What Are the Different Types of Mobile Phone Radiation Protection?

Cell phone radiation, radio waves generated when a cell phone transmits information through electromagnetic waves. Mobile phone radiation is measured by SAR values. The marathon debate about whether cell phones radiate the human body has never stopped.

Cell phone radiation

Cell phone radiation, cell phone pass

1.Power density standard

Power density refers to the radiated power received per unit area. It measures the signal strength, which can be expressed by the electric field strength and magnetic field strength, but the power density is more commonly used. The following figure is the regulations on the limits of public exposure in China's current "Electromagnetic Radiation Protection Regulations" (GB8702-88). The first two lines in the figure are medium and short waves and do not belong to the mobile communication frequency band. 3MHz to 30MHz is used by the military. The short-wave band has little to do with the public and need not be concerned. For electromagnetic waves 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, from the perspective of the impact on the human body, the higher the frequency, the greater the allowed power density, ie From 0.4W / m at 30MHz to 2W / m at 30,000MHz.

The peak power of the mobile phone is 2W. The American Institute of Electrical Engineers (IEEE) does not consider safety issues below 7W, but the National Radiation Protection Measurement Commission (NCRP) advocates stricter standards. The US Federal Communications Commission (FCC) The radiation limit specified for the 900MHz frequency band used is 6W / m.

China's current electromagnetic radiation protection regulations, GB8702-88, is one of the international standards. The establishment of base stations by communications companies and the inspection by the Ministry of Environmental Protection are based on this standard. The radiation power of some netizens' base stations is getting smaller, and the radiation power density is showing a downward trend.

After 88 years of national standards, the Ministry of Environmental Protection has launched a solicitation standard that intends to replace the GB8702-88 standard. The limit of the mobile phone frequency band has not changed. It is still 0.4W / m. The standard will include electromagnetic equipment from 1MHZ to 300GHz. The equivalent power of the exemption management is set to 100W, that is, equipment that does not radiate to the shielded space below 100W does not need to be submitted for approval, and those higher than 100W do not mean that it cannot be done, just to be approved. The single station power of the base station is about 20W. According to this standard for comments, it may exceed the standard.

Generally, the height of the GSM base station antenna is 35 to 55 meters. The Ministry of Environmental Protection has supervised and tested thousands of base stations. The results show that the base station has a radio power of 20 watts and the power density of the first 10 meters of the base antenna is 0.006 W / m.

Electromagnetic radiation such as mobile phones and base stations will not affect human health. This is a consensus in the scientific community. It has never been a problem abroad, but it has caused public panic in China. The reason is that the radiation rumours spread by operators for competition are the source. When the CDMA mobile phone was promoted, a certain operator developed the pseudo-concept of "green mobile phone", taking low radiation as a selling point, and deceiving the public to increase competitiveness. . In fact, the radiated power of a CDMA mobile phone is not less than that of GSM. The peak power of a GSM mobile phone is 2W. In actual use, it only transmits at 1/8 of the time, so the maximum average power is 250mW, while CDMA is continuously transmitted, and the maximum average power is about At 250mW, there is not much difference between the two.

The public does not need to know the specific principle, and only by common sense can judge that the radiation of CDMA mobile phones is roughly equivalent to that of GSM, because the battery capacities of the two mobile phones are similar. Except for the same energy required for system operation, the rest of the energy is radiated. Standby and continuous talk time are similar. If the radiated power of a CDMA mobile phone is far less than that of GSM, where is the remaining energy? Doesn't the law of conservation of energy hold?

Although the maximum average power of both GSM and CDMA mobile phones is about 250mW, the actual transmit power will be much lower than this level, which stems from the base station's automatic control mechanism for mobile phone power. Because the mobile phone is at a different distance from the base station, and the mobile phone radiates the same power, the base station receives strong signal power from the nearby mobile phone and weak signal power from the remote mobile phone. The mobile phone itself does not know the distance from the base station. At the beginning, it will use the maximum power transmission. After receiving the base station, it will send a step-by-step instruction to reduce the transmission power to the mobile phone. The mobile phone will adjust the transmission power to a very low level, such as 0.02W, in a very short time.

