The mechanism of electromagnetic radiation endangering human body is mainly thermal effect, non-thermal effect and accumulation effect.
Thermal effect: More than 70% of human body is water, and water molecules rub against each other after being radiated by electromagnetic waves, which causes the body to heat up, thus affecting the normal work of other organs of the body.
Non-thermal effect: There are weak electromagnetic fields in human organs and tissues, which are stable and orderly. Once disturbed by external electromagnetic waves, the weak electromagnetic field in equilibrium will be destroyed, and the normal circulation function of human body will be destroyed.
Cumulative effect: after thermal and non-thermal effects act on human body, if the damage to human body is radiated by electromagnetic waves again before it can repair itself, the damage degree will accumulate and become permanent pathological or life-threatening. For groups exposed to electromagnetic radiation for a long time, even if the power is very small and the frequency is very low, unexpected lesions will be induced, so be alert!
Scientists from all over the world have proved through long-term research that long-term exposure to electromagnetic radiation will lead to decreased immunity, metabolic disorder, decreased memory, premature aging, arrhythmia, decreased vision, decreased hearing, abnormal blood pressure, pimples and rough skin, and even lead to various cancers. The reproductive capacity of men and women is declining, and women are prone to menstrual disorders, abortion, teratogenesis and other diseases.
With the improvement of people's living standard, TV, computer, microwave oven, electric blanket, refrigerator and other household appliances are becoming more and more popular, and electromagnetic wave radiation is more and more harmful to human body. However, because electromagnetic waves are invisible, intangible and imperceptible, and their destruction is slow and hidden, it has not attracted widespread attention. Try not to put household appliances in the bedroom, nor put them in the center or use them at the same time.
Don't watch TV for more than 3 hours and keep a distance of more than 3 meters from the screen; Stay away from the TV immediately after turning it off, open the window for ventilation, and wash your face with facial cleanser or soap.
Don't talk for more than 3 minutes, and don't talk too many times. Turn on 1 for a second or two, and try to switch to face-to-face chat to reduce the radiation harm of electromagnetic wave of mobile phone to human body.
The foods that can prevent electromagnetic radiation are: green tea, kelp, seaweed, sundew, Va, Vc, Vb 1, lecithin, pig blood, milk, soft-shelled turtle, crab and other animals with high quality protein.
Electromagnetic wave and human health
On the earth, all kinds of electromagnetic waves are filled with human living space. Radio broadcasting, television, mobile communication, radio remote control, navigation and high-voltage transmission and distribution lines radiate powerful electromagnetic wave energy to the air and the ground. Induction heating equipment, such as high-frequency quenching, welding, melting, cutting, plastic sealing, wood drying, electromagnetic physiotherapy, microwave therapy, microwave heating and so on, will emit and leak certain intensity of electromagnetic energy to the environment, and human beings live in such a sea of electronic cigarettes.
Electromagnetic wave pollution
Since the advent of electronic industry, it has not only brought revolutionary changes to science and technology and industrial production, but also brought convenience and comfort to people's lives. However, electromagnetic waves radiated by various electronic products and equipment sometimes pollute the environment and become one of the important environmental pollution factors, endangering human health, thus becoming another public hazard to the human environment after waste gas, waste water, waste residue and noise.
Electromagnetic wave and its classification
Electromagnetic wave is a propagating alternating electromagnetic field. All kinds of light and rays are electromagnetic waves with different wavelengths, of which radio waves have the longest wavelength and cosmic rays have the shortest wavelength. Electromagnetic waves described in this section refer to radio waves. Radio waves can be divided into long wave, medium wave, short wave, microwave and mixed wave according to wavelength; According to frequency, it can be divided into low frequency, high frequency, ultrahigh frequency and ultrahigh frequency.
