Light emission. It accounts for 30~35% of the energy of a nuclear explosion. Under the light radiation of a nuclear explosion is understood electromagnetic radiation of the ultraviolet, visible and infrared spectrum. The source of light radiation is the luminous area of the explosion. The duration of the light radiation and the size of the luminous area depend on the power of the explosion. With its increase, they increase. By the duration of the glow, you can roughly determine the power of a nuclear explosion.
From the formula:
where X- glow duration (s); e is the power of a nuclear explosion (kt), it can be seen that the time of action of light radiation during a ground and air explosion with a power of 1 kt is 1 s; 10 kt - 2.2 s, 100 kt - 4.6 s, 1 mgt - 10 s.
The damaging factor of exposure to light radiation is light pulse - the amount of direct light energy incident on 1 m 2 of a surface perpendicular to the direction of propagation of light radiation for the entire duration of the glow. The magnitude of the light pulse depends on the type of explosion and the state of the atmosphere. It is measured in the Si system in joules (J / m 2) and calories per cm 2 in the off-system system of units. 1 Cal / cm 2 \u003d 5 J / m 2.
Exposure to light radiation causes burns of varying degrees in a person:
- 2.5 Cal/cm 2 - redness, soreness of the skin;
- 5 - blisters appear on the skin;
- 10-15 - the appearance of ulcers, necrosis of the skin;
- 15 and above - necrosis of the deep layers of the skin.
Disability occurs when receiving burns of the second and third degree of open areas of the body (face, neck, hands). If light enters the eyes directly, it may burn the fundus.
Temporary blindness occurs with a sudden change in the brightness of the field of view (twilight, night). At night, blinding can be massive and last for minutes.
When exposed to materials, an impulse of 6 to 16 Cal/cm 2 causes them to ignite and leads to fires. With light fog, the magnitude of the impulse decreases by 10 times, with thick fog - by 20.
It leads to numerous fires and explosions as a result of damage to gas communications and electrical networks.
The damaging effect of light radiation is reduced with timely notification, the use of protective structures and PPE (clothes, light-protective glasses).
Penetrating radiation (4-5% of the energy of a nuclear explosion) is a stream of y-quanta and neutrons emitted for 10-15 s from the luminous region of the explosion as a result of a nuclear reaction and radioactive decay of its products. The fraction of neutrons in the energy of penetrating radiation is 20%. In explosions of low and ultra-low power, the proportion of penetrating radiation increases significantly.
The radius of damage by penetrating radiation is insignificant (a half dose reduction occurs when overcoming 4-5 km in the air).
The neutron flux causes induced radioactivity in the environment due to the transition of atoms of stable elements into their radioactive isotopes, mainly short-lived ones. The impact of penetrating radiation on a person causes radiation sickness in him.
Radioactive contamination (contamination) of the environment (RZ). It accounts for 10-15% of the total energy of a nuclear explosion. Occurs as a result of the fallout of radioactive substances (RS) from the cloud of a nuclear explosion. The molten mass of soil contains radioactive decay products. With a low air, ground and especially underground explosion, the soil from the funnel formed by the explosion, being drawn into the fireball, melts and mixes with radioactive substances, and then slowly settles to the ground both in the area of the explosion and beyond it in the direction of the wind. Depending on the power of the explosion, 60-80% (RV) falls locally. 20-40% rises into the atmosphere and gradually settles to the ground, forming global areas of contaminated territories.
During air explosions, RS do not mix with the soil, but rise into the atmosphere, spreading in it and slowly falling out in the form of a dispersed aerosol.
In contrast to an accident at a nuclear power plant, where the trace of an accidental release of radioactive substances has a mosaic shape due to frequent changes in wind direction in the surface layer, an elliptical trail is formed during a nuclear explosion, since the wind direction practically does not change during the local fallout of radioactive substances.
Sources of RP in the area are fission products of the material of a nuclear explosion, as well as unreacted particles of the material. (II 235, P1; 239). An insignificant share in the total mass of radioactive substances is radioactive elements - products of the action of induced radiation, formed as a result of exposure to neutron radiation.
A characteristic feature of RZ is the constantly occurring decline in the level of radiation due to the decay of radionuclides. For a time multiple of 7, the radiation level decreases by 10 times. So, if one hour after the explosion, the radiation level is taken as the initial level, then after 7 hours it will decrease by 10 times, after 49 hours - by 100 times, and after 14 days - by 1000 times compared to the initial level.
In case of an accident at a nuclear power plant, the decrease in the level of radiation occurs more slowly. This is due to a different isotopic composition of the radioactive cloud. Most of the short-lived isotopes decay during reactor operation, and their number during an accidental release is much less than during a nuclear explosion. As a result, the decrease in the level of radiation during an accident over a seven-fold period of time is only halved.
Electromagnetic pulse (EMP). During nuclear explosions in the atmosphere, as a result of the interaction of γ-radiation and neutrons with the atoms of the environment, short-term powerful electromagnetic fields arise with a wavelength from 1 to 1000 m or more. (Corresponds to the range of radio waves.) The damaging effect of EMR is due to the occurrence of powerful electric fields in the wires and cables of communication lines, in radio station antennas and other electronic devices. The damaging factor of EMR is the strength of the electric and (to a lesser extent) magnetic fields, depending on the power and height of the explosion, the distance from the center of the explosion, and the properties of the environment. EMR has the greatest damaging effect during space and high-altitude nuclear explosions, disabling radio-electronic equipment located even in buried rooms.
One nuclear explosion upper layers atmosphere is capable of generating EMP sufficient to disrupt the operation of electronic equipment throughout the country. So, on July 9, 1962, in the city of Ohau in Hawaii, which is located 1300 km from Johnston Island, located in the Pacific Ocean, where nuclear tests were carried out, street lights went out.
The warhead of a modern ballistic missile is capable of penetrating up to 300 meters of rock and fires in specially fortified command posts.
A new type of HO has appeared - "a compact ultra-low power atomic bomb." When it explodes, radiation occurs, which, like a "neutron bomb", destroys all life in the affected area. Its basis is the chemical element hafnium, the atoms of which are activated upon irradiation. As a result, energy is released in the form of y-radiation. By brisance (destructive power) 1 g of hafnium is equivalent to 50 kg of TNT. The use of hafnium in ammunition can create miniature projectiles. There will be very little radioactive fallout from the explosion of a hafnium bomb.
Today, about 10 countries are practically very close to creating nuclear weapons. However, this type of weapon is the most easily controlled due to its inevitable radioactivity and the technological complexity of production. The situation is more complicated with chemical and biological weapons. Recently, many enterprises with various forms of ownership have emerged, operating in the field of chemistry, biology, pharmacology, and the food industry. Here, even in artisanal conditions, it is possible to prepare agents or deadly biological preparations; In the city of Obolensk near Moscow, there is the world's largest center for biological research, in which unique collection strains of the most dangerous pathogenic bacteria. The chain went bankrupt. There was a real threat of loss of a unique collection.
radiation is called a ray-like spread of something from the center to the circumference.
Exists different types radiation, which, unlike visible light and heat, is not perceived by our senses. Man lives in a world where there are no places where there would be no radiation. It is believed that it was the ability of radioactive radiation to cause mutations that served as the main reason for the continuous evolution of biological species. According to biologists, about 1 billion species of living organisms have evolved since the beginning of life on Earth. Currently, according to various estimates, there are from 2 to 15 million species of flora and fauna left. Without exposure to radiation, our planet would probably not have such a variety of life forms. The presence of a radiation background is one of the essential conditions for life on Earth, radiation is just as necessary for life as light and heat. With a slight increase in the radiation background, the metabolism in the human body improves somewhat, with a decrease in the radiation background, the growth and development of living organisms slows down by 30 - 50%. With "zero" radiation, plant seeds cease to grow, and living organisms cease to multiply. Therefore, one should not succumb to radiophobia - the fear of radiation, but it is necessary to know what threat high levels of radiation pose, learn to avoid it, and, if necessary, survive in conditions of radiation danger. natural radiation is a natural component of the human environment. Conventionally, radiation can be divided into ionizing and non-ionizing. non-ionizing radiation is light, radio waves, radioactive heat from the Sun. This type of radiation does not cause damage to the human body, although it has a harmful effect at high intensity. Radiation is considered ionizing in the event that it is capable of breaking the chemical bonds of the molecules that make up living organisms. For simplicity, ionizing radiation is simply called radiation, and its quantitative characteristic is called dose. To register the indicators and characteristics of radioactive radiation, special devices are used - dosimeters and radiometers.
The normal radiation background is considered to be 10 - 16 μR/h.
Under the influence of natural background radiation, a person is exposed to external and internal radiation. Sources external exposure - this is cosmic radiation and natural radioactive substances located on the surface and in the depths of the Earth, in the atmosphere, water, and plants. cosmic radiation includes galactic and sunny radiation. The intensity of cosmic radiation depends on geomagnetic latitude (increases from the equator to northern latitudes), height above sea level. Compared with the dose of cosmic radiation received by people near the equator, at the latitude of Moscow it increases 1.5 times, at an altitude of 2 km - 3 times, 4 km - 6 times, in an airplane at an altitude of 12 km - 150 times. The level of cosmic radiation increases significantly during solar flares.
The main amount of natural radioactive substances is contained in the rocks that make up the thickness of the earth's crust. They are distributed unevenly in the earth's crust, depending on the type of rocks; accordingly, the radiation dose for people living in different places will be different. There are 5 geographical regions on Earth where the natural radiation background is significantly increased. These places are located in Brazil, India, France, Egypt and on the island of Nice in the Pacific Ocean. So, on some beaches of the resort town of Guarapari (Brazil), the radiation level exceeds the norm by about 500 times. This is due to the fact that the city stands on sands rich in thorium.
