Abstract: In this investigation, activity concentration of 226Ra, 232Th, and 40K, of some ceramic tile materials used in the local market of Jordan for interior decoration were determined by making use of High Purity Germanium (HPGe) detector. Twenty samples of different country of origin and sizes used in Jordan were analyzed. The concentration values of the last-mentioned radionuclides ranged from 30 Bq.kg-1 (Sample from Jordan) to 98 Bq.kg-1 (Sample from China) for 226Ra, 31 Bq.kg-1 (Sample from Italy) to 98 Bq.kg-1 (Sample from China) for 232Th, and 129 Bq.kg-1 (Sample from Spain) to 679 Bq.kg-1 (Sample from Italy) for 40K. Based on the calculated activity concentrations, some radiological parameters have been calculated to test the radiation hazards in the ceramic tiles. In this work, the following parameters: Total absorbed dose rate (DR), Annual effective dose rate (HR), Radium equivalent activity (Raeq), Radon emanation coefficient F (%) and Radon mass exhalation rate (Em) were calculated for all ceramic tiles and listed in the body of the work. Fortunately, the average calculated values of all parameters are less than the recommended values for each parameter. Consequently, almost all the examined ceramic materials appear to have low radon emanation coefficients. As a result of that investigation, no problems on people can appear by using those ceramic tiles in Jordan.
Abstract: The distributions of naturally occurring and anthropogenic radioactive materials were determined in surface sediments taken at 27 different locations along the bank of Negombo Lagoon in Sri Lanka. Hydrographic parameters of lagoon water and the grain size analyses of the sediment samples were also carried out for this study. The conductivity of the adjacent water was varied from 13.6 mS/cm to 55.4 mS/cm near to the southern end and the northern end of the lagoon, respectively, and equally salinity levels varied from 7.2 psu to 32.1 psu. The average pH in the water was 7.6 and average water temperature was 28.7 °C. The grain size analysis emphasized the mass fractions of the samples as sand (60.9%), fine sand (30.6%) and fine silt+clay (1.3%) in the sampling locations. The surface sediment samples of wet weight, 1 kg each from upper 5-10 cm layer, were oven dried at 105 °C for 24 hours to get a constant weight, homogenized and sieved through a 2 mm sieve (IAEA technical series no. 295). The radioactivity concentrations were determined using gamma spectrometry technique. Ultra Low Background Broad Energy High Purity Ge Detector, BEGe (Model BE5030, Canberra) was used for radioactivity measurement with Canberra Industries' Laboratory Source-less Calibration Software (LabSOCS) mathematical efficiency calibration approach and Geometry composer software. The mean activity concentration was found to be 24 ± 4, 67 ± 9, 181 ± 10, 59 ± 8, 3.5 ± 0.4 and 0.47 ± 0.08 Bq/kg for 238U, 232Th, 40K, 210Pb, 235U and 137Cs respectively. The mean absorbed dose rate in air, radium equivalent activity, external hazard index, annual gonadal dose equivalent and annual effective dose equivalent were 60.8 nGy/h, 137.3 Bq/kg, 0.4, 425.3 mSv/year and 74.6 mSv/year, respectively. The results of this study will provide baseline information on the natural and artificial radioactive isotopes and environmental pollution associated with information on radiological risk.
Abstract: This study aims to determine the natural radioactivity levels in some foodstuffs produced in Turkey. For this purpose, 48 different foods samples were collected from different land parcels throughout the country. All samples were analyzed to designate both gross alpha and gross beta radioactivities and the radionuclides’ concentrations. The gross alpha radioactivities were measured as below 1 Bq kg-1 in most of the samples, some of them being due to the detection limit of the counting system. The gross beta radioactivity levels ranged from 1.8 Bq kg-1 to 453 Bq kg-1, larger levels being observed in leguminous seeds while the highest level being in haricot bean. The concentrations of natural radionuclides in the foodstuffs were investigated by the method of gamma spectroscopy. High levels of 40K were measured in all the samples, the highest activities being again in leguminous seeds. Low concentrations of 238U and 226Ra were found in some of the samples, which are comparable to the reported results in the literature. Based on the activity concentrations obtained in this study, average annual effective dose equivalents for the radionuclides 226Ra, 238U, and 40K were calculated as 77.416 µSv y-1, 0.978 µSv y-1, and 140.55 µSv y-1, respectively.
Abstract: Usually, phosphate deposits contain 238U and 232Th in addition to their decay products. Due to their different pathways in the environment, the 238U/232Th activity concentration ratio usually found to be greater than unity in phosphate sediments. The presence of these radionuclides creates a potential need to control exposure of workers in the mining and processing activities of the phosphate minerals in accordance with IAEA safety standards. The greatest dose to workers comes from exposure to radon, especially 222Rn from the uranium series, and has to be controlled. In this regard, radon (222Rn) was measured in the atmosphere (indoor and outdoor) of Al-Jalamid phosphate-mines working area using a portable radon-measurement instrument RAD7, in a purpose of radiation protection. Radon was measured in 61 sites inside the open phosphate mines, the phosphate upgrading facility (offices and rooms of the workers, and in some open-air sites) and in the dwellings of the workers residence-village that lies at about 3 km from the mines working area. The obtained results indicated that the average indoor radon concentration was about 48.4 Bq/m3. Inside the upgrading facility, the average outdoor concentrations were 10.8 and 9.7 Bq/m3 in the concentrate piles and crushing areas, respectively. It was 12.3 Bq/m3 in the atmosphere of the open mines. These values are comparable with the global average values. Based on the average values, the annual effective dose due to radon inhalation was calculated and risk estimates have been done. The average annual effective dose to workers due to the radon inhalation was estimated by 1.32 mSv. The potential excess risk of lung cancer mortality that could be attributed to radon, when considering the lifetime exposure, was estimated by 53.0x10-4. The results have been discussed in detail.
