First of all, the electromagnetic wave band used by wifi wireless Internet access is generally 2.4GHz to 5GHz, which is close to the radio frequency band used by mobile phones (slightly higher than the frequency used by mobile phones). It belongs to non-ionizing radiation, and the heating effect on human tissues may affect health, which requires relatively high intensity to cause harm.
In the past decades, researchers have done a lot of research on the relationship between electromagnetic radiation in this band and the onset of some diseases, and there are many results that they think will have an impact, but most of these studies are just guesses or weak ties, which have not been widely recognized and have not risen to a worrying level.
In 2007, the Hong Kong Telecommunications Authority measured the radiation intensity around 62 wifi wireless routers in restaurants, convenience stores, libraries, houses, offices and other places in the city, and found that the measured values were only 0.03% to 0.3% of the safety upper limit of the International Commission on Non-ionizing Radiation, and these radiation values were measured very close to the wireless routers. In most cases, the radiation received from the router will be much lower than these values.
For wifi users, the main source of wireless Internet radiation is not those routers that look "very professional and radiant", but laptops in their hands when surfing the Internet.
Because when surfing the Internet wirelessly, the antenna in the user's laptop and the antenna on the router send and receive information to each other. The radiation emitted by the antenna in the notebook computer is not much smaller than that of the router, but the power of electromagnetic wave radiation is inversely proportional to the second power of the distance. The general wireless router may be several meters away, and the laptop is in front of you, but it is only a few centimeters. In this way, your laptop is often the real radiation source.
So how does the wireless internet access function of notebook computer compare with the radiation size of mobile phone? According to the research of the British Health Protection Agency, the SAR value of the radiation absorption rate (electromagnetic radiation energy absorbed per kilogram of human tissue in any 6 minutes on average) of the laptop wireless Internet access is only 1% of that when using the mobile phone to answer the phone, and the main reason is the distance mentioned above.
Because mobile phones can be close to the brain, and laptops are far from the body. But we surf the internet wirelessly, which takes several hours at a time, and the mobile phone has a chance to talk for several minutes at a time. Considering the length of time, the radiation of laptop wireless internet access and mobile phone radiation should be about an order of magnitude.
Whether it is a laptop or a mobile phone, their radiation value is usually at the level of milliwatts per square meter, which is far lower than the safety upper limit stipulated by the International Commission on Non-ionizing Radiation-10 watts per square meter (this upper limit is only a safety limit in case of emergency, which does not mean that you will get sick if you exceed this value, but there will be slight health risks).
Conclusion: Just like the radiation of mobile phones, the radiation of wireless Internet routers and laptops are within the safe range, so there is no need to panic.
Usually, we call the effect of electromagnetic waves on objects radiation, which is divided into electromagnetic radiation (light, microwave, Wifi signal, etc. ) and ionizing radiation (x-rays, gamma rays, etc. The ability of electromagnetic radiation is very low, and only long-term and large-dose exposure (such as sunbathing) may cause harm to human body. Even ionizing radiation, as long as it helps to protect, will not cause harm to human body.
Electromagnetic waves can be divided into FM signals, cell phone signals, Wifi signals, visible light, X-rays and gamma rays according to different frequencies. The frequency of Wifi is 2400 MHz, which belongs to decimeter wave. Millimeter wave, centimeter wave and decimeter wave are collectively called microwave.
▲ Frequency, wavelength and energy of electromagnetic waves and their applications
Wifi signal is a kind of microwave, and the main effect of microwave on human body is thermal effect. The thermal effect is mainly that the polar molecules in the organism rotate repeatedly and rapidly under the action of microwave high-frequency electric field, and heat is generated through friction, which is mainly water in the human body. The power of Wifi signal is very small, and biological tissues absorb less microwave energy. It can radiate absorbed microwave energy (heat) to the whole body or outside the body through blood circulation and its own thermal regulation system.
We already know that the influence of Wifi on human body is mainly thermal effect, and the generated heat can be recovered through the regulation system of human body, so it has little influence on human body. At the same time it can be compared with other electromagnetic waves. Because the energy of electromagnetic wave is directly proportional to its frequency, the frequency of visible light is about 200,000 times that of electromagnetic wave. That is to say, at the same intensity, the energy of visible light is about 200,000 times that of WIFI signal, and the radiation of WIFI to human body is far less than that of light. Comparing the radiation of WIFI signal with that of microwave oven, the frequency of WIFI signal is basically the same as that of microwave oven, but the radiation intensity of microwave oven is about 6.5438+ten thousand times that of WIFI signal, and the radiation in microwave oven is much larger than that of WIFI signal.
