Time protection
The principle of time protection is that the cumulative dose of people in the radiation field is proportional to time. Therefore, under the condition of constant irradiation rate, shortening the irradiation time can reduce the irradiation dose, or people may work in a limited time to ensure their personal safety (only in special circumstances), so as to achieve the purpose of protection. The focus of time protection is to minimize the contact time between human body and radiation (shorten the exposure time of human body).
Remote protection
Distance protection is an effective external radiation protection method. The basic principle of ray with distance protection is that when the radiation source is a point source, the exposure and absorbed dose of a point in the radiation field are inversely proportional to the square of the distance from the point to the source. We call this law inverse square law, that is, the radiation intensity is inversely proportional to the square of the distance (when the radiation intensity of the source is constant, the dose rate or exposure is inversely proportional to the square of the distance from the source). Increasing the distance between the radioactive source and the human body can reduce the dose rate or exposure, or work at a certain distance, so that the radiation dose received by people is lower than the maximum allowable dose, and personal safety can be guaranteed. So as to achieve the purpose of protection. The focus of distance protection is to maximize the distance between human body and radiation source.
Shielding protection
The principle of shielding protection is that the intensity of radiation will be weakened when it contains penetrating substances, and shielding substances with a certain thickness can weaken the intensity of radiation. Setting a shield (shielding material) with sufficient thickness between the radiation source and the human body can reduce the radiation level, reduce the dose people receive at work to below the maximum allowable dose, ensure personal safety and achieve the purpose of protection. The key point of shielding protection is to place a shielding material that can effectively absorb radiation between the radiation source and the human body. The shielding materials commonly used for X-rays are lead plates and concrete walls, or barium cement (cement containing barium sulfate-also known as barite powder) walls. 1. Common electromagnetic radiation sources Generally speaking, radar systems, television and radio transmission systems, radio frequency induction and medium heating equipment, radio frequency and microwave medical equipment, various electrical processing equipment, communication transmitting stations, satellite earth communication stations, large power stations, power transmission and transformation equipment, high-voltage and ultra-high-voltage transmission lines, subway trains and electric trains, and most household appliances can generate electromagnetic radiation sources of various forms, different frequencies and different intensities. 2. Division of electromagnetic radiation field Generally speaking, electromagnetic radiation field is divided into far field and near field. 2. 1 Near field and its characteristics The area within the wavelength range centered on the field source is usually called near field, which can also be called induced field. The near field usually has the following characteristics: in the near field, there is no definite proportional relationship between the electric field intensity and the magnetic field intensity. Namely: e? 377H. Generally speaking, the electric field is much stronger than the magnetic field for high-voltage and low-current field sources (such as transmitting antennas and feeders), and the magnetic field is much larger than the electric field for low-voltage and high-current field sources (such as the molds of some induction heating equipment). The intensity of electromagnetic field in the near field is much greater than that in the far field. From this point of view, the focus of electromagnetic protection should be in the near field. The intensity of electromagnetic field in the near field changes rapidly with distance, and the space is uneven. 2.2 The far field and its characteristics are called far field, which can also be called radiation field. The main feature of the far field is that in the far field, all electromagnetic energy is basically radiated in the form of electromagnetic waves, and the radiation intensity of this field is much slower than that of the induction field. In the far field, the intensity of electric field and magnetic field have the following relations: in the international system of units, E=377H, and the running directions of electric field and magnetic field are perpendicular to each other, both perpendicular to the propagation direction of electromagnetic waves. The far field is weak, and its electromagnetic field intensity is small. 2.3 The significance of the division of near-field and far-field Generally speaking, for a fixed electromagnetic radiation source that can generate a certain intensity, the electromagnetic field intensity of near-field radiation is relatively large, so special attention should be paid to the protection of near-field electromagnetic radiation. The near-field protection of electromagnetic radiation is firstly the protection of operators and personnel in the near-field environment, and secondly the protection of various electronic and electrical equipment located in the near-field environment. For the far field, because the electromagnetic field is weak, it usually does less harm to people. At this time, the main factor we should consider is signal protection. In addition, there should be the concept of near field. For the frequency band range from short wave 30MHz to microwave 3000MHz, the wavelength range is from 10 m to1m. ..
