Radiation: a lethal dose for a person

Radiation is the ionizing radiation of microscopic particles and physical fields. Radiation radiation does not include ultraviolet rays and the range of visible light. The ability to ionize the counterpart does not have radio waves and microwaves, this is not radiation. A lethal dose for a person is not created artificially with the help of chemical processes, radiation refers to physical action.

Power and dose

The power of radiation is the amount of ionization over a certain time interval. For power, there is a unit of measurement - microroentgen per hour.

The dose obtained is measured by the total dose determined by the radiation power multiplied by the time of action of the microparticles, thus, a lethal dose of radiation is calculated for a person that leads to a lethal outcome. To measure the equivalent dose, a sievert (Sv) is used, the power for calculation is determined in sieverts per hour (Sv / h).

To calculate the equivalent dose from the effects of different types of rays, the intensity of the sought radiation with respect to the sievert is taken into account. For example, when determining the total dose from the action of gamma rays, equate 100 x-rays to 1 Sv. Small doses, less than 1 Sv, are calculated with respect to:

• 1 mSv (millisievert) is equal to 1/1000 sievert;
• 1 μSv (microsievert) is equal to 1/1000 millisievert or 1 / 100,000,000 sievert.

Device for measuring radiation

A standard common device for determining the dose rate or power, directed to the device and to the operator of the device, is a dosimeter. Dosimetry is carried out during exposure to radiation, for example, a work shift or the time of rescue work.

The lethal dose of radiation for a person in X-rays depends on the intensity of radiation at the location of the employee, if the total figure is more than 600 units, then such exposure is dangerous for life. The transported goods, objects are examined, the background from buildings and buildings is measured. Everyone who visits places with the danger of radiation contamination acquires a dosimeter for permanent personal use.

Going to an unknown area, for example, mountains, lakes, going on a hike or for berries and mushrooms, take the device to examine the terrain before long-term stay. The radiation intensity of a plot before construction or when buying land is determined. The radiation background does not go down and is not removed from the walls of buildings and objects, therefore a danger is detected with a dosimeter beforehand.

The concept of radioactivity

Some atoms contain unstable nuclei, which can be converted or decay. This process promotes the release of free ions. There is a radioactive radiation, energetically powerful, capable of acting on the surrounding substance and provoking the appearance of new ions of a negative and positive charge. A lethal dose of radiation in rad appears when a person is irradiated with 600 rad, while 100 radians (an extra-system unit) = 100 x-rays.

Causes of radioactive contamination

The effect of various factors and circumstances causes an increased radiation background:

• The deposition of a radioactive material from a nuclear cloud during an explosion;
• When there is an induced radiation produced by the formation of radioactive isotopes with instantaneous action of gamma rays and neutrons released during a nuclear explosion;
• The action of external gamma and beta-ray radiation;
• A fatal dose of radiation is manifested when internal irradiation occurs after ingress of radioactive isotopes into the human body from the air or with food;
• Radioactive contamination is provoked in peacetime by technogenic catastrophes at nuclear facilities, improper transportation and disposal of nuclear waste.

Kind of radiation

Dangerous to humans is the radiation of microparticles, leading to diseases of the body and death. The magnitude of the impact depends on the type of rays, duration of action and frequency:

• Heavy alpha particles positively charged after the decay of nuclei (to them include thoron, cobalt-60, uranium, radon);
• Beta particles are the usual electrons of strontium-90, potassium-40, cesium-137;
• Gamma radiation is represented by particles with a large penetrating power (cesium-137, cobalt-60);
• Hard X-ray radiation resembling gamma particles, but less energetic, provides americium-241, a constant source of occurrence is the sun;
• Neutrons arise as a result of the decay of plutonium nuclei, their accumulation is observed in the environment of atomic reactors.

Variety of doses

An equivalent fixed effective dose is the determination of radiation doses to the body as a result of the arrival of a certain amount of harmful substance. This indicator takes into account the sensitivity of internal organs and the time the radioactive substance is in the body (sometimes throughout life). In some cases, the lethal dose of radiation in X-rays is measured for one selected organ.

The ambivalent dose equivalent is determined by the amount that a person could receive if he were present in the area where dosimetry is done, the indicator is measured in sievert.

