Thank you for reading environmental radioactivity from natural industrial and military sources. As you may know, people have look hundreds times for their chosen novels like this environmental radioactivity from natural industrial and military sources, but end up in malicious downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they are facing with some malicious bugs inside their laptop.

Environmental Radioactivity From Natural Industrial And Military Sources

The development of protective agents against harmful radiations has been a subject of investigation for decades. However, effective (ideal) radioprotectors and radiomitigators remain an unsolved problem. Because ionizing radiation-induced cellular damage is primarily attributed to free radicals, radical scavengers are promising as potential radioprotectors. Early development of such agents focused on thiol synthetic compounds, e.g., amifostine (2-(3-aminopropylamino) ethylsulfanylphosphonic acid), approved as a radioprotector by the Food and Drug Administration (FDA, USA) but for limited clinical indications and not for nonclinical uses. To date, no new chemical entity has been approved by the FDA as a radiation countermeasure for acute radiation syndrome (ARS). All FDA-approved radiation countermeasures (filgrastim, a recombinant DNA form of the naturally occurring granulocyte colony-stimulating factor, G-CSF; pegfilgrastim, a PEGylated form of the recombinant human G-CSF; sargramostim, a recombinant granulocyte macrophage colony-stimulating factor, GM-CSF) are classified as radiomitigators. No radioprotector that can be administered prior to exposure has been approved for ARS. This differentiates radioprotectors (reduce direct damage caused by radiation) and radiomitigators (minimize toxicity even after radiation has been delivered). Molecules under development with the aim of reaching clinical practice and other nonclinical applications are discussed. Assays to evaluate the biological effects of ionizing radiations are also analyzed.

https://www.mdpi.com/2227-9059/8/11/461/pdf

Radioprotection and Radiomitigation: From the Bench to Clinical Practice.

Studying of the effects of low doses of γ-irradiation is a crucial issue in different areas of interest, from environmental safety and industrial monitoring to aerospace and medicine. The goal of this work is to identify changes of lifespan and expression stress-sensitive genes in Drosophila melanogaster, exposed to low doses of γ-irradiation (5 – 40 cGy) on the imaginal stage of development. Although some changes in life extensity in males were identified (the effect of hormesis after the exposure to 5, 10 and 40 cGy) as well as in females (the effect of hormesis after the exposure to 5 and 40 cGy), they were not caused by the organism “physiological” changes. This means that the observed changes in life expectancy are not related to the changes of organism physiological functions after the exposure to low doses of ionizing radiation. The identified changes in gene expression are not dose-dependent, there is not any proportionality between dose and its impact on expression. These results reflect nonlinear effects of low dose radiation and sex-specific radio-resistance of the postmitotic cell state of Drosophila melanogaster imago.

/pdf/effect-of-low-doses-5-40-cgy-of-gamma-irradiation-on-52sfngp490.pdf

Effect of Low Doses (5-40 cGy) of Gamma-irradiation on Lifespan and Stress-related Genes Expression Profile in Drosophila melanogaster

nuclear cardiology and cardiac computed tomography imaging: a report from the European Association of Cardiovascular Imaging (EACVI), the Cardiovascular Committee of European Association of Nuclear Medicine (EANM), and the European Society of Cardiovascular Radiology (ESCR) Alessia Gimelli*, Stephan Achenbach, Ronny R. Buechel, Thor Edvardsen, Marco Francone, Oliver Gaemperli, Marcus Hacker, Fabien Hyafil, Philipp A. Kaufmann, Patrizio Lancellotti, Koen Nieman, Gianluca Pontone, Francesca Pugliese, Hein J. Verberne, Matthias Gutberlet, Jeroen J. Bax, and Danilo Neglia

/pdf/strategies-for-radiation-dose-reduction-in-nuclear-5bfqw6kgg8.pdf

Strategies for radiation dose reduction in nuclear cardiology and cardiac computed tomography imaging: a report from the European Association of Cardiovascular Imaging (EACVI), the Cardiovascular Committee of European Association of Nuclear Medicine (EANM), and the European Society of Cardiovascular Radiology (ESCR).