According to the national standard of electromagnetic radiation, the radiation level of Wifi is 1% of the national standard, and the Ministry of Environmental Protection does not take it as the supervision object, that is, it is exempted from management, indicating that the management department also believes that Wifi signals are safe for people.
WiFi signals of wireless routers will generate radiation.
Where does the radiation exist?
Radiation refers to the phenomenon that part of the electromagnetic energy emitted by the field source propagates far away from the field source and never returns to the field source. It is generally believed that everything in nature will produce radiation, except objects whose absolute temperature is zero.
The word "radiation" itself belongs to a neutral concept, but because some special radiation may bring harm, people mistakenly think that radiation is harmful and exaggerate its negative significance.
What are the classifications of radiation?
Radiation can be divided into ionizing radiation and non-ionizing radiation, in which ionizing radiation can ionize atoms of substances because of its sufficient energy. For human beings, because our cells are made of atoms, ionization will undoubtedly cause harm to human body, and in severe cases, it can cause cancer.
What is electromagnetic radiation?
As we all know, electromagnetic waves are everywhere in people's living environment, and all kinds of household appliances (including wires) will produce electromagnetic waves during operation. Both natural sunlight and light in life are in the form of electromagnetic waves.
Electromagnetic wave is produced by the interaction between electric field and magnetic field. Through the constant conversion of electric field and magnetic field energy, electromagnetic waves can propagate in free space, and energy consumption or leakage will occur during the propagation process, which is called electromagnetic radiation.
Is the electromagnetic radiation generated by WiFi harmful to human body?
The energy of electromagnetic radiation is closely related to temperature and power, and excessive electromagnetic radiation is fatal to human body. Therefore, the World Health Organization encourages countries to adopt the relevant standards formulated by the International Commission on Non-ionizing Radiation Protection (ICNIRP), while China has formulated more stringent electromagnetic control standards than ICNIRP standards, such as Control Limits of Electromagnetic Environment (GB 8702-20 14) and Regulations on Electromagnetic Radiation Protection (GB8702-88). 300 GHz) public exposure control level, electromagnetic radiation safety value, etc.
Generally speaking, if the electromagnetic radiation level is lower than 0.4W/ m2, it can be regarded as harmless to human body, and all mobile communication base stations in China meet this standard.
In fact, all electronic products (mobile phones, wireless routers) put into the market in China must pass China's compulsory product certification (3C), which specifies the products in terms of safety performance, electromagnetic compatibility and electromagnetic radiation prevention. Therefore, electronic products (including wireless routers) that meet 3C certification can be used safely.
To sum up, electromagnetic radiation exists around people all the time, which is not terrible in itself, but needs correct understanding and treatment. For friends who are very concerned about electromagnetic radiation, the author gives the following suggestions:
First, reduce staying in areas with strong electric and magnetic fields, such as high-voltage facilities and medical radiation areas;
The second is to avoid long-term exposure to radiation sources, such as playing computer for a long time;
The third is to minimize close contact with electronic products, such as making long phone calls.
I hope the author's point of view is helpful to you!
Where there are radio waves, there is radiation, and the radiation with high frequency is higher than that with low frequency. Usually, the power of radio waves reaches a certain amount before it has a certain radiation impact on people. For example, being close to high-power TV and radio transmitting antennas for a long time and using mobile phones for a long time will cause certain harm to people.
The line patrol is a digital signal, and the power is very small, so the radiation hazard can be ignored. Although the wireless router is a high-frequency radio wave, the power is very small (much smaller than the mobile phone); Moreover, it is not as close to people as mobile phones, and the radiation hazard is much smaller than mobile phones.
Wired and wireless pedestrians are harmless to people!
There are many articles on the Internet touting the harm of "Wi-Fi radiation" and how high it is to your health. Don't worry: this is a bunch of nonsense.
If you don't want to read another sentence, that's good. We give you the whole article: Wi-Fi will never threaten anyone's health. If you are curious about the reasons (maybe you can explain these things to your overly anxious friends), we will be happy to outline what happened.
If you wander around the internet, you can hardly find any articles about any danger. Articles about how dangerous modern drugs are, how dangerous mobile phones are, how dangerous microwave cooking is, and how dangerous wireless Wi-Fi is. People claim that Wi-Fi routers will wake them up at night, leading to cancer, ADHD, and all kinds of unfounded and absurd claims.
To understand why Wi-Fi is harmless to health, you need to know some basic knowledge of radio communication and the radiation that makes it possible.
Radiation is a terrible word for outsiders. Radiation was in the 1960 s, when students were taught to climb under the table, which prompted Americans frightened by the cold war to build backyard bomb shelters. Radiation is a substance that causes nuclear power plants to collapse, pollutes the ocean and makes the land uninhabitable for hundreds of years.
