 0.74, respectively.

Radioactivity Assessment of 40K, 238U and 232Th in Surface Soil Samples of Igbokoda, Southwest of Nigeria

Natural radionuclides are found in soil and are capable of disintegrating leading to the release of ionizing radiations that can have harmful effects on individuals exposed to them most especially when exceeding the recommended global limits of radiological parameters. Assessment of activity concentrations of 40 K, 238 U and 232 Th in surface soil samples from different locations at Igbokoda where crude oil exploration was taking place, at Ondo State in Nigeria, had been determined by gamma spectrometry using NaI (TI) detector coupled with a pre-amplifier base connected to a multiple channel analyzer (MCA) which was used to calculate the radiological indicators. 10 samples were collected from the study area putting into consideration the densely populated parts where crude oil exploration and drilling its wells were taking place. The mean activity concentrations of 40 K, 238 U and 232 Th obtained from the soil samples were 494.64 ± 10.46 , 19.76 ± 3.09 and 31.98 ± 5.10 Bq kg –1 , respectively. The mean external hazard index (H ex ) and mean internal hazard index (H in ) for all the soil samples were 0.2836 and 0.3370, respectively, while the mean radium equivalent activity was 104.92 Bq kg –1 . The mean absorbed dose rate value was 49.68 nGy hr –1 with mean annual effective dose equivalent of 0.0610 mSv yr –1 . The mean excess lifetime cancer risk for outdoor exposure was 0.2132 x 10 –3 . The values of the radiological parameters: mean external and internal hazard indices, mean radium equivalent activity, mean absorbed dose rate, mean annual effective dose equivalent and mean excess lifetime cancer risk were within the recommended limits of 1.0 Bq kg –1 , 370 Bq kg –1 , 55.00 nGy hr –1 , 1.0 mSv yr –1 and 1.45 x 10 –3 , respectively. Keywords: Activity concentration, Exposure, Health implication, surface soil

Vertical distribution and radiological risk assessment of 137Cs and natural radionuclides in soil samples

The aims of this study were to investigate the vertical distributions of natural radionuclides 232Th, 226Ra and 40K as well as anthropogenic radionuclide 137Cs in soil samples and to analyze the correlation among the radioactivity of these radionuclides and the physiochemical characteristics of soil samples namely pH, grain size, carbonate content and organic matter. Risk assessment of the radiological hazard has also been estimated. Forty-four soil samples were collected from eleven locations in Qatar at four depth levels from 0 to 16 cm. The average concentrations of 232Th, 226Ra, 40K and 137Cs in the soil depth of 16 cm were 10, 17, 201 and 4 Bq/kg, respectively, which were within the reported world mean. The external absorbed gamma dose rate, the annual effective dose, the mean radium equivalent activity, the external hazard index and the lifetime cancer risk were 22 nGy/h, 0.027 mSv/y, 47 Bq/kg, 0.125 and 0.096 × 10−3, respectively. These values were far below the minimum recommended international values. The level of radioactivity concentrations in the soil was affected by the physiochemical characteristics of the soil. The positive correlation with highest R2 value was found among the radioactivity concentrations of 232Th and 40K and the soil clay content. Total organic carbon was also positively correlated for 226Ra and 137Cs activity concentrations, whereas, carbonate content was negatively correlated with the radioactivity concentrations of 232Th and 40K. As far as soil moisture content is concerned, the positive correlation with highest R2 value was obtained for 226Ra activity concentrations.

Assessment of radiological parameters and metal contents in soil and stone samples from Harrat Al Madinah, Saudi Arabia

The current work deals with measurement and distribution of natural radionuclides for twelve (12) soil and fifteen (15) stone samples collected from Harrats Al Madinah in western region of Saudi Arabia. Two methods were used in this investigation gamma-ray spectrometer (GRS) and X-ray fluorescence (XRF).The activity concentrations of radionuclides (226Ra, 232Th and 40K) were measured using ?-ray spectrometer NaI(Tl) model (A320) made in the U.S.A. The average values of the concentrations of 226Ra, 232Th and 40K were 37.5?±?0.1, 28.0?±?0.5 and 300.6?±?1.7?Bq/kg respectively. The obtained results show that the mean radium equivalent activity, annual effective dose, external and internal hazard indices and radiation level index were 100.67?BqKg-1, 55.63µSv, 0.27, 0.37 and 0.73 respectively. The results were compared with the recommended limits in the literature from other locations and with the global allowable limits recommended by International Commission on Radiological Protection and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The obtained results are concordant with the magnitude of safe criteria and exposure risks which were recommended in public papers. The current study is considered as the first baseline data for the natural radioactivity and metal contents measured by X-ray fluorescence method in the Harrat Al Madinah city.