Although the transmission power of the base station is greater than that of the mobile phone, because the mobile phone is close to the human body, the radiation amount of the mobile phone to the human body is much greater after comprehensive comparison. Resisting base stations because of fear of radiation is the most stupid way. There is no one. Because the distance between the mobile phone and the base station is far, mobile phone users will be exposed to stronger radiation. This is probably not what the resisters thought.

Operators have paid the price for the original radiation rumors. It is difficult for base stations to enter the community, driven by residents everywhere, and the tricks of disguising base stations as light poles and big trees are no longer effective. Even today, there are still operators playing fake green cards and still doing this silly thing to quench their thirst. It's amazing.

2.Specific absorption rate standard

The specific absorption rate (SAR) is defined as the differential value of the energy micro-elements absorbed by the mass micro-elements within a given density volume micro-element as a function of time, which is actually the electromagnetic energy absorbed by unit time and mass of a single organism The unit is W / kg.

Compared with the power density standard introduced earlier, this standard takes more consideration of the human condition and should be a more worthy reference standard, but it is difficult to operate. The test of the power density standard is very simple. It can be measured with a field strength meter or a spectrum analyzer, but the test of the specific absorption rate standard requires the cooperation of a human body model, and the subsequent data algorithms are also very complicated.

The American Standard for Radiation Protection and Measurement (NCRP) and the American Institute of Electrical and Electronics Engineers (IEEE) set SAR 1.6W / kg, and the European Standard for Non-Ionizing Radiation Protection (ICNIRP) established the European standard SAR 2.0W / kg, of which the European standard is the standard recommended by the World Health Organization (WHO). China's "Partial Exposure Limits for Electromagnetic Radiation from Mobile Phones" (GB21288-2007), the main content of which is only one page, in fact, a word is said: China complies with the European standard 2.0W / kg standard recommended by the WHO .

There are standards, but how do you test them? The current standard is the communication industry standard YD / T 1644.1-2007 of the People's Republic of China, Part 1: The SAR Evaluation Procedures for Handheld Wireless Communication Equipment Used Near the Ear (Frequency Range 300MHz ~ 3GHz), Part 2: Handheld SAR evaluation procedures for body wearing equipment in the human head and body (frequency range 300MHz ~ 6GHz).

Test the electromagnetic energy absorbed inside the skull. Of course, we cannot open a living person. We can only make a standard human head model that is equivalent to the shape, density and dielectric constant of the skull. The above standardization standardizes the model to ensure the measurement results. Consistency and comparability. The standard requires a suspension of sugar and salt to simulate the interstitial fluid of the head. The mobile phone has two standard test positions: face-to-face and tilt. There are also a set of specifications for signal frequency and power, probe specifications, and test procedures.

The content of this standard is very detailed, and a total of 65 relevant standards and documents from European and American countries have been referenced. However, the actual content is basically related to European and American standards. It is interesting that the head model data used in China's standards actually come from the anthropometric report of the US military in 1988, which is completely consistent with the relevant US standards.

In the standard, according to the statistics of the head size of American male soldiers, the heads of adult men are divided into 1 to 10 numbers in ascending order, with the number 1 being the smallest and the number 10 being the largest. The head size is definitely smaller than that of No.9, so that more than 90% of all users will have smaller heads than the model, and will suffer lower radiation, so that the SAR standard based on this No.9 model is conservative And safe.

The media often claims that the SAR value is based on the head model of adult men and that stricter standards should be adopted for children. There is no scientific basis for this statement. According to dosimetry studies, adult men have larger heads than women and children. The greater the amount of radiation, this already constitutes the worst-case electromagnetic radiation.

The probe used in the human head model is not a thermometer, but a receiving antenna that receives electromagnetic radiation energy. After obtaining the test data, it must be processed by a complex algorithm to obtain the SAR value. The probe antenna needs to be calibrated according to different frequency bands. The measurement steps and data estimation are unprofessional and complicated.

According to previous test results, the maximum temperature rise caused by mobile phone radiation on the head is 0.194 degrees Celsius. According to IEEE safety standards, the threshold for local temperature rise in the human body does not exceed 3.5 degrees Celsius. If the normal temperature of the human body is 36.5 degrees Celsius, the local temperature It cannot be higher than 40 degrees Celsius, and the highest temperature caused by mobile phone radiation is less than 37 degrees Celsius, of course, it is irrelevant, and humans can also adjust their own local temperature through the flow of their body fluids.

