Radiation equivalent man

Rem Radiation Equivalent Man the unit of dose equivalence commonly used in the United States. 

REM Radiation Equivalent Man, the unit of dose equivalent takes into account the effectiveness of different types of radiation. 

Dj is the absorbed dose averaged over the tissue organ T, due to radiation R. Hj is measured in sieverts (Sv) 1 Sv = 1 J kg. The earlier, but similar concept was the rent (radiation equivalent man), where 1 Sv equaled 100 rem. Until 1990, Hj was called dose equivalent. Dj is measured in the units of gray (Gy). The summation is taken over all sources irradiating the target. 

While a curie is a measure of the physical amount, the roentgen is a measure of the amount of ionization produced by a specific material. It is the amount of x-ray or gamma radiation that produces 2 billion ionizations in 1 cm of dry air. A RAD is the radiation-absorbed dose (roughly equal to a roentgen). The radiation equivalent man (REM), also roughly equal to a roentgen, is a term for how much radiation has been absorbed, or the biological effect of the dose. 

The rad is a unit of absorbed radiation dose in terms of energy actually deposited in the tissue. The rad is defined as an absorbed dose of 0.01 joules of energy per kilogram of tissue. The rem (radiation equivalent man) is the unit of human exposure and is a dose equivalent (DE). The international or SI unit for human exposure is the sievert, which is defined as equal to 100 rem [2]. It takes into account the biological effective of different types of radiation. The biologically effective dose in rems, is the radiation dose in rads multiplied by a quality factor, which is an assessment of the effectiveness of that particular type and energy of radiation. 

Rem (Rbntgen equivalent man) The unit of measure of the radiation dose to the internal tissues. 

The biological effect of radiation is expressed in rems (radiation equivalent for man). The number of rems is found by multiplying the number of rads by a "damage" factor, n ... 

Roentgen equivalent man (rem) The amount of ionizing radiation of any type that produces the same damage to humans as 1 roentgen of radiation. One rem = 1 roentgen equivalent physical (rep)/relative biological effectiveness (RBE). In the latest nomenclature, 100 rem = 1 Sievert (Sv). 

Rem (acronym for roentgen-equivalent man) The unit of dose of ionizing radiation that produces the same biological effect as a unit of absorbed dose of ordinary x-rays. 

Exposure to radiation from man-made sources is estimated to deliver an average annual effective dose equivalent of about 0.6 mSv (60 mrem) to the general population (Thble 4.1). The largest contribution comes... 

REM (rem). A unit of dose equivalent in the field of radiation dosimetry. One rem equals the amount of ionizing radiation of any type which produces the same damage to humans as 1 roentgen of approximately 200 kilovolts x-radiation. (The unit is abbreviation of Roentgen Equivalent Man.)... 

The dose equivalent is the actual dose modified to take into account the different destructive powers of the various types of radiation in combination with various types of tissue. It is obtained by multiplying the actual dose (in rads) by the value of Q for the radiation type. The result is expressed in a unit called a roentgen equivalent man (rem) ... 

REM. Rontgen Equivalent Man. A measure of the effects of radiation, other than gamma or X-rays, derived by multiplying the energy yield of the radiation by a ratio which expresses that radiation s effect on man Ref E. Luttwak, A Dictionary of Modern War , Harper Row, NY (1971), 164-R... 

Radiation, roentgen absorbed doses (RADs), and roentgen-equivalent man (REM) ... 

Rem This older term is the short abbreviation for roentgen equivalent man. It is defined as the dose of radiation absorbed, multiplied by a modifying factor called quality factor Q, or relative biological effectiveness, RBE that takes into account the type of radiation (of any kind) and how the radiation is absorbed. Thus, for beta, gamma and X-rays, the quality factor is 1 for alpha radiation it may be as high as 20, and for neutrons it varies from 3 to 10. 

Different types of radiation affect biological materials in different ways, so a different unit is needed to describe the dose necessary to produce an equivalent biological damage. Historically, this unit is the rem (roentgen-equivalent-man). The dose in rem is equal to the dose in rad multiplied by a quality factor, which varies with the type of radiation. For )3 -, y-, and X-ray radiation, the quality factor is 1 for neutrons, it is 2-11, depending upon the energy of the particle and for a-particles, the quality factor is 20. The SI unit for equivalent dose is the sievert (Sv), which is equivalent to 100 rem. 

Different kinds of radiation have different ionization efficiencies and are absorbed in different ways. In order to compensate for this the unit rem ( roentgen equivalent, man ) was introduced. It is defined as the quantity of radiation of any type which produces the same biological effect in man as that produced by 1 r of X-ray or y ray radiation. However, the biological effect depends upon the part of the body irradiated and on the type of radiation. This problem is dealt with by estimating a relative biological effectiveness (RBB), in relation to y-rays, for various parts of the body. For example, as far as the production of cataracts is concerned, 1 rad of fast neutrons is ten times as effective as 1 rad of y-rays. Thus if the eyes were... 

Roent- gen Relative biological effectiveness Radiation absorbed dose Roentgen equivalent man... 

Values of RBE for various types of radiation are listed in Table 10-1. The final unit of interest, the r m or roentgen equivalent man, is a true measure of the biological injury produced from various types of radiation. The dosage can be expressed in terms of units of total energy absorption multiplied by the relative biological effectiveness ... 

For evaluation of the risk of exposure to ionizing radiation in humans, the dose equivalent in rem (roentgen equivalent man) is defined as... 

Rem—Roentgen equivalent man, the nnit of dose of any ionizing radiation that produces the same biological effect on human tissne as one roentgen of x-rays. 

Roentgen equivalent man— A unit of eqnivalent dose that relates the absorbed dose in human tissue to the effective biological damage of the radiation. 

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