Electromagnetic waves Waves are the propagation of vibrations in space. For example, sound waves propagating in the air, water waves propagating on the water surface, and seismic waves propagating in the earth's crust are all vibrations emitted by the vibration source propagating in the elastic medium. These waves are collectively called mechanical waves. Light waves, thermal radiation, microwaves, radio waves, etc. are all electromagnetic oscillations emitted by a vibration source that propagate in space. These waves are called electromagnetic waves. Electromagnetic waves are classified according to the length of the wavelength and the way in which electromagnetic radiation is generated. The classification range of electromagnetic waves is,,,,,wavelength (cm),,,,,,,frequency (Hz),,,,,,wave number (cm-1) Radio Wave,,,,gt;30,,,,,,,,,lt;109,,,,,,,lt;0.03 Microwave,,,,,30?-?0.1,,,,,,?1 ?x?109?-?3?x?1011,,,,0.03-10 far infrared,,0.1?–5?x?10-3,,,,,,3?x?1011?–6x?1012, ,,, 10-200 mid-infrared, 6?x?10-3-2.5?x?10-4,, 6? , 2.5? ?–3.8?x?10-5, , 3.8? -5,,,7.9?x?1014–1.5?x?1015,,26,300-50,000 Far UV,2? x?10-15?–3?x?1016,,50,000-1x106x?ray?,10-6?-?10-8,,,,,,,3?x?1017?–3?x? 1019,,,,1x106-1x108γ?ray?,,,lt;10-8,,,,,,,,,gt;?3?x?1019?,,,,,,,gt;1x108
2. Electromagnetic waves and human health Various electromagnetic waves on the earth fill the human living space. Radio broadcasting, television, mobile communications, radio remote control, navigation, high-voltage transmission and distribution lines, etc. all radiate powerfully to the air and ground. of electromagnetic wave energy. Induction heating equipment such as high-frequency quenching, welding, smelting, cutting, plastic heat sealing, wood drying, electromagnetic physiotherapy, microwave treatment, microwave heating, etc. will emit and leak electromagnetic energy of a certain intensity into the environment. Human beings live in such a sea of ??electronic smog. inside. Since the advent of the electromagnetic wave pollution electronic industry, it has not only revolutionized science, 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 cause pollution to the environment, becoming one of the important environmental pollution factors and endangering human health, thus becoming another problem of the human environment after waste gas, waste water, waste residue and noise. Big public nuisance. 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 radio waves have the longest wavelength and cosmic rays have the shortest wavelength. The electromagnetic waves explained in this section refer to radio waves. Radio waves can be divided into long waves, medium waves, short waves, microwaves and mixed waves according to wavelength; they can be divided into low frequency, high frequency, ultra high frequency and ultra high frequency according to frequency. 1? High frequency. That is medium wave and short wave. Wavelength 10~3000 meters, frequency 105~3×107Hz, such as high-frequency quenching, smelting, welding, cutting and other induction heating equipment, high-frequency medium heating equipment, plastic processing, food drying equipment, radio broadcasting and communications, etc. 2?Ultra high frequency. That is, short wave is 1~10 meters, frequency is 3×107~3×108Hz, such as radio communications, television signal transmission, medical electrical equipment, electrified railways, etc. 3? UHF. That is microwave.
