The word “radiation” most often refers to ionizing radiation associated with radioactive decay. At the same time, a person experiences the effects 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 man-made sources of pollution resulting from major accidents. These are the most dangerous events for humanity, since, as in a nuclear explosion, iodine (J-131), cesium (Cs-137) and strontium (mainly Sr-90) can be released. Weapons-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 polluted by radioactive products of atomic and hydrogen bombs. Of course, at the moment, radioactive fallout occurs only in connection with natural disasters, such as volcanic eruptions. But, on the other hand, when a nuclear charge splits at the moment of explosion, the radioactive isotope carbon-14 is formed with a half-life of 5,730 years. The explosions changed the equilibrium content of carbon-14 in the atmosphere by 2.6%. Currently, 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 natural background radiation.

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

Medical procedures using sources ionizing radiation almost all inhabitants of the Earth are exposed. But this is a more complex question, which we will return to a little later.

In what units is radiation measured?

Various units are used to measure the amount of radiation energy. In medicine, the main one is the sievert - the effective equivalent dose received in one procedure by the entire body. It is in sieverts per unit time that the level of background radiation is measured. The becquerel serves as a unit of measurement for the radioactivity of water, soil, etc., per unit volume.

Other units of measurement can be found in the table.

Consequences of radiation

The effect of radiation on humans is called exposure. Its main manifestation is acute radiation sickness, which has varying degrees of severity. Radiation sickness can occur when exposed to a dose equal to 1 sievert. A dose of 0.2 sievert increases the risk of cancer, and a dose of 3 sievert threatens the life of the exposed person.

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

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

The effects of radiation can manifest themselves after a long time - this is the so-called stochastic effect. It is expressed in the fact that the incidence of certain cancers may increase among irradiated people. Theoretically, genetic effects are also possible, but even among the 78 thousand Japanese children who survived the atomic bombing of Hiroshima and Nagasaki, no increase in the number of cases of hereditary diseases was found. This is despite the fact that the effects of radiation have a stronger effect on dividing cells, so 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 cancer, but it is very difficult to identify the direct effect of radiation, separating it from the effect of chemically harmful substances, viruses and other things. It is known that after the bombing of Hiroshima, the first effects in the form of increased incidence began to appear only after 10 years or more. Cancer of the thyroid gland, breast and certain parts is directly associated with radiation.

Natural background radiation is about 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 the instantly absorbed radiation dose and the constant background dose). Is this too much? 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, radiation levels reached several thousand microsieverts per hour.

During a 2–3-hour flight over an ecologically clean area, a person receives radiation exposure of 20–30 μSv. The same radiation dose threatens if a person takes 10–15 pictures in one day using a modern X-ray apparatus - a visiograph. A couple of hours in front of a cathode ray monitor or TV gives the same radiation dose as one such photo. The annual dose from smoking one cigarette per day is 2.7 mSv. One fluorography - 0.6 mSv, one radiography - 1.3 mSv, one fluoroscopy - 5 mSv. Radiation from concrete walls is 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 a maximum dose of 50,000 μSv (5 rem) per year.

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

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

Are x-ray examinations dangerous?

Most often we encounter radiation during medical research. However, the doses we receive in the process are so small that there is no need to be afraid of them. The exposure time of an old X-ray machine 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 out in SanPiN 2.6.1.1192-03, when carrying out preventive medical x-ray procedures, the radiation dose should not exceed 1,000 µSv per year. How much is it in pictures? Quite a bit of:

• 500 targeted images (2–3 μSv) obtained using 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 for the whole year we take one picture on a visiograph, add to this a couple of computed tomograms and the same number of orthopantomograms, 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 (SanPiN 2.6.1.1192-03), irradiation in the form of X-rays can be carried out only in the second half of pregnancy, with the exception of cases when the issue of abortion or the need for emergency or urgent care must be resolved.

Paragraph 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 for two months of undetected pregnancy. If the fetus receives a dose exceeding 100 mSv, the doctor is obliged to warn the patient about possible consequences and recommend terminating the pregnancy.”

Young people who will become parents in the future need to protect their abdominal area and genitals from radiation. X-ray radiation has the most negative effect on blood cells and germ cells. In children, in general, the entire body should be shielded, except for the area being examined, and studies should be carried out only if necessary and as prescribed by a doctor.

Sergei Nelyubin, Head of the Department of X-ray Diagnostics, Russian Scientific Center for Surgery named after. B.V. Petrovsky, candidate medical sciences, assistant professor

How to protect yourself

There are three main methods of protection against X-ray radiation: protection by time, protection by distance and shielding. That is, the less you are in the area of ​​X-rays and the further 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, for example, fluorography and. Well, every patient must have a radiation passport (it is included in the medical card): in it the radiologist enters information about the dose received during each examination.

