Harmful to human body. Magnetic field belongs to electromagnetic radiation. Although it has a long wavelength, it also has a certain amount of energy. Nuclear magnetic vibration belongs to an experimental technology that uses electromagnetic radiation in this band to achieve detection purposes. What it can cause is the spin motion of the nucleus. So I always think it should be harmful. I have consulted several nuclear experts at home and abroad, especially foreign professionals in Varian, and I ask questions every year when I visit. For so many years, the answer I got was "no impact". I care so much because I don't think it has any effect, but my family has always been wary and scared, especially when my wife was pregnant a few years ago. People who do MRI say it's nothing, but it's better for pregnant women to be less exposed to electromagnetic fields. Because the so-called no effect is because the shielding effect of the machine is better, it does not mean that the magnetic field is harmless to the human body. For 300MHz instruments, you can do super shielding inside the magnet; But for high-field instruments, the 5 gauss line is still outside the magnet. Moreover, the super shield is horizontal, so it is inevitable to remove the magnet when changing the probe for tuning. Changes of blood properties under (1) strong magnetic field and its influence on the body. The orientation behavior of human and animal whole blood under strong magnetic field and the action mechanism of main red blood cells have been studied internationally. Changes of blood rheological characteristics under strong magnetic field: changes of blood fibrin activity under strong magnetic field and its influence on biological metabolism: magnetic force, magnetic levitation and light absorption characteristics of human blood under strong magnetic field. (2) The characteristics and application of protein polymer under strong magnetic field. The orientation of peptides in phospholipids under strong magnetic field has been studied internationally. Phosphorus metabolism of muscle cell protein in magnetic field: structural changes of neuropeptide amino acids and exchange of protein amide and hydrogen under strong magnetic field. (3) Medical application. In addition to the development of human imaging system, in recent years, the activity of blood fibrin under 4-8 Tesla strong magnetic field and its influence on intravascular thrombolysis have been studied internationally. The influence of strong magnetic field and magnetic field gradient on cellulose dissolution process: the activity of strong magnetic field on animal blood cells and its influence on myocardial protection characteristics; the influence of external magnetic field on platelet fluidity and its application in medical treatment. Influence of electromagnetic wave on human body When human body is in an electric field, the conductivity of human body makes current flow into the earth through the skin, and the magnetic field may affect iron molecules in blood when it passes through human body. The electric field passing through the skin may cause skin diseases such as eczema. Some people say that women who often use computers are prone to skin aging. Similarly, people realize that electromagnetic waves are more harmful to tissues with rapid cell proliferation, such as blood cells, genitals and lymph, and to children. Let's take the influence of magnetic field on human body as an example to see the harm of electromagnetic wave. When the human body is in a strong magnetic field, various magnetic substances in the body will be attracted by magnetic force. At the same time, due to magnetic induction (the object forming a magnetic field magnetizes other objects), magnetization occurs, that is, magnetic objects such as iron (Fe) in red blood cells in the body are attracted or magnetized, thus affecting other magnetic substances. Obviously, this will be harmful to health. If there are magnetic substances in blood or cells, magnetic induction will hinder the normal activities of blood and cells. The accumulation of heavy metals in the body and the susceptibility to magnetic induction give a fatal blow to the body. However, it is difficult to find out the influence of electromagnetic waves on human body scientifically and carefully. Because various environmental factors act on people comprehensively, it is difficult to do long-term follow-up investigation. The influence of electromagnetic waves on human body has been confirmed by epidemiological investigation and animal experiments. University of Colorado 1979 N? Professor wertheimer and E? Professor Ripper made an epidemiological investigation between high-voltage power lines and childhood cancer. The results show that the incidence of leukemia in children under strong electromagnetic field is more than three times higher than that in other children. The so-called epidemiological investigation is a research method to compare the factors that cause cancer with the increase rate of cancer patients. A famous epidemiological study is "smoking and lung cancer", that is, comparing the number of lung cancer patients among a large number of smokers and non-smokers. What is studied here is the relationship between smoking and lung cancer. This method is used to study the relationship between electromagnetic waves and childhood cancer. The report has had a great influence not only on the United States, but also on European countries, making people actively study the influence of extremely low frequency electromagnetic waves on the human body. At present, experts and scholars in the United States, Europe, Japan and other countries believe that strong electromagnetic waves are harmful to human body through various animal experiments. 