Extremely low-frequency electromagnetic fields (high-voltage lines, nuclear magnetic **** vibration, electrified railroads, welding, electric sewing and other extremely low-frequency electromagnetic field prevention recommendations) WHO International Agency for Research on Cancer (IARC) and the WHO Thematic Working Group evaluated that extremely low-frequency (>0Hz-100kHz) magnetic fields are related to childhood leukemia and brain cancer, and that when the exposure to industrial frequency (50/60Hz) magnetic fields exceeds 0.3μT or 0.4μT, the risk of childhood leukemia increases by 2 times, and according to WHO statistics, about 1% to 4% of children exposed to long-term exposure to electromagnetic radiation have a 2-fold increase. When the intensity of industrial frequency (50/60Hz) magnetic field exposure exceeds 0.3 μT or 0.4 μT, the risk of childhood leukemia increases twofold, and according to WHO statistics, about 1% to 4% of children are chronically exposed to industrial frequency magnetic fields with an intensity of more than 0.3 μT. Although the epidemiological data of the population and the laboratory research data cannot prove the causal relationship between IFMF and childhood leukemia, WHO emphasizes in its newly published (2007) monograph on very low frequency electromagnetic fields of environmental health criteria that although the mechanism of biological effects of low-level environmental electromagnetic radiation has not yet been elucidated, one cannot exclude that low-level environmental electromagnetic radiation can produce harmful health effects. At the same time, because of the ubiquity of electromagnetic radiation, to which almost everyone in the world is exposed, even if the effects on human health are very mild, they will have a huge impact on human public **** health; and if some of these health effects are irreversible (e.g., tumors), the resulting economic health losses will be painful.
WHO believes that appropriate measures should be taken to prevent known health hazards to the public from very low frequency electric and magnetic fields, in view of the existence of a certain degree of scientific uncertainty in the study of the health effects of electromagnetic radiation, WHO believes that countries in the development of preventive strategies for electromagnetic radiation should be taken into account in the electric power industry's great contribution to society and the economy, should be used to low-cost precautions should be adopted, and should not be subjective The exposure limits should be lowered to a level that is not in accordance with the laws of science.
(The following is translated from WHO Environmental Health Criteria 2007 Monograph - Extremely Low Frequency Electromagnetic Fields) WHO recommends the following:
1. Decision makers in all countries should develop guidelines on the exposure to extremely low frequency electric and magnetic fields for the general public and for occupationally exposed populations; the International Exposure Guidelines (IEGs) are the best available exposure guidelines.
2. Decision makers should develop protection plans for very low frequency electromagnetic fields, and test for electromagnetic radiation from various emitting sources to ensure that public and occupationally exposed populations are not exposed above the exposure limits.
3. Low-cost measures should be taken to prevent exposure to extremely low-frequency electric and magnetic fields without jeopardizing the health benefits, social benefits, and economic benefits of the power industry.
4. Decision makers, community planners and manufacturers should take low-cost measures to prevent exposure to extremely low-frequency electric and magnetic fields in the construction of new electrical facilities and the design of new electrical equipment, including appliances.
5. Modifications to existing processes to reduce the level of exposure to very-low-frequency EMFs from equipment or facilities may be considered if other additional benefits (e.g., increased safety) can be realized, or if there is no or very low additional cost.
6. When considering changes to existing sources of very low frequency electromagnetic field emissions, a combination of safety, reliability and economic benefits should be considered.
7. Local governments should strengthen netting management, and should reduce unintentional ground currents to ensure safety when building new power facilities or modifying the wiring of existing power facilities; it is costly and possibly unreasonable to take proactive measures to prevent netting violations or to judge existing netting management problems.
8. State management should use an effective, interactive and open strategy to engage all property owners to make informed decisions; this strategy should include ways to minimize each owner's own level of exposure.
9. Local governments should improve the planning of UHF EMF facilities, and there should be good consultation between businesses, local governments and the public when selecting sites for large UHF EMF sources.
