The magnetic field belongs to the electromagnetic radiation, its wavelength is long but also has a certain energy, nuclear magnetic **** vibration belongs to the use of this band of electromagnetic radiation to achieve the purpose of detection of an experimental technology, he can cause is the atomic nucleus of the spin movement. So it always seems like it should be harmful.
I have consulted with several domestic and foreign experts in nuclear magnetism, especially Varian's foreign professionals, who must ask the question when they visit every year. The answer over the years has been "no effect".
The reason why I am so concerned is that I myself believe that there is no effect, but my family has always been cautious and fearful, especially when my wife was pregnant a few years ago, she refused to step into the MRI room.
The NMR people say it's fine, but it's better for pregnant women to stay away from electromagnetic fields. Because the so-called no effect is because the shielding effect of the machine is better, not that the magnetic field is harmless to the human body, for the 300MHz instrument, the super shielding can be done inside the magnet; but for the high-field instrument, the 5 gauss line is still outside the magnet. Moreover, the super-shield is in the horizontal direction, when the operation of changing probes, tuning, etc. is carried out, it is inevitable to go under the magnet.
(1) Changes in the performance of blood in a strong magnetic field and the effect on the organism. International research on human and animal whole blood under the strong magnetic field orientation behavior and its role in the main body - the role of blood erythrocytes mechanism; blood in a strong magnetic field under the change in rheological properties; blood fiber protein activity changes in a strong magnetic field and the effect on biological metabolism; human blood in a strong magnetic field in the magnetic force, magnetic levitation characteristics and light absorption properties of human blood in a strong magnetic field.
(2) Properties of protein macromolecules in strong magnetic fields and their applications. Internationally, we have investigated the orientation of phospholipids in phosphatidylinositol under strong magnetic field; the phosphorus metabolism of muscle cell proteins in magnetic field; the structural change of neuropeptide amine acid and the exchange of protein amide and hydrogen under strong magnetic field.
(3) Medical applications. In addition to the continued development of human imaging systems, in recent years, international research has also studied the activity of blood fiber proteins under a strong magnetic field of 4-8 Tesla and the effect of thrombus dissolution in blood vessels; the effect of strong magnetic field and magnetic field gradient on the dissolution process of blood fibrin; the activity of strong magnetic field on animal blood cells and its effect on the myocardial protective properties; the effect of the applied magnetic field on the platelet mobility property and its application in medical treatment, etc.
Effects of Electromagnetic Waves on the Human Body
When the human body is exposed to an electric field, the conductivity of the human body allows the electric current to flow through the skin into the earth, while the magnetic field passing through the human body may affect the iron molecules in the blood. The passage of electric fields through the skin can cause skin diseases such as eczema. It has been said that women who use computers regularly tend to have aging skin. It is also recognized that electromagnetic waves are more harmful to blood cells and tissues such as the genitals and lymphatic tissues, which have a higher rate of cellular growth, as well as to children. Let's take the effect of magnetic fields on the human body as an example to see the harm of electromagnetic waves. When the human body is in a strong magnetic field, all kinds of magnetic substances in the body will be subject to magnetic attraction. At the same time, due to magnetic triggering effect (the formation of magnetic field objects, magnetization of other objects) to produce magnetization phenomenon, that is, attraction or magnetization of red blood cells in the body of iron (Fe) and other magnetic objects, thereby affecting the rest of the magnetic material. Obviously, this would be detrimental to health. If magnetic substances are present in the blood or cells, the magnetically induced action will prevent the normal activities of the blood and cells. Accumulation of heavy metals in the body, and susceptibility to magnetically induced action gives the body a fatal blow. However, it is difficult to scientifically and meticulously explore the effects of electromagnetic waves on the human body. Because a variety of different environmental factors combined effect on the human body, and it is difficult to do long-term tracking survey. The effect of electromagnetic waves on the human body through epidemiological investigations and animal experiments to obtain verification.
