Little is known about ionizing radiation

1. What are the common ionizing radiation?

According to whether it is charged or not, it is divided into charged particles (α particles, β particles, protons, etc. ) and uncharged particles (x-rays, gamma rays, neutrons, etc. ).

1.α ray

It consists of helium nuclei (also known as alpha particles) moving at high speed. Positive charge is 2 units, mass number is 4, ionization effect is large, and penetration ability is small. 10cm air, thin glass plate, surgical gloves, clothes, a piece of paper or the skin of biological tissue are enough to stop α particles. However, the ionization ability of alpha particles is particularly great. Once the alpha particle emitter accidentally enters the human body, the harm caused by a large amount of ionization caused by irradiation in alpha particles is particularly great. The key point of protection is to prevent the emitter of alpha particles from entering the body and avoid internal irradiation damage.

2. Beta rays

This is a high-speed electron flow. With unit charge and light weight. Its ionization effect is small and its penetration ability is large. Beta particles can cause radiation damage in vivo and in vitro. In order to protect beta rays, materials with lower atomic number should be used. Aluminum, clothes or plexiglass with a thickness of several millimeters can better protect against external irradiation of beta rays.

3. Gamma rays

Gamma rays are photons with no charge and no static mass. They are electromagnetic waves with short wavelength and belong to electromagnetic radiation. The ionization effect is small and the penetration ability is large. Mainly caused by external irradiation damage. Commonly used protective materials are water, brick, concrete, aluminum, iron, copper, lead, tungsten and depleted uranium.

Neutrons are uncharged particles with a mass of about one atomic mass unit. Neutron protection: use water, plastic and paraffin with high hydrogen content to slow down fast neutrons; Absorb slow neutrons with lithium, boron, etc. Materials with high atomic number are used to protect gamma rays produced during neutron deceleration and absorption.

2. What are the ionizing radiation that people are exposed to in their daily life?

People are exposed to natural radiation all the time, including cosmic rays, rays emitted by radioactive substances in soil, water, food and air. Radon is a radioactive inert gas in nature and the main natural radiation source. The most common artificial radiation that people are exposed to is medical radiation, such as X-ray photography, CT examination and radiotherapy.

The radiation dose unit related to human health is usually expressed by Sv. The average annual effective dose of natural radiation in the world is about 2.4 msv (65 65,438+0 SV = 65,438+0,000 msv), of which 0.4mSv comes from cosmic rays, 0.5mSv from ground gamma rays, 65,438+0.2 msv from inhalation (mainly radon) and 0.3mSv from ingestion. Thus, radon is the main source of natural radiation. A small amount of radiation exposure will not endanger human health.

In daily life, the effective dose of X-ray diagnosis of chest, mouth and limbs is 0.01msv; ; X-ray diagnosis of head and neck was 0.1msv; ; X-ray diagnosis of chest and abdomen and CT scan of head were 65438±0 msv；; Abdominal CT, barium meal and barium * * * were10 msv; Traveling 2000 kilometers by plane is about 0.01msv; ; Smoke 20 cigarettes a day, about 0.5mSv a year.

3. What is ionizing radiation

Ionizing radiation is a general term for all kinds of radiation that can cause ionization of substances. There are many kinds of high-speed charged particles, such as alpha particles, beta particles, protons and uncharged particles, such as seeds, X-rays and gamma rays.

Alpha rays are a stream of charged particles, which are easily ionized wherever they go. Alpha rays have strong ionization energy and can be used.

It also brings some harm, and it has great destructive ability to the tissues in the human body. Because of its large mass and poor penetration ability, its range in the air is only cm, which can be blocked by a piece of paper or healthy skin.

β -ray is also a kind of high-speed charged particle, its ionization power is much less than α-ray, but its penetration power is greater than α-ray, but its range with X and γ-ray is shorter than β-ray, so it is easily absorbed by aluminum foil, plexiglass and other materials. X-rays and gamma rays are basically the same in nature. They are both electromagnetic waves and have no wavelength of radio waves, so they are collectively called photons.

Both of them have strong penetrating power, so special attention should be paid to accidental irradiation protection. Ionizing radiation exists in nature, but at present, artificial radiation has spread all over various fields, and those who specialize in the production, use and research of ionizing radiation are called radiation workers.