SAR is not related to the mobile phone standard (such as SM or CDMA). Many years of research data in many foreign laboratories show that SAR and power density are not converted, but they are often compared in China to qualitatively explain the problem.

On April 23, 2012, the United States Federal Communications Commission (FCC) issued a revised draft of six KDB documents on RF exposure and SAR compliance requirements, of which KDB8 65664 is for SAR testing at 100MHz to 6GHz. This revision is mainly It is in compliance with the objective requirement that the radio signal frequency in the new generation mobile communication specifications such as LTE rises to 700MHz ~ 6GHz, while the radio signals considered in the past were mainly below 2GHz.

There are three main changes in the new file. The first is that the diameter of the antenna inserted into the head model used for signals below 2GHz was 6mm ~ 7mm, and the signal frequency became higher, so the wave was shortened accordingly, requiring 3 mm ~ 4mm. At 6GHz, an antenna with a diameter of 1.5mm is required. Why is the antenna short when the signal frequency is high? Because the frequency of the signal is inversely proportional to the wavelength, when the length of the antenna is proportional to the wavelength, the efficiency of transmission and reception will be higher. Therefore, the signal frequency is higher, the wavelength is shorter, and the antenna is shorter. Second, because the frequency bandwidth of a single signal is not suitable for a single probe, separate multiple probes have become the trend of future testing; third, The simulation liquid in the head model, the previous sugar and salt liquid are not suitable for signals above 1G, and new mixed liquids such as mineral oil and glycerin are required. Through literature search, it has not been found that relevant departments and institutions in China have followed up on these changes.

The last item of the "Partial Exposure Limits for Electromagnetic Radiation of Mobile Phones" (GB 21288-2007) standard sets requirements for the identification of mobile phone products. The SAR of the product should be indicated in bold in the description, and the outer packaging of the product is encouraged to be marked The maximum value of SAR. At least at this stage, I have no hope for this requirement. As mentioned earlier, measuring a product's SAR is a highly professional and complicated process. There are not many scientific research institutions capable of this capability, and it must be granted by the state. Otherwise, it will be as invalid as the butcher holding his own quarantine stamp on the pork. Therefore, in the case where SAR detection has not yet been carried out, if the SAR value is indicated in the manual of a certain mobile phone, we have to verify. Where was this data measured? Has this institution been granted the relevant qualifications?

Like other popular rumors, the fear of electromagnetic radiation is widespread in China. Popular science people, including me, have done a lot of work, but far from becoming the mainstream voice. The truth that "electromagnetic radiation in daily life is not harmful to human health" It also failed to agree with most people, which made me feel helpless for years of efforts to eliminate the fear of electromagnetic radiation.

I have heard about it, and I have a specialty in surgery. You do not need to understand the scientific knowledge mentioned in this article, but you can vote for science. You should not abstain, and you must not vote for rumors. Please forward this article to more friends, and contribute a positive energy to "remove unnecessary fear and pursue a better life".

Related standards

SAR (Specific Absorption Rate) of mobile phones: SAR stands for the allowable amount of radiation per unit kilogram of living organisms (including the human body). This SAR value represents the impact of radiation on the human body. It is the most direct test value. SAR is aimed at the whole body. , Local, limb data. The lower the SAR value, the less the radiation is absorbed. The SAR standard value for the brain part must be lower than 1.67

The frequencies used by mobile phones are microwaves, and the strength of the transmitted signal varies in different states. For example, when the mobile phone is switched on and connected to the network, it is necessary to establish a connection with the base station, and the transmitted signal power is large; in subways, elevators, and other places, the wireless transmission signal between the mobile phone and the base station is greatly attenuated and the signal becomes weak. The control technology will increase the transmission power of the mobile phone, and the radiation effect will be relatively large. At present, our country stipulates that the peak power of mobile phone terminals must meet national standards. This power is within a safe range, but it does not rule out that some cottages will increase the mobile phone s transmit power in order to pursue the effect of talking, and thus generate large radiation ^{[ 2]}

