On the earth all kinds of electromagnetic waves filled with human living space, radio broadcasting, television, mobile communications, radio remote control, navigation, high-voltage transmission and distribution lines, etc. are to the air and the ground to radiate powerful electromagnetic energy. High-frequency quenching, welding, smelting, cutting, plastic heat, wood drying, electromagnetic therapy, microwave therapy, microwave heating and other induction heating equipment will be launched into the environment with the leakage of a certain strength of the electromagnetic energy, the human race is living in such a sea of electronic smoke.
Electromagnetic wave pollution
Electronic industry since its inception, not only to make science and technology and industrial production has undergone a revolutionary change, but also to bring convenience and comfort to people's lives. But a variety of electronic products and equipment radiating electromagnetic waves, sometimes polluting the environment, becoming one of the important elements of environmental pollution, and endangering human health, thus becoming the human environment following the waste gas, waste water, waste and noise after another major public health hazards.
Electromagnetic waves and their classification Electromagnetic waves are propagating alternating electromagnetic fields. All kinds of light and rays are electromagnetic waves with different wavelengths, among which the wavelength of radio waves is the longest and the wavelength of cosmic rays is the shortest. The electromagnetic waves described in this section are radio waves. Radio waves according to the wavelength can be divided into long waves, medium waves, short waves, microwaves and mixed waves; according to the frequency can be divided into low-frequency, high-frequency, ultra-high frequency and ultra-high frequency.
1?High frequency. That is, medium wave and short wave. Wavelength 10 ~ 3000 meters, frequency 105 ~ 3 × l07Hz, such as high-frequency quenching, melting, welding, cutting and other induction heating equipment, high-frequency dielectric heating equipment, plastics processing, food drying equipment, radio broadcasting and communications.
2?UHF. That is, short-wave 1 ~ 10 meters, frequency 3 × 107 ~ 3 × l08Hz, such as radio communications, television signal transmission, medical electrical equipment, electrified railroads.
3?UHF. That is, microwave. Wavelength 1 ~ <0.07 meters, frequency 3 × l08 ~ 3 × l0?10?Hz, radio positioning, navigation, radar and so on. Are man-made sources of electromagnetic waves generated.
Sources of electromagnetic wave pollution Residents of a certain place in China found that the indoor lights do not need to switch on and off every day, a pick up the phone handset inside the sound of music. After investigation, the original nearby radio station's transmitter antenna from the residents too close to the residence, the electromagnetic wave signal emitted by the residents of the lights, the telephone inducted by the electricity, which is electromagnetic radiation on the surrounding environment caused by electromagnetic wave pollution examples. Caused by electromagnetic wave pollution is caused by various reasons, with the development of cities, urban expansion, building land is becoming increasingly tense, so that the original high-power electromagnetic transmitters in the suburbs, television broadcasting transmitter stations gradually surrounded by newly built residential areas; the development of satellite communications, making the city appeared in a large number of satellite ground stations, some areas of the transmitter antennae are too dense (more than 20 in some areas of Beijing); the rapid development of mobile communications technology, its electromagnetic wave signals using a straight line. The rapid development of mobile communication technology, its electromagnetic wave signals using straight-line propagation, in the urban high-rise buildings set up a number of liaison role of the base station, antennae stand, the formation of mutual cross-talk interference, and some of the unreasonable antennae set up on the nearby high-rise residential residents electromagnetic wave pollution; transmission of electric power of the ultra-high-voltage transmission lines and the urban transportation system so that the electromagnetic pollution increases; in addition, home computers, color TV, stereo, microwave ovens In addition, home computers, color TVs, stereos, microwave ovens, electromagnetic stoves, wireless cell phones, and electric blankets all radiate electromagnetic waves, which also cause environmental electromagnetic pollution. If the use of improper on the human body to cause harm, which, the harm of electric blankets in particular should cause high vigilance.
Electronic products or equipment in the space formed by many electromagnetic waves not only interfere with each other, so that they function abnormally, such as display screen image is not clear, short-wave communication lines serious interference, the decline in the quality of words, the decline in the quality of broadcasting and television signal reception, the television is suddenly not clear, the radio appeared silk pulling murmur, etc., but also when it reaches a certain level of intensity, in the invisible harm to the person.? Electromagnetic wave harm to people
Electromagnetic wave pollution can not be seen, touched, smelled, but everywhere. The human body is always in a certain energy electromagnetic wave radiation environment, when its frequency exceeds 105HZ or more harmful to the human body. Electromagnetic wave radiation source output power, the greater the intensity of radiation, the shorter the wavelength, the higher the frequency, the closer the distance, the longer the contact time, the higher the temperature of the environment, the greater the humidity, the air is not circulating, the greater the degree of pollution of the environment, and the more serious harm to women and children.