Activation of T cells, a major fraction of peripheral blood lymphocytes (PBLCS), is essential for the immune response. Genotoxic stress resulting from ionizing radiation (IR) and chemical agents, including anticancer drugs, has serious impact on T cells and, therefore, on the immune status. Here we compared the sensitivity of non-stimulated (non-proliferating) vs. CD3/CD28-stimulated (proliferating) PBLC to IR. PBLCs were highly sensitive to IR and, surprisingly, stimulation to proliferation resulted in resistance to IR. Radioprotection following CD3/CD28 activation was observed in different T-cell subsets, whereas stimulated CD34+ progenitor cells did not become resistant to IR. Following stimulation, PBLCs showed no significant differences in the repair of IR-induced DNA damage compared with unstimulated cells. Interestingly, ATM is expressed at high level in resting PBLCs and CD3/CD28 stimulation leads to transcriptional downregulation and reduced ATM phosphorylation following IR, indicating ATM to be key regulator of the high radiosensitivity of resting PBLCs. In line with this, pharmacological inhibition of ATM caused radioresistance of unstimulated, but not stimulated, PBLCs. Radioprotection was also achieved by inhibition of MRE11 and CHK1/CHK2, supporting the notion that downregulation of the MRN-ATM-CHK pathway following CD3/CD28 activation results in radioprotection of proliferating PBLCs. Interestingly, the crosslinking anticancer drug mafosfamide induced, like IR, more death in unstimulated than in stimulated PBLCs. In contrast, the bacterial toxin CDT, damaging DNA through inherent DNase activity, and the DNA methylating anticancer drug temozolomide induced more death in CD3/CD28-stimulated than in unstimulated PBLCs. Thus, the sensitivity of stimulated vs. non-stimulated lymphocytes to genotoxins strongly depends on the kind of DNA damage induced. This is the first study in which the killing response of non-proliferating vs. proliferating T cells was comparatively determined. The data provide insights on how immunotherapeutic strategies resting on T-cell activation can be impacted by differential cytotoxic effects resulting from radiation and chemotherapy.

/pdf/sensitivity-of-cd3-cd28-stimulated-versus-non-stimulated-17tspxvydi.pdf

Sensitivity of CD3/CD28-stimulated versus non-stimulated lymphocytes to ionizing radiation and genotoxic anticancer drugs: key role of ATM in the differential radiation response.

The world is naturally radioactive and approximately 82% of human-absorbed radiation doses, which are out of control, arise from natural sources such as cosmic, terrestrial, and exposure from inhalation or intake radiation sources. In recent years, several international studies have been carried out, which have reported different values regarding the effect of background radiation on human health. Gamma radiation emitted from natural sources (background radiation) is largely due to primordial radionuclides, mainly 232Th and 238U series, and their decay products, as well as 40K, which exist at trace levels in the earth's crust. Their concentrations in soil, sands, and rocks depend on the local geology of each region in the world. Naturally occurring radioactive materials generally contain terrestrial-origin radionuclides, left over since the creation of the earth. In addition, the existence of some springs and quarries increases the dose rate of background radiation in some regions that are known as high level background radiation regions. The type of building materials used in houses can also affect the dose rate of background radiations. The present review article was carried out to consider all of the natural radiations, including cosmic, terrestrial, and food radiation.

A review on natural background radiation

Background: The exposure of human being to ionize radiation from natural sources is a continuing, inescapable feature of life on earth. Direct measurement of absorbed dose rates in air has been carried out in many countries of the world during the last few decades. Such investigations can be useful for assessment of public dose rates, the performance of epidemiological studies, and keeping reference-data records to ascertain possible changes in the environmental radioactivity duo to nuclear, industrial, and other human activities. Materials and Methods: The measurements of the outdoor and indoor- environmental exposures including cosmic and terrestrial components were accomplished by a portable Geiger Muller detector (RDS -110). The measurements were made during daylight from September to October 2009, in five areas within nine big cities of Lorestan province. In each area, one building was randomly selected for indoor and outdoor measurements. Measurements were made for each region and an average value was used to calculate the exposure rate from gamma background radiation. Results: The results showed the Maximum and minimum outdoor dose rates as 166±44 and 65±8 nSvh-1 in Borujerd and Pol-e- dokhtar, respectively. The average of outdoor dose rates was determined 113±26 nSvh-1. Also the maximum and minimum values of indoor dose were 157±52 and 74±14 nSvh-1 in Borujerd and Pol-e-dokhtar, respectively. The average indoor dose rates were determined as 119±27 nSvh-1. Conclusion: The average annual effective dose for gamma background radiation in Lorestan province has been 0.72 mSv, with the range of 0.3– 0.6 mSv which was more than the global value (0.48 mSv). A poor correlation coefficient between was observed altitude and absorbed dose rates. Iran. J. Radiat. Res., 2011; 9(2): 89­93