1? High frequency. Namely, medium wave and short wave. The wavelength is 10 ~ 3000m, and the frequency is 105 ~ 3× l07hz, such as induction heating equipment for high-frequency quenching, melting, welding and cutting, high-frequency medium heating equipment, plastic processing and food drying equipment, radio broadcasting and communication.
2? Uhf. That is, the short wave is1~10m, and the frequency is 3× 107 ~ 3× L08Hz, such as radio communication, TV signal transmission, medical electrical equipment, electrified railways, etc.
3? Uhf. Namely microwave. Wavelength 1 ~ < 0.07m, frequency 3× l08 ~ 3× l0? 10? Hertz, radio positioning, navigation, radar, etc. Is the source of artificial electromagnetic waves.
Electromagnetic wave pollution source residents in a certain place in China found that the indoor lights were on every day, and there was no switch. As soon as they picked up the telephone receiver, music came out. After investigation, it is found that the transmitting antenna of the nearby radio station is too close to the residential building, and the emitted electromagnetic wave signal induces electricity in the lights and telephones of the residential building. This is an example of electromagnetic wave pollution caused by electromagnetic radiation to the surrounding environment. There are many reasons for electromagnetic wave pollution. With the development of the city, the expansion of the urban area and the increasing shortage of construction land, the high-power electromagnetic transmitting stations and TV broadcasting transmitting stations originally located in the suburbs are gradually surrounded by new residential areas. With the development of satellite communication, there are many satellite ground stations in cities, and the transmitting antennas in some areas are too dense (more than 20 in some areas of Beijing); With the rapid development of mobile communication technology, its electromagnetic wave signal is transmitted in a straight line. There are many base stations and antennas on high-rise buildings in urban areas, which interfere with each other. Some unreasonable antennas have caused electromagnetic wave pollution to residents of nearby high-rise buildings. EHV transmission lines and urban transportation systems increase electromagnetic pollution; In addition, home computers, color TVs, stereos, microwave ovens, induction cookers, wireless mobile phones, electric blankets, etc. will radiate electromagnetic waves and cause environmental electromagnetic pollution. If used improperly, it will cause harm to human body, and the harm of electric blanket should be highly vigilant.
Many electromagnetic waves formed by electronic products or equipment in space not only interfere with each other, but also make their functions abnormal, such as unclear display screen images, serious interference of short-wave communication lines, declining voice quality, declining reception quality of radio and television signals, sudden unclear television, radio noise and so on. And when it reaches a certain strength, it will hurt people invisibly.
Harm of electromagnetic waves to people
Electromagnetic wave pollution can't be seen, touched or smelled, but it is everywhere. The human body is always in an electromagnetic radiation environment with a certain energy. When its frequency exceeds 105HZ, it is harmful to the human body. The greater the output power of electromagnetic radiation source, the greater the radiation intensity, the shorter the wavelength, the higher the frequency, the closer the distance, the longer the contact time, the higher the environmental temperature and humidity, the less the air circulation, the greater the environmental pollution and the more serious the harm to women and children.
Electromagnetic waves will disturb the natural circadian rhythm of the human body, lead to imbalance of the body, and cause neurasthenia symptoms such as headache, dizziness, insomnia and forgetfulness. Make people tired, lose appetite, be agitated and irritable; It can also make the body's thermal regulation system out of balance, leading to increased heart rate, increased or decreased blood pressure, respiratory disorders and leukopenia; It contributes to the occurrence and deterioration of cardiovascular diseases. Electromagnetic waves cause disturbance and disorder of bioelectricity in the body, which leads to abnormal EEG and ECG examination, delays disease diagnosis and affects treatment. Because of its strong penetrating power, electromagnetic waves not only act on the body surface, but also penetrate into internal tissues and organs. Often the human body has not felt the pain, and the internal tissues have been damaged. It will also promote the growth of cancer tissue, leading to an increase in cancer incidence. Electromagnetic waves can also cause vision loss. When the electromagnetic wave with the intensity of 100 MW/cm2 irradiates the eyes, the lens will be edematous, which may develop into cataract and even lead to blindness. Electromagnetic wave with intensity of 5 MW/cm2 ~ 10 MW/cm2 may not be obvious to human skin, but it may affect fertility and heredity. Under the action of electromagnetic waves, the menstrual cycle of women has changed obviously, which can lead to abortion and genetic defects of pregnant women and increase the incidence of cancer after birth. The incidence of cancer in children exposed to strong electromagnetic waves for a long time is 2 ~ 5 times higher than that in children exposed to low electromagnetic waves. Electromagnetic wave is also the inducement of leukemia, lymphoma and brain tumor.
