Assessment of natural radiation in contaminated automobile workshop soils.

The presented study aims to identify and quantify the natural radionuclides activity concentrations on the top and sub-soils around mechanic workshops in Ojo and Ijegun, Lagos, Nigeria. Based on these measured radionuclides activity concentrations, radiological hazard indices are assessed. Twenty oil-contaminated soil samples were collected, and the levels of natural radionuclides activity are measured by applying gamma spectrometry The measured radionuclides with authoritative regularity are linked with the natural decay series of 238U (226Ra) and 232Th as well as the series of non-decay 40K. The obtained results show that the mean radionuclides activity concentrations in the collected oil-contaminated soils samples are 14 ± 4 Bq kg-1, 105 ± 55 Bq kg-1, and 90 ± 33 Bq kg-1, for 226Ra, 232Th, and 40K respectively. It was founded that the 226Ra radionuclide is the lower present in the oil-contaminated soils samples. The radiological assessments were evaluated in terms internal hazard index (0.54), and external hazard index (0.55) both of which are below the UNSCEAR-2000 standard limit. Consequently, the radiological assessment indicated that long-time exposure to those radionuclide's strength confuses integral hazards.

An extended assessment of natural radioactivity in the sediments of the mid-region of the Egyptian Red Sea coast.

In this study, nearly 84 marine sediment samples were collected from twelve points in four cities (Quseir, Safaga, Hurghada, and Ras Gharib) along the Egyptian Red Sea sectors. The collected samples were extensively examined to estimate the natural radioactivity level. The obtained results were compared to the reported ranges from other locations in different countries. Hazardous radiation parameters such as radium equivalent, annual dose, and external hazards were estimated and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended levels. The values were recorded in the first natural radioactivity database of coastal sediments from Egyptian Red Sea cities. The dose rate for certain organs was evaluated. The results showed that Red Sea beach sediments are safe in terms of natural radioactivity. It can be concluded that they do not pose a risk to tourists going to the beaches for recreation or to sailors and fishers involved in economic activities along the Egyptian Red Sea coast.

Assessment of absorbed dose for Zr-89, Sm-153 and Lu-177 medical radioisotopes: IDAC-Dose2.1 and OLINDA experience.

OBJECTIVE: In this article, IDAC-Dose2.1 and OLINDA computer codes are compared as they are the most widely used software tools for internal dosimetry assessment at the present time. OLINDA/EXM personal computer code was created as a replacement for the widely used MIRDOSE3.1 code. IDAC-Dose2.1 was developed based on the ICRP specific absorbed fractions and computational framework of internal dose assessment given for reference adults in ICRP Publication 133. IDAC uses cumulated activities per administered activity in hours and calculates the absorbed dose and the effective dose. The program calculates the dose in the Eckerman stylized family phantoms. It is useful in standardizing and automating internal dose calculations, assessing doses in clinical trials with radiopharmaceuticals, making theoretic calculations for existing pharmaceuticals, teaching, and other purposes. METHODS: To produce such a comparison, the results of this work were compared with available published data in the literature on radiopharmaceuticals. Radiopharmaceuticals with 89Zr, 153Sm, 177Lu radionuclides are used as the basis for the comparison. 89Zr, 153Sm, 177Lu radionuclides are regarded as the future of radiopharmaceutical treatment. For 89Zr, two different labelled carriers, Zr-89_cMAb U36 and Zr-89 Panitumumab, were used on patients. RESULTS: The results show a clear difference in terms of absorbed dose of the Zr-89 radiopharmaceuticals for red bone marrow when calculated by IDAC-Dose2.1 (0.76 mGy/MBq), while the estimated absorbed dose in literature results is 0.07 mGy/MBq and 0.14 mGy/MBq when the calculation is done by OLINDA program. In the case of 177Lu-EDTMP, the absorbed dose in red bone marrow is in reasonable agreement (0.63 mGy/MBq and 0.8 mGy/MBq for IDAC-Dose2.1 and OLINDA, respectively). A significant difference was found for the absorbed dose in the bone surface, which was almost twice as high for OLINDA (2.1 mGy/MBq for IDAC-Dose2.1 and 5.4 mGy/MBq for OLINDA). In some direct cases, the calculated absorbed dose in the urinary bladder wall with OLINDA is ten times higher compared to WinAct (which was utilized to calculate the total activity in the organs and tissues) and IDAC 2.1. These results are considered key to greater accuracy in internal dose calculation.

Estimation of radon excess lung cancer near some dumpsites in, Lagos, Nigeria.