X-ray primarily affects the endocrine glands and lungs. The same applies to small doses of radiation during accidents and releases of active substances. Therefore, as a preventative 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, unprocessed rice, prunes are useful.

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

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

Before or after exposure to radiation, dietary supplements and anti-radiation medications are used. The most well-known medications are high in iodine, which helps to effectively combat the negative effects of its radioactive isotope, which is localized in the thyroid gland. To block the accumulation of radioactive cesium and prevent secondary damage, “Potassium orotate” is used. Calcium supplements deactivate the radioactive drug strontium by 90%. Dimethyl sulfide is indicated to protect cellular structures.

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 a myth at all. This really helps to remove radioactive isotopes from the body in the simplest cases.

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

Ionizing radiation or radiation is harmful to health, everyone knows this. But what diseases arise from radiation, what dose can be safe for a person, and what dose can kill him?

Radiation - an invisible danger

Safe dose of radiation

Where does a person receive doses of radiation? Don't forget about natural radiation. IN different points planets, the radiation background can differ significantly. So, on mountain peaks the radiation is higher, because there the atmosphere has lower protective properties. Increased radiation can also occur in places where there is a lot of dust and sand with thorium and uranium in the air.

What dose of radiation can be safe, maximum permissible, and the body will not suffer? It should not exceed 0.3-0.5 μSv per hour. But if you stay in this room for a short time, then the human body can tolerate radiation with a power of 10 µS per hour without harm to health, this is the maximum permissible level of radiation.

Dangerous dose of radiation

If the maximum permissible level of radiation is exceeded, changes occur in the victim's body. How does radiation affect a person, what can happen in the body under its influence? The table below shows radiation doses and their effects on humans.

Diseases that appear due to radiation

There are chemical elements (plutonium, radium, uranium, etc.) that are capable of spontaneous transformations. They are accompanied by a flow of radiation. It was first discovered in radium, so it was called radioactive decay, and the radiation was called radioactive. Another name for it is penetrating radiation.

The genetic consequences of penetrating radiation are poorly understood

Mutations

Scientists know that radiation causes mutations. Damaging radiation causes changes. But so far the genetic consequences and mutations of penetrating radiation are poorly understood. The fact is that mutations make themselves felt only after generations, and it will take many hundreds of years for mutations to appear. And it is not clear whether their occurrence is related to radiation or whether the mutations are caused by other reasons.

Another difficulty is that most children with abnormalities do not have time to be born; women have spontaneous abortions; a child with abnormalities may not be born. Mutations can be dominant (they immediately make themselves felt) and recessive, which appear only if the child’s father and mother have the same mutant gene. Then the mutations may not appear for several generations or may not affect the life of a person and his descendants at all.

After the tragedy in Hiroshima and Nagasaki, 27 thousand children were studied. Their parents felt the effects of significant doses of radiation. They only had two mutations in their bodies. And the same number of children, whose father and mother were not exposed to such strong radiation, did not have a mutation at all. However, this still does not mean anything. The study of the effect of radiation on humans and mutations began not so long ago, and perhaps other “surprises” await us.

Radiation sickness

It occurs either with a single strong irradiation or with constant irradiation with relatively small doses. Damaging radiation is dangerous to human life. This is the most common disease associated with penetrating radiation.

Leukemia

Leukemia is caused by penetrating radiation

Statistics show that penetrating radiation is often the cause of leukemia. Back in the 40s of the last century, it was noticed that radiologists often died after leukemia, the body could not withstand the radiation. Later, the effect of penetrating radiation on the development of leukemia was confirmed by observations of residents of Hiroshima and Nagasaki.

This time there was no talk about exact radiation doses; approximate figures were taken, focusing on the epicenter of the explosion and the symptoms of acute radiation injury. Only 5 years after the bombing, cases of leukemia began to be recorded. 109 thousand people who survived the bombing were examined:

• The group of irradiated people (dose more than 1 Gy) from 1950 to 1971 - 58 cases of the disease, which is 7 times more than the figure that scientists expected.
• The group of irradiated people (dose less than 1 Gy) - 64 people fell ill, although it was expected that 71.

In subsequent years, the number of cases decreased. The consequences of leukemia are dangerous for people who survived exposure to radiation before the age of 15. The disease does not immediately make itself felt after penetrating radiation. Most often, 4-10 years pass after the damaging radiation struck. There is no consensus on what amount of radiation causes such consequences; everyone gives different permissible doses (50, 100, 200 r). The pathogenesis of radiation-induced leukemia is also not completely understood, but scientists are working in that direction and proposing their theories.

