The Effect Of Shielding Materials On The Intensity And Propagation Of Ionizing Radiation

The average annual radiation dose received by Americans is 360 millirems (or "mrems"), about 300 of which come from naturally occurring sources like radon. By contrast, you would get only 0.01 mrems per year as a result of living 50 feet from a nuclear power plant. Even a single annual cross-country airplane flight exposes you to 3 mrems, while a medical X-ray gives you a dose of 20 mrems.

Beginning with the accident at Three Mile Island in 1979, a widespread belief has proliferated that all levels of ionizing radiation are dangerous. Since 1980, radiation hormesis studies have shown there is actually a threshold of danger with high level exposures, but below that threshold low dose radiation is essentially safe and quite possibly beneficial to life. Yet, this relatively new, seemingly contradictory understanding of radiation's health effects has gone essentially unknown to the general public. In order to grasp the reasons why, we must again return to the bombing of Hiroshima and Nagasaki.

When you combine the use of proper collimation and lead shielding in any x-ray procedure you will drastically reduce the amount of exposure received by the patient. Melissa Culp, James Barba, and Melissa Jackowski state in their article titled Shield Placement: Effect on Exposure that "the current study is significant for radiologic technologists because it reinforces the finding that collimation does not eliminate exposure outside the field of view entirely. Shielding should be used in conjunction with collimation to reduce exposure as much as possible. "4 The use of shielding outside of the collimation light will confine the ionizing radiation to the part under analysis and keep the neighboring body parts from being exposed. Sadly, this step is easily forgotten by hurried radiologic technologists which means that this topic should be stressed at a greater extent in the workplace and throughout the radiologic technologist's

The new United States Coast Guard Radiological Isotope Identification Device (RIID) is being promulgated with the next six months. Currently CG-721, DOL-44, nor the Maritime Law Enforcement Academy (MLEA) have discussed implementation processes for the RADSEEKER. This type of oversight could result in Radiation Detection Level II personnel the inability to determine the legitimacy of a radiological source. This poses a risk to national security and the safety of Coast Guard personnel. As MLEA’s Radiation Course Managers there needs to be an effective formulated plan of creating training material, integrating training material to academy staff, and procedures for members in the fleet to become proficient.

Areas that are typically shielded include reproductive organs, breast tissue, and the thyroid area. The most common type of shielding is gonadal shielding. Gonadal shielding is a unisex shield and is used on a patient that is within child bearing years or younger. The reproductive organs should be used if they are going to be within 5 cm of the primary beam during the exam. Other types of shielding are flat contact, rolling, flat contact gonadal shielding, breast shielding, and scoliosis shielding. Shadow shielding is a cast over the patient’s reproductive organs to block out the primary beam. Three of the basic principles of radiation protection are time, distance, and shielding. As the length of time a tech is exposed increases the dose of exposure increases as well. A tech should be behind a lead wall, dressed in a lead apron, and thyroid collar in case a patient needs assistance. Another way to reduce exposure time is to avoid holding the patient during exams. The most effective way to reduce exposure is distance. When performing an x-ray exam a tech should be at least six feet from the source of radiation. When time and distance techniques are not able to be used shielding should be used. Gloves, thyroid collars, and protective aprons are made up of impregnated vinyl. The recommended is a 0.5 mm lead equivalent for protective

Radiation from nuclear bombs releases radiation that is very harmful and has many weird effects to people and the environment. Radiation is defined as the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization. Beside shock, blast, and heat a nuclear bomb generates this high intensity radiation. This radiation has basically two different kinds, electromagnetic and particulate, and is emitted not only at the time of the detonation, which is called initial radiation, but also for long periods of time afterward called residual radiation. This means bombs are extremely dangerous and should not be taken lightly.

