Radioactivity and life. YK Kudrytski (MD) 1971 Part 12.

First in importance in this regard is to characterize the body's ability to respond to radiation irritation, ie, its reactivity to ionizing radiation. Body's ability to respond to radiation exposure is usually called its radiosensitivity, since it depends on the species, age, gender, health status, as well as the factors peluchevoy nature, affecting its reactivity.
Mammalian organism has a high radiosensitivity. In the example above with the phenomenon observed rentgenfosfena ability of the visual analyzer in the beam ogvechat irritation, similar to the level of natural background ionizing radiation. For comparison radnochuvsgvitelnosti different species of animals is convenient to use one of its characteristics - radioresistance, ie, the body's ability to resist the damaging action of IO! 1Iziruyuschey radiation. Usually are given a dose of poluletalnoy.
Radioresistance is greatest in the lower organisms.
Thus, the microorganisms found in water reactor circuits, where
. doses reach hundreds of thousands and millions of X-rays. The more vysokoorganieovan body, so as a rule, lower than its radioresistance. Among mammals, noted the same trend (Table 4). According to some recent data, poluletal-
nuyu dose for humans can be taken as 285 p. . • ..
Table 4 Velichiia semi-legal dose to various animal species (in roentgens)
Amoeba 100 000 550 Mouse
Snail 20 000 Monkey 550
Hamster 900 Pig 430
Rabbit 800 dog 400
Donkey b50 guinea pig 400
BOO rat Goat 350
Tolerance to the effects of neblagopriyagnym is known to depend on age. She, as a rule. is highest in middle age and less pronounced in the developing organism, as well as during aging. In the same way with age and varies radioresistance. It was found that the most radiosensitive period of fetal life is the most radioresistance - a period of maturity. By the age radnochuvstvitelnost increases. For many diseases. weakened when the adaptive, protective features op-. organism, its radiosensitivity increases. Therefore, according to our sanitary regulations. to work with sources