Radiation-related occupations include: systematic exploration, mining, smelting and finishing of raw materials for nuclear industry, production, use and research of nuclear fuel and reactors; Agricultural irradiation to cultivate new varieties, vegetable and fruit insurance, grain storage; Medical X-ray fluoroscopy, photographic diagnosis, radionuclide determination of human organs, tumor radiotherapy, etc. Various accelerators, ray generators and electron microscopes, electronic speed welding machines, color TV picture tubes, high-voltage electron tubes, etc. In the industrial sector.

4. How harmful is ionizing radiation to people?

When the dose of radiation to human body exceeds a certain limit, it will have harmful effects. Under the action of electric radiation, the reaction degree of the body depends on the type, dose, irradiation conditions and sensitivity of the body.

Ionizing radiation can cause radiation sickness, which is a systemic reaction of the body. Almost all organs and systems have pathological changes, but the changes in nervous system, hematopoietic organs and digestive system are the most obvious.

The damage caused by ionizing radiation can be divided into acute radiation damage and chronic radiation damage. Receiving a certain dose of radiation in a short time will cause acute damage to the body, which is usually seen in patients with nuclear accidents and radiotherapy.

However, long-term scattered exposure to a certain dose can cause chronic radiation damage, such as skin damage, hematopoietic dysfunction, leukopenia, and impaired fertility. In addition, excessive radiation can also cause cancer, leading to fetal death and deformity.

The annual average effective dose determined by the audit department for five consecutive years (but not retrospective average), 20mSv；; Effective dose in any year, 50mSv；; Annual equivalent dose of ocular lens,150msv; ; Annual equivalent dose of limbs (hands and feet) or skin, 500 milliSewart.

For apprentices 16~ 18 years old who have received employment training related to radiation exposure and students 16 ~ 18 years old who need to use radioactive sources during their studies, their occupational exposure should be controlled within the following limits: annual effective dose, annual equivalent dose of 6 msv eye lens, 50mSv；; Annual equivalent dose of limbs (hands and feet) or skin, 150mSv.

Extended data:

Daily protection against ionizing radiation;

Equipment and radiation sources that can generate radiation are strictly controlled. Before the radioactive project is put into use, it is necessary to pre-evaluate the occupational hazard factors and evaluate the control effect.

Radioactive workplaces need to be tested every year to ensure the safety of radiation workers and the public. No matter where you see signs of ionizing radiation, stay away, don't approach, and don't break in casually. The hospital will do relevant radiological examination, and family members will accompany it if necessary.

Hospitals are equipped with relevant protective equipment. Under the guidance of a doctor, you can wear corresponding protective equipment according to different examinations, and pay attention to strengthening the protection of glasses, thyroid gland and gonads. For children with active growth and development, more attention should be paid to wearing protective equipment.

Sogou encyclopedia-ionizing radiation

5. Nuclear radiation protection knowledge

Personal radiation protection knowledge 1. How does the public respond to nuclear and radiation emergencies? In the event of a nuclear and radiation emergency, the first thing the public should do is to obtain as much credible information about the emergency as possible and understand the decisions and notices of the * * * department.

It is necessary to maintain information communication with local authorities through various means, and remember not to believe rumors or gossip. The second thing is to take necessary protective measures to protect yourself quickly.

For example, you can choose the nearest building for concealment, close the doors and windows, and close the ventilation equipment. According to the arrangement of the local * * * organized and orderly evacuation.

When judging radioactive scattering events, remember not to run in the wind or with the wind. Try to hide to the side of the wind direction and quickly enter the building for concealment. Take respiratory protection measures, including covering your nose and mouth with a wet towel and cloth to filter out radioactive particles.

If you suspect radioactive pollution on your body surface, you should take a bath and change clothes to reduce radioactive pollution. Prevent eating contaminated food or water.

In the event of nuclear and radiation emergencies, the public should pay special attention to maintaining a stable mentality and never panic. 2. What are the early protective measures for nuclear and radiation emergencies? Early stage refers to the protective measures that can be taken for personnel within 1~2 days after nuclear and radiation emergencies, such as concealment, respiratory protection, taking stable iodine, evacuation, controlling import and export channels, etc.

Among them, respiratory protection is the action of covering your nose with dry towel or wet towel, which can prevent or reduce the inhalation of radionuclides. Taking stable iodine can prevent or reduce the radioactive iodine in smoke plume from depositing in thyroid after entering the body.

