California Radiation Control Regulations: Responsibility of the Supervisor and Operator
Robert J. Parelli in Principles of Fluoroscopic Image Intensification and Television Systems, 2020
Shielding is one of the most important principles for radiation protection. Shielding refers to the different means used to stop radiation or to prevent exposure to it. To be able to apply shielding methods, one must have some understanding of the manner in which x-radiation is attenuated (absorbed) in an absorbing medium. Energy is lost three ways:A photoelectric effect, which is a collision between a photon of x-radiation and an orbital electron of an atom where the electron is knocked out of its orbit and the photon looses all its energy.Compton scatter, which is an interaction of a photon of x-radiation with an orbital electron of the absorber atom, producing a recoil electron and a photon energy which is less than that of the incident photon.Pair production, which is an incident in which a photon is annihilated in the vicinity of the nucleus of the absorbing atom with subsequent production of an electron and a positron.
Radiochemical Processing of Activated Targets
Frank Helus, Lelio G. Colombetti in Radionuclides Production, 2019
The unusually strong foundations upon which many radiochemical production facilities are constructed is ample testimony to the amount of lead and other shielding materials which are used for radiation protection. The amount of shielding required depends upon the type and energy of emitted radiation. Simple “shadow shields” are often adequate for shielding physically small sources which are contained in a given location. Shielding of a processing system, in which activity moves from place to place often requires more careful consideration. In this case, the use of specially constructed “hot cells” or lead lined fume hoods can be used to advantage to totally enclose the entire system. Indirect observation through the use of mirrors or TV monitors can be used if progress through a scheme must be determined by visual inspection.
Introduction to medical imaging
David A Lisle in Imaging for Students, 2012
The basic rule of radiation protection is that all justifiable radiation exposure is kept as low as is reasonably achievable (ALARA principle). This can be achieved by keeping in mind the following points: Each radiation exposure is justified on a case-by-case basis.The minimum number of radiographs is taken and minimum fluoroscopic screening time used.Mobile equipment is only used when the patient is unable to come to the radiology department.US or MRI should be used where possible.Children are more sensitive to radiation than adults and are at greater risk of developing radiation-induced cancers many decades after the initial exposure.In paediatric radiology, extra measures may be taken to minimize radiation dose including gonad shields and adjustment of CT scanning parameters.
Experimental studies on the biological effects of chronic low dose-rate radiation exposure in mice: overview of the studies at the Institute for Environmental Sciences
Published in International Journal of Radiation Biology, 2018
Ignacia Braga-Tanaka, Satoshi Tanaka, Atsushi Kohda, Daisaku Takai, Shingo Nakamura, Tetsuya Ono, Kimio Tanaka, Jun-ichiro Komura
The biological significance of altered gene expressions in a several organs from mice exposed to radiation, particularly at low doses and low dose-rates, remain uncertain due to substantial knowledge gaps of protein response to radiation exposure in terms of dose, time from exposure, organ and tissue differences as well as inter-individual variability (Marchetti et al. 2006). Nakajima et al. (2017) showed that altered proteins after chronic low-dose radiation exposures largely mediate apoptosis signaling, whereas acute radiation exposure mediates proteins involved in defense pathways and inflammatory reactions. Understanding the effects of chronic radiation exposure on signaling pathways would contribute toward radiation protection, reducing risk, evaluation of radiation damage and treatment of the effects of radiation exposure. With regards to DNA damage, so far, no comparisons have been made between the biological effects associated with the repair of spontaneous damage versus damage due to ionizing radiation has been done (BEIR VII).
Small is beautiful: low activity alpha and gamma sources for small-scale radiation protection research experiments
Published in International Journal of Radiation Biology, 2021
Magdalena Płódowska, Milagrosa Lopez-Riego, Pamela Akuwudike, Daniel Sobota, Mateusz Filipek, Mariusz Kłosowski, Urszula Kaźmierczak, Beata Brzozowska, Agnieszka Baliga, Halina Lisowska, Janusz Braziewicz, Paweł Olko, Lovisa Lundholm, Andrzej Wojcik
Since the 1990s, the focus of radiation protection research has been directed toward biological effects of low doses and low doses rates in an attempt to better understand the health risks associated with chronic exposure to low doses (Cho et al. 2019; Wojcik and Harms-Ringdahl 2019). Given the fact that cellular effects induced by low dose exposures are likely to be modest, it was argued that large, systems biology approaches are necessary to unravel the mechanisms and health effects of low dose exposures. The first large funding programme for low dose research was initiated by the United States Department of Energy (DOE) in 1998 and lasted for 10 years (Brooks 2018). In 2009, a High Level Expert Group (HLEG), consisting of experts from several European Union countries, supported by EURATOM, published a report on European low dose risk research (HLEG 2009). The aim of the report was to summarize the state of science and challenges in low dose research and to propose a European research strategy (Belli et al. 2015). The basic line of thinking was that uncertainties and confounding factors that are associated with epidemiological studies on low dose effects can only be overcome by large concerted research actions. Large projects require access to large radiation sources where many cells can be irradiated in a high throughput set up.
Evaluating the physical, psychosocial and ergonomic burden of lead aprons among Jordanian interventionists: a nationwide study
Published in International Journal of Occupational Safety and Ergonomics, 2022
Hanna Al-Makhamreh, Farah Al-bitar, Aseel Saadeh, Abdallah Al-Ani, Muayad Azzam, Dana Alkhulaifat, Asim Khanfar, Yousef Toubah, Lujain Aburaddad, Kamal Hassan, Hashim Al-Ani
Although lead aprons are of vital importance in radiation shielding, the present literature indicates that they are frequently associated with higher rates of injury. In fact, higher apron-related total caseloads are strongly associated with orthopedic disease [2,8,17]. Moore et al. [9] demonstrated that frequent apron users and long-term apron users report more back pain and severe limiting back pain in comparison with less frequent users. Multiple reports support the aforementioned statement, as prolonged apron usage is associated with increased forefoot load in the elderly, increased thoracic kyphosis in the young and contributes to indiscriminate body aches [5,18]. It has been demonstrated through infrared thermography that apron strain affects axial posture and results in accelerated muscle fatigue, which could affect performance and introduce vital operative errors [19]. In addition to increased frequency of apron use and duration of procedures, MSK injuries are frequently associated with the female gender, older age, poor ergonomic practices and lack of physical fitness throughout the literature [7,12,17,20,21]. On the other hand, interventionists and surgeons have been shown to report significantly less back pain on days devoid of apron usage [18]. The variable specifications of aprons in terms of age, size and shape, in addition to their improper usage, could contribute to an increased likelihood of MSK injuries.
Related Knowledge Centers
- Dosimeter
- Dosimetry
- Ionizing Radiation
- Irradiation
- Sievert
- Radioactive Contamination
- Gray
- Acute Radiation Syndrome
- Radiation-Induced Cancer
- Alarp