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Terrestrial radiation - Natural background radiation that results from the presence
of naturally occurring radioactivity in the soil and earth
Cosmic radiation - Natural background radiation that results from the interaction
of particles originating in outer space with the earth's atmosphere
Internal Radioactivity - Natural background radiation due to naturally occurring
radionuclides that have been deposited in the human body via either ingestion
or inhalation
300 millirem - Average annual effective dose equivalent in the US (200
millirem attributed to radon gas)
Medical radiation - average per capita effective radiation dose equivalent is
approximately 53 millirem per year
Department of Transport - DOT
Occupational safety and Health Administration - OSHA
Environmental Protection Agency - EPA
Nuclear Regulatory Commission - NRC
International Commission on Radiological Protection - ICRP
National Council on Radiation Protection and Measurements - NCRP
DOT, OSHA, EPA, NRC, ICRP, NCRP - Agencies responsible for radiation safety and
control
5 rems per year - Occupational Dose Limit for effective dose equivalent
15 rems per year - Occupational Dose Limit for Lens of the eyes
50 rems per year - Occupational Dose limit for any organ or tissue
.5 rem per gestation period - Occupational dose limit for embryo/fetus of a declared
pregnancy
.1 rem per year - General Public dose limit for effective dose equivalent
, NCRP recommends that the EDE due to work-related exposure not exceed the
worker's age in years - Additional guidelines of NCRP
As low as reasonably achievable - ALARA acronym
Maintain radiation doses to personnel in medical institutions to 10% or less of
the federal limits of occupational exposure - ALARA implementation
Personnel Dosimeters - devices worn by individuals exposed to ionizing radiation to
evaluate and document their cumulative external radiation doses
Body Dosimeters - utilize "optically stimulated luminescence (OSL)". Called
"Luxel" dosimeters. Very sensitive to ionizing radiation.
Ring Dosimeters - are "thermoluminescent dosimeters (TLDs)". Used to measure
doses to the hands of certain personnel. Should be worn like a conventional ring.
Shallow dose, deep dose, lens dose - three doses the luxel body dosimeter can report
Shallow dose - dose equivalent computed for a tissue depth of 0.007 cm (skin dose)
Deep dose - dose equivalent computed for a tissue depth of 1.0 cm
Lens dose - dose equivalent computed for a tissue depth of .3 cm (thickness of the lens
of each eye)
Geiger-Muller instruments, Ionization Chamber survey instruments, Scintillation survey
instruments - Three types of portable survey instruments
Geiger Muller Instruments - utilize a gas detector that is capable of detecting beta,
gamma, and x-radiation. Uses mR/hr for gamma and x, but uses counts per
minute (cpm) for beta.
Ionization Chamber Survey Instruments - Measure radiation exposure in roentgens.
CAn be used at higher exposure rate levels. Considerably more expensive than Geiger
Scintillation Survey Instruments - utilize a solid sodium iodide crystal coupled to a
sensitive photomultiplier tube as a detector. Excellent at locating multiple sources or
identifying areas of contamination
Recognizing sources of potential external exposure and controlling
internal contamination - Good radiation hygiene
Time, Distance, and Shielding - three cardinal principles for controlling external radiation