3. What are the medium-term protective measures for nuclear and radiation emergencies? In the middle of the incident, a considerable amount of radioactive materials have been deposited on the ground. At this time, for individuals, other early protective measures can continue to be taken except for respirators.

In order to avoid excessive accumulated dose caused by long-term stay, the competent department can take a controlled and planned way to relocate the personnel in the polluted area. Consideration should also be given to restricting the sale and consumption of locally produced or stored food and drinking water.

According to the characteristics of personnel exposure in this period, protective measures can also be taken: using stored feed in animal husbandry, disinfecting personnel's body surface, treating the wounded and sick, etc. 4. What are the protective measures for nuclear and radiation emergencies? In the later stage of the accident (recovery period), the question is: can normal social life be restored and when? Still need to take further protective measures? At the later stage of the incident, the main exposure routes are in vivo exposure caused by ingestion of contaminated food and inhalation of resuspended substances.

Therefore, protective measures can be taken, including controlling import and export routes, avoiding migration, controlling food and water, using stored feed and purifying areas. 5. Under what circumstances should hidden measures be taken and what should the public pay attention to? When a large number of radioactive substances are released into the atmosphere, concealment is one of the main protective measures in the early and middle stages of emergencies.

Most buildings can reduce the inhalation dose of people in the building by about half. After hiding for a period of time, the concentration of radionuclides in the air in the hidden body will increase after the smoke plume passes, so ventilation is needed to reduce the radioactive concentration in the air to a level equivalent to the outdoor cleanliness.

Therefore, for long-term release, the hidden protection effect is poor. It is generally believed that the concealment time should not exceed 2 days.

6. Under what circumstances do you need to take personal protective measures and what should the public pay attention to? When the air is polluted by radioactive substances, some personal protective measures need to be taken. Covering your nose and mouth with handkerchiefs, towels and cloth can reduce the dose caused by inhaling radioactive substances by about 90%.

The protection of body surface can be used in all kinds of daily clothes, including hats, headscarves, raincoats, gloves, boots and so on. It is very simple to decontaminate people whose body surfaces have been or are suspected to be contaminated by radioactivity. Just tell the relevant personnel to take a shower with water and take off the contaminated clothes, shoes, hats, etc. And store them until they have time to monitor or process them later.

It is necessary to prevent radioactive pollution from spreading to unpolluted areas. 7. Under what circumstances should I take stable iodine? After nuclear and radiation emergencies, people may ingest radioactive iodine and concentrate it in the thyroid gland, thus exposing this organ to a large dose of radiation.

Taking stable iodine at this time can reduce the absorption of radioactive iodine by thyroid. If you take stable iodine while inhaling radioactive iodine, you can block 90% of radioactive iodine deposition in the thyroid gland.

Taking stable iodine within a few hours of inhaling radioactive iodine can still reduce the amount of radioactive iodine absorbed by thyroid by about half. The recommended dosage is 0/00 mg iodine for adults, 50 mg iodine for pregnant women and children aged 3- 12, and 25 mg iodine for children under 3 years old.

8. What should I pay attention to when taking stable iodine? For newborns within one month after birth, the dose of stable iodine should be kept at the lowest effective level. For some people, such as patients with thyroid nodules, patients with cured exophthalmos, patients treated with radioactive iodine, patients with chronic inflammatory diseases of thyroid, patients with unilateral thyroidectomy, patients with subclinical hypothyroidism, patients with iodine allergy, patients with certain skin diseases (acne, eczema, psoriasis), etc. Stable iodine should be used with caution or not.

9. Can iodine tablets (KI) protect against radiation? How does it protect against radiation? Physiologically, the main source of human iodine is the absorption of thyroid gland, which produces thyroid hormone. KI is stable iodine, which can saturate iodine in thyroid and prevent the intake of radioactive iodine.

The experience of Chernobyl shows that radioactive iodine is the main factor affecting the Chernobyl accident, which has caused more than 5,000 cases of thyroid cancer in children, and the exposed population is between 0 and 18 years old. Therefore, the primary target of KI distribution is young children and pregnant women.

Iodine tablets cannot protect external radioactivity and radioactive substances other than iodine absorbed by the body. This is also the reason why iodine thyroid block will be combined with other protective measures (such as hiding indoors and closing doors and windows). ) on most occasions.

In order to give full play to the blocking effect of stable iodine on iodine thyroid, it is necessary to take stable iodine tablets as soon as possible before or after irradiation. Even a few hours after the accident, taking it can still prevent the thyroid gland from absorbing 50% iodine.