High-frequency welding, high-frequency quenching, high-frequency melting, RF sputtering, silicon tube docking, semiconductor packaging, short-wave and microwave physiotherapy, microwave heating and other fields are widely used in industry, medical care, transportation and other fields. The transmission power of radio and television, communication base stations and signal transmitting stations (towers) is increasing, and various mobile communication base stations are densely covered with antennas, which makes the electromagnetic intensity in local space too high. The people most directly and seriously affected by electromagnetic waves are TV stations, radio stations, radar communication stations (stations) and residents around transmission towers. These powerful electromagnetic waves (general power 10 ~ 90 kW) can damage human blood and eyes, damage chromosomes, produce deformed fetuses, and even lead to central nervous system disorders.
After long-term research, it is found that the criss-crossing high-voltage lines not only destroy the beautiful environment, but also produce electromagnetic fields around them, which have harmful effects on people nearby. This mainly depends on the strength of the electromagnetic field. When people are exposed to the electromagnetic field with the intensity of 50 ~ 200 kV/m, they may have symptoms such as headache, dizziness, fatigue, poor sleep, loss of appetite, abnormal blood, cardiovascular system and central nervous system. Of course, this refers to EHV transmission lines with voltages above 100 km. According to the regulations, they are generally not allowed to pass through residential areas, so ordinary people can be protected from them. The common distribution lines in cities and residential areas are below 1 km, which are erected at a specified height and have little impact on human body. 1 ~ 100 km high-voltage transmission lines should pass through residential areas, and the erection height should be above 6.5 meters from the ground according to regulations.
Relevant data show that the electromagnetic radiation emitted by computer monitors will have adverse effects on women's endocrine and reproductive functions for a long time, endangering the development of germ cells and early embryos, and the harm to the fetus in the first three months of pregnancy is far greater than that in the second and third trimesters of pregnancy.
People are very concerned about the electromagnetic radiation of mobile phones. Although so far, there is no conclusion about the harm of electromagnetic waves from mobile phones to users, especially the pathogenic mechanism, the monitoring results of mobile phone radiation by environmental protection departments show that there are strong electromagnetic waves exceeding the standard limit in the local environment when using mobile phones. Although the transmitting power of the mobile phone is reduced, the antenna of the mobile phone is too close to the brain (5 ~ 10 cm) during the call, and the long-term call is exposed to electromagnetic radiation. At present, studies and reports show that frequent use of mobile phones will cause adverse reactions to the human body (such as headache, local fever in the head, eye pain, tears and so on). ). Because the influence of electromagnetic radiation on people has a cumulative process, the research needs a long period, and there is no conclusion at present, but it should arouse people's vigilance.
Electromagnetic wave protection control measures
In order to control the electromagnetic wave pollution to the environment and protect people's health, the Ministry of Health of our country promulgated the environmental electromagnetic wave health standard (GB9 175-88) on February 22nd, 989, which stipulated the limit value of electromagnetic wave intensity in residential areas. In order to prevent electromagnetic waves from harming all people who live, work and live for a long time (including babies, pregnant women, the elderly, patients and the disabled), electromagnetic waves should be less than? 10 microvolt/m? , for ultrashort wave should be less than 5 volts/meter, for microwave should be less than 65438 00 microwatts/cm2. Adequate sanitary protection distance should be kept between TV tower and residential area. In view of the development of mobile communication, the environmental protection departments of Beijing and other cities have also made corresponding regulations on the erection of mobile communication base station antennas to prevent them from causing electromagnetic pollution to the environment.
