Assessment of Naturally Occurring Radionuclides Accumulation in Palm Oil from Soil

Hyper Pure Germanium (HPGe) radiation detector was used to estimate the activity concentration of fifteen soil and palm oil samples collected from the oil palm plantations in the southwestern, southeastern, and south southern states of Nigeria, and the risk assessments was evaluated. The activity concentrations at a soil depth 0 – 15 cm ranged from 187.4 to 514.4, 2.328 to 6.571, and 1.509 to 6.121 Bq/kg for 40K, 238U, and 232Th, respectively. The activity concentrations at a soil depth 15 – 30 cm ranged from 163.4 to 3188.8, 1.345 to 9.410, and 1.476 to 6.275 Bq/kg for 40K, 238U, and 232Th, respectively. The activity concentrations in the palm oil ranged from 122.3 to 968.0, 1.240 to 6.651, and 1.199 to 8.061 Bq/L for 40K, 238U, and 232Th. For the risk assessments of surface soil samples, the absorbed dose rate (D) ranged from 5.09 to 24.54 nGy/h, while the annual effective dose equivalent (E) ranged from 0.612 × 10-2 to 16.49 × 10-2 mSv/y. The radium equivalent, gamma absorbed dose rate, and the annual effective dose rate in the palm oil samples ranged from 9.981 to 88.00 Bq/L, 4.315 to 46.29 nGy/h, and 0.53 × 10-2 to 56.90 x 10-2 mSv/y, respectively. The activity concentrations reported for soil and palm oil samples were lower than the recommended world average values given by UNSCEAR. Hence, the hazard and risk assessments indicated a low radiation risk within the studied areas.

Investigation of gamma background in parks and recreation areas of the city of Petropavlovsk-Kamchatsky

Работа посвящена исследованию гамма-фона в городской среде Петропавловска-Камчатского (Камчатский край), а именно в парках и зонах отдыха. Измерения мощности поглощенной дозы проводились на разработанном коллективном Томского политехнического университета (ТПУ) дозиметре с использованием органического сцинтиллятора ВС-408, который является схожим по техническим характеристикам с БДКГ-01. С целью вычисления поправочного коэффициента для перевода показаний дозиметра из имп/с в нЗв/ч был проведен ряд калибровочных измерений с точечными источниками гамма-излучения – 60Co и 137Cs. Разработанным дозиметром проводились измерения длительностью не менее 5 минут в различных районах города Петропавловска-Камчатского, особое внимание уделялось исследованию объектов техносферы из материалов, являющимися природными источниками повышенного гамма-излучения. Исследования показали, что памятник В. И. Ленину и стела «Город воинской славы» в центре города Петропавловска-Камчатского содержат граниты у их основания, которые дают завышенный гамма-фон The work is devoted to the study of the gamma background in the urban environment of Petropavlovsk-Kamchatsky (Kamchatka Territory), namely in parks and recreation areas. Measurements of the absorbed dose rate were carried out on a scintillation organic dosimeter developed by the team of the Tomsk Polytechnic University (TPU), which is a more budgetary analogue of the BDKG-01. In order to calculate the correction factor for converting the dosimeter readings from impulses/s to nSv/h, a number of calibration measurements were carried out with point sources of gamma radiation – 60Co and 137 Cs. The developed dosimeter carried out measurements with a duration of at least 5 minutes in various districts of the city of Petropavlovsk-Kamchatsky, special attention was paid to the study of technosphere objects made of materials that are natural sources of increased gamma radiation. Studies have shown that the monument to V. I. Lenin and the stele « City of Military Glory » in the center of the city of Petropavlovsk-Kamchatsky contain granites at their base, which give an overestimated gamma background.

ASSESSMENT OF RADIATION DOSE RATE LEVELS AND RADIATION RISK AT THE COBALT -60 UNIT, KOMFO ANOKYE RADIOTHERAPY CENTER, GHANA.