Other cancers

Penetrating radiation affects the occurrence of cancer

Scientists are studying the effects of radiation on humans, including trying to understand whether penetrating radiation affects the occurrence of cancer. But we cannot talk about accurate information, since scientists cannot conduct experiments on people. Experiments are being conducted with animals, but it is impossible to judge from them how damaging radiation affects the human body. To ensure that the information is reliable, it is important to comply with the following conditions.

• You need to know the amount of absorbed dose.
• It is necessary that the radiation hits either the entire body or a specific organ evenly.
• The experimental group must be examined regularly, and this must be done for decades.
• There must be another "control" group of people so that the level of disease can be compared.
• Both groups must include a huge number of people.

It is impossible to conduct such an experiment, so scientists have to study the consequences associated with exposure to penetrating radiation after accidental exposure. So far the data obtained is inaccurate. Thus, scientists believe that there is no permissible dose of penetrating radiation; any dose increases the risk of developing cancer and can cause this disease. Most often, after penetrating radiation, people experience:

1. Leukemia comes first.
2. Mammary cancer. 10 women out of 1000 develop this disease.
3. Thyroid cancer. After exposure to radiation, 10 out of 1000 people develop the disease. It is now curable and the mortality rate is very low.
4. The consequence of radiation is lung cancer. Information that penetrating radiation affects the incidence of this disease on the human body appeared not only from data collected after the bombing of Japan, but also after examination of miners in uranium mines in Canada, the USA and Czechoslovakia.

• Want to know what it is?
• and environment

Japanese authorities reported that on Tuesday, March 24, the level of radiation at the Fukushima-1 nuclear power plant briefly rose to a level at which it could harm human health.

To all residents settlements within a radius of 20 km from the nuclear power plant, it was ordered to immediately leave this area. Those who live at a distance of 20 to 30 km from the station were advised not to leave their homes and isolate their homes to reduce the risk of contaminated air entering them.

Experts say that these actions, if taken immediately, can reduce any negative impact on the human body to a minimum.

What are the first consequences of exposure to radioactive radiation on human health?

The dose of absorbed radiation is measured in grays (one gray is equal to one joule of energy per kilogram of mass of the irradiated substance).

A radiation dose of more than one gray is considered moderate, but even at such a dose symptoms of radiation sickness appear.

In the first hours after irradiation, nausea and vomiting often begin, followed by diarrhea, headaches and fever. These symptoms disappear after a while, but new and more severe symptoms may appear within a few weeks.

At higher doses of radiation, symptoms of radiation sickness may appear immediately, along with multiple and potentially fatal damage to internal organs. Radiation doses of 4 Gy are lethal to about half of healthy adults.

By comparison, when treating cancerous tumors with radiotherapy, patients receive several doses from 1 Gy to 7 Gy, but with radiotherapy the effect is on strictly limited areas of the body.

Different tissues of the body react differently to radioactive radiation. The average effect on biological tissue is measured in sieverts; one sievert is the amount of energy absorbed by a kilogram of biological tissue, equal in effect to 1 Gy.

Radiation doses (millisieverts per year unless otherwise stated) and effect

2 - average background radiation (in Australia on average 1.5 mSv, in North America- 3 mSv);

9 - radiation exposure to which the crew of the New York-Tokyo flight via the North Pole is exposed;

20 is the average limit for nuclear energy workers;

50 is the former radiation standard for nuclear energy workers. Also found naturally in parts of Iran, India and Europe;

100 is the threshold from which an increase in cancer incidence is clearly noticeable;

350 mSv over a lifetime is the threshold for relocating people after Chernobyl accident;

A single dose of 1000 mSv causes short-term (non-fatal) radiation sickness with nausea and a decrease in the content of leukocytes in the blood. The severity of the disease increases with the dose:

A single dose of 5000 mSv - up to half of those who receive such a dose of radiation die within a month.

How can radiation sickness be treated?

The first step is to limit the possibility of further infection by removing clothing and shoes. After this you need to wash with soap.

There are drugs that increase the formation of white blood cells; this helps combat the effects of radiation on the bone marrow and reduces the risk of infectious diseases resulting from weakening immune system.

In addition, it is possible to use medications to reduce the effects of radiation on human internal organs.

How does radiation affect the human body?

Radioactive materials that undergo spontaneous decay emit ionizing radiation, which can cause serious damage to the internal processes of the human body. In particular, they violate chemical bonds between the molecules that make up human tissue.

