All living and inanimate nature on the planet is exposed to radioactive radiation throughout its existence.Avoid this absolutely impossible.
Radioactive substances may be inside the body and outside it - this is primarily due to the presence of the natural background, which form naturally occurring isotopes.They are present in all membranes of the globe: underground in the soil, water, air.
Conditionally radioactive substances can be divided into three major groups:
- isotopes that are produced from uranium 232, thorium 232 and 235.
- actinouranium radioactive elements potassium-40, calcium 48, rubidium 87 and other, non-geneticallythe first group.
- isotopes that are produced during nuclear reactions, continually going in the world due to the impact of cosmic rays (for example, carbon-14 and tritium 3).
In turn, these substances are divided into natural and artificial radioactive.The natural isotopes are long-lived, which exist in the natural compounds of elements.Their half-life is from one hundred to a thousand years.
artificial radioactivity is the result of nuclear reactions, running man.For example, during a nuclear explosion produced about 250 isotopes, of which 225 are radioactive.These isotopes occur as a result of nuclear fission of so-called "heavy" components and their subsequent decay products.The activity of a radioactive substance directly depends on the number of nuclei that decay over time.The larger nuclei formed, the higher the activity.
immediate danger of radiation on living organisms are toxic radionuclides (Ra 226, Th 228, Pb 21, Ru 106, Na 22, Sr 89, etc.), Composed of undivided nuclei of atoms of plutonium and uranium - tons.e.part of the nuclear fuel, which is not entered in the fission reaction.
mankind could create more than two hundred artificial radionuclides and learned to use nuclear energy for various purposes, and not very peaceful.Thus, the energy of a nuclear explosion is used in medicine, weaponry, to search for mineral deposits and production of inexpensive energy.Thus increasing the total dose of inhabitants of the Earth.
The most common radioactive substances enter the body through food, water and air.The quantity and toxicity of radionuclides in food is determined by the radiation situation which has developed in the region.
Plants absorb radiation not only from the ground, but also from natural rainfall.Most accumulated radionuclides in the cabbage and beets, and least of all them is contained in the ordinary grass.
Cleaning and subsequent thermal treatment plant significantly reduces the amount of radiation in them.For example, when cleaning the potatoes and beets is removed to 40% of radionuclides, and when cooking - 10-15%.When cooking meat animals radioactive substances also pass into the broth (from 20% to 50%).
To reduce the radionuclide content of dairy products, they are best converted into fat and protein concentrates.
What is the danger of radiation?
First of all, even small doses it can start a chain of events in the body that lead to genetic disorders or cancers.Radiation in high doses destroys cells and tissues, causing death of the organism.At the cellular level, damaged the mechanism of cell division and its chromosomal apparatus, blocks the process of renewal and formation of cells with subsequent regeneration of tissues.
most destructive radioactive substances act on the bone marrow, thyroid, gonads and spleen - that is, those organs which require constant updating of cells and tissues.