Internal exposure 2/3 of a person from natural sources comes from the ingress of radioactive substances into the body with food products, drinking water inhaled air. Quite often, radionuclides enter the human body through the so-called food or biological chains. For example, a radionuclide in the soil enters plants with water, a cow eats the plants, and a radioactive substance enters the human body with milk or meat from this cow.
The greatest contribution to the natural internal exposure of a person is made by radioactive gas - radon. This gas is everywhere released from the earth's crust. With prolonged exposure to radon, a person can develop cancer. According to the UN Scientific Committee on the Effects of Atomic Radiation, nearly 20% of all lung cancers can be caused by exposure to radon and its decay products. The concentration of radon indoors is 8 times higher than outdoors. Radon gives 44% of the total radiation dose in Russia.
The emergence of sources artificial radiation contributed to an increase in the radiation load on humans. People are periodically exposed to radiation from televisions, computers, medical X-ray machines, radioactive fallout from nuclear weapons tests, and from nuclear power plants.
Significant a source increasing background radiation on the planet - nuclear power plant accidents. The reasons for such emergencies are varied - from human error and equipment wear and tear to malicious intent. There is a high probability of terrorist attacks on nuclear power plants. In isolated cases, emergencies at nuclear power plants can turn into catastrophes that cause enormous damage. In 2004 at enterprises Russian Federation 4 accidents with the release of radioactive substances were registered (in 2005 - 0).
There are currently about 45,000 nuclear warheads in the world. During nuclear explosions, radiation damage to people occurs due to penetrating radiation and radioactive contamination of the area (Fig. 3.7).
Fig.3.7.
Penetrating radiation - a stream of gamma rays and neutrons emitted from the nuclear explosion zone in all directions for several seconds.
Nuclear pollution - this is the result of a huge amount of radioactive substances falling out of the explosion cloud. Falling to the earth's surface, they create a contaminated area, called a radioactive trace.
Man-made and natural radiation are similar in nature and can have harmful effects on human health.
Action
ionizing radiation:
- the effect of radiation on the body is imperceptible by a person (people do not have sense organs that would perceive ionizing radiation);
- ionizing radiation can have a harmful effect on human health (the boundaries between the harm and benefit of radiation have not yet been established, therefore, any ionizing radiation should be treated as dangerous);
- the individual characteristics of the human body are manifested only at low doses of radiation (the younger the person, the higher his sensitivity to radiation; starting from the age of 25, a person becomes the most resistant to radiation);
- the greater the dose of radiation received by a person, the higher the likelihood of him developing radiation sickness;
- visible lesions of the skin, malaise, characteristic of radiation sickness, do not appear immediately, but only some time later;
- summation of doses occurs secretly (over time, radiation doses are summed up, which leads to radiation sickness).
As a result of exposure to radiation in the human body, the course of biochemical processes and metabolism is disrupted. Depending on the absorbed dose and individual features body changes can be reversible or irreversible. At a small dose, the affected tissue restores its functional activity, while a large dose with prolonged exposure can cause irreversible damage to individual organs or the whole organism.
In the event of an emergency accompanied by ionizing radiation, it is necessary to take all measures so that the dose received is as small as possible. There are three effective ways to protect against radiation: protection by time, protection by distance, protection by shielding and absorption (Fig. 3.8).
Rice. 3.8.
time protection means limiting the time spent on the ground or objects affected by radioactive contamination (the shorter the period of time, the lower the received radiation dose).
Under distance protection refers to the evacuation of people from places where it is observed or expected high level radiation.
In conditions of impossibility of evacuation, it is carried out protection by shielding and absorption. With this method of protection, shelters, shelters and means are used. personal protection.
Notification of the population about radioactive contamination is organized by the authorities of the Civil Defense Emergencies.
"Radiation Hazard"- a signal that is given when the beginning of radioactive contamination of a given settlement (district) is detected or when there is a threat of radioactive contamination within the next hour. It is brought to the population through local radio and television networks, and is also served by sirens. Upon notification of a radiation hazard, the public should immediately act on the advice received through the media.
The light source is divided into:
chemical source
Photoluminescent
Radioluminescent (phosphor 31)
Incandescent lamps (Lodygin)
Discharge lamps (Yablochkov)
Semiconductor light sources (LEDs) (Alferov)
Non-electric sources
Characteristics of light sources:
Rated voltage (usually 220 or 127)
Lamp power
Rated luminous flux [F nom ]
Color design of industrial interior. Performance to a certain extent depends on the color design.
Red color - excites
Orange - invigorates
Yellow - fun
Green - soothes
Blue - regulates breathing
Black - sharply lowers mood
White - causes apathy
Noise and vibration
The impact of noise on human activity.
Noise– any unwanted sound that has a harmful effect on the human body.
Noise damage:
Reduces attention
Impairs reaction
Depresses the nervous system
Promotes metabolic disorders
noise sickness– occupational disease (some organs cease to function due to noise).
Sound vibrations are divided into:
Infrasound (less than 20 Hz)
Audible (20 Hz to 20 kHz)
ultrasonic range
Low frequency (20 to 400 Hz)
Average frequency (from 400 to 1000)
High Frequency (1000 to 4000)
Intensity- the ratio of power to the area of transferred energy. [W/m2]
sound wave pressure(measured in pascals).
The increase in the power of sensation
Measured in Bels
Noise regulation
Normalized by:
Limit spectrum (constant noise)
Equivalent noise level (intermittent noise)
Up to 35 dB - does not bother a person
40 to 70 causes neuroses
Above 70 dB leads to hearing loss
up to 140 causes pain
over 140 death
Noise protection
Reducing the sound power of the noise source
Noise redirection
Rational layout of production sites
The most rational way to reduce noise is to reduce the sound power of its source. The reduction of mechanical noise is achieved by: improving the design of mechanisms; replacement metal parts on plastic; replacement of impact technological processes with non-impact ones.
The effectiveness of these measures to reduce the noise level gives an effect of up to 15 dB.
The next way to reduce noise is to change the direction of its radiation.
This method is used when the operating device emits noise directionally. An example of such a device is a pipe for discharging compressed air into the atmosphere in the direction opposite to the workplace.
Rational planning of enterprises and workshops. If there are several noisy workshops on the territory of the enterprise, then it is advisable to concentrate them in one or two places, as far as possible from other workshops and residential areas.
The next way to deal with noise is associated with a decrease in sound power along the path of noise propagation (sound insulation). In practice, this is achieved by using soundproof enclosures and casings, soundproof booths and control panels, soundproof and acoustic screens.
It is recommended to use concrete, reinforced concrete, brick, ceramic blocks, wooden sheets, glass as materials for soundproofing fences.
Soundproof casings usually completely cover the noise-producing device. Casings are made of sheet metal (steel, duralumin) or plastic. As with soundproof enclosures, enclosures are more effective at reducing noise at high frequencies than at low frequencies.
5. Sound absorption. In industrial premises, the sound level increases significantly due to the reflection of noise from building structures and equipment. To reduce the level of reflected sound, a special acoustic treatment of the room is used using sound absorption means, which include sound-absorbing linings and piece sound absorbers. They absorb sound. In this case, the oscillatory energy of the sound wave is converted into heat due to friction losses in the sound absorber.
For sound absorption, porous materials are used (i.e., materials that do not have a continuous structure), since friction losses in them are more significant. Conversely, soundproof structures that reflect noise are made of massive, hard and dense materials.
Personal protective equipment
Ear plugs (reduce up to 20 dB)
Earbuds (up to 40 dB)
Helmets (up to 60-70 dB)
Vibration. The impact of vibration on life
Vibration are mechanical vibrations of a rigid body around the equilibrium position.
From a physical point of view, vibration is an oscillatory process, as a result of which the body passes through the same stable position at certain intervals.
Frequency characteristics of vibration:
Frequency range for general vibrations (F=0.8*80Hz)
Average geometric frequencies (1, 2, 4, 8, 16, 32, 63 Hz)
Frequency range for local vibrations (from 5 to 1400 Hz)
SNG (8, 16, 32, 63, 125, 250, 500, 1000)
Absolute vibration parameters
Amplitude [A] [U] is measured in meters
Vibration velocity [V] m/s
Vibration acceleration [a] m/s 2
Relative vibration parameters
Vibration velocity level
α v =20Lg(V/V 0) [dB]
V 0 =5*10 -8 m/s Threshold value
Vibration acceleration level
α a \u003d 20Lg (a / a 0) dB
Vibration is divided into two types:
Local vibration (acts on individual parts of the body)
General vibration (acts on the entire body through the supporting surfaces (floor, seat)).
Vibration is very dangerous for the body. When external vibrations and vibrations of the body coincide, a resonance occurs (6-9 Hz).
Vibration disease (not treated):
Stage 1: change in skin feelings; pain and weakness in the bones; changes in blood vessels
Stage 2: violation of skin sensitivity; spasms of the fingers
Stage 3: atrophy of the shoulder girdle; changes in the central nervous system (central nervous system) and CCC (cardiovascular system)
Sources of vibration
In accordance with SSBT (GOST 12), vibration sources are divided into:
Transport sources (road, rail and water)
Transport and technological (cranes, excavators)
Technological (machines, compressors and pumps)
Manual cars
Hand tool
Local
Vibration regulation
Vibration is normalized in accordance with sanitary standards (industrial vibration, vibration of residential and public premises).