Abstract: Radon is a radioactive gas emitted from radium, a daughter product of uranium that occurs naturally in rocks and soil. Radon, together with its decay products, emits alpha particles that can damage lung tissue. The activity concentration of 222Ra has been analyzed in water samples collected from borewells and rivers in and around Hassan city, Karnataka State, India. The measurements were performed by Emanometry technique. The concentration of 222Rn in borewell waters varies from 18.49±1.89 to 397.26±12.3 Bql-1 with geometric mean 120.48±12.87 Bql-1 and in river waters it varies from 92.63±9.31 to 93.98±9.51 Bql-1 with geometric mean of 93.16±9.33 Bql-1. In the present study, the radon concentrations are higher in Adarshanagar and Viveka Nagar which are found to be 397.26±12.3 Bql-1 and 325.78±32.56 Bql-1. Most of the analysed samples show a 222Rn concentration more than 100 Bql-1 and this can be attributed to the geology of the area where the ground waters are located, which is predominantly of granitic characteristic. The average inhalation dose and ingestion dose in the borewell water are found to be 0.405 and 0.033 µSvy-1; and in river water it is found to be 0.234 and 0.019 µSvy-1, respectively. The average total effective dose rate in borewell waters and river waters are found to be 0.433 and 0.253 µSvy-1, which does not cause any health risk to the population of Hassan region.
Abstract: Coal is an important non-renewable energy source of
and can be associated with radioactive elements. In Figueira city,
Paraná state, Brazil, it was recorded high uranium activity near the
coal mine that supplies a local thermoelectric power plant. In this
context, the radon activity (Rn-222, produced by the Ra-226 decay in
the U-238 natural series) was evaluated in groundwater, river water
and effluents produced from the acid mine drainage in the coal reject
dumps. The samples were collected in August 2013 and in February
2014 and analyzed at LABIDRO (Laboratory of Isotope and
Hydrochemistry), UNESP, Rio Claro city, Brazil, using an alpha
spectrometer (AlphaGuard) adjusted to evaluate the mean radon
activity concentration in five cycles of 10 minutes. No radon activity
concentration above 100 Bq.L-1, which was a previous critic value
established by the World Health Organization. The average radon
activity concentration in groundwater was higher than in surface
water and in effluent samples, possibly due to the accumulation of
uranium and radium in the aquifer layers that favors the radon
trapping. The lower value in the river waters can indicate dilution and
the intermediate value in the effluents may indicate radon absorption
in the coal particles of the reject dumps. The results also indicate that
the radon activities in the effluents increase with the sample
acidification, possibly due to the higher radium leaching and the
subsequent radon transport to the drainage flow. The water samples
of Laranjinha River and Ribeirão das Pedras stream, which,
respectively, supply Figueira city and receive the mining effluent,
exhibited higher pH values upstream the mine, reflecting the acid
mine drainage discharge. The radionuclides transport indicates the
importance of monitoring their activity concentration in natural
waters due to the risks that the radioactivity can represent to human
health.
Abstract: Tritium activity concentration in Danube river water
in Serbia has been determinate using a liquid scintillation counter
Quantulus 1220. During December 2010, water samples were taken
along the entire course of Danube through Serbia, from Hungarian-
Serbian to Romanian-Serbian border. This investigation is very
important because of the nearness of nuclear reactor Paks in
Hungary. Sample preparation was performed by standard test method
using Optiphase HiSafe 3 scintillation cocktail. We used a rapid
method for the preparation of environmental samples, without
electrolytic enrichment.
Abstract: The gamma radiation in samples of a variety of
natural tiling rocks (granites) produced and imported in Iran use in
the building industry was measured, employing high-resolution
Gamma-ray spectroscopy. The rock samples were pulverized, sealed
in 0.5 liter plastic Marinelli beakers, and measured in the laboratory
with an accumulating time between 50000 and 80000 second each.
From the measured Gamma-ray spectra, activity concentrations were
determined for 232Th (range from 6.5 to 172.2 Bq kg-1), 238U (from
7.5 to 178.1 Bq kg-1 ),226Ra( from 3.8 to 94.2 Bq kg-1 ) 40K (from
556.9 to 1539.2 Bq kg-1). From the 29 samples measured in this
study, “Nehbndan ( Berjand )" appears to present the highest
concentrations for 232Th,“Big Red Flower (China) "for 238U , “
Khoram dareh" for 226 Ra and “ Peranshahr" for 40K , respectively.
Abstract: The amounts of radioactivity in the igneous rocks
have been investigated; samples were collected from the total of eight
basalt rock types in the northeastern of Kurdistan region/Iraq. The
activity concentration of 226Ra (238U) series, 228Ac (232Th) series, 40K
and 137Cs were measured using Planar HPGe and NaI(Tl) detectors.
Along the study area the radium equivalent activities Raeq in Bq/Kg
of samples under investigation were found in the range of 22.16 to
77.31 Bq/Kg with an average value of 44.8 Bq/Kg, this value is much
below the internationally accepted value of 370 Bq/Kg. To estimate
the health effects of this natural radioactive composition, the average
values of absorbed gamma dose rate D (55 nGyh-1), Indoor and
outdoor annual effective dose rates Eied (0.11 mSvy-1) . and Eoed
(0.03 mSvy-1), External hazard index Hex (0.138) and internal hazard
index Hin(0.154), and representative level index Iγr (0.386) have been
calculated and found to be lower than the worldwide average values.