Environmental Radiation Measurement and Assessment of Natural Radioactivity in Soil, Water and Vegetation

Environmental radioactivity is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium-90 (90Sr) and technetium-99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (40K), are only present due to natural processes, a few isotopes, e.g. tritium (3H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly uranium-238 (238U), can be affected by human activity because of the constant exposure of Human beings to radiation caused by terrestrial, extra-terrestrial and anthropogenic radio nuclides, it is necessary to determine and estimate the activity of various radio nuclides in environmental media such as vegetation, soil, and water. In the present research, the activities of 226Ra, 232Th and 40K are measured in soil, vegetation and water samples, collected from Yangdong District, Yangxi County, and Yangjiang County of Guangdong Province, China using an HPGe based gamma spectrometry system. The measured mean activity of 226Ra, 232Th and 40K in soil samples was found to be 31.19 ± 1.2, 47.00 ± 2.30 and 589.31 ± 17.52 Bqkg-1, respectively. The measured mean activity of these radionuclides in all water samples was found to be below minimum detectable activity. The measured mean activity of 226Ra, 232Th and 40K in vegetation samples was 19.92 ± 3.09, 25.36 ± 8.11 and 4982.94 ± 85.68 Bqkg-1, respectively. No anthropogenic 137Cs was detected in these environmental samples. Mean radium equivalent activity (Raeq), external radiation hazard index (Hex), internal radiation hazard index (Hin) and absorbed dose rate (D) for the area under study were determined as 142.92 Bqkg-1, 0.38, 0.47 and 66.47 nGyh-1, respectively. The annual effective dose equivalent (AEDE) varied in the range from 0.03 to 0.12 mSvy-1. It is concluded that the surveyed area do not pose any significant radiological risk to the population and environment.

Assessment of natural radioactivity in various commercial tiles used for building purposes in Nigeria

In this study, we evaluated the activity concentration of natural radionuclides (226Ra, 232Th and 40K) for fifteen (15) different brands of tile samples used for building purposes in Nigeria. The tile samples were analyzed using High purity Germanium gamma detector. The mean activity concentrations of 226Ra, 232Th, and 40K were observed to be 61.1?±?5.5?Bq/kg, 70.2?±?6.08?Bq/kg and 514.7?±?59.8?Bq/kg respectively. Various hazard indices such as absorbed dose rate, external and internal hazard index, annual effective dose rate, Gamma activity Index (I?) and Alpha Index (Ia) were calculated. The obtained results showed that the mean radium equivalent activity (Raeq), the absorbed dose rate (D), external and internal hazard index, the annual effective dose (AEDR) equivalent, Gamma activity Index (I?) and Alpha Index (Ia) were: 204.42?Bq/kg, 177.61 nGyh-1, 0.55, 0.77, 0.96 mSvyr-1, 0.74 and 0.32 respectively. The average value of radium equivalent obtained in this study is less than that of the recommended value of 370?Bq/kg but the average values of the other radiological hazards for some samples are found to be slightly above international recommended values except Hex, Hin and AEDE which are within the international reference value of unity. The measured concentrations of these radioactive materials were correlated with other previous result obtained from similar tile materials used in other countries and found to be in good agreement with the international standard, however, the tiles are recommended for decoration purposes in Nigeria.

Determination of natural radiation levels and lifetime cancer risk in Kırıkkale, Turkey

