The quantity and quality of DNA damage is deter- mined by the radiation type and dose . For instance, high and low linear-energy-transfer (LET) radiations in- duce different spectra and qualities/complexity of DNA lesions, due to the differences in radiation track struc- tures . This also impacts on the dose per cell deliv- ered by individual tracks at low doses which will be radiation quality dependent. Specifically, as shown in Fig. 1, from the point of view of radiation micro- dosimetry, for low-dose exposure, such as from environ- mental radiation, or low-dose rates of radiation, the en- ergy deposition of radiation is localized along its track, resulting in a non-uniform distribution of exposed or unexposed cells in irradiated tissue [13, 14]. Thus, for environmentalradiation, there are possible interactions between the irradiated and the non-irradiated cells and the dynamics of these cells in the tissue involved in radiation-induced biological responses at the whole- tissue level . In fact, it is well known that cells that
ESA programs related to bacterial experiments in space: research program MESSAGE (Microbial Experiments in the Space Station About Gene Expression) studied the ef- fect of space conditions on micro-organisms in general us- ing some well-known bacteria. During another experiment, MESSAGE 2, the samples and detectors stayed in space for ten days, of which eight were in the service module of the ISS. This dosimetry experiment was a collaboration between different institutes (School of Cosmic Physics, Institute for Advanced Studies, Dublin, Ireland, Johnson Space Centre Houston, USA, Department of Radiation Dosimetry, National Physics Institute, Czech Republic De- partment of Physics, Oklahoma State University, Still- water, USA and SCK-CEN, Mol, Belgium), so that the doses could be estimated by different techniques. For the high LET doses (>10 keV/μm), two types of track etch detectors were flown. The low LET part of the spectrum was measured by three types of thermoluminescent de- tectors ( 7 LiF:Mg,Ti; 7 LiF:Mg,Cu,P; Al
Radiation of natural origin at the earth’s surface consists of two components, namely cosmic rays and radiation of the radioactive nuclides in the earth’s crust, the latter component, the terrestrial radiation, originates mainly from the so-called primordial radioactive nuclides originated in the early stage of the formation of the solar system. Uranium, thorium and potassium are the main elements contributing to natural terrestrial radioactivity. Uranium has two pri- mary isotopes 238 U (T = 4.47 × 109 y) and 235 U (T = 7.07 × 108 y) which, at
Fungi are used as biomonitors of forest ecosystems, having comparatively high uptakes of anthropogenic and naturally occurring radionuclides. However, whilst they are known to accumulate radionuclides they are not typically considered in radiological assessment tools for environmental (non-human biota) assessment. In this paper the total dose rate to fungi is estimated using the ERICA Tool, assuming different fruiting body geometries, a single ellipsoid and more complex geometries considering the different components of the fruit body and their differing radionuclide contents based upon measurement data. Anthropogenic and naturally occurring radionuclide concentrations from the Mediterranean ecosystem (Spain) were used in this assessment. The total estimated weighted dose rate was in the range 0.31 - 3.4 µGy/h (5 th – 95 th
Radiation is present in every environment of the Earth’s surface, beneath the Earth and in the atmosphere. Ac- cording to UNSCEAR (1993), about 87% of the radiation dose received by mankind is due to natural radiation sources and the remaining is due to anthropogenic radia- tion . It is observed that most of natural radioactive elements present in soil are primordial radionuclides from the uranium series, thorium series, and 40 K . The man and the animal kingdom however make adjustment to the natural radiation sources. But the advent of artifi- cial or man-made radiation sources, when man succeeded in fissioning of the uranium atomic nucleus, their wide- spread application and accidental uncontrolled release of radioactivity in the environment have altered the balance. Nuclear weapons test release radioactive fissions prod- ucts into the atmosphere and its depositions over the earth’s surface are termed “fallout”. The distribution of this fallout in the environment takes place in various
Table 4 summarizes the calculated typical mean values and concentrations variation intervals of the studied parameters in the environmental samples collected in the 2014–2017 period. These data were compared with the data sets collected for water, soil and plants (pine needles, grass, pear, and apple leaves) collected over the IRT site during the previous periods of observation starting from 1961 and the reactor’s commissioning, during its operation, and after shut- down of the IRT reactor in July 1988.
A major reason for introducing the IRR 1999 regulations was to give effect to the lower dose limits for radiation workers and members of the public recommended in ICRP Publication 60. 19 Annual dose limits for non-classified workers were reduced from 15 mSv to 6 mSv for staff and from 5 mSv to 1 mSv for members of the public. As emphasised above, scatter dose from bone densitometry equipment is mostly very low, and the majority of operators should receive doses well below the new limits. However, these changes emphasise the need for care in the operation of some types of fan-beam DXA systems to ensure that operator dose is well below the new Controlled Area limit (Figure 2). For equipment giving higher doses it will be necessary to define the scanning table and the immediate surrounding area as a Controlled Area. Advice should be sought from the hospital Radiation Protection Adviser, who if necessary can help with performing radiation measurements and advise on drawing up appropriate Local Rules and appointing a Radiation Protection Supervisor.