Vibration is normalized according to two indicators:
Vibration local
Vibration general
Both vibrations are normalized by the speed level in dB.
Very often both noise and vibration are normalized at the same time.
Noise is normalized:
By equivalent sound level
According to the sound pressure of infrasound
According to the sound pressure of air ultrasound
According to the level of vibration velocity of ultrasound.
4) Vibration protection
Vibration damping (vibration damper) Mechanical energy is converted into thermal energy
Vibration damping (array, foundation)
Vibration isolation (room isolators)
Vibration reduction at the source
Vibration reduction along its propagation path
Personal protective equipment
The main personal protective equipment is vibration-proof shoes and vibration-proof gloves
Compliance with the regime of work and rest
The degree of impact of vibration on a person depends on the time of continuous operation of the vibro tool. Doctors have established that every 30 minutes to take breaks for 10-15 minutes, then vibration sickness can be avoided.
Electromagnetic radiation (EMR)
The impact of electromagnetic radiation on humans.
Non-ionizing electromagnetic radiation includes:
Ultraviolet radiation
visible light
Infrared radiation
radio waves
Ionizing species include x-rays and gamma rays.
From the point of view of life safety, non-ionizing electromagnetic radiation is divided into three groups:
EMF (electromagnetic radiation) radio frequencies
EMF (electromagnetic radiation of industrial frequency)
Permanent magnetic fields
Radio Frequency Electromagnetic Emissions
Basic parameters of electromagnetic radiation:
Sources of electromagnetic radiation:
microwaves
Mobile and radio telephones
Computers
Radio engineering objects
Radios and Cellular Base Stations
Thermal shops
household sources
Zones of influence of electromagnetic fields(often in an exam)
(impact is characterized only by the energy flux density [I])
Human exposure to electromagnetic radiation is associated with a thermal effect. Electromagnetic radiation (EMR) - transfers a certain amount of energy to the human body, this energy is converted into heat up to a certain limit, the body removes this heat, when it ceases to cope with heat removal, the person becomes ill.
Organs that are more susceptible to EMR: eyes; brain stomach liver
Symptoms: fatigue and changes in the blood, then tumors and allergies occur.
Rationing of the electromagnetic environment
SanNPiN 2.2.4. 191-03 - electromagnetic fields in industrial conditions
TRL of the earth's magnetic field
Maximum permissible levels of magnetic fields
Maximum allowable levels of electrostatic fields
Maximum permissible levels of electric and magnetic fields of industrial frequency
Maximum permissible levels of electromagnetic fields (by range)
Energy flux density - in the CIS
In the USA, the characteristic is the specific power absorption
Electromagnetic safety
It is carried out by the following methods:
Reflective (Foucault currents dampen these waves)
Absorbent
time protection
distance protection
Protection by rational compensation of the source of ionizing radiation
Reducing the power of sources of ionizing radiation
Shielding
The use of personal protective equipment (gowns with a metal base)
Cell Phone Rules
The energy flux density of a mobile phone in the brain area is (16 W / m 2 exposure per minute, and the allowable rate is 10 W / m 2)
The greatest power occurs at the time of the call
Ear distance (do not lean too hard)
Transferring from hand to hand (i.e. from one ear to the other)
Using headphones (headset)
Harmful factors that arise when working with a computer
Working posture and lighting
Heat (infrared radiation)
Noise and vibration
Static electricity
electromagnetic fields
Security measures:
Compliance with the ergonomics of the workplace (convenient location and lighting)
Microclimate (temperature should not exceed 35 degrees; humidity 65%, air from 0.1 to 02 m / s)
Room volume (at least 20 m2 per user)
Air volume (at least 20 m 3 / hour)
Distance to the display (at least 60 cm)
Rest time (10 minutes per hour)
Radiation safety
Types of ionizing radiation
Radiation refers to ionizing radiation.
ionizing radiation- this is the radiation whose interaction with the medium leads to the formation of ions.
Ionizing radiation is divided into:
Characteristics of sources of ionizing radiation. (Activity)
A source of ionizing radiation is a substance and installation, the use of which produces ionizing radiation.
The characteristic of sources of ionizing radiation is activity[A].
Activity is the number of units formed by the radiation source per unit time. (Measured in Bq - Becquerel and Curie).
1 Bq is the activity of the source in which 1 decay occurs in 1 second.
1 Curie - the activity of the source in which 37 billion decays occur in 1 second.
Specific activity is the activity of 1 kilogram (mass unit) of the source, i.e. the ratio of activity to mass. (Bq/kg).
Volume activity is the ratio of activity to source volume. (Bq/m 3)
surface activity is the ratio of source activity to its area. (Bq/m 2)
The law of radioactive decay determines the change in activity over time. A t = A 0 e - λt
Wigner Wey's Law– during explosions and accidents, the activity of the source changes according to the exponential law. A t \u003d A 0 (t / t 0) - n
Characteristics of the interaction of ionizing radiation with the environment. (Dose characteristics)
To characterize the impact of ionizing radiation, the concept " dose measurement».
Depending on the task, different doses are used. If it is necessary to determine the amount of electricity created by ionizing radiation, then the exposure dose is used.
Exposure dose is the amount of electricity created by ionizing radiation per unit mass of a substance. The dose is measured in roentgens. [x-ray]
Absorbed dose- the amount of energy absorbed by a unit mass of a substance during the passage of radiation through it.
Dose equivalent is the dose equivalent to gamma radiation. . In the SI system, the equivalent dose is measured in sieverts, and the off-system unit is rem.
Effective dose.
With uniform irradiation, the effective dose is equal to the equivalent dose. When irradiating the whole person, an effective dose is used.
The dose is an integral indicator. Dose rate is used as a differential indicator. 
Dose rate characterizes the field of ionizing radiation. It was determined that the dose rate is directly proportional to the activity and inversely proportional to the square of the resistance. 
Any screen attenuates ionizing radiation exponentially.
Exposure of a person in everyday conditions
The OPA is composed of household and background radiation.
Background exposure consists of a natural radioactive background (background of the Earth and space) and a man-made radioactive field (background from nuclear explosions and nuclear energy).
Household exposure consists of medical exposure and exposure to electronic equipment.
ERF - the background of the Earth and space.
TIRF - background from nuclear explosions and energy 
Each person receives an average of 3 mSv/year.
Exposure limitation requirements
Federal Law No. 3 on Radiation Safety of the Population
Radiation safety standard NORB 99/2009
Basic codes of practice on radiation safety 99 (OSPORB-99)
Group A personnel (20 mSv/year)
Group B personnel (5 mSv/year)
All population (1 mSv/year)
Building materials - granite, radon, radiation devices.
Section 3 (BJD technique)
electrical safety
Technical means of ensuring electrical safety
Means of ensuring electrical safety.
electrical safety- this is a system of organizational and technical measures and means that provide protection from harmful and dangerous factors: (often asked during the exam)
Electric arc
electromagnetic radiation
Static electricity
The impact of electric current on a person
From the impact of current, injuries occur, which are called electrical injuries.
Electrical injuries can be:
electrical burns
electrical signs
Leather plating
Electric shock (divided into 5 degrees)
Local (i.e. hit at the point of contact with the current) are usually at high frequencies.
General (the whole body is affected).
1 degree (the occurrence of convulsions)
Grade 2 (appearance and cramps and pain)
Grade 3 (convulsions and loss of consciousness)
Grade 4 (loss of consciousness + or cessation of breathing or cessation of heartbeat)
Grade 5 (clinical death) cessation of breathing, heartbeat.
electric shock
Factors that determine the outcome of electric shock
Ohm's law- the current through a person is proportional to the voltage and inversely proportional to the resistance.
Factors of electric shock.
1 factor. Current I (for 50 Hz)
There are three criteria:
Threshold current (approximately 1 mA).
Threshold not releasing (approximately 10 mA)
Threshold fibrillation (lethal) approximately 100 mA.
2nd factor. Touch voltage. A voltage of 20 V is considered acceptable.
Touch voltage- this is the voltage between two points of the electrical network, which a person has touched.
3 factor. resistance of the human body.
In the normal mode of operation of electrical installations, the resistance of the human body takes 6.7 kOhm. In an emergency condition, the equipment resistance is reduced to 1 kOhm. If the temperature is above 35 degrees and the humidity is above 75%, the resistance decreases by another 3 times.
4th factor. The duration of the impact of electric current on a person.
The human cardiocycle determines the additional time of exposure to electric current. (t=0.2 - 1 sec)
5th factor. The path of current through the human body.
The most dangerous current paths through a person are hand - hand, hand - legs (because they pass through the human body).
6 factor Type of current.
The most dangerous variable. Less dangerous standing and upright.
7 factor Current frequency.
The most dangerous current with a frequency of 20 to 100 Hz. The higher the frequency of the current, the lower the chance of electric shock and the higher the chance of electric burn.
8 factor. Contact at acupuncture points.
9 factor. Attention. Electric current is in the human blood. The more attention, the more current. It mitigates the effects.
10 factor. Individual properties of a person.
11 factor. Switching scheme.
The most dangerous is two-phase touch (most likely death).
Single-phase contact in a network with isolated neutral. (less dangerous than the previous one)
Single-phase contact in networks with grounded neutral (dangerous). Especially when a person with bare feet.
12 factor. Conditions of the external environment.
According to the environmental conditions, all premises are divided into 4 classes:
Premises without increased danger
High risk area
Premises especially dangerous
Premises with especially adverse conditions.
