What is radiation and where does it come from?
Radiation is a fairly broad concept. In a general sense, it means any radiation, that is flow energy in the form of particles or waves—even sunlight.
Radiation can be non-ionizing and ionizing. Non-ionizing has lower energy, which is not enough to separate electrons from atoms or molecules. But its power is enough to make molecules vibrate and generate heat. For example, it heats food in the microwave.
Ionizing radiation is powerful enough to cause changes at the atomic level. As a result, ions are formed – electrically charged particles, hence the name. In large doses, this type of radiation damages living cells and affects DNA. This is what we are talking about when in ordinary life we talk about radiation.
Ionizing radiation can come from unstable atoms when they change to a more stable state, releasing energy in the process. This ability of nuclei is called radioactivity. Depending on the type of particles or waves that the nucleus emits to become stable, allocate different types of radioactive radiation. For example:
- Alpha radiation. It has a low penetrating ability, so even plain paper can protect against it. Such radiation is dangerous only if it has internal effects on organs and tissues, if alpha particles enter the body with food, air, or through damage to the skin.
- Beta radiation. It has average penetrating ability, and an obstacle for it Maybe become a layer of clothing or a thin sheet of aluminum. This is radiation use for medical purposes, for example for the treatment of certain malignant tumors.
- Gamma radiation. It is an electromagnetic wave that travels at the speed of light and has the greatest penetrating power. Only an impressive obstacle, such as a thick concrete wall, can stop him. Gamma radiation is used for radiation therapy, food preservation and in the space industry.
Radiation sources are divided into natural and artificial. To natural include cosmic radiation, solar radiation and radioactivity of the earth’s crust, to artificial – residual effects of nuclear tests, nuclear energy and medical radiological procedures, such as x-rays.
From the point of view of the impact on humans, radiation can be external and internal. Internal appears because of the radioactive isotopes that we get from water and food. For example, bananas and Brazil nuts contain radioactive potassium-40. From within on us affects and the radioactive gas radon, which is inhaled in the air. However, all these substances enter the body in small doses, so they do not pose a serious danger. Only large doses of radiation pose a real threat.
How and in what way is radiation measured?
The International System of Units has three units of measurement for radioactivity: becquerel, gray and sievert. In becquerels measure activity of radioactive sources. The absorbed radiation dose is expressed in grays, and the equivalent dose is expressed in sieverts, which characterizes the biological effect on the body, taking into account the type of radiation and the sensitivity of tissues and organs. The level of background radiation is recorded in sieverts per unit time.
For measuring radiation levels and monitoring radiation dose apply spectrometers, radiometers and dosimeters. Professional dosimeters are used by personnel who work with radiation sources. Household dosimeters can only be useful in cases of severe radioactive contamination, which is rare. And almost pointless using them to measure the radioactivity of products or building materials – this requires other methods and specialist knowledge.
What doses of radiation exposure are permissible?
According to sanitary and epidemiological rules and regulations in Russia, the safe dose of radiation is counts 1 millisievert per year. The maximum permissible dose is 5 millisieverts per year.
The dose we receive from natural background radiation is hesitates within 2–4 millisieverts per year. When flying at an altitude of 10 km, for example, we on average subjected to exposure equal to 0.003 millisieverts per hour is lessthan with a chest x-ray.
How radiation affects health
Possibility of serious problems depends on the radiation dose: the higher it is, the higher the risk. If the dose is low and lasts for a long time, the health harm may be reduced as our body is able to repair damaged cells.
However, even minor radiation exposure is contraindicated in some cases. This applies primarily to pregnant women and children under 14 years of age. According to sanitary rules and regulations, they are not subject to X-ray examinations for preventive purposes. Such studies are carried out only for clinical indications.
High doses of radiation cause the appearance of acute symptoms: nausea, vomiting, redness of the skin, hair loss, radiation burns and radiation sickness, which is often fatal.
After the atomic bombings of Hiroshima and Nagasaki, cases of radiation sickness were mainly recorded during radiation accidents, such as the accident at the Chernobyl nuclear power plant in 1986. In addition to industrial disasters, sources of high doses of radiation sufficient to cause radiation sickness include the detonation of a nuclear weapon, a small radioactive device, or a conventional explosive device that disperses radioactive material, such as a dirty bomb.
Exceeding the permissible radiation dose in the long term can lead to the development of cancer.
Overall health effects depend from many factors: from the type of radiation and duration of exposure to the age and gender of the person. Because radiation affects people differently, impossible name the exact lethal dose. It is estimated that 50% of victims will die within 30 days if they receive a whole-body radiation dose of 3,500 to 5,000 millisieverts over a period of minutes to several hours.
How to protect yourself from radiation
To protect yourself from ionizing radiation, There is three ways:
- Time protection, when the less you are in the radiation source area, the better.
- Protection by distance, when the further you are from the source, the lower the radiation dose.
- Shielding is when there is a barrier between you and the source, such as lead, concrete or water, when it comes to protection from x-rays and gamma rays.
In everyday life, we are most often exposed to radiation when we seek medical care. To minimize all possible risks, it is better to undergo X-ray examinations only as prescribed by a doctor or when absolutely necessary. Also, you should not schedule several studies on one day, for example, do fluorography and mammography at the same time. Information about the radiation dose received during each procedure, must enter into your medical record.
What to do in case of radiation danger
If you are in a radiation hazard area, it is important to follow three principles: stay indoors, stay up to date with current information, and follow instructions. Specialists from the Ministry of Emergency Situations give the following recommendations:
- Take shelter in a residential building. The walls of wooden houses attenuate radiation by 10–12 times, stone ones by 10–15 times, and basements by up to 100 times.
- Eliminate the flow of air from the street: close all windows, doors and ventilation openings, seal any cracks.
- Collect supplies of drinking water, and then turn off all taps and cover the wells with film or a lid. In the village this needs to be done first.
- Prepare for possible evacuation. Collect things, documents, valuables, medicines and food for 2-3 days. It is better to take canned food and products that were stored indoors.
- Pack things in plastic bags, bags made of thick paper or fabric, and then put them in a bag or backpack.
- Wear outerwear, a thick fabric headdress and high-top shoes.
- Listen carefully to official messages and follow them.
- Try not to leave the shelter unless absolutely necessary and wait for rescuers.
If you find yourself in the affected area and receive a radiation dose due to an accident, first of all necessary carry out decontamination. Quickly and carefully remove clothing and shoes containing radiation carriers, put them in a sealed plastic bag and put them away. Then take a shower. If this is not possible, wash your face, hands, and other exposed areas of the body with plenty of soap and water. As a last resort, use wet wipes. Afterwards, change into clean clothes. If you don’t have one, cover your nose and mouth, shake the one you were wearing, and put it on again.
Negative effect of increased radiation exposure on the body can reduce vitamins E, C, A and D. If possible, it is worth adding more foods that contain them to your diet.
Drink potassium iodide to protect yourself from radiation no need. It prevents the accumulation of only radioactive iodine and only in the thyroid gland.
Self-treatment can be carried out when there is no way to see a doctor and only in case of real and not fictitious radiation exposure.
This material was first published in 2016. In 2023, we updated the text.
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