In 1979, Prof. N. Wertheimer and Prof. E. Leeper of Colorado University made an epidemiological investigation between high-voltage power lines and children's cancer. The result shows that the incidence of leukemia in children in the strong electromagnetic field is more than 3 times higher than the incidence of other children. The so-called epidemiological study is a research method that compares the factors that are considered to be the cause of cancer with the rate of increase in the number of cancer patients. A famous epidemiologic study is "Smoke and Lung Cancer," which compares the number of lung cancer patients among heavy smokers with the number of lung cancer patients among non-smokers, and the relationship between smoke and lung cancer is studied here. The study of the relationship between electromagnetic waves and cancer in children utilizes this very methodology. The report has had a great impact not only on the United States but also on European countries, causing people to actively study the effects of ELF electromagnetic waves on the human body. At present, through a variety of animal experiments, the United States, Europe, Japan and other countries, experts and scholars believe that strong electromagnetic waves on the human body has a great harm. 1995 November Sweden and Denmark **** with the research organization in the European Journal of Cancer published the results of the study, the study report that is in the more than 5MG magnetic field of the children's leukemia incidence rate is higher than the incidence rate of normal children by a factor of 5.
A variety of animal experiments show that electromagnetic waves (1) to make changes in nerve conduction substances (2) to make chickens, pigs, rats, intracellular and surface calcium content changes, leading to malformed fetuses, triggering malignant lymphoma (3) to reduce the rat's ability to respond, reduce testicular weight, change the brain chemistry, reduce the body's growth rate. The third point in particular will affect the birth of pregnant women and the growth of children. The effects of electromagnetic waves on the human body can be broadly categorized into thermal effects, stimulation and non-thermal effects.
Long-time low-frequency microelectromagnetic waves, whether or not to affect the health of the current electromagnetic wave theory of the focus of the debate on the harmful effects. The harmful effects of strong electromagnetic waves on human body have been scientifically verified, so the world's countries in order to protect the health of human beings, the maximum time limit for exposure to electromagnetic fields.
1. Thermal effects
The thermal effects of electromagnetic waves can trigger the rise of the temperature of the tissues and cells of living organisms. Studies have shown that microwaves with wavelengths below 3Cm can pass through the skin by 1Cm, while microwaves of 0.25-1m can pass through the skin to reach various organs of the human body. Microwaves absorbed by the skin are converted into heat, causing the temperature of body tissues to rise. The results of animal experiments show that the temperature of living organisms rises, causing changes in actions and producing abnormal actions. Moreover, the uterine temperature above 39℃ affects the immune function of the organism. It has been analyzed that the most vulnerable places in the organism to this thermal effect are the eye crystals and testes, which are almost devoid of blood vessels. The most serious danger to the eyes from electromagnetic waves is crystal cataracts. At this time, the convex lens in the eyeball due to the temperature rise to produce opaque parts, so that people can not see the object. 1-10GHZ microwave easily make people produce such cataracts. Some people have done this kind of animal experiments, will be 2450MHZ electromagnetic wave (belong to the microwave oven frequency range) irradiation rabbit eyes for 10 minutes, the results began to appear the cataract phenomenon. The temperature of the testes, the collection of male germ cells, is low relative to body temperature (about 36°C) and is very sensitive to heat. An increase in temperature has a decisive effect on the germ cells undergoing meiosis.
2. Stimulating effect
The stimulating effect of electromagnetic waves has a galvanic effect. Electrical signals regulate all the functions of the body. Observation of nerve cells, muscle cells and other cells that can be excited by the smallest unit of all the functions of the body shows that the potential difference between the two ends of such cells reaches a certain level, then to the nervous system to convey signals of excitement or contraction of muscles. However, an external electric current flowing into the body produces an abnormality in the circuit system of the organism in the nerve excitation conduction system and the muscle movement system, which causes a certain change in the body. This external current stimulates nerve cells to produce an electric shock sensation, while stimulation of muscles produces muscle contraction or involuntary muscle movement. Stimulation of the heart muscle causes the ventricles to soften and the heart to stop beating, while stimulation of the respiratory muscles stop breathing.
3. Non-thermal effects
Most of the epidemiological findings such as pediatric leukemia triggered by electromagnetic fields from high-voltage power lines cited above fall into this category. The effects of non-thermal effects are difficult to recognize at present and therefore cannot be clearly explained. Calcium ion efflux was found in the cerebral cortex of chicks and cats placed in UHF and VHF with low frequency modulation. Calcium ions are indispensable for information transmission, immune system function, and cell growth. Experimental results show that calcium ions also flow out of the low frequency wave of 50-60HZ. It can be seen that general home appliances (60HZ) are also harmful to the human body.