The danger is determined by: temperature (35 degrees limit), humidity (75% limit), electrical conductivity of the floors, the presence of dust in the air, the presence of grounded equipment.
Classification of electrical networks
All electrical networks can be divided into 2 large groups:
Networks with voltage up to 1000 V
Networks with voltage over 1000 V
In addition, electrical networks are divided depending on the grounding of the neutral:
with earthed neutral
With isolated neutral
Depending on the number of wires:
Three-wire
Four-wire
five wire
The most common are four-wire networks with a grounded neutral. These networks are called TNCs. 
1 letter T terra (indicates that electrical conductors are grounded)
2 letter N. Indicates that the electrical installation is closed to the neutral wire.
3 letter C. Shows that zero protective and zero grounded are included in one wire.
Currently, five-wire networks have become the most widely used. In these networks, the neutral wire is working and the neutral wire is disconnected. Designated TN-S. 
For portable electrical equipment, a three-wire network with an isolated neutral is used. Designated IT. The scheme is effective if it is short, well maintained, and located in a dry room.
Technical ways to ensure electrical safety
Electrical safety includes the following elements:
Electrical isolation (at least 500 kΩ)
Zeroing
grounding
Safety shutdown
Electrical separation of networks
Application of low voltages
Fencing of current-carrying parts
The use of alarms, blocking, as well as safety signs and posters.
Technical security measures
Personal protective equipment
Organizational events
Regulations
Zeroing(Basic diagram of zeroing)
Zeroing- this is the connection of the housing to a grounded neutral wire.
Operating principle: Turns a ground fault into a short circuit.
Application area: Three-phase four-wire networks with a solidly grounded neutral
Protective earth
Protective earth– deliberate connection of the housing to the ground.
Operating principle: reduction to a safe value of the current through a person.
Application area: three-phase three-wire networks with isolated neutral (for networks up to 1000 V).
Electrical protective equipment (called personal protective equipment PPE)
Basic. Allows you to work under pressure. (Dielectric gloves, insulating pliers and voltage gauges)
Additional. (dielectric galoshes, insulating pads, rugs)
Portable facilities, including temporary portable fences and insulating pads.
Portable shielding equipment
Means isolating
Enclosing means
Shielding means
Safety means
These are means that protect against damaging factors of a non-electrical nature that occur when working with electrical equipment. (glasses, shields, safety belts, gas masks, non-flammable gloves).
Organizational bases of electrical safety
Above, we considered the technical basis of safety, but as the analysis of accidents shows, many people die due to poor organization of electrical safety.
The main organizational activities include:
work and rest
Transition to other jobs
Completion of works
Registration of work on electrical installations should be carried out: according to orders or orders. If the work is carried out for more than 1 hour or more than three people participate in them, then an order for these works must be issued. If the work is less than an hour and less than three people, then the order.
People who carry out electrical work must have a work permit. To do this, they are assigned a classification. There are only 5 groups.
Work Supervision
Compliance with the regime
First aid for electric shock
First aid should be available within 1 minute.
Necessary: establish the presence of breathing, pulse, shock; organize an ambulance call; carry out resuscitation measures: restore breathing, chest compressions.
Department of BJD
Test
discipline: Life safety
on the topic: Ionizing radiation
Perm, 2004
Introduction
Ionizing radiation is called radiation, the interaction of which with the environment leads to the formation of electric charges of various signs.
Ionizing radiation is the radiation that radioactive substances possess.
Under the influence of ionizing radiation, a person develops radiation sickness.
The main goal of radiation safety is to protect the health of the population, including personnel, from the harmful effects of ionizing radiation by observing the basic principles and norms of radiation safety without unreasonable restrictions on useful activities when using radiation in various areas of the economy, in science and medicine.
Radiation safety standards (NRB-2000) are used to ensure human safety under the influence of ionizing radiation of artificial or natural origin.
Main characteristics of ionizing radiation
Ionizing radiation is called radiation, the interaction of which with the environment leads to the formation of electric charges of various signs. The sources of these radiations are widely used in engineering, chemistry, medicine, agriculture and other areas, for example, in measuring soil density, detecting leaks in gas pipelines, measuring the thickness of sheets, pipes and rods, antistatic treatment of fabrics, polymerization of plastics, radiation therapy of malignant tumors, etc. However, it should be remembered that sources of ionizing radiation pose a significant threat to the health and life of people using them.
There are 2 types of ionizing radiation:
corpuscular, consisting of particles with a rest mass other than zero (alpha and beta radiation and neutron radiation);
electromagnetic (gamma radiation and x-rays) with a very short wavelength.
alpha radiation is a stream of helium nuclei with high speed. These nuclei have a mass of 4 and a charge of +2. They are formed during the radioactive decay of nuclei or during nuclear reactions. Currently, more than 120 artificial and natural alpha-radioactive nuclei are known, which, emitting an alpha particle, lose 2 protons and 2 neurons.
The energy of alpha particles does not exceed a few MeV (mega-electron-volt). The emitted alpha particles move almost in a straight line at a speed of about 20,000 km/s.
Under the path length of a particle in air or other media, it is customary to call the greatest distance from the radiation source at which it is still possible to detect a particle before it is absorbed by a substance. The path length of a particle depends on the charge, mass, initial energy, and the medium in which the motion occurs. With an increase in the initial energy of the particle and a decrease in the density of the medium, the path length increases. If the initial energy of the emitted particles is the same, then heavy particles have lower velocities than light ones. If the particles move slowly, then their interaction with the atoms of the substance of the medium is more efficient and the particles quickly waste their energy reserve.
The path length of alpha particles in air is usually less than 10 cm. Due to their large mass, alpha particles quickly lose their energy when interacting with matter. This explains their low penetrating power and high specific ionization: when moving in air, an alpha particle forms several tens of thousands of pairs of charged particles - ions per 1 cm of its path.
beta radiation is a stream of electrons or positrons resulting from radioactive decay. About 900 beta radioactive isotopes are currently known.
The mass of beta particles is several tens of thousands of times less than the mass of alpha particles. Depending on the nature of the source of beta radiation, the speed of these particles can lie within 0.3 - 0.99 of the speed of light. The energy of beta particles does not exceed a few MeV, the path length in air is approximately 1800 cm, and in soft tissues human body~ 2.5 cm. The penetrating power of beta particles is higher than that of alpha particles (due to their lower mass and charge).
neutron radiation is a stream of nuclear particles that do not have an electric charge. The mass of a neutron is approximately 4 times less than the mass of alpha particles. Depending on the energy, slow neutrons are distinguished (with an energy of less than 1 KeV (kilo-electron-Volt) \u003d 10 3 eV), neutrons of intermediate energies (from 1 to 500 KeV) and fast neutrons (from 500 KeV to 20 MeV). During the inelastic interaction of neutrons with the nuclei of atoms of the medium, secondary radiation arises, consisting of charged particles and gamma quanta (gamma radiation). During elastic interactions of neutrons with nuclei, the usual ionization of matter can be observed. The penetrating power of neutrons depends on their energy, but it is much higher than that of alpha or beta particles. Neutron radiation has a high penetrating power and represents the greatest danger to humans of all types of corpuscular radiation. The neutron flux power is measured by the neutron flux density.
Gamma radiation It is electromagnetic radiation with high energy and short wavelength. It is emitted during nuclear transformations or the interaction of particles. High energy (0.01 - 3 MeV) and short wavelength determines the high penetrating power of gamma radiation. Gamma rays are not deflected in electric and magnetic fields. This radiation has a lower ionizing power than alpha and beta radiation.
x-ray radiation can be obtained in special X-ray tubes, in electron accelerators, in the environment surrounding the source of beta radiation, etc. X-ray radiation is one of the types of electromagnetic radiation. Its energy usually does not exceed 1 MeV. X-ray radiation, like gamma radiation, has a low ionizing ability and a large penetration depth.
To characterize the effect of ionizing radiation on a substance, the concept of radiation dose has been introduced. The dose of radiation is the part of the energy transferred by radiation to the substance and absorbed by it. The quantitative characteristic of the interaction of ionizing radiation and matter is absorbed radiation dose(E), equal to the ratio of the average energy dE transferred by ionizing radiation to a substance in an elementary volume, to the mass of the irradiated substance in this volume dm:
Until recently, only X-ray and gamma radiation, based on their ionizing effect, was taken as a quantitative characteristic. exposure dose X is the ratio of the total electric charge dQ of ions of the same sign, arising in a small volume of dry air, to the mass of air dm in this volume, i.e.
To assess the possible damage to health during chronic exposure to ionizing radiation of arbitrary composition, the concept equivalent dose(H). This value is defined as the product of the absorbed dose D and the average radiation quality factor Q (dimensionless) at a given point in the tissue of the human body, i.e.:
There is another characteristic of ionizing radiation - dose rate X (respectively absorbed, exposure or equivalent) representing the dose increment over a small period of time dx divided by this period dt. Thus, the exposure dose rate (x or w, C / kg s) will be:
X \u003d W \u003d dx / dt
The biological effect of the considered radiations on the human body is different.
Alpha particles, passing through matter and colliding with atoms, ionize (charge) them, knocking out electrons. In rare cases, these particles are absorbed by the nuclei of atoms, transferring them to a state of higher energy. This excess energy contributes to the flow of various chemical reactions that do not proceed without irradiation or proceed very slowly. Alpha radiation has a strong effect on the organic substances that make up the human body (fats, proteins and carbohydrates). On the mucous membranes, this radiation causes burns and other inflammatory processes.