Radiation is also something that bathes the world in warm sunshine and makes life on earth possible. Radiation is also the reason why we can turn on the radio and listen to wireless music. Radiation is the way we change TV channels (for anyone who gets TV programs through wireless channels or satellite TV, the first thing is how to send them to their homes).
When it comes to radiation, the most critical concept is the difference between ionizing radiation and non-ionizing radiation. Ionizing radiation is a dangerous substance, including X-ray radiation, gamma radiation and a certain amount of high-end ultraviolet rays in the ultraviolet spectrum. The key factor here is the wavelength of the radiation type.
Ionizing radiation gets its name because it has enough energy to excite electrons and knock them out of orbit or ionize them. Exposure to this radiation for a long time will seriously endanger your health. Over time, even if the exposure is small but continuous, it will greatly increase the risk of cancer, because exposure will cause cell mutation. Even if it is used for beneficial purposes (such as diagnosing patients with X-ray machines), the exposure should be carefully controlled by using lead vests and shielding materials to benefit patients and machine operators and minimize exposure. If you are worried about radiation, this is the radiation you should be worried about. Even so, you shouldn't be so worried, because the amount of radiation you get in the routine medical procedures in your life is less than that you get in the plane when you are on business and vacation. )
Instead, we have non-ionizing radiation. This radiation does not have enough energy to ionize atoms, and includes all other things in the radiation spectrum, including infrared radiation, visible light and radio waves-including radio waves in the microwave part of everything from low-energy radio waves used in walkie-talkies to higher energy.
People exposed to non-ionizing microwave radiation will be exposed to very high power doses at very close distances. The magnetron in your ordinary household microwave oven generates about 700 watts of microwave energy, and the microwave discharge is safely contained in the microwave body due to proper shielding. Even if the microwave breaks down and the shielding begins to fail, you won't even feel that there is something standing and equipment in a room.
In contrast, even a very powerful high-end Wi-Fi router can only generate about 1 watt of microwave energy, and unlike the magnetron in a microwave oven, the energy radiated by a Wi-Fi router in a small container similar to a bubble is only 1 watt, so generally speaking, the radiation of WIFI will not affect your body. If it does, the impact will be at least minimal.
People often tell me not to use the computer for a long time. Too much radiation is harmful to the body, but in fact, the WIFI signal sent by the high-power wireless router has radiation to the human body, but it is small and harmless.
People usually use mobile phones close to their brains, but the wireless route of the connection may be far away in other rooms (don't forget inverse square law). Experiments show that people who make phone calls for 20 minutes absorb more microwave radiation than those who use wireless routing for one year. The microwave radiation of 20 laptops plus 2 wireless routers is almost the same as that of a mobile phone.
Radio signals follow the inverse square law like light, sound waves and gravity, that is, the distance is doubled and the energy is reduced to a quarter. In other words, the signal strength decreases rapidly with the increase of distance.
At the usual distance, the signal strength of wireless network is so weak that there is no need to worry at all: it is only part of the "radio smoke" formed by radio, TV signal, alternating current, household motor and the vast universe. As my colleague Charles Arthur pointed out, the wavelength of wireless network signal is the same as that of cosmic background radiation: both are 12cm. If you are still worried, don't go out at all.
There have been hundreds of attempts to find out that wireless routers or mobile phones are related to threats to human health. We can only say that wireless network signals have no potential security risks, but we can't prove this conclusion wrong. Of course, it makes sense to minimize hidden dangers. Of course, it must be aimed at the main, not irrelevant. If you want to do this, you have to start with mobile phones.
By the way, the microwave oven at home is safe enough, because its design ensures that it can resist microwave leakage well. But you can check whether there is microwave leakage in the microwave oven at home, or stay away from it when heating food (the "far point" here is about 1 meter).
First of all, thank you very much for answering this question here. Let me take you into this question. Now let's discuss it together.
In fact, when it comes to radiation, sunlight is a kind of radiation, which belongs to very strong radiation. Solar radiation affects the earth's water cycle, ocean currents, rock weathering, soil formation, complex and changeable weather phenomena, diverse climate differences, and the survival of all living materials. At present, the main energy sources used by human society are: coal, oil, natural gas, wind energy, hydropower, biomass energy and so on. Are all related to solar radiation.
People often tell me not to use the computer for a long time. Too much radiation is harmful to the body, but in fact, the WIFI signal sent by the high-power wireless router has radiation to the human body, but it is small and harmless.
People usually use mobile phones close to their brains, but the wireless route of the connection may be far away in other rooms (don't forget inverse square law). Experiments show that people who make phone calls for 20 minutes absorb more microwave radiation than those who use wireless routing for one year. The microwave radiation of 20 laptops plus 2 wireless routers is almost the same as that of a mobile phone.