How can editors prevent electromagnetic radiation in this life?
According to experts, we should pay attention to the following points in preventing electromagnetic radiation: ● Don't put household appliances too concentrated or often use them together, especially TV sets, computers and refrigerators in the bedroom. So as not to expose yourself to the danger of excessive radiation. ● Various household appliances, office equipment, mobile phones, etc. Should be avoided for a long time. When electrical appliances, such as televisions and computers, need to be used for a long time, attention should be paid to leaving every hour, and the way of looking far away or closing your eyes should be adopted to reduce the fatigue of eyes and the influence of radiation. ● When the electrical appliance is suspended, it is best not to let it stand idly by, because it can generate weak electromagnetic field at this time and radiation accumulation for a long time. ● Keep a safe distance when using various electrical appliances. For example, the distance from the eyes to the TV screen is generally about 5 times the width of the screen; Leave one meter away after the microwave oven is turned on, and pregnant women and children should stay away from the microwave oven as far as possible; When using a mobile phone, the distance between the head and the antenna of the mobile phone should be as far as possible, and it is best to use a separate earphone and microphone to answer the phone. ● People living and working near high-voltage lines, radar stations, TV stations and electromagnetic wave transmission towers, patients wearing pacemakers and people living in modern electrical automation environment, especially pregnant women, children and the elderly with weak resistance, should be equipped with shielding protective clothing to block electromagnetic radiation if possible. ● TV, computer and other electrical equipment with display screen can be equipped with electromagnetic radiation protection screen, and users can also wear radiation protection glasses. The radiation generated by the display screen may cause dry skin, accelerate skin aging and even lead to skin cancer, so wash your face in time after use. ● The electromagnetic radiation released at the moment when the mobile phone is switched on is the largest. So it's best to put your mobile phone aside and wait until it is connected, or connect it with radiation-proof headphones. ● Eat foods rich in vitamins A, C and protein, such as carrots, tomatoes, kelp, lean meat, animal liver, etc., to strengthen the body's ability to resist electromagnetic radiation. Radiation protection at home and environmental pollution are everywhere. For expectant mothers, radiation is the enemy that harms the health of mother and baby. A staff member surnamed Song of the Pollution Management Office of the Municipal Environmental Protection Bureau said that radiation sources hidden in our homes are also everywhere. At present, some of the natural decorative stones used in household decoration have radioactive pollution, and many building materials made of industrial waste residue, such as coal ash brick and slag brick GRC, also have excessive radioactivity. Therefore, whether the newlyweds buy a house or rent a house, they must first do a thorough radiation check to avoid living in an unhealthy environment. If you can't change your residence, try to find the place with the strongest radiation, shield or adjust the position of furniture, keep your family away from radioactive substances and reduce the radiation time. 1. Choose brand-name household appliances from regular manufacturers. Generally, the radiation of household appliances of big brands has been strictly tested by relevant state departments to ensure safety. 2. The use of all kinds of electrical appliances should keep a safe distance. Pregnant women should stay away from microwave ovens and computers at least 1 meter away. The distance between TV and people should be 4 to 5 meters, and the distance between TV and lamp should be 2 to 3 meters. Be sure to turn off the power supply for unused appliances. Radiation parts are generally motors, electric coils, electric fans and other parts, and these parts should keep a distance of more than 60 cm from people. Don't put household appliances too concentrated. Especially televisions, computers and refrigerators. Not suitable for pregnant women's bedrooms; Don't use the hair dryer to cling to the scalp when using the hair dryer; Don't stand at the air outlet of the air conditioner. Keep a safe distance after turning on the air conditioner. 4. shorten the time of using electrical appliances. All kinds of household appliances should avoid long-term operation and simultaneous use, and pregnant women should not hang their mobile phones on their chests when answering. Try not to use electric blankets when it is cold, especially for expectant mothers who cover them. The electromagnetic wave of light bulb is lower than that of fluorescent lamp, so fluorescent lamp can be used less. 5. Conditional pregnant women can wear radiation protection suits when they go to work, and they can take a shower and change clothes after work; Use computer, TV radiation screen, etc. 6. Microwave ovens and induction cookers are electrical appliances in the electromagnetic radiation market at home, and pregnant women should try to avoid using them. The coil and motor of the refrigerator are behind the refrigerator, so when you open the refrigerator door to get something, don't use it for too long and keep a safe distance. 