Under the action of beta radiation, radiolysis (decomposition) of water contained in biological tissues occurs, with the formation of hydrogen, oxygen, hydrogen peroxide H 2 O 2, charged particles (ions) OH - and HO - 2. The decomposition products of water have oxidizing properties and cause the destruction of many organic substances that make up the tissues of the human body.
The action of gamma and X-ray radiation on biological tissues is mainly due to the free electrons formed. Neutrons passing through matter produce the strongest changes in it in comparison with other ionizing radiations.
Thus, the biological effect of ionizing radiation is reduced to a change in the structure or destruction of various organic substances (molecules) that make up the human body. This leads to a violation of the biochemical processes occurring in the cells, or even to their death, resulting in damage to the body as a whole.
Distinguish between external and internal irradiation of the body. External exposure is understood as the effect on the body of ionizing radiation from sources external to it. Internal exposure is carried out by radioactive substances that have entered the body through the respiratory organs, the gastrointestinal tract or through the skin. Sources of external radiation - cosmic rays, natural radioactive sources in the atmosphere, water, soil, food, etc., sources of alpha, beta, gamma, X-ray and neutron radiation used in engineering and medicine, charged particle accelerators, nuclear reactors (including accidents at nuclear reactors) and a number of others.
Radioactive substances that cause internal irradiation of the body enter it when eating, smoking, drinking contaminated water. The entry of radioactive substances into the human body through the skin occurs in rare cases (if the skin has damage or open wounds). Internal irradiation of the body lasts until the radioactive substance decays or is removed from the body as a result of physiological metabolic processes. Internal exposure is dangerous because it causes long-term non-healing ulcers of various organs and malignant tumors.
When working with radioactive substances, the hands of operators are exposed to significant radiation. Under the influence of ionizing radiation, a chronic or acute (radiation burn) damage to the skin of the hands develops. Chronic lesion is characterized by dry skin, cracking, ulceration and other symptoms. In acute lesions of the hands, edema, tissue necrosis, ulcers occur, at the site of formation of which the development of malignant tumors is possible.
Under the influence of ionizing radiation, a person develops radiation sickness. There are three degrees of it: the first (light), second and third (severe).
Symptoms of radiation sickness of the first degree are weakness, headaches, sleep disturbance and appetite, which increase in the second stage of the disease, but they are additionally accompanied by disturbances in the activity of the cardiovascular system, metabolism and blood composition change, and digestive organs are upset. At the third stage of the disease, hemorrhages are observed, hair loss, the activity of the central nervous system and sex glands is disrupted. In people who have undergone radiation sickness, the likelihood of developing malignant tumors and diseases of the hematopoietic organs increases. Radiation sickness in an acute (severe) form develops as a result of irradiation of the body with large doses of ionizing radiation in a short period of time. The impact on the human body and small doses of radiation is dangerous, since in this case a violation of the hereditary information of the human body can occur, mutations occur.
Low level of development mild form radiation sickness occurs at an equivalent radiation dose of approximately 1 Sv, a severe form of radiation sickness, in which half of all exposed people die, occurs at an equivalent radiation dose of 4.5 Sv. A 100% lethal outcome from radiation sickness corresponds to an equivalent radiation dose of 5.5–7.0 Sv.
Currently, a number of chemical preparations (protectors) have been developed that significantly reduce the negative effect of ionizing radiation on the human body.
In Russia, the maximum permissible levels of ionizing radiation and the principles of radiation safety are regulated by the "Radiation Safety Standards" NRB-76, "Basic Sanitary Rules for Working with Radioactive Substances and Other Sources of Ionizing Radiation" OSP72-80. In accordance with these regulatory documents, exposure standards are established for the following three categories of persons:
For category A persons, the main dose limit is the individual equivalent dose of external and internal radiation per year (Sv / year) depending on the radiosensitivity of organs (critical organs). This is the maximum allowable dose (MAD) - the highest value of the individual equivalent dose per year, which, with uniform exposure for 50 years, will not cause adverse changes in the state of health of personnel detected by modern methods.
For category A personnel, the individual equivalent dose ( H, Sv) accumulated in the critical organ over time T(years) from the beginning of professional work, should not exceed the value determined by the formula:
H = SDA ∙ T. In addition, the dose accumulated by the age of 30 should not exceed 12 SDA.
For category B, a dose limit per year (PD, Sv/year) is set, which is understood as the highest average value of the individual equivalent dose per calendar year for a critical group of people, at which uniform exposure for 70 years cannot cause adverse changes in the state of health, detected by modern methods. Table 1 shows the main dose limits of external and internal exposures depending on the radiosensitivity of organs.
Table 1 - Basic values of dose limits for external and internal exposure
IONIZING RADIATIONS, THEIR NATURE AND IMPACT ON THE HUMAN BODY
Radiation and its varieties
ionizing radiation
Sources of radiation hazard
The device of ionizing radiation sources
Ways of penetration of radiation into the human body
Measures ionizing effect
The mechanism of action of ionizing radiation
Consequences of irradiation
Radiation sickness
Ensuring safety when working with ionizing radiation
Radiation and its varieties
Radiation is all types of electromagnetic radiation: light, radio waves, solar energy and many other radiations around us.
The sources of penetrating radiation that create the natural background of exposure are galactic and solar radiation, the presence of radioactive elements in soil, air and materials used in economic activities, as well as isotopes, mainly potassium, in the tissues of a living organism. One of the most significant natural sources of radiation is radon, a gas that has no taste or smell.
Of interest is not any radiation, but ionizing, which, passing through the tissues and cells of living organisms, is able to transfer its energy to them, breaking chemical bonds within molecules and causing serious changes in their structure. Ionizing radiation occurs during radioactive decay, nuclear transformations, deceleration of charged particles in matter and forms ions of different signs when interacting with the medium.
ionizing radiation
All ionizing radiations are divided into photon and corpuscular.
Photon-ionizing radiation includes:
a) Y-radiation emitted during the decay of radioactive isotopes or particle annihilation. Gamma radiation is, by its nature, short-wavelength electromagnetic radiation, i.e. a stream of high-energy quanta of electromagnetic energy, the wavelength of which is much less than the interatomic distances, i.e. y< 10 см. Не имея массы, Y-кванты двигаются со скоростью света, не теряя её в окружающей среде. Они могут лишь поглощаться ею или отклоняться в сторону, порождая пары ионов: частица- античастица, причём последнее наиболее значительно при поглощении Y- квантов в среде. Таким образом, Y- кванты при прохождении через вещество передают энергию электронам и, следовательно, вызывают ионизацию среды. Благодаря отсутствию массы, Y- кванты обладают большой проникающей способностью (до 4- 5 км в воздушной среде);
b) X-ray radiation that occurs when the kinetic energy of charged particles decreases and / or when the energy state of the electrons of the atom changes.
Corpuscular ionizing radiation consists of a stream of charged particles (alpha, beta particles, protons, electrons), the kinetic energy of which is sufficient to ionize atoms in a collision. Neutrons and other elementary particles do not directly produce ionization, but in the process of interaction with the medium they release charged particles (electrons, protons) that can ionize the atoms and molecules of the medium through which they pass:
a) neutrons are the only uncharged particles formed in some reactions of nuclear fission of uranium or plutonium atoms. Since these particles are electrically neutral, they penetrate deeply into any substance, including living tissues. Distinctive feature neutron radiation is its ability to convert atoms of stable elements into their radioactive isotopes, i.e. create induced radiation, which dramatically increases the danger of neutron radiation. The penetrating power of neutrons is comparable to Y-radiation. Depending on the level of carried energy, fast neutrons (with energies from 0.2 to 20 MeV) and thermal neutrons (from 0.25 to 0.5 MeV) are conditionally distinguished. This difference is taken into account when carrying out protective measures. Fast neutrons are slowed down, losing ionization energy, by substances with a low atomic weight (the so-called hydrogen-containing ones: paraffin, water, plastics, etc.). Thermal neutrons are absorbed by materials containing boron and cadmium (boron steel, boral, boron graphite, cadmium-lead alloy).
Alpha -, beta particles and gamma - quanta have an energy of only a few megaelectronvolts, and cannot create induced radiation;
b) beta particles - electrons emitted during the radioactive decay of nuclear elements with an intermediate ionizing and penetrating power (run in air up to 10-20 m).
c) alpha particles - positively charged nuclei of helium atoms, and in outer space and atoms of other elements, emitted during the radioactive decay of isotopes of heavy elements - uranium or radium. They have a low penetrating ability (run in the air - no more than 10 cm), even human skin is an insurmountable obstacle for them. They are dangerous only when they enter the body, as they are able to knock out electrons from the shell of a neutral atom of any substance, including the human body, and turn it into a positively charged ion with all the ensuing consequences, which will be discussed later. Thus, an alpha particle with an energy of 5 MeV forms 150,000 pairs of ions.
Characteristics of the penetrating power of various types of ionizing radiation
The quantitative content of radioactive material in the human body or substance is defined by the term "radioactive source activity" (radioactivity). The unit of radioactivity in the SI system is the becquerel (Bq), which corresponds to one decay in 1 s. Sometimes in practice the old unit of activity, the curie (Ci), is used. This is the activity of such a quantity of a substance in which 37 billion atoms decay in 1 second. For translation, the following dependence is used: 1 Bq = 2.7 x 10 Ci or 1 Ki = 3.7 x 10 Bq.
Each radionuclide has an invariable, unique half-life (the time required for the substance to lose half of its activity). For example, for uranium-235 it is 4,470 years, while for iodine-131 it is only 8 days.