Purpose: A study was conducted to estimate the Annual Effective Dose Equivalent (AEDE) and Excess Lifetime Cancer Risk (ELCR) caused by the presence of an artificial cobalt-60 radioactive source producing ionizing radiation levels within the radiotherapy facility at Komfo Anokye Teaching Hospital (KATH) in Ghana. This study validated the safety of cobalt-60 radioactive sources, as well as the notion of calculating the Annual Effective Dose Equivalent (AEDE) and Excess Lifetime Cancer Risk (ELCR), which contributed to reducing occupational and public exposures inside the facility. Methodology: The investigation was carried out with the use of a portable OD-01 Ionization Chamber Survey Meter. The absorbed dose rate (ADR) in air was changed between 5 m and 40 m, with measurements taken inside and around the cobalt 60 bunker, as well as at sixteen other sites within the radiation facility. Findings: From 5 m to 40 m surrounding the Cobalt-60 source, the estimated Absorbed Dose Rate in air inside the cobalt-60 bunker ranged from 0.299 0.001 to 0.977 0.005 Sv/h, with an average of 0.498 0.005 Sv/h. The estimated Annual effective dose equivalent varied from 1.100 mSv/yr to 3.595 mSv/yr around the cobalt-60 source inside the Co-60 bunker. Radiation exposure levels ranged from 0.268 0.008 Sv/h to 0.678 0.005 Sv/h, with an average of 0.440 0.004 Sv/h observed around the fifteen sites chosen. Excess Lifetime Cancer has values ranging from 3.85 10-3 to 12.58 10-3 and 3.45 10-3 to 8.73 10-3. Risks were evaluated for the cobalt and the sixteen places inside the plant. The absorbed dose values at 5 m, 10 m, and 15 m inside the Co-60 bunker and the location Co-60 bunker as part of the facility exceeded the ICRP-recommended limit of 0.57. The AEDE and ELCR levels were within the ICRP's acceptable limits. The AEDE and ELCR statistics acquired indicate that the Cobalt-60 unit and its surroundings are radiation safe, although the likelihood of employees contracting cancer from the absorbed dose and background ionizing radiation is significant over a lifetime. Recommendation: However, it is recommended that absorbed dose level monitoring and evaluation of the Radiation Therapy Technologist (RTT) and other workers surrounding the unit be monitored on a regular basis. It is also recommended that Occupational Staff, such as RTTs, spend as little time as possible in the bunker

Radiological Hazard Evaluation of Some Egyptian Magmatic Rocks Used as Ornamental Stone: Petrography and Natural Radioactivity

Magmatic rocks represent one of the most significant rocks due to their abundance, durability and appearance; they can be used as ornamental stones in the construction of dwellings. The current study is concerned with the detailed petrography and natural radioactivity of seven magmatic rocks. All are commercial granitic rocks and are identified as black Aswan, Nero Aswan, white Halayeb, Karnak, Verdi, red Hurghada and red Aswan. Their respective mineralogical compositions are classified as porpheritic granodiorite, granodiorite, tonalite, monzogranite, syenogranite, monzogranite and syenogranite. A total of nineteen samples were prepared from these seven rock types in order to assess their suitability as ornamental stones. Concentrations of 226Ra, 232Th and 40K radionuclides were measured using NaI (Tl) scintillation gamma-ray spectrometry. Among the studied magmatic rocks, white Halayeb had the lowest average values of 226Ra (15.7 Bq/kg), 232Th (4.71 Bq/kg) and 40K (~292 Bq/kg), all below the UNSCEAR reported average world values or recommended reference limits. In contrast, the other granitic rocks have higher values than the recommended limit. Except for the absorbed dose rate, other radiological hazard parameters including radium equivalent activity, annual effective dose equivalent, external, and internal hazard indices reflect that the White Halyeb rocks are favorable for use as ornamental stone in the construction of luxurious and high-demand residential buildings.