10. Both governments and businesses should promote research on electromagnetic radiation to reduce scientific uncertainty about the health effects of exposure to very-low-frequency electromagnetic fields. Some people who have been exposed to stronger or longer electromagnetic radiation, there have been pathological manifestations, mainly reflected in:
1. Effects on the cardiovascular system: manifested as headaches, palpitations, some women's menstrual disorders, bradycardia, decreased cardiac blood flow, sinus arrhythmia, leukocyte and platelet reduction, fatigue , immune function decline, etc..
2. Effects on the nervous system: manifested as memory loss, easily agitated, insomnia.
3. Effects on the visual system: for the clouding of the eye crystals, causing cataracts in severe cases, is irreversible organic damage, affecting vision.
4. The effect on the reproductive system: manifested as a decrease in sexual function, men's sperm quality, so that pregnant women have spontaneous abortions and fetal deformities and so on.
5. Long-term exposure to high electromagnetic radiation in the environment, will make the blood, lymph fluid and cell protoplasm changes, affecting the human circulatory system, immunity, hormone secretion, reproduction and metabolism function, the serious will accelerate the human body's proliferation of cancer cells, induced cancer, as well as diabetes, hereditary diseases and other diseases, and even children may also induce leukemia.
6. Patients with pacemakers are exposed to high electromagnetic radiation, which affects the normal use of pacemakers.
Internationally, it is generally recognized that the main role of electromagnetic radiation on the human body is thermogenic and non-thermogenic effects. Electromagnetic radiation includes non-ionizing radiation and ionizing radiation, ionizing radiation in the body molecules inside the organic molecules can be positive and negative charge to pull apart, and then will produce irreversible organic lesions. Non-ionizing radiation is generally referred to as radio-type radiation, which carries a small amount of quantum energy, not enough to separate the positive and negative charges of the molecules, in the removal of the external field of action or in the case of low field strength can be restored to the organic molecules.
The pathogenic effect of electromagnetic waves increases with the frequency of the magnetic field vibration, and the frequency of more than 100,000 hertz can pose a potential threat to the human body. Working in this environment for too long, electromagnetic interference, so that the original electric field of the molecules within the human tissue changes, to the composition of the brain cells of various biological molecules to a certain degree of destruction. Produce too much peroxide and other harmful metabolites, and even make the DNA code of brain cells arranged wrongly, creating some non-physiological neurotransmitters. If the human body is exposed to radiation doses exceeding the safety standards for a long time, human cells will be killed or killed in a large scale. About electromagnetic pollution standards of the academic debate continues, but we still need to work and live in a variety of electromagnetic radiation environment, as a member of this world's ordinary and weak life, people should be how to prevent and mitigate electromagnetic radiation on their own harm?
1. Do not place the household appliances too centralized, or often used together, so as not to expose themselves to the hazards of radiation in excess of the dose. Especially TV, computer, refrigerator and other electrical appliances should not be placed in the bedroom.
2. All kinds of household appliances, office equipment, cell phones and so on should try to avoid prolonged operation. Such as television, computers and other electrical appliances need to be used for a long time, it should be noted that at least once every hour to leave, with a look into the distance or close your eyes in order to reduce eye fatigue and the impact of radiation.
3. When the appliances are suspended, it is best not to leave them in standby mode, because this time can produce a weak electromagnetic field, a long time will also produce radiation accumulation.
4. The use of various electrical appliances, should maintain a certain safety distance. Such as eyes away from the distance of the TV screen, generally about 5 times the width of the fluorescent screen; microwave ovens to leave at least 1 meter away after opening, pregnant women and children should try to stay away from microwave ovens; cell phone use, should try to make the head and cell phone antenna distance away from some of the best use of separate headset and microphone to answer the phone.
5. Male germ cells and sperm are more sensitive to electromagnetic radiation. Therefore, men should try to minimize and electromagnetic waves too frequent and intensive contact, and contact should also maintain a safe distance, generally more than half a meter.
