Radiation standards indoors
Radioactive radiation surrounds us everywhere, to some extent all objects and even the person himself have it. It is not radiation itself that is dangerous, but when its value exceeds certain values. It's one thing if a person has been exposed to radiation for a short time and quite another when it is exposed for a long time, for example, lives in an infected apartment. Looking ahead, let us say that a safe radiation rate for a person is determined within 30 micro-roentgens per hour (μR / h). There are several more units of measurement. We will discuss other norms and units of its measurement below.
What is radioactivity
The content of the article
What is radiation
Radiation is a form of radiation by charged particles. Such radiation, acting on surrounding objects, ionizes the substance. In the case of humans, it not only ionizes cells, but also destroys them or causes cancer.
Most of the elements of the periodic table are inert and harmless, but some have an unstable state. Without going into details, you can describe it like this. The atoms of some substances disintegrate due to fragile internal bonds. This decay is accompanied by the release of alpha, beta particles and gamma rays.
This release is accompanied by the release of energy with different penetrating ability and has a different effect on the tissues of the body.
Types of radiation
There are several types of radioactivity, which can be divided into non-hazardous, low-hazard and hazardous. We will not dwell on them in detail, rather it is for understanding with than can be encountered indoors. So this:
- alpha (α) radiation;
- beta (β) radiation;
- gamma (γ) radiation;
- neutron;
- x-ray.
Alpha, beta and neutron radiation are particle irradiation. Gamma and X-rays are electromagnetic radiation.
In everyday life, you are unlikely to meet with x-ray and neutron, since they are specific, but with the rest you can. Each of these types of radiation has a different degree of danger, but, besides this, how much radiation a person received must be taken into account.
How is radiation measured?
There are several units of radiation measurement, but generally X-rays associated with it are preferred at the user level. They are shown in the table below. We will not consider them in detail, since, if necessary, find out the radioactive background in the apartment, perhaps only 2 will be needed.
Types of radiation
- Sievert- equivalent dose. 1 Sv = 100 R = 100 RER = 1 Gr.
- Rentin - off-system unit - C / kg. 1 R = 1 RER = 0.01 Sv.
- BER- analogue Sievert, an outdated off-system unit. 1 RER = 1 P = 0.01 Sv.
- Gray- absorbed dose rate - J / kg. 1 Gr = 100 Rad.
- Glad- dose of absorbed radiation J / kg. 1 rad is 0.01 (1 rad = 0.01 Gy).
In practice, the system unit Sievert (Sv) is more in use, mSv is millisievert, μSv is microsievert, named after the scientist Rolf Sievert. Sievert is a unit of measure for equivalent dose, expressed as the amount of energy received per kilogram of mass J / kg.
The expression for radiation in X-rays is also used, albeit less widely. However, converting X-rays to sievert is not difficult.
1 Roentgen is equal to 0.0098 Sv, but usually the value in sievert is rounded to 0.01, which simplifies translation. Since these are very large doses, in reality they use much lower values of m - milli 10-3 and mk - micro 10-6 ... Hence, 100 μR = 1 μSv, or 50 μR = 0.5 μSv. That is, a multiplier of 100 is used.When you need to convert microsieverts into micro-X-rays, you need to multiply some value by one hundred, and if you need to convert X-rays into sieverts, then you need to divide.
The level of radiation that a person can receive during procedures and life
Supervision and regulations
Supervision in this area is carried out by Rospotrebnadzor by special services. Control over the state of radioactive contamination of the environment is carried out by the Russian Federal Service for Hydrometeorology and Environmental Monitoring, and over the level of radiation safety of the population - by the bodies of the Ministry of Health of the Russian Federation.
In Russia, radiation doses for humans are established by SanPiN 2.6.1.2523-09 "Radiation Safety Standards NRB-99/2009" and OSPORB-99. According to them, the maximum permissible dose of radiation for a person is no more than 5 mSv or 0.5 RER, or 0.5 R in year.
Norms for a person
Over the long years of research on radiation, safe and maximum doses have been determined. Unfortunately, not only empirically, but also in practice. Events such as Hiroshima and Chernobyl were not in vain for the planet. Years of radiation observations have shown that exceeding the permissible radiation dose leaves an imprint on all subsequent generations.
Physical quantities in which radiation is measured
Radiation background
4.5 billion years have passed since the birth of the earth, during which time the radioactivity, which during its formation was just gigantic, almost disappeared. The existing natural background, which in our country is 4-15 microR per hour, consists of several components. It:
- Natural, up to 83%. Residual radiation from natural sources - gases, minerals.
- Cosmic radiation - 14%. The most powerful source of radiation is the sun. With a decrease in the earth's magnetic field, the general background will increase, which can lead to an increase in cancers and mutations. The second factor that reduces radiation is the atmosphere. Airplanes and mountain climbers receive an increased dose.
