Shulou(Shulou.com)11/24 Report--

For a variety of reasons, nuclear radiation is always pushed to the forefront again inadvertently.

In the future, will delicious fish, shrimp, crab, shellfish and sea cabbage be contaminated by nuclear radiation?

In the future, will our food culture, which has lasted for thousands of years, be threatened by nuclear radiation?

Although it is 2022, most people will not "talk about nuclear color change" for no reason, but in the face of these questions, countless hearts, or stomach, can not help but tremble!

The definition of radiation is reminiscent of the mushroom cloud that exploded over Hiroshima, the Chernobyl nuclear accident, or the nuclear leak at the Fukushima Daiichi nuclear power plant 10 years ago. Nuclear radiation makes people shudder! Because it may cause biological cells to become cancerous, but also can make the vast land barren.

Human life is tenacious, but it is extremely vulnerable to unimaginable forces from nuclear radiation. Nuclear radiation can not only harm human beings from the outside of the human body, but also enter the interior of the human body to produce effects (that is, external and internal exposure)! Nuclear radiation, it's really horrible!

Perhaps for many people, nuclear radiation is far away. So there has always been doubt in my heart, is the radiation around us so terrible in our daily life? Next, let's take a look at what radiation is and what kind of radiation is nuclear discoloration.

First of all, you should know that radiation refers not only to nuclear radiation, but also to a variety of other characteristics of radiation. According to whether radiation causes ionizing effect, it is divided into two categories-ionizing radiation and non-ionizing radiation. Although there is an one-word difference between the two, they are quite different in nature.

The sign of the two effects is pictured, and the sign of ionizing radiation looks like three blades, solemn and solemn. The signs of non-ionizing radiation are like the signals we see every day.

(source: Sohu net) Ionizing radiation mainly refers to cosmic rays, high-frequency electromagnetic waves and some radiation produced by radioactive materials. This kind of radiation generally carries a large amount of energy, enough to make the electrons in the atoms or molecules of matter become free and ionize these atoms or molecules. Because all ionizing radiation is a kind of carcinogen, which is very frightening.

Non-ionizing radiation is mainly caused by low-frequency electromagnetic waves such as ultraviolet, thermal radiation, radio waves and microwaves. This kind of radiation transfers momentum and energy in the form of waves in space through electric and magnetic fields that oscillate in the same direction and are perpendicular to each other. The low energy of non-ionizing radiation will only cause the particles in matter to vibrate and the temperature to rise.

The radiation produced by electronic devices such as mobile phones and computers that we come into contact with in our daily life belongs to non-ionizing radiation. Moreover, electronic equipment and signal base stations all need to follow the corresponding national standards, the radiation energy generated is very low, and can not ionize electrons, so duck does not need to worry too much.

From a professional point of view, there is a way of radiation: put aside the dose to talk about toxicity, are playing hooligans!

So is there any way to help us understand the "radiation dose"?

In fact, in nuclear science, several proper terms related to radiation dose are often used to denote the amount of radiation related to the interaction of matter, in order to measure the amount of ionizing radiation.

Next, let's learn about some of the proper terms that we are most concerned about that can be used to describe "the effects of radiation on the human body"-absorbed dose, equivalent dose, effective dose.

Absorbed dose: energy obtained by ionizing radiation per unit of mass, the international unit is 1J / Kg, and the special unit is Gy, 1Gy=1J / Kg. The units used to be used in the past are rad, 1rad=0.01Gy.

Equivalent dose: generally speaking, the biological effects of a certain absorbed dose are related to the type of radiation, irradiation conditions, radiation dose, dose rate, biological species and individual differences. The same absorbed dose may not produce the same degree of biological effect. In the work of radiation protection, we are most concerned about the biological effects of organisms after irradiation, so the concept of equivalent dose is introduced.

Therefore, the equivalent dose refers to the product of the average absorbed dose produced by a certain radiation in an organ or tissue with the quality factor and N (some other correction factor). The international system of units is 1J / Kg, and the special units are Sv, 1Sv=1J / Kg. Because mSv is a very large unit, millisieverts (1mSv=0.001Sv) are usually used in daily life.

