Everything you need to know about radiation

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2024-01-18 01:29

On the day of the anniversary of the tragedy at the Chernobyl nuclear power plant, people every year ask questions: maybe it is worth closing all the stations, banning experiments and the use of radiation sources? What is radiation? How and in what doses does it affect a person? Can radiation exposure be avoided in daily life? We answer these and other questions about radiation in our article.

What is radiation and where does it come from

The word "radiation" is more often understood as ionizing radiation associated with radioactive decay. In this case, a person experiences the effect of non-ionizing types of radiation: electromagnetic and ultraviolet.

The main sources of radiation are:

• natural radioactive substances around and inside us - 73%;
• medical procedures (fluoroscopy and others) - 13%;
• cosmic radiation - 14%.

Of course, there are technogenic sources of pollution resulting from major accidents. These are the most dangerous events for humanity, because, as in a nuclear explosion, in this case iodine (J-131), cesium (Cs-137) and strontium (mainly Sr-90) can be released. Weapon-grade plutonium (Pu-241) and its decay products are no less dangerous.

Also, do not forget that over the past 40 years the Earth's atmosphere has been very heavily contaminated with radioactive products of atomic and hydrogen bombs. Of course, at the moment, radioactive fallout falls only in connection with natural disasters, for example, during volcanic eruptions. But, on the other hand, the fission of a nuclear charge at the time of the explosion produces a radioactive isotope carbon-14 with a half-life of 5,730 years. The explosions changed the equilibrium content of carbon-14 in the atmosphere by 2.6%. At present, the average effective equivalent dose rate due to explosion products is about 1 mrem / year, which is approximately 1% of the dose rate due to the natural background radiation.

Energy is another reason for the serious accumulation of radionuclides in humans and animals. Bituminous coals used in CHP plants contain naturally occurring radioactive elements such as potassium-40, uranium-238 and thorium-232. The annual dose in the area of coal-fired CHP is 0.5–5 mrem / year. By the way, nuclear power plants are characterized by significantly lower emissions.

Almost all inhabitants of the Earth undergo medical procedures using sources of ionizing radiation. But this is a more difficult question, which we will return to a little later.

In what units is radiation measured

Different units are used to measure the amount of radiation energy. In medicine, sievert is the main one - an effective equivalent dose received in one procedure by the whole body. It is in sieverts per unit time that the level of the background radiation is measured. Becquerel serves as a unit for measuring the radioactivity of water, soil, and so on, per unit volume.

Other units of measurement can be found in the table.

Term	Units		Unit ratio	Definition
	SI	In the old system
Activity	Becquerel, Bq	Curie, Key	1 Ki = 3.7 × 1010 Bq	The number of radioactive decays per unit of time
Dose rate	Sievert per hour, Sv / h	X-ray per hour, R / h	1 μR / h = 0.01 μSv / h	Radiation level per unit of time
Absorbed dose	Gray, Gr	Radian, glad	1 rad = 0.01 Gy	The amount of ionizing radiation energy transferred to a specific object
Effective dose	Sievert, Sv	Rem	1 rem = 0.01 Sv	Radiation dose, taking into account different sensitivity of organs to radiation

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Radiation consequences

Exposure to radiation on a person is called radiation. Its main manifestation is acute radiation sickness, which has varying degrees of severity. Radiation sickness can manifest itself with exposure to a dose equal to 1 sievert. A dose of 0.2 sieverts increases the risk of cancer, and a dose of 3 sieverts threatens the life of the exposed person.

Radiation sickness manifests itself in the following symptoms: loss of strength, diarrhea, nausea and vomiting; dry, hacking cough; cardiac disorders.

In addition, radiation causes radiation burns. Very large doses lead to the death of the skin, up to damage to muscles and bones, which heals much worse than chemical or thermal burns. Along with burns, metabolic disorders, infectious complications, radiation infertility, and radiation cataracts may appear.

The consequences of irradiation can manifest themselves over a long time - this is the so-called stochastic effect. It is expressed in the fact that the frequency of certain cancers may increase among exposed people. In theory, genetic effects are also possible, but even among 78 thousand Japanese children who survived the atomic bombings of Hiroshima and Nagasaki, no increase in the number of hereditary diseases was found. And this is despite the fact that the effects of radiation have a stronger effect on dividing cells, therefore, radiation is much more dangerous for children than for adults.

Short-term low-dose irradiation, used for examinations and treatment of certain diseases, produces an interesting effect called hormesis. This is the stimulation of any system of the body by external influences that are insufficient for the manifestation of harmful factors. This effect allows the body to mobilize strength.

Statistically, radiation can increase the level of oncology, but it is very difficult to identify the direct effect of radiation, separating it from the action of chemically harmful substances, viruses and others. It is known that after the bombing of Hiroshima, the first effects in the form of an increase in the incidence of diseases began to appear only after 10 years or more. Cancer of the thyroid gland, breast and certain parts of the intestine is directly related to radiation.

What are the maximum permissible radiation doses

The natural background radiation is of the order of 0.1–0.2 μSv / h. It is believed that a constant background level above 1.2 μSv / h is dangerous for humans (it is necessary to distinguish between an instantly absorbed radiation dose and a constant background). Is this a lot? For comparison: the radiation level at a distance of 20 km from the Japanese nuclear power plant "Fukushima-1" at the time of the accident exceeded the norm by 1,600 times. The maximum recorded radiation level at this distance is 161 μSv / h. After the explosion at the Chernobyl nuclear power plant, the radiation level reached several thousand microsieverts per hour.