INITIAL EVALUATIONS OF NATURAL (226Ra, 232Th AND 40K) AND ARTIFICIAL (137Cs) RADIO ISOTOPE ACTIVITIES IN ARZULAR-YITIRMEZ-DÖLEK (GÜMÜSHANE) MINERALIZATION/ALTERATION FIELDS

Within the scope of this study, the first evaluations of natural (226Ra, 232Th and 40K) and artificial (137Cs) radio isotope activities of the Arzular-Yitirmez-Dölek (Gümüşhane) mine/alteration site were carried out. Measurements were carried out with Poptop Ortec gamma rays detector on 22 soil samples collected from the field. When the natural 232Th, 226Ra and 40K activities of the area are compared with the weighted world averages, it has been determined that the 40K and 226Ra activities exceed the world averages in most of the sampling points, and the 232Th activities are below the weighted world average except for a few sampling points. It was observed that the artificial 137Cs activities in the field were above the detection limit and exceeded 2 Bq/kg except for a few sampling points. It has been evaluated that the high 137Cs activities in the field may be associated with a human-induced effect, especially the accident at the Chernobyl nuclear power plant. Parameters such as radiological hazard indices, Ra equivalent activity value, absorbed dose rate and annual effective dose rate were also calculated for the field. Considering the results obtained from these parameters, it was concluded that it would be beneficial to study the Arzular-Yitirmez-Dölek mineralization/alteration field in more detail in terms of natural and artificial radioisotope activities.

INITIAL EVALUATIONS OF NATURAL ( 226Ra, 232Th and 40K) AND ARTIFICIAL ( 137Cs) RADIOACTIVITY OF ESKIKÖY MINERALIZATION AREA (GÜMÜŞHANE, TÜRKIYE)

Within the scope of this study, the natural (226Ra, 232Th and 40K) and artificial (137Cs) radioactivity concentrations of the Eskiköy Mine area within the borders of Gümüşhane, which is located in an important metallogenic belt of Turkey, were investigated. In order to determine the natural and artificial radioactivity of the field soils developed due to mineralization, hydrothermal alteration and weathering, 12 soil samples were taken and activity concentrations of 232Th, 226Ra, 40K and 137Cs radio isotopes were measured with a gamma detector. It was observed that the 40K natural radio isotope activities of the area mostly exceeded the weighted world average, and the 232Th, and 226Ra natural radio isotope activities exceeded the weighted world averages at 5 of the 12 sampling points. It was determined that the artificial 137Cs activity concentrations in the area were above the detection limit at 9 sampling points and above 3 Bq/kg at 8 sampling points. It has been evaluated that the high 137Cs activities detected in the Eskiköy mine area are due to the Chernobyl nuclear power plant accident and similar anthropogenic effects. The mine area was also evaluated in terms of radiation risk in the context of medical geology, with parameters of radiological hazard indices, radium conjugate activity value, absorbed dose rate and annual effective dose rate, and remarkable findings were obtained. When all these findings of the study area are evaluated together, it has been concluded that the Eskiköy mining area should be studied in more detail in terms of natural and artificial radioisotope activity concentrations and their effects on human health.

Radioactivity, Metals Pollution and Mineralogy Assessment of a Beach Stretch from the Ionian Coast of Calabria (Southern Italy)

In the present article, a case study is reported regarding an investigation carried out in order to assess radioactivity concentration, heavy metals pollution and mineralogy of a beach stretch extending from Soverato to Squillace municipalities of the Ionian coast of Calabria, South of Italy, a popular tourist destination, especially in summer. The analysis of radionuclides contents was performed by using a High Purity Germanium (HPGe) gamma-ray detector, in order to quantify the average specific activity of 226Ra, 232Th and 40K natural radionuclides and 137Cs anthropogenic radioisotope. The absorbed dose rate and the annual effective dose equivalent radiological hazard indices were also estimated. Furthermore, X-ray Fluorescence (XRF) spectrometry measurements were carried out for the quantitative elemental analysis of the sand, in order to investigate any possible chemical pollution by heavy metals. For this aim, different indices such as Enrichment Factor (EF), Geoaccumulation Index (Igeo), Contamination Factor (CF) and Pollution Load Index (PLI) were applied to estimate the level of toxicity imposed on the ecosystem by the detected heavy metals. Finally, in order to identify the crystalline mineral components of the investigated sand samples, X-ray Diffraction (XRD) and Micro-Raman Scattering (MRS) measurements were carried out.