In the medical field, basic patient care is something that should be practiced every day. In hospitals and clinics around the United States, one will find groups of people who have undergone years of training and are there to hopefully provide the best patient care they can. Yet every day thousands of practitioners seem to have forgotten the basics of not only protecting patients but themselves as well. More specifically, in the field of radiology, it seems that one of the basics of patient and technologist protections, shielding, has become second place, and used in a manner that deviates from its intended purpose. After witnessing many misuses and even no use

Anything less may result in regret should a low-yield nuclear attack occur. With rules established to control of nuclear materials, like enriched uranium, it would appear on the surface all is safe. However, smuggling and theft of enriched uranium exist. According to Sokova, Potter, and Chuen (2007), trafficking of enriched uranium in Georgia has occurred multiple times. It is probable more smuggling and theft has occurred unknowingly. Sensors exist and work when knowing where the uranium is located but shielding the material is another possibility. According to (Richardt, Hülseweh, Sabath, and Niemeyer, 2013, Chapter 9), all radiation types can be shielded. Alpha is shielded by paper, Beta is shield by plastic, Gamma-Xrays are shielded by lead, and Neutron is shielded by concrete (Fig. 9.2). In (The ABC News Nuclear Smuggling Experiment, 2003), 15 pounds of depleted uranium metal were smuggled into the Unites States (para. 1). Although it was only depleted uranium, natural or weapon grade uranium can be

If a nuclear fallout were to occur, the earth would turn into a radiated wasteland. The earth would be essentially non-liveable, but it could be possible to survive. People, with the help of fallout shelters and bunkers, would be able to survive the initial attack and quite possibly live in the shelters until the radiation has dropped to a level in which they can survive.

Walker et al. (2005) performed this study to determine the differences in producing the maximum dose buildup while using Play-Doh, water soaked gauze, and Superflab. The researchers wanted to determine if Play-Doh and water soaked gauze were adequate alternatives to Superflab. At the beginning they accurately measured the radiation doses to be less than 10.0 cGy. Next, they made each bolus material 5 mm thick and then placed TLDs at the center of the beam where they placed each bolus and irradiated them 5 times each. Then, they calculated the mean dose, standard

The authors measured the effects of air gaps under 10mm bolus to determine how inhomogeneity may affect skin dose. They used an ionization chamber and radiochromic film to measure dose under air gaps at 2mm, 4mm, and 10mm in size, using a 6MV photon. They also examined the effect of different angles of incidence. Their results showed that air gaps under 10mm do not reduce maximum dose below 90%, but that larger air gaps may reduce dose under certain conditions. They also found that dose is lowered more by more oblique angles of incidence. They concluded that small air gaps will not significantly affect the treatment

Before any type of shielding needs to be discussed, the fact of timing needs to be brought up. The Sun periodically creates solar flares that produce very large pockets of energy. These solar flares can be predicted pretty well, and if they are known (approximately) when they are going to happen, a mission can be dictated when would be the best time to go. If you go when there is the best possible radiation environment in solar system, then you reduce the requirements and strain on the devices that are blocking the radiation. Also something to consider is the Forbush decrease. When the Sun produces a coronal mass ejection, it sends out a huge wave of particles into the solar

One of the reasons could be the amount of time it took for an injury to occur after exposure. However, more and more frequent cases describing skin irritation associated with a bad sunburn started to occur. One scientist by the name of Elihu Thoms decided to expose his little finger under radiation 30 minutes a day, for several days. The results were pain, swelling, erythema and blistering. This convinced him, and others the dangers of radiation, and by 1900 the majority of the medical and the scientific community, were familiar of the dangers of over exposure. The decrease of exposure time and incidence was the most evident ways to limit the amount of radiation, or dose, to a patient. They were even experimenting with enclosed tubes and distances to protect themselves from the exposure. Filtration to the x ray beam was actually encouraged before the 1900’s and so was the size of the beam. Some other methods used to minimize patient exposure was using intensifying screens and higher x-ray generating voltages. Even though ex-ray protection was well known by 1905, it would still take many years for it to be universal. Even as late as the 1940’s it was not uncommon to find x-ray units without any safety measures at all. There are three distinctive periods of radiation protection. The evolution of x-ray protection is split into three

Exposure to ionizing radiation induces oxidative damage that leads to alteration of tissue physiological function as observed in the present study. This was evidenced by significant elevation in kidney MDA content. These results match the increase in lipid peroxidation post irradiation obtained by Srinivasan et al. (2007) and Pratheeshkumar and kuttan (2011). Free radicals generated by irradiation react with unsaturated lipids generating hydroperoxides, which in turn can induce changes in lipid bilayer thereby altering the membrane permeability and inducing lipid peroxidation (Suzuki et al. 1997). Also, significant elevation of kidney GSH contents were observed in irradiated rats. This increase in GSH level may be due to transcriptional

There are three factors that control and minimise the amount, or dose, of radiation received from a source; time, distance and shielding. The combination of these factors