During a 2–3-hour flight over an ecologically clean area, a person receives radiation of 20–30 µSv. The same dose of radiation threatens if a person is made 10-15 pictures in one day with a modern X-ray apparatus - a visiograph. A couple of hours in front of a cathode ray monitor or TV gives the same dose of radiation as one such picture. The annual dose from smoking, one cigarette per day - 2, 7 mSv. One fluorography - 0.6 mSv, one radiography - 1.3 mSv, one fluoroscopy - 5 mSv. Radiation from concrete walls - up to 3 mSv per year.

When irradiating the whole body and for the first group of critical organs (heart, lungs, brain, pancreas and others), regulatory documents establish the maximum dose of 50,000 μSv (5 rem) per year.

Acute radiation sickness develops at a single exposure dose of 1,000,000 μSv (25,000 digital fluorographs, 1,000 spine x-rays in one day). Large doses have an even stronger effect:

• 750,000 μSv - short-term insignificant change in blood composition;
• 1,000,000 μSv - mild radiation sickness;
• 4,500,000 μSv - severe radiation sickness (50% of those exposed to death die);
• about 7,000,000 μSv - death.

Are X-ray examinations dangerous?

Most often, we are faced with radiation during. However, the doses that we receive in the process are so small that we should not be afraid of them. The exposure time with an old X-ray apparatus is 0.5-1.2 seconds. And with a modern visiograph, everything happens 10 times faster: in 0.05–0.3 seconds.

According to the medical requirements set forth in, during preventive medical X-ray procedures, the radiation dose should not exceed 1,000 μSv per year. How much is it in the pictures? Quite a bit of:

• 500 sighting images (2–3 µSv) obtained with a radiovisiograph;
• 100 of the same images, but using good X-ray film (10-15 µSv);
• 80 digital orthopantomograms (13-17 µSv);
• 40 film orthopantomograms (25-30 µSv);
• 20 computed tomograms (45-60 µSv).

That is, if every day, throughout the year, we take one picture on a visiograph, add a couple of computer tomograms and the same number of orthopantomograms to this, then even in this case we will not go beyond the permitted doses.

Who should not be irradiated

However, there are people for whom even such types of radiation are strictly prohibited. According to the standards approved in Russia (), radiation in the form of X-ray can be performed only in the second half of pregnancy, except for cases when the issue of abortion or the need for emergency or emergency care should be decided.

Clause 7.18 of the document states: “X-ray examinations of pregnant women are carried out using all possible means and methods of protection so that the dose received by the fetus does not exceed 1 mSv in two months of undetected pregnancy. If the fetus receives a dose exceeding 100 mSv, the doctor is obliged to warn the patient about the possible consequences and recommend to terminate the pregnancy."

Young people who are to become parents in the future need to close the abdominal region and genitals from radiation. X-ray radiation has the most negative effect on blood cells and germ cells. In children, in general, the whole body should be screened, except for the area under study, and research should be carried out only if necessary and as directed by a doctor.

Sergei Nelyubin Head of the Department of X-ray Diagnostics of the N. N. B. V. Petrovsky, Candidate of Medical Sciences, Associate Professor

How to protect yourself

There are three main methods of protection against X-rays: time protection, distance protection and shielding. That is, the less you are in the X-ray range and the farther you are from the radiation source, the lower the radiation dose.

Although the safe dose of radiation exposure is calculated for a year, it is still not worth doing several X-ray examinations, such as fluorography and mammography, on the same day. Well, each patient must have a radiation passport (it is embedded in the medical card): in it, the radiologist enters information about the dose received during each examination.

Radiography primarily affects the endocrine glands, lungs. The same applies to small doses of radiation in accidents and releases of active substances. Therefore, as a preventive measure, doctors recommend breathing exercises. They will help cleanse the lungs and activate the body's reserves.

To normalize the internal processes of the body and remove harmful substances, it is worth consuming more antioxidants: vitamins A, C, E (red wine, grapes). Sour cream, cottage cheese, milk, grain bread, bran, oatmeal, unprocessed rice, and prunes are useful.

In the event that food products inspire certain concerns, you can use the recommendations for residents of the regions affected by the accident at the Chernobyl nuclear power plant.

Products	Methods for reducing radioactive contamination	Pollution reduction
Potatoes, tomatoes, cucumbers	Rinsing in running water	5-7 times
Cabbage	Removal of cover leaves	Up to 40 times
Beets, carrots, turnips	Cutting the corolla of the root crop	15-20 times
Potato	Cleaning the washed tuber	2 times
Barley, oats (grain)	Peeling, removing films	10-15 times

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With actual exposure due to an accident or in an infected area, quite a lot needs to be done. First, you need to carry out decontamination: quickly and accurately remove clothes and shoes with carriers of radiation, properly dispose of it, or at least remove radioactive dust from your belongings and surrounding surfaces. It is enough to wash the body and clothing (separately) under running water using detergents.

Food supplements and anti-radiation drugs are used before or after exposure to radiation. The best known drugs are high in iodine, which helps to effectively fight the negative effects of its radioactive isotope, localized in the thyroid gland. To block the accumulation of radioactive cesium and prevent secondary damage, use "Potassium orotat". Calcium supplements deactivate the radioactive strontium preparation by 90%. Dimethyl sulfide is shown to protect cellular structures and DNA.

By the way, the well-known activated carbon can neutralize the effects of radiation. And the benefits of drinking vodka immediately after irradiation are not at all a myth. It really helps to remove radioactive isotopes from the body in the simplest cases.

Just do not forget: self-treatment should be carried out only if it is impossible to consult a doctor in a timely manner and only in the case of real, and not invented, radiation. X-ray diagnostics, watching TV or flying on an airplane do not affect the health of the average inhabitant of the Earth.