Sources of radiation hazard
1. main reason hazard - radiation accident. A radiation accident is a loss of control over an ionizing radiation source (IRS) caused by equipment malfunction, incorrect actions of personnel, natural disasters or other reasons that could lead or have led to exposure of people above the established norms or to radioactive contamination of the environment. In case of accidents caused by the destruction of the reactor vessel or the melting of the core, the following are emitted:
1) Fragments of the core;
2) Fuel (waste) in the form of highly active dust, which can stay in the air for a long time in the form of aerosols, then, after passing through the main cloud, fall out in the form of rain (snow) precipitation, and if it enters the body, cause a painful cough, sometimes similar in severity to an asthma attack;
3) lava, consisting of silicon dioxide, as well as concrete molten as a result of contact with hot fuel. The dose rate near such lavas reaches 8000 R/hour, and even a five-minute stay nearby is detrimental to humans. In the first period after precipitation of RV, the greatest danger is iodine-131, which is a source of alpha and beta radiation. Its half-life from the thyroid gland is: biological - 120 days, effective - 7.6. This requires the fastest possible iodine prophylaxis of the entire population in the accident zone.
2. Enterprises for the development of deposits and enrichment of uranium. Uranium has an atomic weight of 92 and three natural isotopes: uranium-238 (99.3%), uranium-235 (0.69%), and uranium-234 (0.01%). All isotopes are alpha emitters with negligible radioactivity (2800 kg of uranium are equivalent in activity to 1 g of radium-226). The half-life of uranium-235 = 7.13 x 10 years. The artificial isotopes uranium-233 and uranium-227 have half-lives of 1.3 and 1.9 minutes. Uranium is a soft metal appearance similar to steel. The content of uranium in some natural materials reaches 60%, but in most uranium ores it does not exceed 0.05-0.5%. In the process of mining, upon receipt of 1 ton of radioactive material, up to 10-15 thousand tons of waste is formed, and during processing from 10 to 100 thousand tons. From the waste (containing a small amount of uranium, radium, thorium and other radioactive decay products), a radioactive gas is released - radon-222, which, when inhaled, causes irradiation of lung tissues. When ore is enriched, radioactive waste can get into nearby rivers and lakes. During the enrichment of uranium concentrate, some leakage of gaseous uranium hexafluoride from the condensation-evaporation plant into the atmosphere is possible. Some uranium alloys, shavings, sawdust obtained during the production of fuel elements can ignite during transportation or storage, as a result, significant amounts of burnt uranium waste can be released into the environment.
3. Nuclear terrorism. Cases of theft of nuclear materials suitable for the manufacture of nuclear weapons, even by handicraft, have become more frequent, as well as threats to disable nuclear enterprises, ships with nuclear installations and nuclear power plants in order to obtain a ransom. The danger of nuclear terrorism also exists at the everyday level.
4. Tests of nuclear weapons. Recently, miniaturization of nuclear charges for testing has been achieved.
The device of ionizing radiation sources
According to the device, IRS are of two types - closed and open.
Sealed sources are placed in sealed containers and pose a danger only if there is no proper control over their operation and storage. Military units also make their contribution, transferring decommissioned devices to sponsored educational institutions. Loss of decommissioned, destruction as unnecessary, theft with subsequent migration. For example, in Bratsk, at the building construction plant, IRS, enclosed in a lead sheath, was stored in a safe along with precious metals. And when the robbers broke into the safe, they decided that this massive lead blank was also precious. They stole it, and then honestly divided it, sawing a lead “shirt” in half and an ampoule with a radioactive isotope sharpened in it.
Working with open IRS can lead to tragic consequences in case of ignorance or violation of the relevant instructions on the rules for handling these sources. Therefore, before starting any work using IRS, it is necessary to carefully study all job descriptions and safety regulations and strictly comply with their requirements. These requirements are set out in the Sanitary Rules for the Management of Radioactive Waste (SPO GO-85). The Radon enterprise, upon request, performs individual control of persons, territories, objects, checks, dosages and repairs of devices. Works in the field of IRS handling, radiation protection means, extraction, production, transportation, storage, use, maintenance, disposal, disposal are carried out only on the basis of a license.
Ways of penetration of radiation into the human body
To correctly understand the mechanism of radiation damage, it is necessary to have a clear understanding of the existence of two ways in which radiation penetrates into the tissues of the body and affects them.
The first way is external irradiation from a source located outside the body (in the surrounding space). This exposure can be associated with X-rays and gamma rays, as well as some high-energy beta particles that can penetrate the superficial layers of the skin.
The second way is internal exposure caused by the ingress of radioactive substances into the body in the following ways:
In the first days after a radiation accident, radioactive isotopes of iodine that enter the body with food and water are the most dangerous. There are a lot of them in milk, which is especially dangerous for children. Radioactive iodine accumulates mainly in the thyroid gland, which weighs only 20 g. The concentration of radionuclides in this organ can be 200 times higher than in other parts of the human body;
Through injuries and cuts on the skin;
Absorption through healthy skin during prolonged exposure to radioactive substances (RS). In the presence of organic solvents (ether, benzene, toluene, alcohol), the permeability of the skin to RV increases. Moreover, some RVs that enter the body through the skin enter the bloodstream and, depending on their chemical properties, are absorbed and accumulated in critical organs, which leads to high local doses of radiation. For example, the growing bones of the limbs absorb radioactive calcium, strontium, radium well, and the kidneys absorb uranium. Other chemical elements, such as sodium and potassium, will be distributed throughout the body more or less evenly, since they are found in all cells of the body. At the same time, the presence of sodium-24 in the blood means that the body was additionally subjected to neutron irradiation (i.e., the chain reaction in the reactor was not interrupted at the time of irradiation). It is especially difficult to treat a patient exposed to neutron irradiation, so it is necessary to determine the induced activity of the body's bioelements (P, S, etc.);
Through the lungs while breathing. The penetration of solid radioactive substances into the lungs depends on the degree of dispersion of these particles. From tests conducted on animals, it was found that dust particles smaller than 0.1 micron behave in the same way as gas molecules. When you inhale, they enter the lungs with air, and when you exhale, they are removed with air. Only a small fraction of solid particles may remain in the lungs. Large particles larger than 5 microns are retained by the nasal cavity. Inert radioactive gases (argon, xenon, krypton, etc.) that have entered the blood through the lungs are not compounds that make up tissues, and are removed from the body over time. Do not stay in the body for a long time and radionuclides, the same type with the elements that make up the tissues and consumed by humans with food (sodium, chlorine, potassium, etc.). They are completely removed from the body over time. Some radionuclides (for example, radium, uranium, plutonium, strontium, yttrium, zirconium deposited in bone tissues) enter into a chemical bond with the elements of bone tissue and are hardly excreted from the body. During a medical examination of residents of the areas affected by the Chernobyl accident at the All-Union Hematological Center of the Academy of Medical Sciences, it was found that with a general irradiation of the body with a dose of 50 rads, some of its cells were irradiated with a dose of 1,000 and more rads. At present, standards have been developed for various critical organs that determine the maximum permissible content of each radionuclide in them. These standards are set out in Section 8 "Numerical Values of Permissible Levels" of the NRB Radiation Safety Standards - 76/87.
Internal exposure is more dangerous and its consequences more severe for the following reasons:
The radiation dose increases sharply, determined by the time the radionuclide stays in the body (radium-226 or plutonium-239 throughout life);
The distance to the ionized tissue is practically infinitely small (the so-called contact irradiation);
Irradiation involves alpha particles, the most active and therefore the most dangerous;
Radioactive substances do not spread evenly throughout the body, but selectively, they concentrate in individual (critical) organs, increasing local exposure;
It is not possible to use any protection measures used for external exposure: evacuation, personal protective equipment (PPE), etc.
Measures of ionizing influence
The measure of the ionizing effect of external radiation is exposure dose, determined by air ionization. For a unit of exposure dose (De) it is customary to consider X-ray (P) - the amount of radiation at which in 1 cc. air at a temperature of 0 C and a pressure of 1 atm, 2.08 x 10 pairs of ions are formed. According to the guidelines of the International Company for Radiological Units (ICRU) RD - 50-454-84, after January 1, 1990, it is not recommended to use such values as the exposure dose and its rate in our country (it is accepted that the exposure dose is the absorbed dose in air). Most of the dosimetric equipment in the Russian Federation is calibrated in roentgens, roentgens / hours, and these units are not yet abandoned.
The measure of the ionizing effect of internal exposure is absorbed dose. The rad is taken as the unit of absorbed dose. This is the dose of radiation transferred to the mass of the irradiated substance in 1 kg and measured by the energy in joules of any ionizing radiation. 1 rad = 10 J/kg. In the SI system, the unit of absorbed dose is the gray (Gy), equal to an energy of 1 J/kg.
1 Gy = 100 rad.
1 rad = 10 Gr.
To convert the amount of ionizing energy in space (exposure dose) into that absorbed by the soft tissues of the body, the coefficient of proportionality K = 0.877 is used, i.e.:
1 x-ray \u003d 0.877 rad.
Due to the fact that different types of radiation have different efficiencies (with equal energy costs for ionization, they produce different effects), the concept of “equivalent dose” has been introduced. Its unit of measurement is rem. 1 rem is a dose of radiation of any kind, the effect of which on the body is equivalent to the effect of 1 rad of gamma radiation. Therefore, when assessing the overall effect of exposure to radiation on living organisms with total exposure to all types of radiation, a quality factor (Q) equal to 10 for neutron radiation (neutrons are about 10 times more effective in terms of radiation damage) and 20 for alpha radiation is taken into account. In the SI system, the unit of equivalent dose is the sievert (Sv), equal to 1 Gy x Q.