Radio signals follow the inverse square law like light, sound waves and gravity, that is, the distance is doubled and the energy is reduced to a quarter. In other words, the signal strength decreases rapidly with the increase of distance.
The radiation of mobile phones or routers refers to the radio waves generated when these devices transmit information through electromagnetic waves. The radiation of these devices is measured by SAR value. In the range of 30MHz to 30000MHz, the higher the frequency, that is, the shorter the wavelength, the stronger the ability to penetrate the human body. Therefore, the higher the frequency, the greater the allowable power density, that is, from 0.4W/ m at 30 MHz to 2W/m at 30000 MHz.
These devices use the "microwave" band, and the frequency, penetration and energy of microwaves are not as bright as the sun we bask in every day! If the "microwave" radiated by mobile phones is harmful to our health, then the radiation we receive in the sun every day will exceed the chart.
The answers to this question shared above are all personal opinions and suggestions. I hope the answer to this question I shared can help everyone.
Meanwhile, I hope you like my sharing. If you have a better answer to this question, please share your comments and discuss this topic with me.
Finally, here I am. I wish you all a happy life, good health, a prosperous family and everything, a big fortune every year and a prosperous business. Thank you!
In fact, when it comes to radiation, sunlight is a kind of radiation, which belongs to very strong radiation. Solar radiation affects the earth's water cycle, ocean currents, rock weathering, soil formation, complex and changeable weather phenomena, diverse climate differences, and the survival of all living materials. At present, the main energy sources used by human society are: coal, oil, natural gas, wind energy, hydropower, biomass energy and so on. Are all related to solar radiation.
Everything grows by the sun!
Do you think it's solar radiation or cell phone radiation? Or is the high-power router wifi radiation large?
The solar constant published by the World Meteorological Organization (WMO) at 198 1 is 1368 W/m2. More than 99% of the solar radiation spectrum in the upper atmosphere of the earth is between 0.15 and 4.0 microns. About 50% of solar radiation energy is in the visible spectrum (wavelength 0.4 ~ 0.76 micron), and 7% is in the ultraviolet spectrum (wavelength; 0.76 micron) and the maximum energy is at the wavelength of 0.475 micron. Because the wavelength of solar radiation is much smaller than that of ground and atmospheric radiation (about 3 ~ 120 micron), it is usually called short-wave radiation and long-wave radiation.
The radiation of mobile phones or routers refers to the radio waves generated when these devices transmit information through electromagnetic waves. The radiation of these devices is measured by SAR value. In the range of 30MHz to 30000MHz, the higher the frequency, that is, the shorter the wavelength, the stronger the ability to penetrate the human body. Therefore, the higher the frequency, the greater the allowable power density, that is, from 0.4W/ m at 30 MHz to 2W/m at 30000 MHz.
These devices use the "microwave" band, and the frequency, penetration and energy of microwaves are not as bright as the sun we bask in every day! If the "microwave" radiated by mobile phones is harmful to our health, then the radiation we receive in the sun every day will exceed the chart.
So as long as you don't have any problems in the sun, using a high-power router won't have any adverse effects.
Needless to say, the radiation level of high-power wireless routers is that all the mobile phone chargers we use have radiation, and all the electronic products in our home will radiate radio waves, but the radiation levels are different. The radiation of the router is not as serious as imagined. Generally, the radiation radius of the router is about 50 cm, so as long as the router is placed at a certain distance from us, there will be no problem!
People often tell me not to use the computer for a long time. Too much radiation is harmful to the body, but in fact, the WIFI signal sent by the high-power wireless router has radiation to the human body, but it is small and harmless.
People usually use mobile phones that are close to their brains, but the wireless route of the connection may be far away in other rooms (don't forget inverse square law). Experiments show that people who make phone calls for 20 minutes absorb more microwave radiation than those who use wireless routing for one year. The microwave radiation of 20 laptops plus 2 wireless routers is almost the same as that of a mobile phone.
Radio signals follow the inverse square law like light, sound waves and gravity, that is, the distance is doubled and the energy is reduced to a quarter. In other words, the signal strength decreases rapidly with the increase of distance.
At the usual distance, the signal strength of wireless network is so weak that there is no need to worry at all: it is only part of the "radio smoke" formed by radio, TV signal, alternating current, household motor and the vast universe. The wavelength of wireless network signal is the same as that of cosmic background radiation: both are 12cm. If you are still worried, don't go out at all.
There have been hundreds of attempts to find out that wireless routers or mobile phones are related to threats to human health. We can only say that wireless network signals have no potential security risks, but we can't prove this conclusion wrong. Of course, it makes sense to minimize hidden dangers. Of course, it must be aimed at the main, not irrelevant. If you want to do this, you have to start with mobile phones.