The body tries to restore these connections, but often the scale of the damage does not allow this. Additionally, errors may occur during the natural recovery process.

The cells of the stomach and gastrointestinal tract, as well as bone marrow cells responsible for the production of white blood cells.

Damage to the body depends on the level and duration of radiation exposure.

What are the long-term effects of radiation on the body?

Most of all, the risk of cancer increases. Usually, the cells of the body simply die when they reach their age limit. However, when cells lose this property and continue to multiply uncontrollably, cancer occurs.

A healthy body usually does not allow cells to reach this state. However, radiation exposure disrupts these processes, dramatically increasing the risk of cancer.

Exposure to radiation also leads to irreversible changes - mutations - of the genetic fund, which, in turn, can be passed on to future generations, causing defects and deviations from normal development: reduction in the size of the brain and head, abnormal formation of the eyes, growth delays and learning difficulties.

Are children at greater risk?

Theoretically, yes, since in a young body the process of cell growth and reproduction actively continues. Accordingly, the possibility of deviations from the norm increases in the event of disruption of the normal functioning of cells.

After the Chernobyl disaster in 1986, the World Health Organization recorded a sharp increase in cases of thyroid cancer in children who lived near the nuclear power plant.

The reason for this was the release of radioactive iodine, which accumulates in the thyroid gland.

How dangerous is the situation at the Fukushima nuclear power plant?

At the nuclear power plant itself, ionizing radiation of 400 millisieverts per hour was recorded.

According to radiation specialist Richard Wakeford, professor at the University of Manchester, exposure to radiation of such power is unlikely to lead to the development of radiation sickness. To do this, he said, the irradiation power should be twice as high.

However, even such irradiation can cause a slowdown in the formation of leukocytes in the bone marrow and increases the risk of developing cancer by 2-4%. The average risk of cancer in Japan is 20-25%.

At the same time, Professor Wakeford notes that only those who participated in emergency work at the nuclear reactor were exposed to such radiation. In addition, to reduce the level of exposure, these workers could be involved in work at nuclear power plants only for a short period of time.

The level of exposure of the population, including those living near the nuclear power plant, was much less.

What can Japanese authorities do to reduce negative health impacts?

Professor Wakeford believes that with quick and correct action by the authorities, the consequences of radiation exposure for the population may be minimal.

The main goal, according to Wakeford, should be the evacuation of the population from nearby areas and the prevention of consumption of food products exposed to radiation. To reduce the risk of radioactive iodine accumulation in the thyroid gland, the population may be given iodine tablets. In addition, the Japanese diet is rich in iodine, so this can also help combat the effects of radiation.

Is it possible to compare the accident at the Fukushima nuclear power plant with the Chernobyl disaster?

As Professor Jerry Thomas, who studied the consequences of the Chernobyl accident, said, it is unlikely that what happened in Japan can be compared with Chernobyl.

"An explosion occurred at the Chernobyl nuclear power plant, as a result of which the reactor was completely destroyed, and in environment a huge amount of radioactive substances got in,” says Jerry Thomas.

Professor Thomas emphasizes that the consequences of the Chernobyl accident were mainly observed in those who lived near the nuclear power plant and, mainly, in children.

The level of radiation released at the Japanese Fukushima nuclear power plant is 5% of Chernobyl.

“Chernobyl was a reactor explosion. This is not the case in Japan. Both the structure and the shell were destroyed in our country. There was no explosion.”

Japanese radiation does not threaten Ukraine and Russia in any way.

In the same time:

Employees of the emergency Japanese nuclear power plant "Fukushima-1" were urgently evacuated due to a column of black smoke that rises above the third power unit.

Personnel were withdrawn only from the third and fourth power units. Meanwhile, the Associated Press writes that the evacuation affected the entire power plant.

The removal of employees from the territory of the nuclear power plant was the second in a day. The day before, the evacuation was carried out after white smoke began to rise above the third reactor. It was later suggested that steam was mistaken for smoke, but this information was not confirmed. Soon after the incident, the personnel were returned to the territory of the nuclear power plant. On Wednesday night, an earthquake of magnitude 6 was recorded near the station, but it did not lead to any destruction.

The number of dead and missing in the devastating earthquake and tsunami in Japan has exceeded 25 thousand people. According to the latest data from the Japanese police, 9 thousand 487 people became victims of the disaster.

Last edited: Mar 25, 2011

Considering that the radioactive cloud is already over Germany, we need to think about the safety of ourselves and our loved ones. All iodine-containing drugs were sold out in pharmacies in England, Germany, and America. Our pharmacies still sell iodomarin, which they recommend drinking. There is another option for using iodine - per glass of milk, 2-3 drops of regular pharmacy iodine at a time for an adult. For children, this dose is smaller, but the same is one-time use. We need to consult with doctors.

