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4. Glossary of terms, definitions, units, abbreviations, acronyms
(see also Ref. 211)
becquerel (Bq) New unit of radioactivity = 1 radioactive disintegration per second (= 27 pCi).
CGS Classical centimetre-gram-second system of expressing physical dimensions.
Curie (Ci) Classical unit of radioactivity and that associated with 1 gram of radium. 1 Ci = 3.7 x 1010 Bq. (This unit is now superseded by the Bq).
electron volt (ev) Unit of energy in the context of ionizing radiation. 1 ev is the kinetic energy acquired by a free electron over an electrostatic potential gradient of 1 volt. 1 ev = 1.6 x 10-12 ergs. 1 Mev = 1.6 x 10-6 ergs.
erg CGS unit of energy and is the work done when a force of 1 dyne acts through a distance of 1 cm. 1 erg = 10-7 J .
gray (Gy) New unit of physically-absorbed radiation dose 1 Gy = 1 J kg-1 = 100 red.
joule ( J) SI unit of energy and is the work done when a force of 1 newton acts through a distance of 1 meter. 1 J = 107 ergs.
rad Classical unit of physically absorbed radiation dose. 1 rad = 100 ergs g-1 = 10-2 J kg-1.
rem Classical unit of "absorbed dose equivalent" (H) in the context of radiological health protection which takes into account the different levels of biological damage for the same physically absorbed dose. Thus, H = D x Q where Q is the "quality factor" for the type of radiation absorbed. Q = 1 for normal beta and/or gamma emitters, 10 for neutrons, and 20 for alpha emitters.
roentgen (R) Classical unit of external radiation level. 1 R is equivalent to an energy dissipation of 83 ergs g-1 Of air or 93 ergs g-1 of water or tissue. This unit is now superseded by the Gy or Sv.
sievert (sv) New unit of absorbed dose-equivalent (l Sv = 100 rems). Note: m R hr-1 (old unit still in use for external radiation levels) º 1 m Sv per 168-hr week - approximately.
SI Systèm Internationale of the newer units which include the Gy, Sv, kg, J. etc. which are often expressed in multiples or sub-multiples with standard abbreviations as follows:
Kilo (k) = 103 milk (m) = 10-3
Mega (M) = 106 micro (m )
-10-6
Giga (G) = 109 nano (n) = 10-9
Tera (T) = 1012 pico (p) = 10-12
The following abbreviations appear in the text:
cm centimetre
cm² square cm
cm-2 per square cm
m² square metre
m-2 per square metre
m-3 per cubic metre
km² square kilometre
kg-1 per kg
fur-1 per hour, etc., etc.
Note on "radiation dose" terminology (based on refs. 54;205; 211)
"Dose equivalent" The absorbed radiation dose from an internal or external source taking into account the different biological effects ("quality factor") per unit of physically-absorbed radiation energy (Gy) according to the physical nature of the radiation (e.g., alpha, beta and/or gamma) - expressed in Sv.
"Committed effective dose equivalent" The effective dose equivalent that will be accumulated in an individual during the conventional 50-year period following an intake of radioactive material into the body. This takes into account its physiological distribution within the body, concentration in specific organs, tissues, effective half-life, etc. (see footnotes to Table I in Part 1) - expressed in Sv. This provides the basis for estimating possible "somatic" health effects (i.e., those manifest in the exposed individual) including "non-stochastic effects" (see below) such as skin- burn as a result of an acute exposure which may be dose-related, and for which a threshold dose level may exist (cf. "no-effect" level for pesticide residue).
"Collective effective dose equivalent commitment" The projected (i.e., dose rate-time integrated) total dose equivalent which will be accumulated over infinite time into the future by the exposed population - expressed in man-Sv. This parameter, on the basis of earlier and recently reviewed data (216) on radiation health-risk factors provides for estimating the risks of "hereditary" effects (i.e., those which may become manifest in the descendants of the exposed population). Also of "stochastic effects" which can only be quantified in terms of the probability of their later occurrence in the exposed population, such as the incidence of radiation-induced cancer.
Organizations and acronyms
ALARA - Principle Basic principle that radiation doses should be kept As Low As is Readily Achievable, see ref. 121.
ANS American Nuclear Society
BEIR - Report Report on the Biological Effects of Ionizing Radiation (U.S.A.)
CEC Commission of the European Communities
CIPF Conféderation International du Commerce des Pailles Fourrages tourbes et derives
COE - COA Council of Europe - Committee on Agriculture
DHHS Dept. of Health and Human Services (U.S.A.)
EC European Community
EPA Environmental Protection Agency (U.S.A.)
ESNA European Society of Nuclear Methods in Agriculture
EURATOM Effectively the IAEA of the EC and administered by the CEC
EULEP European Late Effects Project Group
FAO Food and Agriculture Organization of the UN
FAO - SCRE FAO - Standing Committee on Radiation Effects
FDA Food and Drug Administration (U.S.A.)
FDA - FSIS FDA - Food Safety and Inspection Service
GSF Gesellschaft für Strahlen- und Umweltforschung (F.R.G.)
IAEA International Atomic Energy Agency (UN)
IAEA - IAC IAEA - Inter-Agency Committee
ICRP International Commission on Radiological Protection
ICRU International Commission on Radiation Units and Measurement
ICSU - SCOPE International Council of Scientific Union - Scientific Committee on the Problems of the Environment
IIASA International Institute of Applied Systems Analysis
ILO International Labour Organization (UN)
INSAG International Nuclear Safety Advisory Group of IAEA (UN)
IUR International Union of Radioecologists
MHIDAS Major Hazard Incident Data Service (U.K.)
NCRP National Council on Radiation Protection and Measurements (U.S.A.)
NPT Non-Proliferation Treaty (UN)
NRCC National Research Council of Canada
NRPB National Radiological Protection Board (U.K.)
OECD - NEA Organization for Economic Cooperation and Development - Nuclear Energy Agency
SCUAE State Committee on the Utilization of Atomic Energy (U.S.S.R.)
SSI Statens Stralskydds Institute (Sweden)
UN United Nations
UNEP United Nations Environment Programme
UNSCEAR United Nations Scientific Committee on the Effects of Atomic Radiation
USAEC United States Atomic Energy Commission
USDA United States Department of Agriculture
WHO World Health Organization (UN)
WHO - RCE WHO - Regional Centre for Europe
WMO World Meteorological Organization (UN)