The effect of radiation contamination on the human body

Any radiation resulting in the formation of electrical particles with different signs in the environment is considered to be ionizing. The scattered radiation background constantly accompanies a person, it is created by cosmic radiation, the influence of the sun, natural sources of radionuclides, other components of the biosphere.

For work in dangerous conditions, the staff protects with special suits, observe the safety standards. The organism receives irradiation in the workplace during physical and chemical experiments, carrying out flaw detection, medical research, geological surveys, etc.

Mutation from radiation

The lethal dose of radiation for a person in the rad is over 600 units and leads to a lethal outcome. Irradiation in a dose of 400 to 600 rad promotes the appearance of radiation sickness and can cause a mutation of genes. The effect of the ionized transformation of the body is little understood, mutations manifest themselves through generations. The spread of time gives the right to doubt, a mutation has appeared from radioactive influence or is caused by other causes.

Mutations by species are divided into dominant, appearing in a short period after the action of irradiation and recessive. The second kind manifests itself if the mother and child have one mutant gene. The mutation does not wake up for several generations or does not bother the person at all. The fetal degeneration is difficult to determine in the case of premature birth, if the mutation does not allow the fetus to reach the age of birth.

Radiation sickness. Leukemia

The diagnosis of radiation sickness is heavily influenced by radiation. The lethal dose of irradiation leads to a lethal outcome, but radiation levels from 200 to 600 r, which cause radiation sickness, are no less dangerous. Radiation affects a person after a single powerful effect or with a constant penetration of radiation of low power. An example is the work of radiologists who do not stand up to constant irradiation and become ill with characteristic diseases.

The most dangerous is the effect of radiation on a fragile organism up to 15 years. On the size of the dose there is no consensus, the researchers give different doses of tolerance in 50, 100 and 200 rivers. Pathogenesis is studied in research institutes, radiation leukemia becomes more accessible for treatment.

Oncological diseases

The study of the effect of radiation on humans is complicated by the fact that large groups of people are being investigated for the appearance of generalized data, which is impossible without a special experiment. What a lethal dose of radiation is lethal, and what levels cause a person's oncological tumors can not be judged by experimenting with animals.

In terms of the allocation of a dangerous dose that causes cancer, there is no definite data. Any dose of radiation obtained gives an impetus to the body to begin dividing aggressive cells. According to the frequency of manifestations of the disease are divided as follows:

• The most frequent manifestation of leukemia;
• Out of 1000 women at risk, 10 women become ill with breast cancer;
• The same statistics of thyroid cancer.

Degrees of severity of radiation sickness

Symptoms of radiation sickness are a constant headache, movement disorder, gesture coordination, nausea, vomiting, dizziness, indigestion and intestines. What dose of radiation is lethal to humans:

• The first degree is manifested after a latent period of two weeks, the disease is caused by irradiation from 100 to 200 roentgens;
• For the manifestation of the second degree after irradiation with a dose of 200 to 400 roentgen, death occurs in the fourth part of those exposed to irradiation;
• The third stage of radiation sickness is the death rate in 50% of cases, sufficient radiation dose from 400 to 600 X-rays is sufficient for the occurrence;
• The fourth, the most dangerous stage, also causes radiation. The lethal dose is more than 600 roentgen, the lethal outcome occurs in 100% of cases.

Ways of individual protection in case of radiation contamination of the area

The standard actions for the population are determined if there is radiation in the territory. The lethal dose of radiation is dangerous to life, therefore, in order to reduce deaths, people are evacuated to structures that, according to the degree of protection, are divided into capital bomb shelters, cellars, wooden structures and cars. Best protects the first type of structure, the rest are treated as emergency temporary shelters.

Effective measures include protection of the respiratory system, water and food supplies. Shelter essentials do in advance if there is a danger of ejection or explosion. They use antiradiation medicines, do not use milk for fresh food.

Regular sanitization and disinfection of the terrain is carried out, at any convenient opportunity people are evacuated outside the infected area. Reduction of internal radiation due to the exclusion of dust capture is provided by respirators that are effective in 80% of cases. A smaller indicator gives a gauze bandage of four layers, but use all available at your fingertips protection. As a cape water-repellent raincoats, as a last resort, a polyethylene film are applied.

In conclusion, it should be mentioned that the radiation contamination of the terrain does not decrease, the risk of human infection is minimized by the use of personal protective equipment and by monitoring the radiation dose received with dosimeters.