Fukushima targets bones and lungs

Radioactive water containing impurities of iodine-131 and cesium, as well as, probably, even more dangerous plutonium and even polonium, is leaking from the foundation of the Fukushima-1 nuclear power plant. Contaminated water in the Pacific Ocean will evaporate and irradiate the lungs of people within a 300 km radius.

The Fukushima operator, TERSO, continues to withhold information about the situation at the nuclear power plant. The foundation of the second reactor has leaked and radioactive water is flowing into the waters of the Pacific Ocean. At first they tried to track its flow using dyes, they tried in vain to fill the gap with polymer with sawdust and paper, and now they are simply going to dump 11.5 thousand tons of radioactive water into the sea to make room for even more radioactive liquid. No one can explain to society what substances and in what quantities enter the Pacific Ocean. If radiation enters the ocean, it will primarily result in an “aerosol effect.”

Contaminated water, although the degree of its radioactivity is not clear, will evaporate into the air and, along with it, penetrate into the lungs of people, which will contribute to the development of cancer and lung burns.
All living beings within a radius of about 300 kilometers from the place where the water is contaminated will inhale radiation-saturated oxygen.

Radionuclides can reach humans through the meat of Pacific fish and other living creatures. These substances, especially iodine, will be absorbed by plankton and settle with it to the bottom, where the plankton will be eaten by fish. This will poison the fish.

It is curious that the consequences of the same radiation dose for humans and small inhabitants of the sea and land are different. For example, animals the size of a mouse need at least 6–8 sieverts for a dangerous dose of radiation, and to the human body Irreversible damage will be caused by radiation of 4.5–5 sieverts. In 50% of cases, such a dose means certain death for a person.

The Japanese, preventing atomic explosions, filled the reactors with water, and this led to the formation of salt scale in the reactor. Now these deposits work as heat conductors, due to which the temperature of the reactors rises to 1200 degrees. There is only one way out - to wait for a gradual cooling for several years, and to prevent radionuclides from spreading, you will have to cover the station with a concrete sarcophagus, as was done after the accident at the Chernobyl nuclear power plant. Experts fear that the third reactor of the Fukushima nuclear power plant may also leak. It contains a very dangerous substance - polonium. Even the smallest dose can poison thousands of people.

No less dangerous to the human body are other substances that, together with radioactive water, enter the world's oceans. In particular, iodine affects the thyroid gland, but in the atmosphere it breaks down in eight days.

The situation is worse with cesium and strontium: they require about 30 years for their half-life. But if cesium in the body settles in the muscles, from where it is quickly excreted, then strontium is deposited in the bones, where it remains forever.

Plutonium has an even more destructive effect. Getting into the human lungs, it leads to the appearance of a cancerous tumor. The half-life of plutonium will take 26 thousand years. Polonium takes 138 days to self-destruct, but during this time it manages to either kill cells or cause them to mutate.

Radiation is radiation invisible to the human eye, which nevertheless has a powerful effect on the body. Unfortunately, the consequences of radiation for humans are extremely negative.

Initially, radiation affects the body from the outside. It comes from natural radioactive elements that are found in the earth, and also enters the planet from space. Also, external radiation comes in microdoses from building materials and medical X-ray machines. Large doses of radiation can be found in nuclear power plants, special physics laboratories and uranium mines. Nuclear weapons testing sites and radiation waste disposal sites are also extremely dangerous.

To a certain extent, our skin, clothing and even homes protect from the above radiation sources. But the main danger of radiation is that exposure can be not only external, but also internal.

Radioactive elements can penetrate air and water, through cuts in the skin and even through body tissue. In this case, the radiation source lasts much longer - until it is removed from the human body. You can’t protect yourself from it with a lead plate and it’s impossible to get away, which makes the situation even more dangerous.

Radiation dosage

In order to determine the radiation power and the degree of impact of radiation on living organisms, several measurement scales were invented. First of all, the power of the radiation source in Grays and Rads is measured. Everything is quite simple here. 1 Gy=100R. This is how exposure levels are determined using a Geiger counter. The X-ray scale is also used.

But you should not assume that these readings reliably indicate the degree of health hazard. It is not enough to know the radiation power. The effect of radiation on the human body also varies depending on the type of radiation. There are 3 of them in total:

1. Alpha. These are heavy radioactive particles - neutrons and protons, which cause the greatest harm to humans. But they have little penetrating power and are not able to penetrate even the upper layers of the skin. But if there are wounds or particles in the air,
2. Beta. These are radioactive electrons. Their penetration capacity is 2 cm of skin.
3. Gamma. These are photons. They freely penetrate the human body, and protection is only possible with the help of lead or a thick layer of concrete.

