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Radiation LD50 dose

Radiation adversely affects limb regeneration of amphibians, alters DNA metabolism, and increases the frequency of chromosomal aberrations and liver lesions (Table 32.25). In some species of amphibians and reptiles, as in many mammals, mortality rates after acute exposure to radiation do not stabilize within 30 days — effectively invalidating the conventional LD50 (30-day postexposure) value. In the rough-skinned newt (Taricha granulosa), for example, the minimal LD50 dose at 200 days after irradiation was 2.5 Gy, compared with 350 Gy at 30 days (Willis and... [Pg.1713]

For a more complete understanding of radiation injury, let us consider the effects on humans of acute, high-level doses of ionizing radiation. A dose of radiation less than the LD50/30, produces a variety of symptoms depending upon the amount of radiation received. When an individual receives an acute, whole-body radiation dose in excess of a cer-... [Pg.189]

Median Lethal Dose (MLD)—Dose of radiation required to kill, within a specified period (usually 30 days), 50% of the individuals in a large group of animals or organisms. Also called the LD50, or LD50/30 if for 30 days.. [Pg.274]

Lethal dose A dose of ionizing radiation sufficient to cause death. Median lethal dose (MLD or LD50) is the dose required to kill within a specified period of time (usually 30 days) half of the individuals in a large group or organisms similarly exposed. The LD50/30 for man is 400 to 500 rads (4-5 Gy). [Pg.256]

It is seen from this table that, at the LD50 level, the nucleus has received about the same dose, irrespective of whether X-rays, 3H-dThd or 125I-concanavalin are used as the source of ionizing radiation, while the membrane has received an immense dose with 125I-concanavalin and very little with 3H-dThd. As expected, the cytoplasm lies in between these two extremes. Yet, irradiation of the cytoplasm (single-ion-beam experiments) is not without an effect. It may cause mutations (Wu et al. 1999) and the formation of products that induce apoptosis in nearby (unirradiated) cells (bystander effect Shao et al. 2004). [Pg.362]

LD50/30—The dose of a chemical or radiation expected to cause 50% mortality in those exposed within 30 days. For radiation, this is about 350 rad (3.5 gray) received by humans over a short period of time. [Pg.407]

The EPA and OSHA regulations [A-1, A-2, and A-3] apply to facilities from which a release of hazardous material could occur, at or above the quantities specified, as shown in bold in Table 17.A.1. Also shown are the Immediately Dangerous to Life and Health [IDLH] concentrations (for 30-minute exposure) [A-4] the Lower Flammable Limits and Heats of Combustion for combustible materials and the EPA toxic, thermal-radiation, and overpressure endpoints for public-exposure evaluations. N/L indicates that the chemical is not listed in the pertinent document. Estimated values are shown with a superscript ( ). Where no inhalation-toxicity data were available, the oral dose that caused 50% fatalities is shown only to indicate qualitatively the systemic toxicity (for example, an oral LD50 of 1000 mg/kg would be considered relatively nontoxic). The data are for pure chemicals, except where otherwise indicated, that is, without added diluents. Additional hazardous-properties information can be obtained via the Sax No. [A-6]. [Pg.1470]

General. The median lethal dose of radiation that will kill 50 percent of the exposed persons within a period of 60 days, without medical intervention (designated as LD50/60), is approximately 450 cGy. Medically, other figures of interest are the dose that will kill virtually no one, (LD5), and the dose that will kill virtually every one (LD95). Approximations of those doses are within the ranges 200-300 cGy (free in air) and 600-700 cGy (free in air), respectively. [Pg.48]

The lethal dose (LD50) of radiation is defined as the acute dosage of radiation that would be fatal for 50% of the exposed population within 30 days. An esti-naated lethal dose is 500 rems. Some biological effects, however, may be detectable at a level as low as 25 rem. [Pg.290]

LDso Lethal dose 50, or median lethal dose the amount of a pharmacological or toxic substance (such as Ionizing radiation) that causes death in 50% of a group of experimental animals. For each LD50 the species and weight of the animal and the route of administration of the substance Is specified. LD50S ate used both in toxicology and in the bloassay of therapeutic compounds. [Pg.466]

An indication of the lethality of a given substance or type of radiation. Because resistance varies from one individual to another, the lethal dose represents a dose (usually recorded as dose per kilogram of subject body weight) at which for a given percentage of subjects a fatality will occur. The most commonly used lethality indicator is the LD50, a dose at which 50 percent of subjects will die. [Pg.182]

Dose of ionizing radiation required to kill 50 per cent of the animals in a given group. A time limit of 30 days is usually applied (LD50/30) ... [Pg.218]

Until now, we have been discussing the effects of whole-body irradiation exposure. Such exposures are quite uncommon, especially in the biomedical research laboratory setting. Furthermore, protection of a portion of the body from radiation dramatically increases the LD50/30 this fact makes it possible to use localized doses of thousands of rad for radiation treatment of certain kinds of tumors. [Pg.191]

Acute radiation syndrome can be classified according to the dose of radiation received. These dose ranges are not precise figures but do offer a guide to likely symptoms. The LD50 at 60 days without treatment is approximately 3.5 Sv, which increases to >6 Sv with increasing medical intervention (Table 6.5). [Pg.357]


See other pages where Radiation LD50 dose is mentioned: [Pg.291]    [Pg.290]    [Pg.717]    [Pg.112]    [Pg.366]    [Pg.115]    [Pg.66]    [Pg.19]    [Pg.807]    [Pg.2156]    [Pg.2723]    [Pg.291]    [Pg.290]    [Pg.482]    [Pg.115]    [Pg.216]    [Pg.276]    [Pg.234]    [Pg.860]    [Pg.574]    [Pg.189]    [Pg.190]    [Pg.147]   
See also in sourсe #XX -- [ Pg.525 , Pg.532 , Pg.609 ]




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LD50

LD50 dose

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