In order to prevent inhalation of radioactive iodine isotopes, one dose of stable iodine is usually enough, which can be as small as 24.

6. What is ionizing radiation?

Ionizing radiation is a general term for all kinds of radiation that can cause ionization of substances. There are many kinds of high-speed charged particles, such as α particles, β particles and protons, and uncharged particles, such as neutrons, X-rays and γ-rays.

Alpha rays are a stream of charged particles, which are easily ionized wherever they go. Alpha rays have strong ionization energy and can be used. It also brings some harm, and it has great destructive ability to the tissues in the human body. Because of its large mass and poor penetration ability, its range in the air is only cm, which can be blocked by a piece of paper or healthy skin.

β -ray is also a kind of high-speed charged particle, its ionization power is much less than α-ray, but its penetration power is greater than α-ray, but its range with X and γ-ray is shorter than β-ray, so it is easily absorbed by aluminum foil, plexiglass and other materials.

X-rays and gamma rays are basically the same in nature. They are both electromagnetic waves and have no wavelength of radio waves, so they are collectively called photons. Both of them have strong penetrating power, so special attention should be paid to accidental irradiation protection.

Ionizing radiation exists in nature, but at present, artificial radiation has spread all over various fields, and those who specialize in the production, use and research of ionizing radiation are called radiation workers. Radiation-related occupations include: systematic exploration, mining, smelting and finishing of raw materials for nuclear industry, production, use and research of nuclear fuel and reactors; Agricultural irradiation to cultivate new varieties, vegetable and fruit insurance, grain storage; Medical X-ray fluoroscopy, photographic diagnosis, radionuclide determination of human organs, tumor radiotherapy, etc. Various accelerators, ray generators and electron microscopes, electronic speed welding machines, color TV picture tubes, high-voltage electron tubes, etc. In the industrial sector.

Natural radiation:

Humans mainly receive natural radiation from nature. It comes from the sun, cosmic rays and radionuclides in the earth's crust. Radon overflowing from underground is another important source of natural radiation. Cosmic rays from space include quantized photons, electrons, gamma rays and x-rays. The main radionuclides found in the earth's crust are uranium, thorium and polonium, and other radioactive substances. They emit alpha, beta or gamma rays.

Artificial radiation:

Radiation is widely used in medicine and industry. Artificial radiation is mainly used for medical equipment (such as medical and imaging equipment); Research and teaching institutions; Nuclear reactors and their auxiliary facilities, such as uranium mines and nuclear fuel plants. The above facilities will inevitably produce radioactive waste, some of which will leak a certain dose of radiation into the environment. Radioactive substances are also widely used in people's daily consumption, such as luminous watches, glazed ceramics, artificial dentures, smoke detectors and so on.

There are also nondestructive testing of boilers and pressure vessels. The commonly used command source is gamma source, and the X-ray machine emits X-rays. These two methods are commonly used in nondestructive testing industry. Magnetic powder, penetration and ultrasonic are also used now, but X-ray machines and gamma sources are irreplaceable.

7. Who can tell me the difference between electromagnetic radiation and ionizing radiation, and the related radiation media in daily life?

The difference between electromagnetic radiation and ionizing radiation;

First, the production methods are different:

1, ionizing radiation is energy radiation that makes electrons in atoms or molecules of substances free, thus ionizing these atoms or molecules.

2. Electromagnetic radiation is produced by the movement of electric charge.

Second, the harm to people:

1, some electromagnetic radiation has certain influence on human body.

2.20 17,17127 October, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference, and ionizing radiation (all types) was in the list of Class I carcinogens.

Extended data:

Protection principle:

1, time protection:

No matter what kind of radiation, the cumulative dose of human body is directly proportional to the exposure time. The longer the exposure time, the more serious the radiation hazard. Try to shorten the time engaged in radioactive work to reduce the exposure dose.

2, distance protection:

The radiation dose rate at a certain place is inversely proportional to the square of the distance from the radioactive source, and the farther away from the radioactive source, the smaller the dose rate at that place. So try to stay away from radioactive sources when working. In order to achieve the purpose of protection.

3, shielding protection:

Is to set up a protective barrier between people and radioactive sources. Because the radiation passes through substances with large atomic number and will be absorbed in large quantities, the radiation dose reaching the human body will be weakened. Commonly used shielding materials are lead, reinforced cement, lead glass, etc.