Radiation exposure occurs on molecular level. Irradiation leads to the formation of free radicals in body cells, which begin to destroy surrounding substances. But, taking into account the uniqueness of each organism and the uneven sensitivity of organs to the effects of radiation on humans, scientists had to introduce the concept of an equivalent dose.

To determine how dangerous radiation is in a particular dose, the radiation power in Rads, Roentgens and Grays is multiplied by the quality factor.

For Alpha radiation it is 20, and for Beta and Gamma radiation it is 1. X-rays also have a coefficient of 1. The result obtained is measured in Rem and Sievert. With a coefficient equal to one, 1 Rem is equal to one Rad or Roentgen, and 1 Sievert is equal to one Gray or 100 Rem.

To determine the degree of exposure of an equivalent dose to the human body, it was necessary to introduce another risk coefficient. It is different for each organ, depending on how radiation affects individual tissues of the body. For the organism as a whole it is equal to one. Thanks to this, it was possible to create a scale of the danger of radiation and its impact on humans after a single exposure:

• 100 Sievert. This is a quick death. A few hours later, and in best case scenario days nervous system the body stops its activity.
• 10-50 is a lethal dose, as a result of which a person will die from numerous internal hemorrhages after several weeks of suffering.
• 4-5 Sievert – -mortality rate is about 50%. Due to damage to the bone marrow and disruption of the hematopoietic process, the body dies after a couple of months or less.
• 1 sievert. It is from this dose that radiation sickness begins.
• 0.75 Sievert. Short-term changes in the composition of the blood.
• 0.5 – this dose is considered sufficient to cause the development of cancer. But there are usually no other symptoms.
• 0.3 Sievert. This is the power of the device when taking an X-ray of the stomach.
• 0.2 Sievert. This is the safe level of radiation allowed when working with radioactive materials.
• 0.1 – for a given radiation background uranium is mined.
• 0.05 Sievert. Norm of background radiation from medical equipment.
• 0.005 Sievert. Permissible radiation level near nuclear power plants. This is also the annual exposure limit for the civilian population.

Consequences of radiation exposure

The dangerous effect of radiation on the human body is caused by the effect of free radicals. They are formed at the chemical level due to exposure to radiation and primarily affect rapidly dividing cells. Accordingly, the hematopoietic organs and reproductive system suffer to a greater extent from radiation.

But the radiation effects of human exposure are not limited to this. In the case of delicate mucous tissues and nerve cells, their destruction occurs. Because of this, various mental disorders can develop.

Often, due to the effect of radiation on the human body, vision suffers. With a large dose of radiation, blindness can occur due to radiation cataracts.

Other body tissues undergo qualitative changes, which is no less dangerous. It is because of this that the risk of cancer increases many times over. Firstly, the structure of tissues changes. And secondly, free radicals damage the DNA molecule. Due to this, cell mutations develop, which leads to cancer and tumors in various organs of the body.

The most dangerous thing is that these changes can persist in descendants due to damage to the genetic material of the germ cells. On the other hand, the opposite effect of radiation on humans is possible – infertility. Also, in all cases without exception, radiation exposure leads to rapid deterioration of cells, which accelerates the aging of the body.

Mutations

The plot of many science fiction stories begins with how radiation leads to mutation in a person or animal. Typically, the mutagenic factor gives the main character various superpowers. In reality, radiation affects a little differently - first of all, the genetic consequences of radiation affect future generations.

Due to disturbances in the DNA molecule chain caused by free radicals, the fetus may develop various abnormalities associated with problems of internal organs, external deformities or mental disorders. Moreover, this violation may extend to future generations.

The DNA molecule is involved not only in human reproduction. Each cell of the body divides according to the program laid down in the genes. If this information is damaged, cells begin to divide incorrectly. This leads to the formation of tumors. It is usually contained by the immune system, which tries to limit the damaged area of ​​tissue, and ideally get rid of it. But due to immunosuppression caused by radiation, mutations can spread uncontrollably. Because of this, tumors begin to metastasize, turning into cancer, or grow and put pressure on internal organs, such as the brain.