In order to prevent health hazards caused by electromagnetic pollution, the room should be regularly ventilated to keep the indoor air flowing. When using a mobile phone, try to reduce the call time; the top of the mobile phone antenna should be as far away from the head as possible, and try to extend the antenna; observe that the mobile phone signal is connected, then move it to the ear; install headphones on the mobile phone, at present Considered the safest option. In addition, it is recommended to take a certain amount of vitamin C every day, or eat more vegetables rich in vitamin C, such as peppers, bell peppers, toon, cauliflower, spinach, garlic sprouts, mustard mustard, cabbage, Chinese cabbage, water radish, and carrots , sweet potatoes, etc.; eat more fresh fruits such as citrus, dates, strawberries, hawthorn, etc. Pay attention to eating more foods rich in vitamins A, C and protein, such as tomatoes, lean meat, animal liver, bean sprouts, etc. Through these dietary measures, it is beneficial to strengthen the defense function and can also play a positive role in prevention to a certain extent. and reduce the harm caused by electromagnetic radiation to the human body. Electromagnetic wave radiation is a new environmental pollution that has only been recognized by people in the past thirty or forty years. Now people are still in the understanding and research stage of electromagnetic radiation, and people's understanding of it is still very limited. Because it is invisible, intangible, difficult to detect, and very unfamiliar, it easily arouses people's doubts. In addition, some reports on electromagnetic radiation are not objective and lack scientific basis, causing unnecessary misunderstandings and panic. Generally speaking, to determine whether electromagnetic radiation causes pollution to the living environment, we should comprehensively consider the electromagnetic wave radiation intensity, height, distance between the main radiation direction and the radiation source, and duration. When it reaches a certain level, it will cause direct harm to people. . Communication base station antennas installed on high-rise buildings in cities, if the transmitting power is appropriate, the erection height and main beam direction are reasonable, based on the current level of scientific understanding, they will not have a direct impact on the surrounding environment. Therefore, while strengthening electromagnetic protection, we should also adopt an objective analysis and scientific attitude towards electromagnetic wave pollution. We must not follow others' opinions and blindly exaggerate irresponsibly, 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 mankind?
3. The mechanism of electromagnetic radiation harming the human body is mainly thermal effect, Non-thermal effects and cumulative effects, etc. 1． Thermal effect: The human body is composed of water for more than 70% of the body. Water molecules rub against each other after being radiated by electromagnetic waves, causing the body to heat up, thus affecting the normal work of the organs in the body. 2． Non-thermal effects: There are weak electromagnetic fields in the organs and tissues of the human body, which are stable and orderly. Once disturbed by external electromagnetic fields, the weak electromagnetic fields in a balanced state will be destroyed, and the human body will also suffer damage. 3. Cumulative effect: After the thermal effect and non-thermal effect act on the human body, the damage to the human body has not yet had time to repair itself (usually called the human body's endurance---internal resistance). If it is exposed to electromagnetic wave radiation again, the degree of damage will accumulate. Over time, it will become a permanent condition and endanger life. For groups who have been exposed to electromagnetic wave radiation for a long time, even if the power is very small and the frequency is very low, it may induce unexpected lesions, so we should be vigilant. The harm caused by electromagnetic radiation to the human body cannot be felt within a few months, but is a cumulative effect. The direct consequences of electromagnetic waves of various frequencies, especially high-frequency waves and strong electromagnetic fields, acting on the human body are unknowingly leading to a loss of energy and physical strength, easily causing cataracts, leukemia, brain tumors, cardiovascular disease, brain dysfunction, and miscarriage in women. and infertility, etc., and even lead to low human immune function, thereby causing cancer and other diseases. This is one of the reasons why some pregnant women who are exposed to electromagnetic radiation will have deformed babies. It is also one of the main reasons why people in high-tech industries such as IT die from overwork.
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4. Who needs radiation protection? Those who work and live in strong radiation sources for a long time People in relatively close areas should consider electromagnetic radiation protection.
In order to reduce the radiation dose received, it mainly includes the following groups of people:? 1. Computing and operating personnel of large, medium and small computers? 2. Computer software design, programming, and input personnel? 3. Professional computer users Including: finance, accounting, savings, securities salespersons, commercial cashiers, computer image designers, such as advertising design, architecture, machinery, art, animation design, etc., and secretarial (typing and copying)? 4. Radio and television, communications, navigation , radar and other transmitter room near-field workers? 5. Metallurgy, electronics, chemical industry, papermaking, wood, grain and food processing and other industries use high-frequency and microwave equipment for smelting, welding, heating, exhaust, sputtering, drying, Operators of pest control, disinfection and other processes? 6. Personnel who operate medical equipment such as radio frequency and microwave for a long time? 7. Sales staff who specialize in heating fast food in microwave ovens? 8. Debugging personnel in the production of electronic equipment and instruments? 9. ?Staff in power generation and high-voltage transmission and substations? 10. ?Staff in the equipment experimental area of ??military electronic stations? 11. ?Those who frequently surf the Internet for long periods of time? 12. ?Staff in anti-static and explosion-proof places? 13. ?Those with heart and kidney function defects Mobile phone users: 14. People with low immunity who live near radio, television, and communication stations.