Optimizing the Schedule of PARP Inhibitors in Combination with 177Lu-DOTATATE: A Dosimetry Rationale

177Lu-DOTATATE for neuroendocrine tumours is considered a low-toxicity treatment and may therefore be combined with other pharmaceuticals to potentiate its efficacy. One approach is to add a poly-[ADP-ribose]-polymerase (PARP) inhibitor to decrease the ability of tumour cells to repair 177Lu-induced DNA damage. To decrease the risk of side effects, the sequencing should be optimized according to the tumour-to-normal tissue enhanced dose ratio (TNED). The aim of this study was to investigate how to enhance 177Lu-DOTATATE by optimal timing of the addition of a PARP inhibitor. Biokinetic modelling was performed based on the absorbed dose to the bone marrow, kidneys and tumour; determined from SPECT/CT and planar images from 17 patients treated with 177Lu-DOTATATE. To investigate the theoretical enhanced biological effect of a PARP inhibitor during 177Lu-DOTATATE treatment, the concept of relative biological effectiveness (RBE) was used, and PARP inhibitor administration was simulated over different time intervals. The absorbed dose rate for the tumour tissue demonstrated an initial increase phase until 12 h after infusion followed by a slow decrease. In contrast, the bone marrow showed a rapid initial dose rate decrease. Twenty-eight days after infusion of 177Lu-DOTATATE, the full absorbed dose to the bone marrow and kidney was reached. Using an RBE value of 2 for both the tumour and normal tissues, the TNED was increased compared to 177Lu-DOTATATE alone. According to the modelling, the PARP inhibitor should be introduced approximately 24 h after the start of 177Lu-DOTATATE treatment and be continued for up to four weeks to optimize the TNED. Based on these results, a phase I trial assessing the combination of olaparib and 177Lu-DOTATATE in somatostatin receptor-positive tumours was launched in 2020 (NCT04375267).

ASSESSMENT OF TC-99M MDP ABSORBED DOSE AND RESIDENCE TIME AFTER BONE SCAN EXAMINATION: PERSONAL DOSIMETER MEASUREMENTS AND SEMI-EMPIRICAL FORMULA FOR 210 PATIENTS IN TAIWAN

Subject: This study assessed the absorbed dose for patients who underwent Tc-99m Methylene Diphosphonates (MDP) bone scan examination based on a series of personal dosimeter measurements and a derived semi-empirical formula. Material and methods: 210 volunteers among the patients, who were administrated 925 MBq Tc-99m MDP for the bone scan examination in the Department of Nuclear Medicine in the Dalin Tuzchi Hospital, Taiwan, underwent personal dosimeter measurements at 30, 120, and 180[Formula: see text]min after the injection. A personal dosimeter was held at a 30[Formula: see text]cm distance from the patient’s stomach. The acquired data were analyzed to derive the residence time of Tc-99m radionuclide in the patient’s body. Five biological parameters (gender, age, BMI, eGFR, and creatinine) of these 210 patients were collected and processed by the STATISTICA program, yielding a nonlinear 16-term first-order semi-empirical formula for the radionuclide residence time prediction. The respective four- and three-factor calculations, excluding creatinine and eGFR, provided poor correlation. Results and Conclusion: According to the phantom concept, treating a patient’s body as a homogenous spherical ball, a simplified formula was used to assess the absorbed dose rate and magnitude. Therefore, the derived residence time, dose rate, and absorbed dose were [Formula: see text][Formula: see text]min, [Formula: see text]Sv/min, and [Formula: see text]Sv, respectively. These results were lower than those obtained in previous studies, which can be attributed to accelerated radionuclide excretion of patients who drank 2000 cc of water after the procedure, yielding shorter residence times.