Gamma background radiation measurement in Lorestan province, Iran

Introduction In radiography, dose and image quality are dependent on radiographic parameters. The problem is caused from incorrect use of radiography equipment and from the radiation exposure to patients much more than required. Therefore, the aim of this study was to implement a quality-control program to detect changes in exposure parameters, which may affect diagnosis or patient radiation dose. Materials and Methods This cross-sectional study was performed on seven stationary X-ray units in sixhospitals of Lorestan province. The measurements were performed, using a factory-calibrated Barracuda dosimeter (model: SE-43137). Results According to the results, the highest output was obtained in A Hospital (M1 device), ranging from 107×10-3 to 147×10-3 mGy/mAs. The evaluation of tube voltage accuracy showed a deviation from the standard value, which ranged between 0.81% (M1 device) and 17.94% (M2 device) at A Hospital. The deviation ranges at other hospitals were as follows: 0.30-27.52% in B Hospital (the highest in this study), 8.11-20.34% in C Hospital, 1.68-2.58% in D Hospital, 0.90-2.42% in E Hospital and 0.10-1.63% in F Hospital. The evaluation of exposure time accuracy showed that E, C, D and A (M2 device) hospitals complied with the requirements (allowing a deviation of ±5%), whereas A (M1 device), F and B hospitals exceeded the permitted limit. Conclusion The results of this study showed that old X-ray equipments with poor or no maintenance are probably the main sources of reducing radiographic image quality and increasing patient radiation dose.

http://ijmp.mums.ac.ir/article_4770_f629c152d1c834f377e79bec6678f774.pdf

The Evaluation of Conventional X-ray Exposure Parameters Including Tube Voltage and Exposure Time in Private and Governmental Hospitals of Lorestan Province, Iran

Background: Gonad shielding is one of the fundamental methods by which to protect reproductive organs in patients undergoing conventional radiological examinations. A lack of or inadequate shielding of the gonads may increase the exposure of these organs and result in malignancies future generations.

Objectives: The aim of this study is to investigate the prevalence of gonad shielding in patients undergoing conventional radiological examinations and the availability of gonad shields and gonad shielding protocols in radiology departments.

Materials and Methods: A retrospective, observational cross-sectional study on the application of gonad shielding, the availability of gonad shields and the existence of gonad shielding protocols in radiology departments was performed in five different hospitals in Ahvaz, Iran.

Results: The highest application of gonad shielding was 6.6% for the pediatric hospital. The prevalence of gonad shielding was less than 0.2%. In 64.3% of the radiography rooms, at least one flat-contact gonad shield of a large size was available. Only large-sized gonad shields were available. Curved-contact and shadow gonad shields did not exist. Gonad shielding protocols were not existence in any of the fourteen radiography rooms investigated.

Conclusions: Comprehensive protection programs with on-the-job training courses for staff members are strongly recommended, as well as, the provision of radiological shields and gonad shielding protocols in radiology departments to reduce the patient’s radiation dose during radiological examinations.

Gonad shielding for patients undergoing conventional radiological examinations: is there cause for concern?

Background
It is remain a main concern that pediatric chest radiographies contribute to the significant radiation
exposure to the thyroid gland as a more susceptible organ to radiation induced cancer. The aim of this
study was to assessment the entrance surface dose (ESD) of pediatric chest radiography compared to
the diagnostic reference levels (DRL) and evaluation the efficacy of the lead (Pb) shield in radiation
dose reduction to the thyroid gland.
Materials and Methods
After assessing each patient against specific inclusion-exclusion criteria, 40 pediatric patients who
were undergoing anterior-posterior (AP) projection of the chest x-ray were considered eligible for this
study. The ESD of the chest and also ESD of thyroid gland with and without a 1 mm butterfly-shaped
lead shield which placed on the thyroid gland were measured using high sensitive thermo luminescent
dosimeters (TLD-GR 200).
Results
The average of ESD for chest radiography was 0.068+ 0.04 mGy (0.021 - 0.232 mGy). The
unshielded average thyroid ESD was 0.065+0.053 mGy compared to the shielded average thyroid
ESD of 0.001 + 0.034 mGy. The use of Pb-shield produced a statistically significant decrease in the
average thyroid dose by about 97% (P< 0.001).
Conclusion
It seems that the Pb-thyroid shield has potential to reduced radiation dose significantly without
compromising image quality. The use of thyroid shield in the AP projection of pediatric chest
radiography may be an effective method to reduce patient's radiation risk and its usage should be
encouraged.
Key Words: chest x-ray, pediatrics, radiation exposure, thyroid gland

http://ijp.mums.ac.ir/article_7081_b6dbe47be642f9b0b516650c9a73ec92.pdf

Mehrdad Gholami

Papers

A review on natural background radiation

Gamma background radiation measurement in Lorestan province, Iran

The Evaluation of Conventional X-ray Exposure Parameters Including Tube Voltage and Exposure Time in Private and Governmental Hospitals of Lorestan Province, Iran

Gonad shielding for patients undergoing conventional radiological examinations: is there cause for concern?

Dose Reduction to the Thyroid Gland in Pediatric Chest Radiography