7. There is radiation in general wires at home. In modern families, the general fixed wires are "hidden wires", which is not a big problem, but if very dense wiring boards or plugs are placed at the bedside or in the most frequent places, it may affect health. Therefore, the bedside should not be equipped with electrical appliances or plugs. Radiation protection in working environment 1. X-ray radiation of computer screen: This radiation can usually be blocked by only one piece of glass fiber. If there is no glass fiber, pregnant women should try to keep a distance of more than 30 cm from the computer screen. Radiation from the electric coil on the back of the computer: This radiation is harmful, but most people don't work behind the computer. If there is a mother-to-be working in the computer room, pay attention to it and try to avoid doing homework behind the computer. 2. The radiation of mobile phone is also tiny. Although its efficacy is not as strong as that of microwave oven, it will also cause harm to human body. Therefore, it is best for expectant mothers to reduce the chances of using mobile phones and try to avoid hanging them around their waists. At present, there is still a debate about "CDMA mobile phone or GSM mobile phone, which is more radiation." Therefore, no matter what mobile phone the expectant mother uses, she should be as careful as possible. It is suggested that mothers use hands-free when using mobile phones, or wear radiation-proof headphones. 3. Copier When the expectant mother uses the copier, the body is 30 cm away from the machine as a safe distance. At present, the newer copiers on the market all install the radiation parts on the chassis, which does little harm to the body. The medical environment is protected from the influence of X-ray radiation on the fetus, which is more likely to lead to embryonic disability, fetal malformation, brain dysplasia and increased probability of childhood cancer. But usually in the early stage of pregnancy, exposure to X-rays is more likely to cause major injuries, and the closer to the expected date of delivery, the smaller the impact. According to the staff of the radiology department of Jilin City Hospital, if a pregnant woman receives 5 thunder X-rays, it is equivalent to taking 20 abdominal X-rays. Doctors suggest that unless there is an emergency, you should choose to take X-rays within 10 days after menstruation begins, so you don't have to worry about taking X-rays after pregnancy. So, what about pregnant women who have already taken X-rays? It is understood that pregnant women who are unknowingly exposed to X-ray radiation should try their best to keep filming records so that doctors can help you judge the safety of the fetus. Generally, during pregnancy, if you just take an abdominal X-ray, the exposure will be about 0.5 rays, and the impact on the fetus is not enough to require pregnant women to have an abortion; However, only a small amount of radiation, such as chest X-rays or dental X-rays, has even less impact on the fetus. Therefore, as long as it is not aimed at high-dose X-ray radiation in or near the abdomen, expectant mothers need not worry too much. Radiation granite marble steps that may be encountered when going out: Many people will regard the marble steps in front of department stores as reclining chairs, but they don't know that this granite marble is a high radiation material. If a closed room is decorated with such materials, it is likely to lead to nasopharyngeal carcinoma or lung cancer. Substations and high-voltage electricity: No matter where you choose to live or play, it is best to stay away from substations and high-voltage electricity, especially nuclear power plants. Airplane: Flight attendants are most likely to miscarry or have an impact on the fetus in the early pregnancy due to long-term exposure to cosmic waves. Studies have pointed out that long-term flight during pregnancy should not exceed 100 hours, so as not to affect the health of the fetus. The experience of users using "radiation protection suits" is different. Now it has entered the fourth generation. For example, the radiation of PHS widely used by citizens is about 30-50 dB, while the radiation of mobile phones is above 250db. Nowadays, the fourth-generation radiation protection suits are also different in style, but one thing is certain: the first floor can shield the cell phone signal (for example, put the cell phone in the pocket of the radiation protection suit). Moreover, many clothes are covered with something similar to a hood, which is much more convenient to clean. As for sleeping, it's up to you. For example, unplugging the closed electrical equipment at home can also reduce some unnecessary radiation. According to scientific research, closed equipment radiates more than open equipment. I live in Telecom, we 10000 and the women in the front desk business hall. In the past two years, no one has been pregnant or aborted. . . Although fatigue is also a reason at ordinary times, a large number of computer radiation around is also a factor that cannot be ignored. If you want to have children, it is best to start radiation protection when you are ready to get pregnant, so as to avoid abnormal sperm and eggs. Grass has become a huge psychological and physical loss. The first three months of the fetus is the key period of brain development, and it begins to develop in the fourth week. 10 is the period of "rapid brain growth". In the meantime, special attention should be paid to reducing radiation. After all, the fetus is unstable in the first three months and is most prone to miscarriage. Finally, radiation protective clothing has a protective effect, but it is not omnipotent. It is most important to protect yourself.