Electromagnetic waves will disrupt the body's natural physiological rhythms, leading to disorders of body balance, triggering headaches, dizziness, insomnia, forgetfulness and other neurasthenia symptoms; make people tired, loss of appetite, irritability; can also make the human body heat regulation system is out of whack, resulting in faster heart rate, blood pressure or lower, breathing disorders, white blood cell reduction; the occurrence of cardiovascular disease and deterioration of the role played by the push waves. Electromagnetic waves cause interference and disturbance of bioelectricity in the body, leading to abnormalities in EEG and ECG, delaying the diagnosis of diseases and affecting treatment. Due to the strong penetrating power of electromagnetic wave, it not only acts on the body surface, but also penetrates into the inner layer of tissues and organs, often the human body has not yet felt the pain, the inner layer of tissues has been damaged, and it also promotes the growth of cancerous tissues, resulting in the increase of cancer incidence. Electromagnetic waves can also cause vision loss. When the intensity of 100 mW/cm2 electromagnetic wave irradiation eyes, will make the crystal edema, can develop into cataract, and even lead to blindness. Intensity of 5 mW/cm2 ~ 10 mW/cm2 of electromagnetic waves, human skin sensation is not obvious, but can affect fertility and heredity. Women under the action of electromagnetic waves, menstrual cycle changed significantly, can cause pregnant women miscarriage and genetic defects, can increase the incidence of pediatric cancer after birth. Long-term in the role of strong electromagnetic waves in children, the incidence of cancer than in the low electromagnetic waves under the children's high 2 to 5 times, electromagnetic waves are also leukemia, lymphoma, brain tumors causative factors.
High-frequency welding, high-frequency quenching, high-frequency melting, radio frequency sputtering, electronic tube row of silicon docking, semiconductor sealing capacitance, short-wave and microwave therapy, microwave heating and other widely used in industry, medical, transportation and other fields, broadcasting, television and communications base stations and signal transmitters (towers) transmitting power is getting bigger and bigger, all kinds of mobile communication base stations densely populated, antennae standing, so that the local electromagnetic space in the space of the intensity of the other too high. The most direct and serious impact of electromagnetic waves are television stations, radio stations, radar communication stations (stations) and the residents around the transmission tower. These powerful electromagnetic waves (general power 10 ~ 90 kilowatts), can damage human blood and eyes, damage to chromosomes, produce deformed fetuses, and even lead to central nervous disorders.
People through long-term research found that the crisscrossing high-voltage lines in addition to the destruction of environmental aesthetics, due to the generation of electromagnetic fields around it, the neighborhood will have a harmful effect. This is mainly determined by the electromagnetic field strength. People exposed to electromagnetic field strength of 50 to 200 kV / m, can appear headache, dizziness, fatigue, poor sleep, loss of appetite, blood, cardiovascular system and central nervous system abnormalities. Of course, this refers to the voltage in the 100 kilometers above the ultra-high voltage transmission lines, according to the general regulations are not allowed to pass from the residential areas, so the general public can be free from its harm. The city and residential areas are common voltage 1 km below the distribution lines, set up at a prescribed height, the impact on the human body is very small. 1 ~ 100 km between the high-voltage transmission lines, had to pass through residential areas, according to the regulations should be set up from the ground height of 6.5 meters above.
Related data show that: computer monitors emit electromagnetic radiation, long-term role, will make women's endocrine and reproductive functions have a negative impact on the harm to germ cells and early embryonic development, the first three months of pregnancy caused by the degree of harm to the fetus than the late gestation to be much greater.
People are very concerned about the electromagnetic radiation from cell phones. Although so far, about the cell phone on the user's electromagnetic harm, especially the pathogenic mechanism has not been concluded, but the environmental protection department of the cell phone radiation monitoring results have shown that the use of cell phones, the local environment has more than the standard limit of strong electromagnetic waves. Although the transmitter power of cell phone calls has been reduced, but due to the call when the cell phone antenna is too close to the brain (5 to 10 cm), a long time to talk to the electromagnetic radiation. At present, there have been some studies and reports show that the regular use of cell phone calls, will produce adverse effects on the human body (such as headache, head localized heat, eye pain, tears, etc.), due to the role of electromagnetic radiation on the human body there is an accumulation of the process, the study also needs a longer period, so, at present, there is no conclusive, but should cause people to be vigilant.