Along with the amount of energy, type of irradiation, material and mass of the organ an important factor is the so-called biological half-life radioisotope - the length of time required for excretion (with sweat, saliva, urine, feces, etc.) from the body of half of the radioactive substance. Already 1-2 hours after the RV enters the body, they are found in its secretions. The combination of the physical half-life with the biological half-life gives the concept of "effective half-life" - the most important in determining the resulting amount of radiation to which the body is exposed, especially critical organs.
Along with the concept of "activity" there is the concept of "induced activity" (artificial radioactivity). It occurs when slow neutrons (products of a nuclear explosion or nuclear reaction) are absorbed by the nuclei of atoms of non-radioactive substances and converted into radioactive potassium-28 and sodium-24, which are formed mainly in the soil.
Thus, the degree, depth and form of radiation injuries that develop in biological objects (including humans) when exposed to radiation depend on the amount of absorbed radiation energy (dose).
The mechanism of action of ionizing radiation
The fundamental feature of the action of ionizing radiation is its ability to penetrate biological tissues, cells, subcellular structures and, causing simultaneous ionization of atoms, damage them due to chemical reactions. Any molecule can be ionized, and hence all structural and functional destruction in somatic cells, genetic mutations, effects on the fetus, illness and death of a person.
The mechanism of this effect is the absorption of ionization energy by the body and the breaking of the chemical bonds of its molecules with the formation of highly active compounds, the so-called free radicals.
The human body is 75% water, therefore, the indirect effect of radiation through the ionization of the water molecule and subsequent reactions with free radicals will be of decisive importance in this case. When a water molecule is ionized, a positive HO ion and an electron are formed, which, having lost energy, can form a negative HO ion. Both of these ions are unstable and decompose into a pair of stable ions, which recombine (reduce) to form a water molecule and two free OH radicals and H, characterized by exceptionally high chemical activity. Directly or through a chain of secondary transformations, such as the formation of a peroxide radical (hydrated water oxide), and then hydrogen peroxide H O and other active oxidants of the OH and H groups, interacting with protein molecules, they lead to tissue destruction mainly due to vigorous processes oxidation. At the same time, one active molecule with high energy involves thousands of molecules of living matter in the reaction. In the body, oxidative reactions begin to prevail over reduction ones. There comes a retribution for the aerobic method of bioenergy - saturation of the body with free oxygen.
The impact of ionizing radiation on humans is not limited to changes in the structure of water molecules. The structure of the atoms that make up our body is changing. The result is the destruction of the nucleus, cell organelles and rupture of the outer membrane. Since the main function of growing cells is the ability to divide, its loss leads to death. For mature non-dividing cells, destruction causes the loss of certain specialized functions (production of certain products, recognition of foreign cells, transport functions, etc.). Radiation-induced cell death occurs, which, unlike physiological death, is irreversible, since the implementation of the genetic program of terminal differentiation in this case occurs against the background of multiple changes in the normal course of biochemical processes after irradiation.
In addition, the additional supply of ionization energy to the body disrupts the balance of energy processes occurring in it. After all, the presence of energy in organic substances depends primarily not on their elemental composition, but on the structure, arrangement and nature of the bonds of atoms, i.e. those elements that are most easily amenable to energy impact.
Consequences of irradiation
One of the earliest manifestations of irradiation is the mass death of lymphoid tissue cells. Figuratively speaking, these cells are the first to take the impact of radiation. The death of lymphoids weakens one of the main life support systems of the body - the immune system, since lymphocytes are cells that are able to respond to the appearance of antigens foreign to the body by producing strictly specific antibodies to them.
As a result of exposure to radiation energy in small doses, changes in the genetic material (mutations) occur in cells that threaten their viability. As a result, degradation (damage) of chromatin DNA (breaks of molecules, damage) occurs, which partially or completely block or distort the function of the genome. There is a violation of DNA repair - its ability to restore and heal cell damage with an increase in body temperature, exposure to chemicals, etc.
Genetic mutations in germ cells affect the life and development of future generations. This case is typical, for example, if a person was exposed to small doses of radiation during exposure for medical purposes. There is a concept - when a dose of 1 rem is received by the previous generation, it gives an additional 0.02% of genetic anomalies in the offspring, i.e. in 250 babies per million. These facts and long-term studies of these phenomena have led scientists to the conclusion that there are no safe doses of radiation.
The impact of ionizing radiation on the genes of germ cells can cause harmful mutations that will be passed from generation to generation, increasing the "mutation load" of humanity. Life-threatening conditions are those that double the “genetic load”. Such a doubling dose is, according to the conclusions of the UN Scientific Committee on Atomic Radiation, a dose of 30 rad for acute exposure and 10 rad for chronic exposure (during the reproductive period). With increasing dose, it is not the severity that increases, but the frequency of possible manifestations.
Mutational changes also occur in plant organisms. In the forests affected by radioactive fallout near Chernobyl, as a result of a mutation, new absurd plant species have arisen. Rust-red coniferous forests appeared. In a wheat field located near the reactor, two years after the accident, scientists discovered about a thousand different mutations.
Impact on the fetus and fetus due to maternal exposure during pregnancy. The radiosensitivity of a cell changes at different stages of the process of division (mitosis). The most sensitive cell is at the end of dormancy and the beginning of the first month of division. The zygote, the embryonic cell that is formed after the fusion of the spermatozoon with the egg, is especially sensitive to radiation. In this case, the development of the embryo during this period and the influence of radiation, including X-ray, radiation on it can be divided into three stages.
Stage 1 - after conception and until the ninth day. The newly formed embryo dies under the influence of radiation. Death in most cases goes unnoticed.
Stage 2 - from the ninth day to the sixth week after conception. This is the period of formation of internal organs and limbs. At the same time, under the influence of an irradiation dose of 10 rem, a whole spectrum of defects appears in the embryo - a splitting of the palate, a halt in the development of limbs, a violation of the formation of the brain, etc. At the same time, growth retardation of the organism is possible, which is expressed in a decrease in body size at birth. The result of exposure of the mother during this period of pregnancy can also be the death of a newborn at the time of delivery or some time after them. However, the birth of a live child with gross defects is probably the greatest misfortune, much worse than the death of an embryo.
Stage 3 - pregnancy after six weeks. Doses of radiation received by the mother cause a persistent lag in the body in growth. In an irradiated mother, the child is undersized at birth and remains below average height for life. Pathological changes in the nervous, endocrine systems, etc. are possible. Many radiologists suggest that the high probability of having a defective child is the basis for terminating a pregnancy if the dose received by the embryo during the first six weeks after conception exceeds 10 rads. Such a dose was included in the legislative acts of some Scandinavian countries. For comparison, with fluoroscopy of the stomach, the main areas of the bone marrow, the abdomen, and the chest receive a radiation dose of 30-40 rad.
Sometimes a practical problem arises: a woman undergoes a series of x-rays, including images of the stomach and pelvis, and is subsequently found to be pregnant. The situation is aggravated if the exposure occurred in the first weeks after conception, when pregnancy may go unnoticed. The only solution to this problem is not to expose the woman to radiation during this period. This can be achieved if a woman of reproductive age undergoes an X-ray of the stomach or abdominal cavity only during the first ten days after the start of the menstrual period, when there is no doubt about the absence of pregnancy. In medical practice, this is called the ten-day rule. In an emergency, x-ray procedures cannot be postponed for weeks or months, but it is prudent for a woman to tell the doctor about her possible pregnancy before taking x-rays.
In terms of sensitivity to ionizing radiation, the cells and tissues of the human body are not the same.
The testes are among the most sensitive organs. A dose of 10-30 rads can reduce spermatogenesis within a year.
The immune system is highly sensitive to radiation.
In the nervous system, the retina of the eye turned out to be the most sensitive, since visual impairment was observed during irradiation. Taste sensitivity disorders occurred during radiation therapy of the chest, and repeated irradiation with doses of 30-500 R reduced tactile sensitivity.
Changes in somatic cells can contribute to the development of cancer. A cancerous tumor occurs in the body at the moment when the somatic cell, having gone out of control of the body, begins to rapidly divide. The root cause of this is mutations in genes caused by repeated or strong single irradiation, leading to the fact that cancer cells lose their ability to die by physiological, or rather programmed, death even in the event of an imbalance. They become, as it were, immortal, constantly dividing, increasing in number and dying only from a lack of nutrients. This is how the tumor grows. Especially rapidly develops leukemia (blood cancer) - a disease associated with the excessive appearance in the bone marrow, and then in the blood of defective white cells - leukocytes. However, in recent years it has become clear that the relationship between radiation and cancer is more complex than previously thought. So, in a special report of the Japanese American Association of Scientists, it is said that only some types of cancer: tumors of the mammary and thyroid glands, as well as leukemia, develop as a result of radiation damage. Moreover, the experience of Hiroshima and Nagasaki showed that thyroid cancer is observed with irradiation of 50 or more rads. Breast cancer, from which about 50% of patients die, is observed in women who have repeatedly undergone x-ray examinations.
A characteristic of radiation injuries is that radiation injuries are accompanied by severe functional disorders and require complex and lengthy (more than three months) treatment. The viability of irradiated tissues is significantly reduced. In addition, complications occur many years and decades after the injury. Thus, there were cases of the occurrence of benign tumors 19 years after irradiation, and the development of radiation cancer of the skin and breast in women after 25-27 years. Often, injuries are detected against the background or after exposure to additional factors of a non-radiation nature (diabetes, atherosclerosis, purulent infection, thermal or chemical injuries in the irradiation zone).