Abstract The aim of this study is to determine the levels of background radiation in nine districts of Kırıkkale, Turkey. The outdoor gamma dose rate in the air was measured using a portable digital environmental radiation detector at 170 locations. The mean outdoor gamma dose rate in the air was determined as 121 nGy h−1 with a range between 23 and 320 nGy h−1. The annual effective dose for districts was between 0.04 and 0.59 mSv year−1 with a mean value of 0.23 mSv year−1. Excess lifetime cancer risk values for districts ranged from 0.14×10−3 to 2.07×10−3 with a mean of 0.80×10−3. The activity concentrations of 226Ra, 232Th, 40K and 137Cs in 84 soil samples were determined using HPGe detector. The mean activity values (ranges) of 226Ra, 232Th, 40K and 137Cs in soil samples were found to be 20.4 (4.9±3.0–53.0±0.8) Bq kg−1, 38.8 (3.7±0.2–163.5±1.8) Bq kg−1, 598.0 (108.5±70.2–1500.5±38.7) Bq kg−1 and 3.9 (0.2±0.1–11.9±0.7) Bq kg−1, respectively. The mean activity concentration of 232Th and 40K was higher than the world’s mean value. The mean radium equivalent activity was 119.76 Bq kg−1 which is lower than the recommended maximum value of 370 Bq kg−1. The mean external terrestrial gamma dose rate was found to be 56.71 nGy h−1. This mean value was lower than the world mean of 60 nGy h−1. The calculated external hazard value was 0.32 and within the acceptable limit which is less than unity (Hex≤1). The indoor radon concentration in 150 houses for the summer and winter seasons was determined using solid state nuclear track detector (CR-39). The mean indoor concentration for the summer season was found to be 63.27 Bq m−3 ranging from 14.0±1.5 to 288.0±21.9 Bq m−3. On the other hand, the mean indoor concentration in the winter season was found to be 86.94 Bq m−3 ranging from 17.0±4.5 to 484.0±26.9 Bq m−3. The present results showed that the radon activity concentrations in winter were 42.3% higher than in the summer. The mean annual effective dose equivalent and lifetime cancer risk were also calculated.

Measurement of Gamma Emitting Radionuclides in Environmental Samples of Talagang Tehsil-District Chakwal

Due to constant exposure of Human beings to radiation caused by terrestrial, extra-terrestrial and anthropogenic radio nuclides, it is necessary to determine/estimate the activity of various radio nuclides in environmental media such as vegetation, soil, and water. In the present research, the activities of 226Ra, 232Th and 40K are measured in soil, vegetation and water samples, collected from Talagang Tehsil-District Chakwal of Pakistan using a HPGe based gamma spectrometry system. The measured mean activity of 226Ra, 232Th and 40K in soil samples was found to be 31.19±1.2, 47.00±2.30 and 589.31±17.52 Bqkg-1, respectively. The measured mean activity of these radionuclides in all water samples was found to be below minimum detectable activity. The measured mean activity of 226Ra, 232Th and 40K in vegetation samples was 19.92±3.09, 25.36±8.11 and 4982.94±85.68 Bqkg-1, respectively. No anthropogenic 137Cs was detected in these environmental samples. Mean radium equivalent activity (Raeq), external radiation hazard index (Hex), internal radiation hazard index (Hin) and absorbed dose rate (D) for the area under study were determined as 142.92 Bqkg-1, 0.38, 0.47 and 66.47 nGyh-1, respectively. The annual effective dose equivalent (AEDE) varied in the range from 0.03 to 0.12 mSv y-1. It is concluded that the surveyed area do not pose any significant radiological risk to the population and environment.

Assessment of Beach sand using Gamma Ray Spectrometer in Thiruvanathapuram District, Kerala of South India

&lt;div&gt;&lt;p&gt;&lt;em&gt;It is well recognized fact that some areas of the world have anomalously high levels of natural background radiation referred to as high background radiation areas (HBRAs). Typical examples include Yangjiang in China, Rasmar in Iran and In India, part of coastal areas of Kerala and Tamil Nadu fall in this category. It has been established earlier that the cause for this high background is the presence of monazite (thorium). This study focuses on the estimation of the environmental radioactivity levels in the beach sands of &lt;/em&gt;&lt;em&gt;Thiruvanathapuram district, Kerala. &lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;/p&gt;&lt;/div&gt;&lt;p&gt;&lt;em&gt;Using high resolution gamma ray spectroscopy activity concentrations of &lt;sup&gt;40&lt;/sup&gt;K, &lt;sup&gt;238&lt;/sup&gt;U &amp;amp; &lt;sup&gt;232&lt;/sup&gt;Th were estimated. Activity concentrations ranged from 17-154 Bq/kg for &lt;sup&gt;40&lt;/sup&gt;K, from 4 to 100 Bq/kg for &lt;sup&gt;238&lt;/sup&gt;U and from 6 to 296 Bq/kg for &lt;sup&gt;232&lt;/sup&gt;Th.The mean activity concentration values obtained for the radionuclide are below than the world average values reported by the UNSCEAR. Subsequently assessed radiological effects show that the mean radium equivalent activity is 65 Bq/kg. The range of the calculated air exposure rate was between 14.2 to 228.1 nGy/h in both 0 m from the Waves and 10 m from the Waves. The values of external and internal radiation hazard indices are found to be less than unity. Measured natural radioactivity, hazard indices and effective dose received by the population were found to within the recommended limits. This work provides a good baseline data of natural radioactive elements for the sand of the area and its radiological significance. &lt;/em&gt;&lt;/p&gt;