Electromagnetic wave protection and control measures
In order to control electromagnetic wave pollution of the environment, to protect the health of the people, China's Ministry of Health, December 22, 1989 promulgated the "Environmental Electromagnetic Wave Health Standards" (GB9175-88), the provisions of the residential area of the environment, electromagnetic wave intensity limit values. In order to prevent electromagnetic waves on long-term residence, work, life of all people (including infants, pregnant women and the elderly, infirm and disabled), will not be subjected to any harmful effects, for the long, medium and short waves should be less than ?10 microvolts / m? For long, medium and short waves, it should be less than ?10 microvolt/meter, for ultra-short waves, it should be less than 5 volts/meter, and for microwaves, it should be less than 10 microwatts/cm2. Sufficient sanitary protection distances should be maintained between the TV towers and the residential areas. For the development of mobile communications, China's Beijing and other cities, environmental protection departments of mobile communications base station antennae also make corresponding provisions to prevent its electromagnetic pollution of the environment.
According to the characteristics of electromagnetic wave attenuation with distance, in order to reduce the harm of electromagnetic wave to the residents, should make the emission of electromagnetic power, may produce strong electromagnetic wave workplaces and facilities, such as television stations, radio stations, radar communication stations, microwave transmission stations, etc., as far as possible located in the suburbs and counties away from the residential area and the terrain of the high areas. Must be set up in the city adjacent to residential areas or residents often activities within the scope of the workplace or facilities, such as substations should be set up with the residential area between the safety protection distance, to ensure that its boundaries in line with the requirements of the environmental electromagnetic wave health standards, at the same time, the source of electromagnetic radiation need to select the electromagnetic wave can be shielded, reflected or absorbed electromagnetic waves of copper, aluminum, steel, wire, polymer film and other materials made of shielding items, the establishment of electromagnetic Shielding measures, electromagnetic radiation energy is limited to the required space.
High-voltage, especially ultra-high-voltage transmission lines should be set up away from homes, schools, sports fields and other crowded areas of the zone; the use of computers and some monitoring and display equipment, should be selected from low-radiation display products, and to maintain the distance between the human body and the display of the front of the screen of not less than 75 centimeters, the side and the back of the screen of not less than 90 centimeters, it is best to install effective shielding devices.
Should ensure that a variety of mobile communications set up in the urban area transmitter base station antenna height higher than the surrounding neighborhood residential housing, the main antenna transmitting direction to avoid the direction of residential housing; especially in the kindergarten, school buildings, hospitals and other facilities around a certain range of transmitting antennas shall not be established.
In order to prevent health hazards caused by electromagnetic pollution, should be often ventilated to the room, keep the indoor air clear. When using cell phone calls, try to reduce the duration of the call; the top of the cell phone antenna should be as far away from the head as possible, and try to stretch the antenna; observe that the cell phone signal is connected, and then move it to the ear; adding a headset to the cell phone call is considered to be the safest option at the present time.
In addition, it is recommended that you can take a certain amount of vitamin C every day, or eat more vitamin C-rich vegetables, such as chili peppers, persimmon peppers, parsnips, cauliflower, spinach, garlic shoots, potherb mustard, kale, cabbage, water rooibos, red rooibos, sweet potatoes and so on; consume more fresh fruits, such as mandarin oranges, jujubes, strawberries, hawthorn and so on. Pay attention to eat more food rich in vitamin A, C and protein, such as tomatoes, lean meat, animal liver, bean sprouts, etc.; through these dietary measures to strengthen the defense function is beneficial, but also to a certain extent can play an active role in preventing and mitigating the damage caused by electromagnetic radiation on the human body.
Electromagnetic radiation is the last three or four decades only to be recognized by the people of a new environmental pollution, now people are still in the electromagnetic radiation is still in the stage of understanding and research, people's knowledge of it is still very limited. Because it is invisible, untouchable, imperceptible and unfamiliar, it is easy to arouse people's suspicion. In addition, some reports on electromagnetic radiation is not very objective, lack of scientific, so as to cause some unnecessary misunderstanding and panic.
Generally speaking, to determine whether electromagnetic radiation pollution of the living environment, should be from the intensity of electromagnetic radiation, height, the main radiation direction and the distance from the source of radiation, duration and so on several aspects of the comprehensive consideration, when it reaches a certain level of direct harm to people. Set up in the city on the high-rise building communication base station antenna, if the transmission power is appropriate, erection height, the main radiation direction is reasonable, from the current level of scientific understanding, will not have a direct impact on the surrounding environment. Therefore, to strengthen electromagnetic protection at the same time, the electromagnetic wave pollution should also take an objective analysis, scientific attitude, must not be cloudy, irresponsible and blindly exaggerated, resulting in confusion of people's understanding. Of course, with the development of science and technology, people's understanding of electromagnetic pollution and its hazards will gradually deepen, and many mysteries will eventually be revealed by mankind
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