Leukemia and other types of cancer

Due to the fact that the effect of radiation on human health primarily affects the hematopoietic organs and circulatory system, the most common consequence of radiation sickness is leukemia. It is also called “blood cancer”. Its manifestations affect the entire body:

1. A person loses weight, and there is no appetite. It is constantly accompanied by muscle weakness and chronic fatigue.
2. Joint pain appears and they begin to react more strongly to environmental conditions.
3. Lymph nodes become inflamed.
4. The liver and spleen enlarge.
5. Breathing becomes difficult.
6. Purple rashes appear on the skin. The person sweats frequently and profusely, and bleeding may occur.
7. Immunodeficiency appears. Infections freely penetrate the body, which often causes the temperature to rise.

Before the events in Hiroshima and Nagasaki, doctors did not consider leukemia to be a radiation disease. But 109 thousand Japanese people examined confirmed the connection between radiation and cancer. It also revealed the likelihood of damage to certain organs. Leukemia came first.

Then the radiation effects of human exposure most often lead to:

1. Mammary cancer. Every hundredth woman who survives severe radiation exposure is affected.
2. Thyroid cancer. It also affects 1% of those exposed.
3. Lungs' cancer. This variety manifests itself most strongly in irradiated miners of uranium mines.

Fortunately, modern medicine can easily cope with cancer in the early stages, if the effect of radiation on human health was short-term and quite weak.

What affects the effects of radiation

The effects of radiation on living organisms vary greatly depending on the strength and type of radiation: alpha, beta or gamma. Depending on this, the same dose of radiation can be practically safe or lead to sudden death.

It is also important to understand that the effects of radiation on the human body are rarely simultaneous. Getting a dose of 0.5 Sievert at a time is dangerous, and 5-6 is fatal. But by taking several x-rays of 0.3 Sievert over a certain period of time, a person allows the body to cleanse itself. Therefore, the negative consequences of radiation exposure simply do not appear, since with a total dose of several Sieverts, only a small part of the radiation will affect the body at a time.

In addition, the various effects of radiation on humans depend greatly on individual characteristics body. A healthy body resists the destructive effects of radiation longer. But the best way to ensure the safety of radiation for humans is to have as little contact with radiation as possible to minimize damage.

There are no shots, explosions, or movement of military equipment here. Invisible danger awaits humans and animals behind every bush. Among the meadows filled with flowers, berries, mushrooms. The name of the phenomenon is radiation. Mysterious rays coming from radioactive elements during decay prevent the use of a terrible zone with radioactive contamination for human life. They can quickly and imperceptibly destroy the body and worsen health.

What is radiation

The discovery of radioactivity is associated with the work of the laureate Nobel Prize in physics by a German scientist Wilhelm Roentgen, French physicist Becquerel. Researchers studied the structure of the atom, the processes occurring inside chemical elements. The term radioactivity, denoting the transformation of nuclei into other nuclei, accompanied by radiation, was introduced Marie Curie. When certain elements, called radionuclides, appear different particles, differing in energy reserves. The flow of such particles was called radiation.

Every day a person is exposed to the effects of radioactive radiation generated in natural conditions from the elements that make up the structure of the earth. Water, air, and soil contain about 60 types of substances that create a natural background of ionizing radiation. For example, radon formed in the soil, in deep artesian wells, rocks. It is considered an important source of harmful radiation. Rays from space that create dangerous levels of radiation at high altitudes. The maximum percentage of radiation comes from man-made sources. This includes diagnostics with modern medical equipment, nuclear energy production systems, and testing of destructive weapons. From the point of view of occurrence of cases of exposure to harmful radiation, the following options exist:

1. Planned, strictly regulated exposure during the diagnosis of diseases on medical equipment.
2. Exposure to known naturally occurring sources of radiation. For example, in housing, near workplaces due to the use of specific building materials, special devices, background radiation from the environment. Special control and protection measures are always provided.
3. Impact in the event of emergency incidents during nuclear disasters, malicious actions that cause radioactive contamination of the area. Thanks to such events, a warning sign appeared on our planet: danger zone, radiation.

A terrible phenomenon of our time is created due to the deposition of radioactive chemical elements from a nuclear mushroom, which appears as a result of thoughtless activity and human mistakes. Big square over the years it has become danger zone radioactive contamination of the area. The formation of the composition of radioactive contamination occurs due to the presence of alpha, beta, and gamma rays. A dangerous cloud is carried by the wind over long distances. At first (20 hours after the explosion), the bulk of radioactive compounds fall out of it. The degree of infection and its scale depend on the weather, landscape, and the force of the explosion. It is customary to distinguish zones of radioactive contamination according to the amount of radiation generated. Moderate(denoted in blue), strong(green color), dangerous (Red color), extremely heavy radioactive contamination, denoted by ominous black . The characteristics of radioactive contamination zones are determined by the quantitative value of the radiation level. In the first zone of radioactive charging, after the explosion it is 8 R/hour. After 10 hours the level drops to 0.5 R/hour. Radiation values ​​of the second zone increase in 10 times. Radiation is detected in the third zone immediately after the explosion 240 R/hour. In the fourth zone, the amount of radioactive contamination of the environment becomes equal to 4000 R/hour.