6. Consumers who have been involved in excessive doses of electromagnetic radiation for a long time should pay attention to the following self-protection measures:
① People who live and work near high-voltage lines, substations, radio stations, television stations, radar stations, electromagnetic wave towers, patients with pacemakers, people who often use electronic instruments, medical equipment, office automation equipment, and people living in the automated environment of modern electrical appliances, and people who live in the environment of modern electrical appliances, and people who live in the environment of modern electrical automation. Modern electrical automation in the environment of the crowd, especially the weaker resistance of pregnant women, children, the elderly and the sick, the conditions should be equipped for electromagnetic radiation, electromagnetic radiation to the maximum extent possible to block the body outside.
② TV, computer and other electrical equipment with a display screen can be installed electromagnetic radiation protection screen, the user can also wear radiation glasses to prevent the screen radiates electromagnetic waves directly on the human body.
③ cell phone connected to the moment of the release of electromagnetic radiation is the largest, so it is best to take the phone a little farther away from the phone is connected to the phone and then take close to listen to, or wear a radiation headset to receive calls.
④ Television, computers and other electrical appliances screen radiation can lead to dry human skin dehydration, accelerate skin aging, serious skin cancer, so the use of the above appliances in a timely manner after washing.
⑤ Eat more carrots, bean sprouts, tomatoes, greens, seaweed, cabbage, lean meat, animal liver and other foods rich in vitamins A, C and protein, in order to help regulate the body's electromagnetic field disorders, and strengthen the body's ability to resist electromagnetic radiation.
We know almost nothing about the long-term effects of electromagnetic radiation. Every day, we are exposed to all kinds of electrical appliances, on us, especially on our pregnant children there is no danger? No one has been able to prove that electric waves and fields are harmless, just as no one has been able to prove that they are harmful, and for more than 20 years research has been going on, with conflicting claims.
What are people worried about? They worry that they cause anxiety, heart attacks, headaches, irritability, cancer from long-term exposure, especially if they live near high-voltage lines, and so on. Yet, all of this has not been proven, and likewise, not refuted with certainty.
In fact, for pregnant women, the fear of electromagnetic waves triggering fetal deformities is not necessary. This is because the fetus is protected by our thick abdominal skin and cellular tissue, and is insulated by amniotic fluid. However, there are still questions about whether electromagnetic waves can cause spontaneous abortions and premature births. There is still a gap in scientific research on this, with no positive or negative conclusions.
In the face of this lack of firm conclusions, experts recommend that small pregnant women should carefully avoid exposure to electromagnetic waves.
Emphasis on life radiation
Many office workers, especially the office of the "computer family" will take a variety of protective measures to self-protection - anti-radiation blanket clothing, masks, anti-radiation protective film. In fact, even part of the building materials at home also has radiation, such as natural marble, tiles, etc., so it is recommended that the home should be ventilated often. Daily life to reduce the use of small appliances time, the best not to work directly behind the computer mainframe, when the cell phone is charging do not call.
But the best way to prevent radiation is still to hide, try to stay away from radiation or minimize the time and frequency of contact with radiation sources, such as radiation stronger hospital body checks, like CT, X-ray, fluoroscopy, etc., should not be done frequently these checks. As CT examinations are more radioactive and women are more sensitive to radiation than men, especially pregnant women, CT examinations are strictly prohibited.
Healthy food to prevent radiation
In addition to paying attention to radiation prevention in life, people are more willing to use dietary supplements to neutralize electromagnetic radiation. If you are close to or live in a strong radiation range for a long time, you are likely to suffer from excessive electromagnetic radiation. Therefore, we should eat more food rich in vitamin B, such as carrots, greens, cabbage and animal liver. These foods are conducive to regulating the human body electromagnetic field disorder state, increase the body's ability to resist electromagnetic radiation pollution. In addition, rich in protein, lycopene and water-soluble dietary fiber food can be consumed, such as kelp is rich in iodine, calcium, iron, vitamin A and other nutrients, can be effective against radiation; greens, bok choy, mustard greens, cabbage, alkaline components of the precipitation of toxins in the cells; pig's blood, black fungus, etc., can be with the human body containing radiation of the metal particles react to the dissolution of the discharged. General
1.1 to prevent pollution by electromagnetic radiation, protect the environment, protect public health, and promote the development of legitimate practices associated with electromagnetic radiation, the development of these provisions.