It must also be taken into account that people who have experienced radiation accident, experience additional stress for several months and even years after it. Such stress can turn on the biological mechanism that leads to the emergence of malignant diseases. Thus, in Hiroshima and Nagasaki, a major outbreak of thyroid cancer was observed 10 years after the atomic bombing.
Studies conducted by radiologists on the basis of data from the Chernobyl accident indicate a decrease in the threshold of consequences from exposure to radiation. Thus, it has been established that exposure to 15 rem can cause disturbances in the activity of the immune system. Even when receiving a dose of 25 rem, the liquidators of the accident showed a decrease in the blood of lymphocytes - antibodies to bacterial antigens, and at 40 rem, the likelihood of infectious complications increases. Under the influence of constant irradiation with a dose of 15 to 50 rem, cases of neurological disorders caused by changes in the structures of the brain were often noted. Moreover, these phenomena were observed in the long term after irradiation.
Radiation sickness
Depending on the dose and time of exposure, three degrees of the disease are observed: acute, subacute and chronic. In the lesions (when receiving high doses), as a rule, acute radiation sickness (ARS) occurs.
There are four degrees of ARS:
Light (100 - 200 rad). The initial period - the primary reaction, as in ARS of all other degrees - is characterized by bouts of nausea. There is a headache, vomiting, general malaise, a slight increase in body temperature, in most cases - anorexia (lack of appetite, up to disgust for food), infectious complications are possible. The primary reaction occurs 15-20 minutes after irradiation. Its manifestations gradually disappear after a few hours or days, or may be absent altogether. Then comes a latent period, the so-called period of imaginary well-being, the duration of which is determined by the dose of radiation and the general condition of the body (up to 20 days). During this time, erythrocytes exhaust their life span, ceasing to supply oxygen to the cells of the body. Mild ARS is curable. Negative consequences are possible - blood leukocytosis, reddening of the skin, decreased efficiency in 25% of those affected 1.5 - 2 hours after exposure. There is a high content of hemoglobin in the blood within 1 year from the moment of exposure. The recovery period is up to three months. Of great importance in this case are the personal attitude and social motivation of the victim, as well as his rational employment;
Average (200 - 400 rad). Short bouts of nausea, passing in 2-3 days after irradiation. The latent period is 10-15 days (may be absent), during which the leukocytes produced by the lymph nodes die and stop rejecting the infection that enters the body. Platelets stop clotting blood. All this is the result of the fact that the bone marrow, lymph nodes and spleen killed by radiation do not produce new red blood cells, white blood cells and platelets to replace the spent ones. Skin edema, blisters develop. This state of the body, called "bone marrow syndrome", leads to 20% of those affected to death, which occurs as a result of damage to the tissues of the hematopoietic organs. Treatment consists in isolation of patients from the external environment, the introduction of antibiotics and blood transfusion. Young and elderly men are more susceptible to moderate ARS than middle-aged men and women. Disability occurs in 80% of those affected 0.5 - 1 hour after irradiation and after recovery remains reduced for a long time. Development of a cataract of eyes and local defects of extremities is possible;
Heavy (400 - 600 rad). Symptoms characteristic of gastrointestinal upset: weakness, drowsiness, loss of appetite, nausea, vomiting, prolonged diarrhea. The hidden period can last 1 - 5 days. After a few days, there are signs of dehydration of the body: weight loss, exhaustion and complete exhaustion. These phenomena are the result of the death of the villi of the intestinal walls, which absorb nutrients from incoming food. Their cells under the influence of radiation are sterilized and lose the ability to divide. There are foci of perforation of the walls of the stomach, and bacteria enter the bloodstream from the intestines. There are primary radiation ulcers, purulent infection from radiation burns. Loss of ability to work 0.5-1 hour after irradiation is observed in 100% of the victims. In 70% of those affected, death occurs a month later from dehydration of the body and poisoning of the stomach (gastrointestinal syndrome), as well as from radiation burns during gamma irradiation;
Extremely heavy (more than 600 rad). In a matter of minutes after irradiation, severe nausea and vomiting occur. Diarrhea - 4-6 times a day, in the first 24 hours - impaired consciousness, skin edema, severe headaches. These symptoms are accompanied by disorientation, loss of coordination, difficulty swallowing, upset stools, seizures, and eventually death. The immediate cause of death is an increase in the amount of fluid in the brain due to its release from small vessels, which leads to an increase in intracranial pressure. This condition is called "syndrome of violation of the central nervous system."
It should be noted that the absorbed dose, which causes damage to individual parts of the body and death, exceeds the lethal dose for the whole body. Lethal doses for individual parts of the body are as follows: head - 2000 rad, lower abdomen - 3000 rad, upper abdomen - 5000 rad, chest - 10000 rad, limbs - 20000 rad.
The level of effectiveness of ARS treatment achieved today is considered to be the limit, as it is based on a passive strategy - the hope for self-healing of cells in radiosensitive tissues (mainly bone marrow and lymph nodes), for supporting other body systems, platelet transfusion to prevent hemorrhage, erythrocyte - to prevent oxygen starvation. After that, it remains only to wait until all the cellular renewal systems start working and the disastrous consequences of radiation exposure are eliminated. The outcome of the disease is determined by the end of 2-3 months. In this case, the following may occur: complete clinical recovery of the victim; recovery, in which his ability to work in one way or another will be limited; poor outcome with progression of the disease or the development of complications leading to death.
The transplantation of a healthy bone marrow is hampered by an immunological conflict, which is especially dangerous in an irradiated organism, as it depletes the already undermined immunity. Russian scientists-radiologists offer a new way of treating patients with radiation sickness. If part of the bone marrow is taken away from the irradiated person, then in the hematopoietic system, after this intervention, the processes of earlier recovery begin than with natural development events. The extracted part of the bone marrow is placed in artificial conditions, and then after a certain period of time it is returned to the same organism. Immunological conflict (rejection) does not occur.
Currently, scientists are working, and the first results have been obtained on the use of pharmaceutical radioprotectors, which allow a person to endure radiation doses that are approximately twice the lethal dose. These are cysteine, cystamine, cystophos and a number of other substances containing sulfidehydryl groups (SH) at the end of a long molecule. These substances, like "scavengers", remove the resulting free radicals, which are largely responsible for enhancing oxidative processes in the body. However, a major drawback of these protectors is the need to introduce it into the body intravenously, since the sulfidehydryl group added to them to reduce toxicity is destroyed in the acidic environment of the stomach and the protector loses its protective properties.
Ionizing radiation also has a negative effect on fats and lipoeds (fat-like substances) contained in the body. Irradiation disrupts the process of emulsification and promotion of fats in the cryptal region of the intestinal mucosa. As a result, droplets of non-emulsified and coarsely emulsified fat, absorbed by the body, enter the lumen of the blood vessels.
An increase in fatty acid oxidation in the liver leads, in insulin deficiency, to increased liver ketogenesis, i.e. An excess of free fatty acids in the blood reduces the activity of insulin. And this, in turn, leads to a widespread disease today. diabetes.
The most characteristic diseases associated with damage from radiation are malignant neoplasms (thyroid gland, respiratory organs, skin, hematopoietic organs), metabolic and immune disorders, respiratory diseases, complications of pregnancy, congenital anomalies, mental disorders.
Recovery of the body after irradiation is a complex process, and it proceeds unevenly. If the restoration of erythrocytes and lymphocytes in the blood begins after 7-9 months, then the restoration of leukocytes - after 4 years. The duration of this process is influenced not only by radiation, but also by psychogenic, social, domestic, professional and other factors of the post-radiation period, which can be combined into one concept of "quality of life" as the most capaciously and fully expressing the nature of human interaction with biological environmental factors, social and economic conditions.
Ensuring safety when working with ionizing radiation
When organizing work, the following basic principles for ensuring radiation safety are used: selection or reduction of source power to minimum values; reducing the time of work with sources; increasing the distance from the source to the worker; shielding of radiation sources with materials that absorb or attenuate ionizing radiation.
In rooms where work is carried out with radioactive substances and radioisotope devices, the intensity of various types of radiation is monitored. These rooms should be isolated from other rooms and equipped with supply and exhaust ventilation. Other collective means of protection against ionizing radiation in accordance with GOST 12.4.120 are stationary and mobile protective screens, special containers for the transportation and storage of radiation sources, as well as for the collection and storage of radioactive waste, protective safes and boxes.
Stationary and mobile protective screens are designed to reduce the radiation level at the workplace to an acceptable level. Protection against alpha radiation is achieved by using Plexiglas a few millimeters thick. To protect against beta radiation, screens are made of aluminum or plexiglass. Water, paraffin, beryllium, graphite, boron compounds, and concrete protect against neutron radiation. Lead and concrete protect against X-ray and gamma radiation. Lead glass is used for viewing windows.
When working with radionuclides, protective clothing should be used. In case of contamination of the working room with radioactive isotopes, film clothing should be worn over cotton overalls: a dressing gown, a suit, an apron, trousers, sleeves.
Film clothing is made from plastics or rubber fabrics that are easily cleaned from radioactive contamination. In the case of film clothing, it is necessary to provide for the possibility of supplying air under the suit.
Workwear sets include respirators, air helmets and other personal protective equipment. To protect the eyes, goggles with glasses containing tungsten phosphate or lead should be used. When using personal protective equipment, it is necessary to strictly observe the sequence of putting on and taking off, and dosimetric control.
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