Generally, in Nigeria dumpsites are open and elevate the pollution by increasing the total environment contamination level. This affects not only the site of dumpsites but also the surrounding buildings and area. In the present work, indoor radon activity concentration is tested inside some buildings in the vicinity of dumpsites in Lagos, Nigeria. A passive technique with CR-39 detectors is used. Different buildings around different eight dumpsites were chosen. Radon concentration had ranged from 16.00 ± 3 to 931.00 ± 186 Bqm-3 in the dumpsites. With Mean concentrations range from 120 ± 24 at OKE-ODO to 334 ± 67, at Solus-4 respectively. The present results explain that 63% of the radon activity concentration in indoor air around the selected dumpsites at Lagos city in Nigeria is below the allowed limit from ICRP 200 Bq m-3 while 37% is more than this limit. Based on the measured radon concentration, the annual effective dose and cancer risk are evaluated. The range of ELC is from 242 to 14086 with mean value 3114 ± 1111.

The plant transfer factor of natural radionuclides and the soil radiation hazard of some crops.

In the present study, the transfer factors of the natural radionuclides 238U, 232Th, and 40K were estimated for several crops cultivated in farms in the suburbs of Baghdad and one farm in Al-Najaf. The transfer factor (TF) is the ratio of activity transfers from soil to plant. The specific activities of the natural radionuclides were measured with a gamma-ray spectrometer with a HPGe detector. The crops include cereals (rice and wheat), fruits (lemons and oranges), podded vegetables (vigna and okra), fruity vegetables (chili peppers and Solanum melongena), and leafy vegetables (Apium graveolens, Raphanus sativus, and Ocimum basilicum). The results showed that the highest transfer factors for 238U, 232Th, and 40K are 0.32, 0.70, and 3.44, respectively, in wheat. The average transfer factors for 238U and 232Th were founded 0.23 and 0.2 which are lower than the default unitiy value but the 1.85 were reported for 40K higher than unity.

Natural radiological characterization at the Gabal El Seila region (Egypt).

Stream sediment is a useful raw material used for building construction, mostly used in the desert parts of the world. Such sediment is a Naturally Occurring Radioactive Material (NORM), and, hence, it requires a radiological characterization to be used. This work aims to study the natural radioactivity in fifty points distributed in surface of stream sediments in the area of Gabal El Seila region, south-eastern desert of Egypt, since there is a lack of information about the radioactivity levels of the sediment samples from such recent growing interest area. The activity concentration of 238U, 232Th and 4 K natural radionuclides using a portable RS-230 γ-ray spectrometer were determined. Mean values are 38.51 ± 10.83, 33.35 ± 8.82, 659.18 ± 110.87 Bq/kg for 238U, 232Th, 4 K respectively. Radiological hazard indexes were computed and compared with the UNSCEAR and other worldwide ranges. All the results are statistically presented and discussed. They show that no significant radiation hazard coming from the studied area, with the most values lower than international recommended limits. The achievements of the present study fall within the measurements of natural environmental radiation in an unexplored area of great interest being a desert. The obtained results can be used as database for future research, and as tool for radiological awareness in the use of sediments as raw material.

Comparative studies on the potential use of 177Lu-based radiopharmaceuticals for the palliative therapy of bone metastases.

Purpose: In recent years, radionuclides like 177Lu have been considered promising material for the creation of therapeutic radiopharmaceuticals. With the therapeutic use of radiopharmaceuticals, the absorbed doses per tumor may exceed 10 Gy. It is extremely important that doses absorbed by healthy organs and tissues do not exceed the threshold for the incidence of deterministic effects.Materials and methods: The potential use of the radionuclide lutetium-177 for the palliative treatment of pain in bone metastases is analyzed. The radionuclide 177Lu is a beta-emitting nuclide with a maximal energy of 0.49 MeV and a half-life of 6.6 days (161 h). Two therapeutic agents were considered: methylene diphosphonate (MDP) and ethylenediamine tetramethylene phosphonic acid (EDTMP). Both drugs contain phosphorus compounds in their composition, which ensures high tropism in bone tissue. For both drugs, biokinetic models of 177Lu's behavior in the human body are created. A number of studies have shown that the radiochemical stability of these drugs is about 99%: these calculations took into account the presence of a free 177Lu radionuclide in each solution. The absorbed doses in organs and tissues when using the radiopharmaceuticals 177Lu-MDP and 177Lu-EDTMP, as well as the currently used drugs 153Sm-EDTMP and 89SrCl2, are compared. In order to assess the risk of the patient's exposure to a radiopharmaceutical, the absorbed doses are calculated for each organ where the radioactive label is mainly deposited: the kidneys, red bone marrow, liver and bone surface.Results: The intensity of dose accumulation when using different drugs on the pathological focus is different. The drug 177Lu-MDP is faster than other drugs when it comes to the full realization of the expected dose; therefore, a therapeutic effect is achieved faster when it is used. The slowest absorbed dose accumulates when strontium chloride is used. To compare the effectiveness of preparations based on the 177Lu radionuclide, an analysis of the radiopharmaceuticals currently used for the palliative therapy of bone metastases (89SrCl2 and 153Sm-EDTMP) was performed. For 89Sr, the most vulnerable organs are the kidneys, red bone marrow and liver, while for 153Sm-EDTMP, red marrow bone is most vulnerable. For radiopharmaceuticals based on the 177Lu radionuclide, the most vulnerable organs are the kidneys, liver and red bone marrow. This proves the effectiveness of the 177Lu-MDP and 177Lu-EDTMP radiopharmaceuticals.Conclusions: According to the results of the calculations, 177Lu-EDTMP and 177Lu-MDP demonstrate the best results for the palliative therapy of bone metastases.