The following radioactive elements appear in the contaminated area:

1. Iodine-131. Emits beta and gamma rays, the most dangerous for living beings. The half-life is 8 days. Causes cell death and mutation. The main concentration occurs in the thyroid gland.
2. Strontium-90. The half-life lasts 29 years. It is dangerous for bone tissue. Enters the environment during accidents at nuclear power plants, nuclear explosions modern weapons.
3. Cesium-137. An element with a half-life of 30 years is considered the main component of radioactive contamination of the environment.

Cobalt (half-life of about 6 years), americium-241, which lives for 433 years, fill the radioactive zone that exists next to humans. The property of radioactive elements is the creation of energy rays that penetrate to different depths. They have different effects on living cells. Alpha radiation is blocked by a simple sheet of paper without penetrating human skin. It will cause harm only when the radioactive substances emitting them enter the body. This occurs through open wounds, with food, water, and air. Beta radiation is characterized by greater penetrating power. Depending on the energy reserves, it passes to a depth of about 10 cm. The most terrible gamma radiation, propagating at the speed of light, can only be stopped by powerful concrete walls and lead.

Severe disasters that led to severe radioactive contamination of the environment are considered to be the accident at the Chernobyl nuclear power plant, the Japanese Fukushima plant, and nuclear weapons tests in Japanese cities. Test site near Semipalatinsk, leakage of radioactive waste in Chelyabinsk region, secret testing grounds of America and Korea. Some accidents became public after many years. It seems that there are still secret areas with the danger of radioactive contamination. Prohibitory signs defining the death zone were placed everywhere. They did not always solve the security issues of the local population.

The consequences of radioactive contamination affect human health in the most severe cases. Skin burns, radiation exposure, bone destruction, changes in blood composition occur when radiation exceeds the permissible level. At the same time, low doses received from radioactive elements increase the risk of various diseases, such as cancer. The dose received by the body is usually classified according to physical quantity measurement called Sievert. This is an effective unit of measurement that allows one to evaluate the strength of ionizing radiation in terms of the amount of harm caused. The absolute value of the sievert is large. In practice they are used millisievert (mSv), microsievert (µSv)).

The physical meaning of the action of radiation is the implementation of the following phenomena:

1. Electrical interaction with tissues. In a very short period of time when radiation passes through human organs and tissues, it provokes the ionization of atoms, destroying living cells.
2. Physico-chemical reactions. An ionized atom and an emerging free electron cannot remain in a new state for a long time. Their participation in the chain chemical reactions, leads to the formation of new molecules of compounds harmful to the body, for example “free radicals”.
3. Chemical processes. The resulting “free radicals” interfere with the normal functioning of living cells, modifying them. Processes occur within millionths of a second.
4. Biological changes. They appear immediately or after years, gradually disrupting important processes in any human organ.

International requirements for radiation protection in 1990, as well as regulatory documents NRB-96 (1996) stipulates the following dose values:

1. Radiation values ​​of 1.5 Sv (150 rem) received over a year or short-term exposure to a dose of 0.5 Sv (50 rem) can create harmful effects.
2. Radiation sickness develops after absorbing a dose of 1-2 Sv (100-200 rem). Having received more than 6 Sv, a person’s condition is characterized by a fatal fourth degree of the disease.
3. Natural radioactive radiation has a value corresponding to 0.05 to 0.2 μSv/h, i.e. from 0.44 to 1.75 mSv per year. During a medical diagnosis, a person receives 1.4 mSv per year.

• The element discovered in the first ranks of radioactive substances by the Curies was named radium, which means “emitting, radiating rays.”
• Over the course of a year, a smoker receives a dose of radiation obtained from 250 X-ray images.
• Brazil nuts are considered the most radioactive product. Tree roots reach deep layers of the earth containing radioactive potassium. The dose does not pose a danger to people.
• In the contaminated zone of Chernobyl, a special type of living organisms appeared, developing in an atmosphere of radiation.
• The unknown effect of radiation on human health at the beginning of the 20th century gave birth to a fashion for the manufacture of numerous items containing radioactive elements. Cosmetics, cigarettes, water, food, dishes, and watch dials contained hazardous substances. Radium was even added to toothpaste and soap.

Amazing discoveries by physicists have been implemented in projects and technologies that are not always safe. The whole world should closely monitor their progress.