Another research report shows that the pineal gland secretion (melatonin) of animal bodies has an inhibitory effect on tumor cells, and low-frequency waves change the secretion of the pineal gland.
ELF,VLF electromagnetic waves not only on the distribution of calcium in the cell membrane of the human body, but also on the distribution of potassium, sodium, chlorine and other ions, thus affecting the human hormone secretion.
As mentioned above, human cells utilize weak electrical signals to conduct sensations such as heat, pain, and vision through nerves, but when such communication between cells is impeded, cell proliferation occurs, resulting in the formation of cancer. The external energy that can trigger a communication barrier is much weaker than expected. In fact, when electromagnetic waves were applied to experimental cultured cells, it was found that the movement of chemicals between cells was altered, the production of genetic factors was impeded, the production of hormones and chemicals was altered, and the activity of cancer cells was increased. Experiments on rats found that electromagnetic waves on their appetite, breathing, sleep and other obstacles, while human experiments found that electromagnetic waves make the pulse weakened, so that the brain waves produce abnormal phenomena.
Three, strengthen the protection
Electromagnetic waves harmful theory by a variety of questions, because at present mankind has not been able to explain the cause of many diseases such as leukemia, even if modern medicine and science is quite developed, but the study of the human body is still far from enough, the early 20th century, a certain scholar put forward when smoking leads to lung cancer has also encountered many scholars, including doctors, the question. It was not until 30 years later that the medical profession recognized that smoking causes lung cancer.
Research on electromagnetic waves has only been going on for more than 20 years, and at the same time, unlike smoking, electromagnetic waves are more complex in terms of intensity, frequency, exposure time, and waveforms, so it is difficult to prove a relationship between them and cancer. As with smoking, people should raise their awareness of the dangers of electromagnetic waves. Comprehensive current epidemiological investigations, people can not deny that electromagnetic waves have an effect on the human body. Therefore, we should avoid exposure to strong electromagnetic fields on our own; we should take appropriate measures when we have to do so.
Hazards and prevention of electromagnetic radiation
Electromagnetic radiation and health
The twentieth century is known as the electrical age, power stations, transmission lines more and more, a variety of electrical appliances into the factories, laboratories, offices, and ordinary residents of the home. However, whether electromagnetic fields, especially those at industrial frequencies (50-60 HZ), have an effect on human health has always been a matter of concern.
In the early 1960s, experts began to discuss this issue. At first, the experts' attention was focused on the role of electric fields and ignored the role of magnetic fields. Because people at that time mistakenly thought that the magnetic component of this electromagnetic field is very small, it is impossible to produce a perceptible effect on human health. The relevant health care standards of many countries only stipulate the standard of the permissible electric field component in the electromagnetic field of industrial frequency; in the manufacture of all kinds of electrical equipment and appliances as well as the erection of transmission lines, only the standard of the electric field component is taken into consideration, but not the permissible maximum limit of the magnetic field component. However, a large number of investigations and statistical analyses later showed that magnetic fields can also affect human health. For example, the probability of the occurrence of a variety of tumors in the human body is closely related to the exposure to low-frequency electromagnetic radiation. Experts and some governmental institutions in many European and American countries are convinced that low-frequency magnetic fields significantly increase the incidence of the following diseases: leukocytosis and leukemia (especially harmful to children), cancer, neonatal physical defects, breast cancer, brain tumors, malignant lymphomas, neurological tumors, the development of astrocytes, chronic myelocyte-like leukemia, chromosomal aberrations and so on. Some reports also indicate that a decrease in the secretion of some hormones under the action of electromagnetic fields may also be responsible for the development of breast tumors.
About the harm of cell phones on the body, so far there is no most direct evidence, but in general with cell phones or to make a long story short.
Electromagnetic radiation know how much
Some survey reports point out that: frequent exposure to electromagnetic radiation, if the role of high temperatures, the risk of breast cancer in their bodies is greater; long-term electrical engineers, and then often in contact with gasoline, pesticides or insecticides, they suffer from acute leukemia, the risk of an increase.