Effective dose: the sum of the equivalent dose of each tissue or organ multiplied by the tissue weight factor of each tissue or organ. In short, each part of the body has different sensitivity to different types of radiation, which is mathematically understood to mean that different tissues and organs of the body have different weights of damage caused by different types of radiation.

For example, human eyes are more likely to be damaged by radiation than limbs, so the tissue weight factor of the eyes is larger. Moreover, the tissue weight factor is a dimensionless constant, and the unit of the effective dose is naturally the same as that of the equivalent dose.

With regard to the units of radiation, the conversion relationship shown in the table below is satisfied.

Radiation dose

SI unit SI unit proper name

Special unit

Absorbed dose

Joule / kg (J/kg) Gory (Gy) 1Gy=1J/kg rad (rad) 1Gy=1J/kg=100rad rad (rad) 1Gy=1J/kg=100rad equivalent dose

Effective dose of joule / kg (J/kg) sievert (Sv) 1Sv=1J/kg sievert (Sv) 1Sv=1J/kg

Ionizing radiation in daily life of Joule / kg (J/kg) Sv (Sv) 1Sv=1J/kg Shivot (Sv) 1Sv=1J/kg

(source: national Energy Information platform) with the development of science and technology, the radiation environment is becoming more and more complex, including not only natural radiation, but also artificial radiation and nuclear explosion radiation born with human development, although they are not close to most people.

Looking back at our daily living environment, we can see that it is also a super complex radiation field. If we live in it, even if we do not go anywhere, within a year, we will receive effective doses of 2.4mSv natural background radiation generated by cosmic rays and ground radiation from nature. In China, the annual effective dose per capita is about 3.1mSv.

When our hospital has a physical examination and a chest X-ray, we will be exposed to radiation of about 0.05mSv; for a chest CT, we will receive a radiation dose of about 6.6mSv; and for a nuclear medicine 18F-FDG PET scan, we will receive a radiation dose of about 3.5-8.0mSv.

In this way, the hospital is the place where we can come into contact with strong radiation on a daily basis. no wonder the hospital posted a big warning sign ⚠️ outside the X-ray.

But there is no need to panic, because studies have shown that radiation doses below 100mSv each year do not change the incidence of cancer.

How many 100mSv are there? It takes a lot of chest shots a year or so for CT to reach this radiation dose.

(source: Qilong Network) in the last words, we should know that the average annual radiation caused by nuclear power plant work in China's residents living around nuclear power plants is 0.01mSv. Moreover, to believe in the power of science and technology, China's nuclear power plants have achieved very safe protection in terms of radiation.

On the other hand, the jade furniture, furnishings and ornaments placed in everyone's home may stretch out their claws in the dark. This is because some rocks contain natural radionuclides, and the decay of these radionuclides can also produce radioactive material.

Therefore, to buy this kind of expensive goods, we must find qualified regular manufacturers.

References:

Yuan long, Fu Ximing, Lei Cuiping, et al. Analysis on the current situation of health emergency response capacity of nuclear radiation emergencies in China [J]. China radiation Hygiene, 2019, 28 (01): 28-32.

[2] Guo Chengzhan. Current situation and countermeasures of nuclear and radiation safety supervision in China [J]. Nuclear Safety, 2013 Regent 12 (S1): 1-14.

[3] ionizing radiation. Https://baike.baidu.com/ item / ionizing radiation / 98607?fr=aladdin.

[4] https://www.sohu.com/ Journal of Concord Medicine. 46842594599939414.

Department of Ecological Environment of Shandong Province. Http://ksd.iqilu.com/ v7 / share / article / 7764070.

[6] key points in the review of radiation hygiene. Http://www.doczj.com/ doc / 1765cf2c48d7c1c708a1454e.html.

This article comes from the official account of Wechat: Institute of Semiconductors, Chinese Academy of Sciences (ID:bdtdsj), author: Yan Xiangning, Editor: fish of six yuan

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