According to the characteristics of electromagnetic wave attenuation with distance, in order to reduce the harm of electromagnetic waves to residents, workplaces and facilities that emit high electromagnetic power and may produce strong electromagnetic waves, such as TV stations, radio stations, radar communication stations, microwave transmitting stations, etc. , should be located as far away from residential areas in suburban counties and high-lying areas. Workplaces or facilities, such as substations, must be located near urban residential areas or places where residents often move, and should keep a safe distance from residential areas to ensure that their boundaries meet the requirements of environmental electromagnetic wave health standards. At the same time, shielding materials made of copper, aluminum, steel plate, metal wire, polymer film and other materials that can shield, reflect or absorb electromagnetic waves should be selected as electromagnetic radiation sources, and electromagnetic shielding measures should be established to limit the electromagnetic radiation energy in a specified space.
High-voltage transmission lines, especially EHV transmission lines, should be set up far away from residential areas, schools, sports fields and other crowded areas. When using computers and some monitoring and display devices, low-emission display products should be selected. The distance between the human body and the front of the display screen should not be less than 75cm, and the side and back should not be less than 90cm. It is best to install effective shielding devices.
We should ensure that the antenna height of various mobile communication transmitting base stations in urban areas is higher than that of nearby residential buildings, and the main transmitting direction of the antenna should avoid the direction of residential buildings; Especially in kindergartens, school buildings, hospitals and other facilities around a certain range shall not set up transmitting antennas.
In order to prevent the harm of electromagnetic pollution to health, the room should be ventilated frequently to keep the indoor air unblocked. When using a mobile phone, try to reduce the talk time; The top of the mobile phone antenna deviates from the head as far as possible, and the antenna is as long as possible; After observing that the mobile phone signal is connected, move it to the ear; Mobile phones and headphones are considered to be the safest choice at present.
In addition, it is suggested that you can take a certain amount of vitamin C every day, or eat more vegetables rich in vitamin C, such as pepper, persimmon pepper, Toona sinensis, cauliflower, spinach, garlic sprout, potherb mustard, Chinese cabbage, Chinese cabbage, carrot and sweet potato. Eat more fresh fruits such as citrus, jujube, strawberry and hawthorn. Pay attention to eat foods rich in vitamins A, C and protein, such as tomatoes, lean meat, animal livers and bean sprouts. Through these dietary measures, it is beneficial to strengthen the defense function, and can also actively prevent and reduce the harm caused by electromagnetic radiation to the human body to a certain extent.
Electromagnetic radiation is a new kind of environmental pollution that has been recognized by people in recent thirty or forty years. At present, people are still in the stage of understanding and research on electromagnetic radiation, and their understanding of it is still very limited. Because we can't see, touch, feel or be familiar with it, it is easy to arouse people's doubts. In addition, some reports about electromagnetic radiation are not objective and scientific, which leads to some unnecessary misunderstandings and panic.
Generally speaking, to judge whether electromagnetic radiation pollutes the living environment, we should comprehensively consider the intensity, height, distance between the main radiation direction and the radiation source, duration and other factors, and only when it reaches a certain level will it cause direct harm to people. The antenna of communication base station installed on high-rise buildings in cities will not have a direct impact on the surrounding environment if the transmission power is appropriate and the erection height and main direction are reasonable. Therefore, while strengthening electromagnetic protection, we should also adopt an objective analysis and scientific attitude towards electromagnetic wave pollution, and we must not blindly and irresponsibly exaggerate it, causing confusion in people's understanding. Of course, with the development of science and technology, people's understanding of electromagnetic wave pollution and its harm will gradually deepen, and many mysteries will eventually be revealed by human beings.