- Technogenic - from 3 to 13%. 75 years have passed since the first atomic explosion. During the tests of atomic weapons, a huge amount of radioactive substances were released into the atmosphere. In addition, man-made accidents - Chernobyl, Fukushima. Extraction and transportation of such substances, as well as operating nuclear power plants. Everything contributes to the general background.
The dose of radiation that a person receives during the year
The norm of the background radiation is a value up to 0.20 μSv / hour or 20 μR / hour. The permissible background is considered to be a level up to 60 μR / hour or 0.6 mSv. For each country, it is set its own, for example, in Brazil, a safe radioactive background is 100 μR per hour.
Safe dose
A safe dose of radiation for humans is the level at which one can live and work without consequences for the body. This level is determined up to 30 μR / h (0.3 μSv / h).
Acceptable dose
The permissible dose of radiation is slightly more safe and shows the level at which the body is exposed to radiation, but without negative health effects.
The permissible level per year assumes up to 1 mSv. If this value is divided by hours, then we get 0.57 μSv / h.
This dose is also used to calculate the average radiation received over several years. For example, a person should receive 5 mSv for 5 years in a row, but working in hazardous production, received an annual rate of 3 mSv. For the next 4 years, he should not receive more than 1 mSv in order to equalize the values and reduce the risk of radiation sickness.
When flying at an altitude above 10 km, the radiation level will be up to 3 μSv / h, which exceeds the norm by 10 times. It turns out that in 4 hours you can get the maximum, total dose of up to 12 μSv.
Radiation that can be treated in flight
Lethal radiation exposure
A dangerous dose can be taken at a level of 0.75 Sv.With this value, a change occurs in a person's blood and although there are no deaths immediately, in the future the likelihood of cancer is quite high.
As already noted above, organs (liver, lungs, stomach, skin) perceive radiation unevenly. Radiation sickness begins with a dose of 1–2 Sievert, and for some it is already a lethal dose. Others can easily survive the infection and recover.
If we proceed from statistics, then the lethal dose will be above 7 Sievert or 700 roentgens.
| Dose. Sievert | Human exposure |
| 1–2 | A mild form of radiation sickness. |
| 2–3 | Radiation sickness. Mortality during the first month up to 35%. |
| 3–6 | Mortality rate up to 60%. |
| 6–10 | Death rate 100% within a year. |
| 10–80 | Coma, death in half an hour |
| 80 and more | Immediate death |
Measurement of radiation in an apartment
The radiation level in the room should not exceed 0.25 μSv / hour. A room in which the radon content is not more than 100 Bq per cubic meter is considered safe. At the same time, in industrial premises, it can be up to 300 Bq and 0.6 microSievert.
If the norms are exceeded, then measures are taken to reduce them. If it is impossible to do this, the tenants should be relocated, and the premises should be converted into non-residential or demolished.
The SanPiN indicates the content of thorium, uranium and potassium-40 used in construction for the construction of housing. The total dose from wall and finishing materials should not exceed 370 Bq / kg.
Materials with increased radioactivity
During construction in Soviet times, all materials were tested in accordance with GOST. Therefore, talk about the fact that the "Khrushchev" five-story buildings have radioactivity is nothing more than a myth. The main source of radiation in an apartment or in any other room is radon gas.
It belongs to natural sources of radiation, since it is present in the earth's crust and released into the environment, contributing its share to the total radiation background. Penetrating into the room through the foundation and floors, it accumulates, increasing the normal radioactive background. Therefore, you should not make the premises too tight. An additional source of radon entering the house is water coming from artesian wells and gas.
Average radioactivity of some building materials
Basic building materials: concrete, brick and wood are not dangerous and are the most harmless. However, in construction and in everyday life, we use materials that emit a fairly large amount of radon. These include:
- pumice;
- granite;
- tuff;
- graphite.
All materials buried in or extracted from the earth's crust may have an increased level of radiation. So it's a good idea to control it yourself.
How to check for radiation
You can check the level of radiation when buying a new apartment, apartment in a disadvantaged area or using suspicious materials in the construction of a house. A person has no sense organs capable of sensing radiation and assessing the danger. Therefore, to detect it, it is necessary to have specialized devices - dosimeters.
Household dosimeters for measuring radiation
They can be household, professional, industrial, or military. Various sensors can be used as a sensitive element: gas-discharge, scintillation crystals, Geiger-Muller mica counters, thermoluminescent lamps, pin diodes.
Household dosimeters are available to us for measurements at home. Depending on the instrument, it can display readings in μSv / h or μR / h. Some devices closer to professional can show in both versions. It should be borne in mind that household dosimeters have a fairly high level of measurement error.