Edit this paragraph and elaborate on the five major electrical radiations harmful to pregnant women.
There are many sayings about electromagnetic radiation in life, such as: "microwave oven can't be used more" and "computer can't be used during pregnancy". If you are a mother-to-be, you need to pay more attention to this problem. It is not enough to provide enough nutrition for the growth and development of the fetus, but also to stay away from all kinds of adverse factors that may cause to the fetus, such as electromagnetic radiation. Associate Professor Cheng Weiwei, director of the Obstetrics and Gynecology Hospital affiliated to Fudan University School of Medicine, explained the reasons in detail for expectant mothers. She stopped using household appliances as soon as she got pregnant. Linlin is a professional woman who is busy with her career. She was just pregnant at the age of 35. For the couple, having children at an advanced age is even more pampered. Just over two months. She wears protective clothing every day, asks for sick leave and rests at home. Linlin thought it was not easy to have a baby, so she tried her best to protect herself. Even the TV, air conditioner, stereo, computer and other home appliances have stopped. Director Cheng told reporters that the effects of electromagnetic radiation on the human body vary widely, and women and children are usually the most sensitive. Especially pregnant women and fetuses are more susceptible to infection. For embryos, electromagnetic radiation will prevent their early cell division, even cause cell death, and will also prevent the normal development of placenta. Science shows that the risk in the first three months of pregnancy is much greater than that in the middle and late stages of pregnancy. Specifically, 1-3 months is the embryonic period, and strong electromagnetic radiation may lead to abortion or fetal limb defect or deformity; 4-5 months is the period of fetal formation, and electromagnetic radiation may damage the central nervous system, leading to mental retardation of infants; 6- 10 month is the fetal growth period, and the main consequences are low immune function, weak constitution and poor resistance after birth. Expectant mothers don't have to be too sensitive. However, experts don't fully agree with the over-panicked expectant mother like Linlin. Experts said that because general household appliances still do a good job of shielding radiation sources, expectant mothers don't have to be too sensitive like frightened birds, and they can do the best protection within the scope of conditions. Therefore, expectant mothers should use electrical equipment as reasonably as possible during pregnancy, keep a safe distance and reduce radiation hazards; At the same time, you can choose electromagnetic radiation protective clothing. When buying protective clothing, you should see clearly the protection frequency range of the product description and choose to buy according to your own requirements; Diet, pay attention to eating foods rich in vitamin A, vitamin C and protein to strengthen the body's ability to resist electromagnetic radiation. Check five suspicious household appliances and computers, which may have X-rays, ultraviolet rays, electromagnetic fields, etc. When operating around them, and the intensity of emission is very weak, which is safe for embryos and fetuses. Only a few centimeters away from the computer can there be trace radiation. Therefore, expectant mothers should not be too close to the computer for too long, and they should walk around a little later. Television also has some radiation. But as long as you stay away from the screen, the radiation will be greatly reduced. Expectant mothers are advised to be at least 1 m away from the screen when watching TV. It is best to choose LCD or rear projection TV, which has less radiation. The radiation of the air conditioner itself will basically not affect pregnant women, but because the doors and windows of the room are closed after the air conditioner is turned on, the indoor air quality will be reduced, and pregnant women may have headaches, dizziness, colds and other symptoms when they stay in the air-conditioned room for a long time, so especially in summer, expectant mothers should use air conditioners with caution. When the mobile phone is in the docking stage, it should be avoided to put the mobile phone close to the ear, which can avoid 80%-90% radiation. Especially in the early stages of pregnancy, expectant mothers should not hang their mobile phones on their chests. It is best to use hands-free mode or wear radiation-proof headphones when answering mobile phones. A good quality microwave oven has only a small amount of electromagnetic radiation around the crack of the door, which is basically undetectable beyond 30 cm. However, if the microwave oven is not well sealed, radiation will leak, which will cause harm to human body.
