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Harm and prevention of electromagnetic radiation

Electromagnetic radiation and health

The 2th century is known as the electrical age, with more and more power stations and transmission lines being built, and all kinds of electrical appliances have penetrated into factories, laboratories, offices and ordinary households. However, whether the electromagnetic field, especially the electromagnetic field with industrial frequency (5-6 Hz) has an impact on human health is a problem that people have been paying more attention to.

in the early 196s, relevant experts began to discuss this issue. At first, the experts focused on the role of electric field and ignored the role of magnetic field. Because at that time, people mistakenly thought that the magnetic field component in this electromagnetic field was very small, and it could not have a perceptible impact on human health. In many countries, the health care standards only stipulate the allowable electric field components in industrial frequency electromagnetic fields; When manufacturing all kinds of electrical equipment and appliances and erecting transmission lines, only the standards specified for electric field components are considered, but the maximum allowable limit for magnetic field components is not considered. However, a large number of investigations and statistical analysis later showed that magnetic fields can also affect human health. For example, the probability of multiple tumor lesions in human body is closely related to the low-frequency electromagnetic radiation received. Experts in many countries in Europe and America and some government agencies are convinced that low-frequency magnetic fields will significantly increase the incidence of the following diseases: leukocytosis and leukemia (especially more harmful to children), cancer, neonatal physical defects, breast cancer, brain tumors, malignant lymphoma, nervous system tumors, the development of astrocytes, chronic myeloid leukemia, chromosome aberration and so on. Some reports also pointed out that the decrease in the secretion of some hormones under the action of electromagnetic fields may also be the cause of the development of breast tumors.

Up to now, there is no direct evidence about the harm of mobile phones to health, but in general, it is better to make a long story short when using mobile phones.

How much do you know about electromagnetic radiation

Some investigation reports point out that people who are exposed to electromagnetic radiation frequently are at greater risk of developing breast cancer if they are exposed to high temperature again; People who have been electrical engineers for a long time will increase their risk of acute leukemia if they are exposed to gasoline, pesticides or pesticides again.

many investigation reports also point out that people who are engaged in "electrical occupation", children and those who improperly use household appliances (children who often play video games, women and children who often use electric blankets and other electric heaters, etc.) are at greater risk of being damaged by low-frequency magnetic fields. Some countries also have such regulations for pregnant women: the baby can't go to the computer for 3-6 months before birth.

The intensity and accumulation of low-frequency magnetic field radiation will affect the probability of disease. Moreover, some people get sick after the incubation period is as long as 1-15 years. According to the international health standards, the allowable upper limit of magnetic induction intensity is 1 microtesla. Electromagnetic radiation is just like the relationship between the sun and ultraviolet rays. If you want to enjoy the sun, you will inevitably receive ultraviolet radiation. Electromagnetic radiation is invisible, intangible and difficult to perceive, so its harm is particularly hidden. From electronic alarm clocks, hair dryers, microwave ovens and electric irons to computers, fax machines and telephones, we are constantly exposed to electromagnetic "comfort". Walking out of the door, power lines and various motor equipment make us very easy to be in the electromagnetic field. The deterioration of electromagnetic environment in the 21st century is a foregone conclusion.

preventive measures against electromagnetic radiation

as we all know, where there is electricity, there is electromagnetic radiation, which is invisible, intangible and hard to prevent. Then what kind of preventive measures people take is very important.

First of all, we should widely publicize the basic knowledge of electromagnetic radiation, and let people know how electromagnetic radiation is generated, what harm it will do to human body, what kind of places and what kind of equipment it uses will produce electromagnetic radiation. This is a long-term patient and meticulous work.

Secondly, take some necessary preventive measures to avoid or reduce electromagnetic radiation. For example, there is a kind of anti-radiation clothing which is made of a variety of anti-electromagnetic radiation raw materials and woven into the fabric of clothes, and its electromagnetic shielding effect is very obvious. If our merchants produce more such clothes, the harm of electromagnetic radiation to human body will be greatly weakened.