1995110 In October, research institutions in Sweden and Denmark published the research results in the European Journal of Cancer. According to the research report, the incidence of leukemia in children with magnetic fields above 5 mg is five times higher than that in normal children. Various animal experiments show that electromagnetic waves (1) change nerve conduction substances (2) change the calcium content in cells and cell surfaces of chickens, pigs and mice, leading to fetal malformation and malignant lymphoma (3) reduce the reaction ability of mice, reduce the weight of testicles, change the chemical composition of the brain and slow down the growth rate of the body. The third point will especially affect the delivery of pregnant women and the growth of children. The influence of electromagnetic wave on human body can be roughly divided into thermal effect, stimulating effect and non-thermal effect. Whether long-term low-frequency electromagnetic waves affect health has become the focus of debate on the harmful theory of electromagnetic waves. The harm of strong electromagnetic waves to human body has been scientifically verified, so all countries in the world have stipulated the maximum time limit of exposure to electromagnetic fields to protect human health. 1. Thermal action The thermal action of electromagnetic waves can raise the temperature of biological tissues and cells. The research shows that the microwave with the wavelength below 3Cm can penetrate the skin 1Cm, while the microwave with the wavelength of 0.25- 1m can penetrate the skin and reach various organs of the human body. Microwave absorbed by the skin is converted into heat, which raises the temperature of body tissues. The results of animal experiments show that the increase of biological body temperature causes behavioral changes and abnormal behaviors. Moreover, the uterine temperature above 39℃ affects the immune function of the body. According to analysis, the most vulnerable places of life are eyes, lenses and testicles, and there are almost no blood vessels. The most serious harm of electromagnetic wave to eyes is lens cataract. At this time, due to the temperature rise, the endoscope produces opaque parts, which makes people unable to see the object clearly. 1- 10GHZ microwave is easy to cause this cataract. Someone has done this animal experiment and irradiated rabbit eyes with 2450MHZ electromagnetic wave (which belongs to the frequency range of microwave oven) for 10 minute. As a result, cataracts began to appear. The testicular temperature of male germ cell aggregate is relatively low (about 36℃) relative to body temperature, and it is very sensitive to heat. The increase of temperature has a decisive influence on the germ cells undergoing meiosis. 2. Inductive effect of stimulating electromagnetic wave in stimulation. Electrical signals regulate all functions of the human body. The observation of nerve cells, muscle cells and other cells with the least function that can be excited in human body shows that when the potential difference between the two ends of such cells reaches a certain level, it sends an exciting signal to the nervous system or contracts muscles. However, the external current flowing to human body makes the excitation conduction system of nerve and the biological circuit system of muscle movement system abnormal, which makes human body change. This external current stimulates nerve cells to feel electric shock, and at the same time stimulates muscles to produce muscle contraction or voluntary movement. Stimulate the myocardium to soften the ventricle, the heart stops beating, and stimulate the respiratory muscles to stop breathing. 3. Non-thermal effects Most epidemiological findings such as childhood leukemia caused by high-voltage power line electromagnetic fields mentioned above belong to this category. At present, it is difficult to confirm the effect of non-thermal action, so it cannot be explained clearly. The cerebral cortex of chickens and cats was placed in UHF and VHF with low frequency modulation, and calcium ions were found to flow out. Information transmission, immune system function and cell proliferation are inseparable from calcium ions. The experimental results show that the low frequency of 50-60HZ also leads to the outflow of calcium ions. It can be seen that general household appliances (60HZ) are also harmful to human body. Another study reports that the secretion of animal pineal gland (melatonin) inhibits tumor cells, while low frequency changes the secretion of pineal gland. Extremely low frequency and extremely low frequency electromagnetic waves not only affect the distribution of calcium in human cell membrane, but also affect the distribution of potassium, sodium and chlorine plasma, thus affecting the secretion of human hormones. As mentioned above, human cells use weak electrical signals to transmit heat, pain, vision and other senses through nerves, but when this communication between cells is hindered, foreign cells will proliferate and form cancer. The external energy that can cause communication barriers is much weaker than expected. In fact, when electromagnetic waves act on the cells cultured in the experiment, it is found that the movement of chemical substances between cells has changed, the production of genetic factors has been hindered, the production of hormones and chemical substances has changed, and the activity of cancer cells has increased. Experiments on mice show that electromagnetic waves will hinder their appetite, breathing, sleep and so on. And human experiments show that electromagnetic waves will weaken the pulse and make brain waves abnormal. Thirdly, the theory of strengthening electromagnetic wave protection is questioned, because at present, human beings can't explain the causes of leukemia and other diseases. Even though modern medicine and science are quite developed, the research on human body is still far from enough. At the beginning of the 20th century, when some scholars suggested that smoking caused lung cancer, they also met with doubts from many scholars, including doctors. It was not until 30 years later that the medical community admitted that smoking caused lung cancer. The research on electromagnetic waves is only over 20 years. At the same time, unlike smoking, electromagnetic waves are very complicated in intensity, frequency, contact time and waveform, and it is difficult to prove their relationship with cancer. Like smoking, people should raise their awareness of the harm of electromagnetic waves. Based on the current epidemiological investigation, people can't deny that electromagnetic waves have an impact on the human body. Therefore, it is necessary to avoid independent contact with strong electromagnetic fields; When contact is needed, appropriate measures should be taken. References:
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