Comparative study on application of177Lu-labeled rituximab, tetulomab, cetuximab and huA33 monoclonal antibodies to targeted radionuclide therapy.

PurposeDose coefficients from rituximab, tetulomab, cetuximab, and huA33 monoclonal antibodies labelled with the radionuclide177Lu were estimated for human organs and tumours via a theoretical simulation based on experimental results.MethodsThe real experimental results were obtained from radiopharmaceutical distribution in hairless mice. Using the Sparks and Aydogan method, the cumulated activity for humans was recalculated. The simulation was used to assess the behaviour of MAbs labelled with177Lu after injection into the human body. The average absorbed doses were calculated for the most exposed organs and tissues.ResultsThe huA33 monoclonal antibodies (MAbs) labelled with 177Lu (Lu-rituximab, Lu-tetulomab, Lu-cetuximab, and Lu-huA33), presented the maximum nuclear transformation per Bq intake for the main organs (blood, kidneys, liver, lung, and spleen, as well as for a tumour) The absorbed dose in the liver is three times lower for Lu-huA33 compared to the other drugs. In the case of cetuximab, the spleen received the lowest dose compared to the other drugs. The dependencies on absorbed dose for the alveolar, bronchioles, bone surface, heart wall, kidneys, liver, lung, lymphatic nodes, and spleen, are presented. For tumours, the absorbed dose for each drug is calculated separately for a sphere of unit volume by using the information on the injected dose.Conclusion, The ratios of the dose coefficient for the tumour to each organ, indicate that lutetium-177 can be recommended for targeted radionuclide therapy since the dose per tumour is much greater than the dose per organ.

Heavy metal contamination in urban surface sediments: sources, distribution, contamination control, and remediation.

Urban road sediments act as large basins for heavy metal contaminants produced as a result of natural processes and anthropogenic activities. This study is aimed at reviewing research over recent decades on heavy metal contamination in different cities around the world. The study reviews literature from Google Scholar, Web of Science, and Scopus journal publications. Cr, Cu, Pb, Zn, Ni, and Cd levels vary from one city to another. Based on the collected results, the pollution level and geoaccumulation index are estimated in each city. The levels of pollution in these cities range from low to extremely high, depending on the sources of pollution at each site (geogenic and anthropogenic sources, etc.) and factors like the distribution of industrial activities, population, and traffic emissions. This review shows that the development of modern cities and rapid urbanization are the major causes of heavy metal contamination in the environment. The contamination of the urban environment has different sources, both natural and anthropogenic in character. Solving the problem of heavy metal contamination in the urban environment requires the use of different techniques such as urban road control treatment and soil remediation.

Assessment of exposure after injection of 99mTc-labeled intact monoclonal antibodies and their fragments into humans.

Human pharmacokinetics and internal radiation dosimetry of normal organs after injection with the 99mTc-labeled monoclonal antibody (intact and fragments) are simulated by the WinAct program and IDAC (Internal Dose Assessment by Computer) software. The WinAct program is used to calculate the cumulative activity in organs and tissues. The calculated cumulative activity is inputted to the IDAC software, an internal dosimetry program for nuclear medicine based on the International Commission on Radiological Protection (ICRP) adult reference voxel phantom, and the absorbed doses by the organs and tissues are estimated. The obtained absorbed doses for the 99mTc-labeled monoclonal antibody (intact and fragments) are compared with the published figures by ICRP-128. The WinAct program method to calculate the cumulative activity is more accurate, as the fraction distribution, Fs, is described and calculated for organs, not only for intake, as in the ICRP model, but also for elimination.