Occupational Radiation Protection
Occupational exposure is the radiation exposure incurred at work, i.e., planned exposure of workers at nuclear power plants and fuel cycle facilities, as well as of workers who use radiation sources, accelerators, and X-ray machines in medicine, scientifi
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Occupational Radiation Protection
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Occupationally Exposed Individuals
Occupational exposure is the radiation exposure incurred at work, i.e., planned exposure of workers at nuclear power plants and fuel cycle facilities, as well as of workers who use radiation sources, accelerators, and X-ray machines in medicine, scientific research, education, agriculture, and industry, etc. Occupational exposure also includes radon in workplaces other than mines [1], and certain occupations involving the handling of naturally occurring radioactive materials (NORM) or technologically enhanced naturally occurring radioactive materials (TENORM). At oil and gas drilling sites, for example, workers can inhale radon gas and be exposed to the alpha and gamma radiation from the decay of naturally occurred radium. Naturally occurred radionuclides can also concentrate in the mineral scales that form in pipes, storage tanks, or other extraction equipment [2]. TENORM can also be found in some building materials where coal ashes are used, in mining wastes from uranium mining, in fertilizers and fertilizer production, in scrap metals, etc. [3]. Some soils may contain residual radioactive materials from past military uses or accidents as well. In most cases, exposure to NORM and TENORM can be reduced just following safety guidance. In the United States, EPA is responsible for setting federal radiation standards for exposure to NORM and TENORM [4]. Each state has one or more programs to address both materials. In aviation, aircrew, who repeatedly fly for years, are also considered occupationally exposed to ionizing radiation from natural sources––galactic cosmic radiation. Pilots are exposed to greater doses than cabin crew, as the passenger cabin provides more shielding than the cockpit. The average individual dose is around 3 mSv/y; however, there is considerable variation in the amount of cosmic radiation which can affect flight crews. The main variables are the flight duration and altitude,
© Springer International Publishing Switzerland 2017 H. Domenech, Radiation Safety, DOI 10.1007/978-3-319-42671-6_12
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Occupational Radiation Protection
geographic latitude, and the solar cycle. Galactic cosmic radiation levels over the Polar Regions are about twice those over the geomagnetic equator, because of the greater amount of radiation shielding provided by the Earth’s magnetic field. Spaceflights that enter the Van Allen radiation belts1 dramatically increase levels of exposure to radiation, an item of concern for astronauts. The Federal Aviation Administration (FAA) of the U.S. Department of Transportation is the authority which recommends the limits for aircrew—20 mSv per year averaged over 5 consecutive years, and no more than 50 mSv in a single year––for pregnant air crew, the limit is 1 mSv, with no more than 0.5 mSv per month [5]. Workers who perform recovery operations, i.e., liquidation or decontamination, after an accident and/or restoration actions in an existing exposure situation, can be regarded as occupationall
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