How to prevent the harm caused by electromagnetic radiation

1. Prevent the influence of electromagnetic radiation on human body:

(1) Shielding room: it is made of metal (sheet, net) and is mostly used to shield the active field of large mechanical groups or control rooms;

(2) shield clothing, shield helmet and shield glasses: these are personal protective devices, which can effectively reduce the intensity of magnetic radiation to protect the health of workers exposed to electromagnetic radiation;

(3) Shielding cover: This is the main method to shield the active field of small instruments, and the materials used for shielding are generally conductive materials with low resistivity, such as copper and aluminum.

(4) Earphones can be worn to reduce the electromagnetic radiation generated by mobile phones. The experiment of Thiel Laboratory of the Institute of Telecommunication Transmission of the Ministry of Information Industry proves that the radiation to the head when talking with headphones is between 1/1 and 1/2 of that when talking directly with mobile phones.

2. The main methods to prevent electromagnetic radiation from leaking your computer secrets are:

(1) Passive mode: electromagnetic shielding to prevent electromagnetic waves from leaking out. The disadvantage of using this mode alone is that if the shielding is not complete, the high-sensitivity electromagnetic receiving equipment can still obtain information;

(2) active mode: emitting electromagnetic waves, so that the electromagnetic receiving equipment used for stealing secrets receives the interfered signals. The disadvantage of using this mode alone is that it is still possible to restore useful information if the received disturbed signal is analyzed by using very well-designed software.

therefore, the best way is to mix the two modes at the same time.

therefore, it is necessary to adopt passive mode to prevent electromagnetic waves from leaking out from these aspects. Simply shielding the display is not enough. When using the computer in secret, all unnecessary cables and peripherals should be removed.

using a battery-powered laptop can eliminate this connection. However, if the public power supply must be used, passive mode filtering equipment or active mode interference signal injected into the power line is a measure that can be considered.

The electromagnetic radiation hazard of living environment quality can't be ignored

At present, with people paying more and more attention to health, buyers have begun to pay attention to environmental quality besides location, price, apartment type, garden and property when choosing housing. It is understood that in order to let people enjoy a safe and healthy living environment, the Law of the People's Republic of China on Environmental Impact Assessment will come into effect on September 1, which means that mandatory environmental impact assessment is required for residential community projects before the project is established in the future.

electromagnetic radiation surfaced

For outdoor environmental quality, noise, air index and electromagnetic radiation are the three issues that people are most concerned about, especially electromagnetic radiation. Because electromagnetic radiation is intangible, invisible and people don't know much about it, many residents living around high-voltage lines, substations, radio stations, TV stations and radar stations have an inexplicable fear. However, experts from the State Environmental Protection Administration pointed out that although electromagnetic radiation is harmful to some extent, on the one hand, electromagnetic radiation is not harmful at any time and any place; On the one hand, electromagnetic radiation can be shielded, so residents need not be nervous about electromagnetic radiation.

Understanding electromagnetic radiation correctly

With the development and progress of society, a large number of TV towers, radio stations, radars, satellite communications, microwaves and other equipment and activities with electromagnetic radiation are also increasing. These devices have played an important role in the improvement of human living standards and the progress of social development, and the electromagnetic waves generated at the same time are also an environmental pollution factor. The more social development progresses, the more serious electromagnetic pollution is. Therefore, electromagnetic wave is not only an information carrier and energy flow carrier beneficial to social development, but also a pollution factor harmful to human life, and its harm has been highly valued by the international environmental protection field. Therefore, it is necessary to take electromagnetic energy as a resource and make full use of it; It is also necessary to strengthen management and control the negative effects of electromagnetic radiation to a minimum.

according to experts from the state environmental protection administration, from a professional point of view, electromagnetic radiation generally refers to electromagnetic waves with a frequency above 1KHZ. The sources of electromagnetic field are natural and artificial. First of all, the earth itself is a big magnetic field. Sunlight itself is also a frequency band of electromagnetic waves, as well as electromagnetic waves generated by thunder and lightning and other planets, all of which are naturally generated, and human beings have evolved in this environment and formed a harmonious relationship with nature. Therefore, natural electromagnetic radiation has no harm to the human body. However, since the 19th century, with the development of science, human beings have invented many facilities that use electromagnetic energy to work. These facilities emit electromagnetic radiation or generate electromagnetic fields in large quantities to the environment, which makes the problem of electromagnetic radiation in the environment more and more serious, thus resulting in the problem of electromagnetic environmental protection. The facilities that generate electromagnetic radiation can be roughly divided into five categories:

1. Radio and television transmission systems, such as TV transmission towers and broadcast relay stations;

2. Wireless communication transmission system, such as mobile phone base station;

3. High-voltage power transmission and transformation systems, such as high-voltage lines and substations;

4. electrified railways, such as maglev trains;

5. electromagnetic energy facilities for industry, science and medical treatment, such as high-frequency smelting furnaces;

Harm of electromagnetic radiation

Humans live in a huge electromagnetic field, and electromagnetic radiation is ubiquitous, so electromagnetic radiation is not as terrible as imagined. Only when the electromagnetic radiation exceeds a certain value will it have a bad influence on people's health. According to the Regulations on Electromagnetic Radiation Protection issued by the State Environmental Protection Agency, if the electric field intensity is lower than 4 volts per meter, it should be safe. Even if it exceeds this value, it does not necessarily cause harm, which depends on the individual's resistance and the time and distance of contact. In addition, experts also pointed out that electromagnetic waves are ubiquitous, which brings infinite convenience to our lives. We should treat them correctly and make rational use of them. There is absolutely no need to worry too much. As long as proper shielding and protection are carried out, the radiation impact can be greatly reduced.

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How terrible is electromagnetic radiation

In recent years, domestic and foreign media have been reporting that electromagnetic radiation is harmful: more than 4 children in Italy suffer from leukemia every year, and experts believe that the cause is serious electromagnetic pollution; A cancer medical foundation in the United States sampled some patients who were injured by electromagnetic radiation. The results showed that the growth rate of cancer cells in people working near high-voltage lines was 24 times faster than that of ordinary people. Of the 2 million children born in China every year, 35, are handicapped children, of whom 25, are mentally handicapped. Some experts believe that electromagnetic radiation is one of the influencing factors.

Is the harm of electromagnetic radiation really so sensational?

In fact, human beings have been living in an electromagnetic environment. The earth itself is a large magnetic field, and both thermal radiation and lightning on its surface can produce electromagnetic radiation. In addition, the sun and other planets also continuously produce electromagnetic radiation from outer space. However, naturally generated electromagnetic radiation is harmless to human body, while artificially generated electromagnetic radiation poses a threat to human body and pollutes the environment.

as early as 168 years ago, Faraday, an Englishman, discovered a wonderful phenomenon: electric field and magnetic field can be generated when current passes through the media, which is later called electromagnetic induction. In the 198s, people used the principle of electromagnetic induction to build the world's first power station. Since then, mankind has strided into the application era of electromagnetic radiation.

From the first global communication in 191 to the large-scale use of mobile communication, as well as the necessary color TV sets and refrigerators, the application of electromagnetic radiation has penetrated into all aspects of human life. While fully enjoying the convenience and comfort brought by electromagnetic radiation, people are increasingly feeling its negative effects. For example, electromagnetic radiation in electromagnetic compatibility has caused navigation system, medical information system, industrial process control and information transmission system to get out of control, and interfered with people's listening to radio and television ...

It is said that as long as household appliances, electronic equipment, mobile communication equipment and other electrical devices are in operation and use, electromagnetic radiation will exist around them. I also heard that electromagnetic radiation can penetrate a variety of substances, including the human body. Therefore, some people compare the pollution caused by electromagnetic radiation of products to "invisible killer" So how much harm will electromagnetic radiation do to human health?

The reporter interviewed Zhao Yufeng, a professor at Beijing Institute of Labor Protection Science.

Professor Zhao said: "Electromagnetic radiation and electromagnetic pollution are two concepts. Although electromagnetic radiation is ubiquitous, electromagnetic pollution will have negative effects on human body only after the electromagnetic radiation exceeds a certain intensity (that is, the limit of safety and health standards), leading to headaches, insomnia, memory decline, blood pressure rising or falling, borderline abnormalities in the heart and other symptoms. If you work in an environment with excessive electromagnetic radiation for a long time, it may seriously cause some people to miscarry, cataracts, and even cause cancer ... "< P > Zhao Yufeng said frankly that although the influence of electromagnetic radiation on people is widespread, it is not terrible. The ability of different people or the same person to withstand electromagnetic radiation at different ages.