Edit the best radiation protection plants in this paragraph.
Cactus or cactus is a good flower variety for beautification in courtyard greening. Although they are covered with thorns, they are beautiful in appearance, can be used for processing medicinal materials and eating, and have the "special function" of absorbing electromagnetic radiation and reducing the harm of computers to human health. Cactus is fleshy and contains a lot of water, which can easily absorb and dissolve electromagnetic radiation toxins in the surrounding environment, reduce indoor and outdoor pollution and benefit human health. Where there are televisions, computers and microwave ovens with electromagnetic radiation, it is advisable to put several pots of cactus at the same time. Eat carrots, bean sprouts, tomatoes, rape, Chinese cabbage, lean meat, animal liver and other foods rich in vitamins A, C and protein to enhance the body's ability to resist electromagnetic radiation. For people who don't like cactus working in front of the computer for a long time, putting aloe and fruit in front of the computer is the best absorbent and deodorant. Put some potted plants with fruits next to the computer, such as pears, oranges, cantaloupes, melons, etc., which are not only environmentally friendly, but also smell natural. As for the office, because there are all kinds of toxic gases and there is little sunshine, I suggest that it is not enough to grow only cacti, but also to mix them well. It can improve the indoor humidity, which is good for our skin and breathing. At the same time, it can also absorb formaldehyde, xylene and ammonia to purify the turbid air. In addition, the small leaves of Ficus pendula make them beautiful decorations in the room, and interior designers often use them to create a cheerful atmosphere. Lighting conditions: neutral plants, suitable for planting in semi-shade. Maintenance: By keeping the basin soil moist, enough water can be removed: formaldehyde, toluene, xylene and ammonia. "Ficus pendula is a very effective air purifier." 2. Millennium Wood: It is deeply loved by interior designers for its attractive appearance and adaptability to the dark and dry environment of the office. As long as we pay a little attention, it can grow for a long time and bring high-quality air. It is difficult for other plants to compare with Millennium wood in inhibiting harmful substances. Leaves and roots can absorb xylene, toluene, trichloroethylene, benzene and formaldehyde and decompose them into non-toxic substances. Lighting conditions: neutral plants, suitable for planting in semi-shade. Maintenance: Keep the soil moist, and regular fertilization can remove: toluene, xylene, trichloroethylene and formaldehyde. 3. kudzu vine: it can "work" in an environment that other indoor plants can't adapt to. Through a process similar to photosynthesis, it can decompose toxic substances released from fabrics, walls and smoke into its own substances. The beautiful heart-shaped leaves of pueraria lobata have unique decoration, especially when they are hung outside the hanging basin. This kind of plant is easy to take care of and can grow well even in dark environment, so it is the best choice for beginners. Lighting conditions: shade-loving plants need maintenance: the humidity is moderate, and trace fertilizers such as formaldehyde, benzene, carbon monoxide and nicotine can be removed.