Radionuclides - a collection of atoms, characterized by a certain mass number, the energy states of nuclei, atomic number, nucleus are unstable and test the radioactive decay.
number of known radioactive nuclides than 1800. By type of decay emit: a-radionuclides, b-radionuclides.The nuclei of some radionuclides are subject to spontaneous fission, while others fall by the type of electron capture, in which the core, capturing an atom with one of the shells, allocates neutrinos.
Most of the radionuclides are radioactive sources, asthe emission of a- and b-particles and electron capture is usually accompanied by the formation of g-radiation, which leads to the formation of electromagnetic radiation.
Natural sources provide the natural background radiation, which is the cosmic radiation and terrestrial origin radionuclides containe
d in soil, water, rocks.These radionuclides are external source of radiation.
example, radionuclides of uranium and thorium, entering the body through food, air, are the body's equilibrium concentrations and are sources of internal radiation.
addition to natural radiation sources, radionuclides may be prepared and an artificial (man-made) by.They are produced in nuclear reactors, in connection with the testing of nuclear weapons, are also used in medicine, agriculture, science and other fields, providing the human body internal and external influences.
Influence on the human body
Getting into a living organism, radioactive elements cause the appearance of particles that have a destructive effect on living cells.Large doses of damage and kill cells, it stops cell division and cause serious tissue damage.Small doses of radiation can cause genetic changes that can occur at the future descendants of exposed radiation.
fastest radioactive substance derived from soft tissue and internal organs (cesium, molybdenum, ruthenium, iodine), and concentrated in bones (strontium, plutonium, barium, yttrium, zirconium) - slowly.
considerable amount of radionuclide enters the body with food.Is a leading supplier of bread;Descending further milk, vegetables, fruits, meat, fish.And radionuclides in marine fish contains less than in freshwater due to the high salinity of sea water.
For the excretion of radioactive substances recommended to consume 2-6 grams per day because of eggshell calcium contained therein.