Many surveys also report that people in "electrical occupations", children, and people who use household appliances inappropriately (children who play video games, women and children who use electric blankets and other electric heaters, etc.) are at greater risk of damage from low-frequency magnetic fields. In some countries, pregnant women are also subject to the rule that babies should not be exposed to microcomputers for 3 to 6 months before they are born.
The intensity and cumulative amount of low-frequency magnetic field radiation affects the probability of disease. And, some people develop the disease after a latency period of up to 10-15 years. The upper limit of permissible magnetic induction is 100 microtesla, as specified in international health standards. Electromagnetic radiation is like the relationship between the sun and ultraviolet rays, you have to enjoy the sunshine will inevitably receive ultraviolet radiation. Electromagnetic radiation is invisible, intangible and difficult to perceive, so its harm is particularly insidious. From electronic alarm clocks, hair dryers, microwave ovens, electric irons, to computers, fax machines, telephones, we are not in contact with electromagnetic "comfort" all the time. Outside the door, the power line, a variety of electrical equipment and make us very easy to be in the electromagnetic field. 21st century electromagnetic environment has deteriorated for the certainty.
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Precautions against electromagnetic radiation
As we all know, where there is electricity, there is electromagnetic radiation, and electromagnetic radiation is unseen, unnoticeable, indefensible. So what kind of precautions people take is crucial.
First of all, we should widely publicize the basic knowledge of electromagnetic radiation, so that people can figure out how electromagnetic radiation is generated, what harm will be done to the human body, what kind of places and use what kind of equipment will produce electromagnetic radiation, this is a long-term patient and meticulous work.
Secondly, take some necessary precautions to avoid or reduce electromagnetic radiation. Such as there is now a variety of anti-electromagnetic radiation of raw materials made of mixed fibers, woven into the fabric of the clothes, made of anti-radiation clothing, its electromagnetic shielding effect is very obvious. If our businessmen to produce more such clothing, electromagnetic radiation on the human body will be greatly weakened.
How to prevent the harm produced by electromagnetic radiation
1. Prevent the effects of electromagnetic radiation on the human body:
(1) shielding room: composed of metal (sheet, net), mostly used for large-scale mechanical groups or control room of the active field shielding;
(2) shielding clothing shielding helmets and shielding glasses: these are personal protective gear can effectively reduce the intensity of magnetic radiation, to protect those engaged in contact with electromagnetic radiation. Radiation intensity to protect the physical health of staff engaged in contact with electromagnetic radiation;
(3) shielding cover: this is the main method of active field shielding of small instruments, shielding the materials used are generally required to be conductive materials with low resistivity, such as copper, aluminum, etc.;
(4) for the electromagnetic radiation generated by the cell phone can be wearing headphones to reduce electromagnetic radiation, the Ministry of Information Industry The Ministry of Information Industry, Telecommunications Transmission Research Institute, Thiel Laboratory experiments prove that the use of headphones when talking to the head of the amount of radiation in the direct use of cell phones to talk to the amount of radiation between 1/100 and 1/200.
2. Prevent electromagnetic radiation leakage of your computer confidentiality methods:
(1) passive mode: electromagnetic shielding, to prevent the leakage of electromagnetic waves to the outside. The disadvantage of using this mode alone is that if the shielding can not be complete, the high sensitivity of the electromagnetic receiving equipment can still access the information;
(2) active mode: the electromagnetic wave emission, so that the electromagnetic receiving equipment used for stealing the secrets of the signal received by the interference. The disadvantage of using this mode alone is that it is still possible and useful information can be restored if the received jammed signals are analyzed by well-designed software.
The best approach, therefore, is to use a mixture of both modes at the same time.
Thus, the passive mode to prevent electromagnetic wave leakage to the outside, we have to start from these aspects. Shielding the monitor alone is not enough. When a computer is to be used in a confidential situation, all unnecessary cables and peripherals should be removed.
Battery-powered laptops can dispense with such connections. However, if it is necessary to use a public power supply, passive mode filtering or active mode interference signal injection into the power cord are measures to be considered.
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Quality of the living environment, electromagnetic radiation can not be ignored
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