What is beta radiation and how to protect it
We continue our acquaintance with the world of radioactivity. This phenomenon was discovered more than a century ago by the French scientist Henri Becquerel. Maria Skladovskaya and Pierre Curie dedicated their lives to studying the properties of the mysterious rays. They were the first to feel their ill effects. What do we know now about radioactivity? It turned out that radioactive radiation has a heterogeneous composition. These are two types of particles (alpha and beta) and gamma quanta.
In this article, we will find out what beta radiation is, where this kind of radioactivity is encountered, how it affects humans, and what kind of protection against it exists.
What is beta radiation
Beta radiation is due to the birth of the decay of atomic nuclei of radioactive elements. Breaking out of the captivity of the intranuclear forces, the beta particles inherit from the parent atom a different energy and, accordingly, a different speed. The speed of flight of these particles ranges from 100 thousand km / s to light speed. Therefore, in the air, they are able to "run" different distances up to 1800 cm. In biological tissues, their vitality is only enough for 2.5 cm of free path. This is quite understandable. Since the penetrating ability of beta radiation depends on the density of the medium.
Due to the negligibly small mass, the beta particles easily deviate from the straight path, describing the most bizarre trajectories in the substance.
Natural sources of beta radiation
Natural beta radiation is a stream of tiny charged particles that carry either a negative or a positive electrical charge.
What are the sources of beta radiation? Nature has not provided for any radiation sources capable of emitting only beta radiation. As a rule, it is only one of the components of the family of natural radioactive emissions. It comes to us from the depths of the cosmos, seeps from the earth's depths in places of occurrence of ores containing radioactive particles.
But some chemical elements in radioactive decay especially actively emit beta particles (promethium, krypton, strontium, and others).
Artificial beta sources
Along with the natural radioactive background, the world around us has to exist among a multitude of artificially created sources of radiation. Induced radioactivity is most often a serious legacy of radiation accidents, when β-decay leads to the birth of a new portion of radioactive atoms, but with a different atomic number in the periodic table.
A technogenic accident at the Fukushima 1 nuclear power plant in September 2013 led to the leakage of radioactive water. As a result, the content of cesium and strontium isotopes emitting beta particles increased thousands of times.
The creation of sources of this radiation is often initiated by a person purposefully, for very specific practical needs.
Use of beta radiation
Just like other types of radioactive radiation, beta radiation is widely used in medicine. This is beta therapy and radioisotope diagnostics.
For therapeutic purposes, applicators emitting beta rays are superimposed on the affected areas.
- For malignant tumors, interstitial and intracavitary beta-therapy is used. The therapeutic effect is achieved due to the damaging effects of beta radiation on pathologically altered tissues.
- Radioisotope diagnostics uses beta particles as a radioactive label to detect tumor tissues.
Sources of beta radiation are used in chemistry, to control a variety of automatic processes, during car repairs, in archeology to determine the age of rocks, etc.
The effect of beta radiation on humans
How do these representatives of the microworld affect the human body? If beta radiation enters the skin of a person, tissue burns occur. The degree of damage depends on the duration of exposure, its intensity and the structure of the tissue. Particularly affected are open areas of the body and mucous membranes of the eyes.
After the accident at the Chernobyl nuclear power plant within a radius of more than 100 meters, people who walked barefoot on the ground experienced severe burns of the feet. But the most serious consequences occur when a substance emitting these tiny, but far from harmless particles into the body. When this occurs, the ionization of molecules, cell death, the release of toxins, leading to poisoning of the body and in the end - to death. The danger of beta radiation is very high! Each beta particle with an average energy value can form about 30,000 ion pairs on its way in the air. That is, its entire path among living tissues is littered with remnants of molecules, which are sources of destructive processes in the body.
In the sphere of human habitation, radioactivity up to a certain norm is the same natural component as, say, oxygen. A safe beta exposure rate is considered to be 0.20 µSv / h. If the radiation background has exceeded this norm by 2 times, then you can stay in this zone without consequences for only half an hour.
Beta radiation protection
When it comes to people whose professional activities are in one way or another connected with beta emitters, the following rules are provided to protect and minimize the consequences of their impact.
When planning short-term work, radioprotectors are used - substances introduced into the body prior to the start of work in the danger zone and capable of weakening the effect of radiation. They are introduced into the body in the form of injections or nutritional supplements.
- However, the main protection against beta radiation consists in reducing its intensity, by moving away from the radiation source as far as possible.
- Maximum reduction of time spent next to the beta emitter.
- The use of protective screens made of glass, plexiglass, sheet aluminum and other metals.
- Use gas masks for respiratory protection.
- Conducting constant dosimetry monitoring of the radiation situation.
What to do if exposure occurred:
- quickly leave the danger zone;
- take off clothes and shoes;
- Wash thoroughly with running water and soap.
What should ordinary people, far from the sphere of atomic energy, know in order not to become the unwitting object of exposure to an additional dose of beta radiation?
If we exclude the necessary medical procedures involving beta sources, then one should be aware that when nuclear reactors are operating, iodine-131 is formed, which is a source of significant beta radiation. Together with green plant mass, they enter animal feed and accumulate in dairy products. Further, this isotope finds “shelter” in the thyroid gland, causing internal irradiation. Regular introduction into the diet of foods rich in stable iodine (seafood) is an effective protection against this danger.
One more example. To facilitate the search for keys in the dark, tritium keyrings are used. Outgoing beta radiation from tritium causes the phosphor to glow. Manufacturers assure the safety of this gadget. However, the violation of the integrity of the body can lead to the ingress of harmful radiation into the human body. Before you buy such a "toy" - ask the components involved in its work.
As a measure of protection against beta radiation, it is completely useful to have a dosimeter in each family, which allows you to assess the radiation situation in your home and check the radioactivity of the products purchased.
Knowing what is beta radiation, and clearly aware of the danger associated with its impact, it is necessary to take very seriously the implementation of all the proposed recommendations. Since the rapid flow of electrons and positrons, despite the negligibly small mass of these particles, is a carrier of very significant energy and is capable of inflicting serious damage to the body due to its active ionizing ability.