1.2 These regulations shall apply to all units or individuals, facilities or equipment within the territory of the People's Republic of China, which generate electromagnetic radiation pollution. However, the protection limits in these regulations do not apply to medical or diagnostic exposures arranged for patients.
1.3 The protection limits in this regulation range from 100KHZ to 300GHZ. The relationship between the protection limits and the frequency is shown in the figure below.
1.4 The protection limits in this regulation are the upper limit of the acceptable level of protection and include the total value of various possible electromagnetic radiation contamination.
1.5 All units or individuals generating electromagnetic radiation pollution, should be based on the principle of "can reasonably achieve as low as possible", and strive to reduce the level of electromagnetic radiation pollution.
1.6 All units or departments that generate electromagnetic radiation pollution, can develop their own management limits (standards), each unit or department's management limits (standards) should be more stringent than the limits of this provision.
Protection limits
2, 1 basic limits
2.1.1 Occupational exposure: in the daily 8H work period, any continuous 6MIN by the whole body average of the specific absorption rate (SAR) should be less than 0.1W/KG.
2.1.2 Public exposure: in a day of 24H, any continuous 6MIN by the whole body average of the specific absorption rate (SAR) should be less than 0.1W/KG. (SAR) should be less than 0.02W/KG.
Table 1 Occupational exposure derived limits Frequency range MHz Electric field strength V/m Magnetic field strength A/m Power density W/m2 0.1 to 3 87 0.25 (20)1) 3 to 30 150/ 0.40/ (60/f) 1) 30 to 3000 (28)2) (0.075)2) 2 3000 to 15000 (0.5 ) 2) (0.0015 )2) f/1500 15000～30000 (61)2) (0.16)2) 10 Note: 1) This is the equivalent value of a plane wave for comparison.
2. 2.2 public exposure: in 1 day 24H, the average of the parameters of the electromagnetic radiation field in any consecutive 6MIN should meet the requirements of Table 2.
Table 2 public exposure derived limits Frequency range MHz Electric field strength V/m Magnetic field strength A/m Power density W/m2 0.1 ~ 3 40 0.1 (40)1) 3 ~ 30 67/ 0.17/ (12/f)1) 30 ~ 3000 (12) 2) (0.032) 2) 0.4 3000 ~ 15000 ( 0. 22/ )2) ( 0.001 )2) f 0.001 )2) f/7500 15000~30000 (27) 2) (0.073) 2) 2) 2 Note: 1) The equivalent value of the plane wave is for reference.
2) For reference, not as a limit value; f is the frequency in the table, the unit is MHz; the data in the table has been rounded.
2, 2, 3 for a radiator emits several frequencies or the existence of multiple radiators, the field of electromagnetic radiation field parameters in any continuous 6MIN within the average value of the sum, should meet the formula (1): where: the ith radiator j frequency band radiation emission level; corresponding to the j splash electromagnetic radiation exposure limit values specified.
2, 2, 4 for pulsed electromagnetic wave, in addition to meet the above requirements, its instantaneous peak value shall not exceed 1000 times the limit values listed in table 1.2.
2,2,5 In the vicinity of industrial, scientific and medical radiation equipment with a frequency of less than 100MHZ, occupational workers can work continuously for 8H under a magnetic field of less than 1.6A/M.
According to the Implementing Rules of the Regulations for the Protection of Electronic Facilities, the horizontal safety distances of the sidings of conductors of all voltage levels from buildings under the condition of calculating the maximum wind deflection of the conductors are as follows: 1.0 meter for less than 1 kV, 1.5 meter for 1 kV to 10 kV, 3.0 meter for 35 kV, 4.0 meter for 66 kV to 110 kV, 5.0 meter for 154 kV to 220 kV, and 6.0 m for 330 kV and 8.5 m for 500 kV. The electric power construction unit is constructed in accordance with strict design standards when erecting the high voltage power frame, giving full consideration to the safety of the high voltage line.
According to the national "urban planning-related regulations", the horizontal distance between a 10,000-volt high-voltage tower and a residential building is generally 5 meters, 10 meters for 110,000 volts, 15 meters for 220,000 volts, and 25 meters for 500,000 volts, while high-voltage towers should try to avoid residential buildings.