A routine test is essentially the same in content as the acceptance test above, but with a different emphasis. The intention is to establish that the equipment continues to operate optimally with respect to staff and patient safety as determined at the acceptance test. Hence, it will only be necessary to confirm that there have been no significant changes to the equipment’s location and its function. Comparison should be made to the baseline data established during the acceptance test. It will be necessary to recognize and further examine any trends that indicate possible deterioration. Recommendations should be made to rectify any identified deficiencies. These should be followed up and the outcomes recorded within the QA Programme. Routine tests should cover all mechanical and electrical systems whose malfunction could result in inadvertent radiation exposure. A record of
Like Kuhn’s generation, trainees in radiation oncology (RO) are facing unrelenting societal and technological change. Thus far, the COVID-19 pandemic has caused an unimaginable death toll within the United States, one that has been inextricable from racial injustice in this country. It has caused the disproportionate deaths of Black, Latinx, and
In the 1960s, the public were suspicious and unduly worried about the x-ray exposure from their colour television. In the 1980s, electromagnetic fields from computer terminals have been erroneously linked as the main cause of miscarriages, birth defects and other health problems. Again, these claims have been overturned. In the 1990s, with the internet revolution, experts have begun to raise their concerns over the internet addiction among its users. Currently it is cell phones and radiation from towers.
of g radiation in a Gammacell 40 (Atomic Energy of Canada, Ltd., Ottawa) and 24 h later were inoculated intraperitoneally with virus. Mice were inspected twice weekly and necropsied when moribund or at 6 to 12 months of age. Tumors and tissues were fixed in Bouins’ solution and embedded in paraffin, and sections were stained with Harris’ hematoxylin and eosin as previously described (5, 13). All gross tumors other than those of bone were confirmed by microscopic examination.
passed to subsurface aquifers, soils, and the atmosphere. Natural environmental radioactivity due to gamma radiation depends on the geological and geographical conditions, and found in various quantities in soils around the world (UNSCEAR, 2000). One of the main determinants of the natural background radiation is the soil radionuclide activity concentration; disintegrated rocks through natural process allow radionuclides to escape to soil by rain and flows. In addition to the natural sources; soil radioactivity is also affected by anthropogenic activities. There are radioactive isotopes in our environments, air, water and ground (Eisenbud and Gesell, 1997; Henriksen and Maillie, 2003) measurement is only reliable source to accurately reflect people’s true exposure. Over-emphasizing the effect caused by radon decays with a series of solid, short-lived radioisotopes that are collectively referred to as radon daughters or radon progeny. Isotopes of such can emit alpha particles of high energy and high mass particles consisting of two protons and two neutrons. When these emissions take place within the lung as inhaled radon progeny decay the genetic material of the cells lining the airways may be damaged and lung cancer may result. (NRC, 1980) Naturally occurring radioactive materials are found in both groundwater and surface water. At high levels, when ionizing radiation strikes a living organism’s cells, it may mutate the organism’s cell. If radiation affects a significant number of cells, the organism may eventually develop cancer among other liable diseases.
The control room and walls A through F receive little measurable radiation. The doors labeled A-F can expect at most about 7 mR/week. Other radiographs are expected to add very little to this area. Because this area is a hallway, any person in the area would be expected to receive 1/16 th of this, or about 0.5 mR/week.
The indoor radiation level measurement of Teaching Sohag Hospital in Egypt was obtained with a hand held dosimeter: RadEye B20 from Thermo Scientific. The selected locations for the study were: MRI, CT, X-ray, US and linear accelerator departments, Cardio thoracic, surgery, General Surgery, Orthopedic, Pediatric, ENT, Obstetrics and Gynecology, Neuropsychiatry, Internal Medicine, Urology, Ophthalmology, oncology departments and In a different place in hospital. Handheld Nuclear Radiation Monitor dosimeter develops safety in laboratories and in the hospital through rapid analysis and determination of radiation levels. The handheld monitor measures alpha, beta, gamma and x-radiation. Its safety-first calibration feature can reduce exposure for personnel. The readings were measured directly (within a minute), exposure rate was taken in μSv/hr and taken four times with each and an average taken and recorded. The indoor ambient dose rate from the survey meter was converted to the indoor annual effective dose rate in for each of the location using this relation by FaraiI : IAEDR (mSv/yr) = (x) μSv/hr x 8760 hr/yr x 0.8 x 0.001 (1)
(Figure 2) with a working volume of about 20 L (RS2400, Rad Source Technologies Inc, Alpharetta, Georgia, USA; http://www.radsource.com). These self-shielded irradia- tors require no special provisions for radiation security. Isotopic irradiators have the advantage that they have a long half-life and that their dose rate is high, but the prob- lems associated with transportation and disposal of radi- oactive materials are becoming increasingly difficult. A self-shielded unit, where the insect container is sur- rounded by several pencils, has the disadvantage that the container size is limited placing important restrictions on the throughput in SIT programmes. Furthermore, dose uniformity is poor, forcing the utilized volume to be fur- ther restricted. Panoramic irradiators are therefore more suitable as several containers can be placed around a radi- ation source in a large irradiation room. The containers are then rotated around their axis to achieve adequate dose uniformity  but dose rates tend to be lower than in self-contained irradiators.