"Electric Power Law" and "Regulations on the Protection of Electric Power Facilities" clearly stipulate that no unit or individual shall construct buildings within the protection zone of overhead power lines, and the concept of power line protection zone does not only refer to the vertical distance between the building and the power line, it is a guide line side line to the outside of the horizontal extension of the ground and perpendicular to the ground in the formation of the two parallel surfaces within the area, in accordance with the State Council promulgated the "Regulations on the Protection of Electric Power Facilities" Article 10, which states that "the protection of electric power facilities" shall not be used to protect residential buildings. Regulations for the Protection of Electric Power Facilities," Article 10 provides that the 110-kilovolt high-voltage line protection zone is the guide line sideline extends outward 10 meters and perpendicular to the ground within the area formed by the two parallel surfaces.
Scientific understanding of "electromagnetic radiation"
Electromagnetic radiation is composed of space *** with the transfer of electrical and magnetic energy, and the energy is generated by the movement of electric charge; for example, is transmitting the signal of the radio frequency antenna sends out a moving charge, it will generate electromagnetic energy. The amount of energy derived from electromagnetic radiation depends on the frequency; the higher the frequency, the greater the energy. The frequency of power transmission equipment is 50 Hz, which is a very low frequency. In electromagnetism will be 50 hertz frequency radiation is called electromagnetic induction, the nature of its radiation is weak, will not jeopardize human health.
Attachment 1: National standards and measured data, cases
I. In 2007, WHO (World Health Organization) recommended to member states to use ICNIRP (International Commission on Non-Ionizing Radiation Protection) Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic, and Electromagnetic Fields to 300 GHz (ICNIRP1998). The standard limits set forth therein are an electric field strength of not more than 5 kV/m and a magnetic field strength of not more than 0.1 mTesla (1 mTesla = 1,000 microTesla), within which very low-frequency (grid frequency fixed at 50 Hz) electromagnetic fields are not harmful to human beings. 2010, based on the results of the ICNIRP assessment and new scientific developments, the ICNIRP Guidelines for the Limitation of Exposure to Time-Varying Electric and Magnetic Fields (300 GHz) (ICNIRP1998) were published. In 2010, based on the evaluation results of the International Electromagnetic Field Program (IMFP) and new scientific advances, ICNIRP revised the new standard for the frequency band below 100 kHz (ICNIRP2010), raising the safety limit for magnetic field strength to 0.2 millitesla.
China's current Technical Specification for Evaluation of the Environmental Impact of Electromagnetic Radiation in 500kV Ultra-High-Voltage Power Transmission and Substation Projects (HJ/T24-1998) is more stringent than the WHO-recommended ICNIRP1998. The specification stipulates that 4 kV/m is used as the evaluation standard for IF electric field in residential areas, and 0.1 mTesla for IF magnetic induction intensity. That is to say, the IF electric field strength around the substation facilities does not exceed 4 kV/m, and the magnetic field strength does not exceed 0.1 mTesla in compliance with the national standard. At the same time, the specification specifies 110 kV, 220 kV power transmission and substation projects electromagnetic environmental impact assessment can refer to the application of this specification.
Two, human life on earth is a large magnetic field, power transmission equipment electromagnetic induction will not harm the human body. Electromagnetic radiation refers to high-frequency radio frequency, the State Environmental Protection Administration of the electromagnetic radiation protection limit value of the minimum frequency of 100,000 Hz, and high-voltage power transmission frequency is only 50 Hz, does not belong to the category of electromagnetic radiation, only produces a weak electromagnetic induction. The World Health Organization and international authoritative organizations have referred to high voltage as electromagnetic induction in their official documents. Electromagnetic induction is common in nature, the earth itself is a large magnetic field, we live in the magnetic field surrounded by every moment. According to the measured data, the electromagnetic induction intensity of the substation is not only much lower than the national standard, but also much lower than our daily use of cell phones, refrigerators, televisions, and other common electronic devices. The impact of the substation on the environment is very weak and will not jeopardize human health.