The size of the mobile phone's radiation mainly depends on its antenna, appearance design and other factors. In actual use, the size of the mobile phone's radiation is also related to the distance between the mobile phone and the base station, the geographical environment around the user, and the setting of the base station. Generally speaking, the closer the mobile phone is to the base station, the smaller the radiation will be, and vice versa. ^[3]

The Ministry of Science and Technology for the Future of Korea announced on August 1, 2013, "Electromagnetic Radiation Level Standards, Marking Objects, and Marking Methods", requiring that from August 1, 2014, all wireless devices such as mobile phones sold in South Korea must be marked with electromagnetic radiation. Ranks to dispel public anxiety. South Korea will also become the first country in the world to make its radiation standards mandatory.

According to the published radiation level standards, the mobile phone's electromagnetic radiation absorption rate (SAR) is less than 0.8W / kg belongs to the first level, and the range of 0.8 ~ 1.6W / kg belongs to the second level. SAR refers to the amount of electromagnetic radiation that may be absorbed by the human body when using a mobile phone. The standard specified by South Korea is 1.6W / kg, which is stricter than the international standard (2W / kg). Products exceeding the relevant standards will be banned from production and sales. The manufacturer of the mobile phone must mark the measured value of the electromagnetic radiation level or electromagnetic absorption rate in the main body of the product, the box, the manual and the information menu in the mobile phone. In addition, the radio equipment, fences, fences and barbed wire of mobile communication base stations should also be marked with electromagnetic radiation levels.

The harmfulness of mobile phone electromagnetic radiation has been controversial, and many studies have proved that electromagnetic radiation does affect human health. The International Cancer Research Organization under the WHO has classified the electromagnetic radiation emitted by wireless communication equipment such as mobile phones as "possible carcinogens". Those who use mobile phones for 30 minutes (more than 10 years) a day have a higher chance of developing brain tumors and acoustic neuromas. 40% higher than the average person.

After the Korean government announced the above regulations, it was accused of being biased towards Korean mobile phone manufacturers. Because the South Korean mobile phone manufacturers such as Samsung and LG have SAR values between 0.353 and 0.745W / kg, they meet the first-class conditions, and some foreign brand mobile phones It is much higher than this standard. They have to improve the functions of mobile phones in order to obtain the first level of certification. Some analysts believe that mobile phone manufacturers may use radiation levels as publicity stunts to attract people who are increasingly concerned about health. ^[4]

Mobile phone radiation is mainly caused by the high-frequency radio waves it emits. According to a study by the American Mobile Phone Association, 60% of the microwave emitted by the whip phone antenna is absorbed by the human brain at close range. The mobile phone antenna is the place where the strongest radiation is generated, and the distance between the human brain and the transmitting antenna is only 2-5 cm, so it is potentially harmful.

The current international mobile phone radiation measurement method is the "Specific Absorbed Radiation-SAR" defined by the International Mobile Telecommunications Association (CTIA). Its unit is W / kg, which represents the electromagnetic radiation energy absorbed per kilogram of human body. The United States has adopted this standard, the Federal Council's regulation is 1.6W / kg. Previously, the Ministry of Health and the State Environmental Protection Administration of China had proposed a 1.0 SAR standard, but it was not enforced. According to industry sources, the technical aspects of the new mobile phone radiation standard have been completed, and the National Standards Commission is currently reviewing it.

Wang Jun, an executive member of the China Medical Equipment CT Professional Committee and an expert at the Institute of Medical Imaging of the Nanjing General Hospital of the Nanjing Military Region, believes that the overall impact of mobile phone radiation on the health of minors and adults is similar. Minors are in the process of growth and development, and suffer more damage than adults.

Wang Jun said that the nervous system of minors is most vulnerable to the negative effects of cell phone radiation. Long-term use of mobile phones can indeed cause minors' memory loss, cognitive decline, and also easily cause irritability, irritability and other symptoms. ^[5]

At present, there is a lack of research on the effects of mobile phone radiation on minors in China, and there are few studies on mobile phone radiation on adults. There is a department in charge of mobile phone quality testing in the country, but in daily life, consumers rarely notice the problem of mobile phone radiation when buying a mobile phone.

It is reported that different brands and models of mobile phones radiate differently to the human body, and China's mobile phone market is mixed and difficult to monitor, which poses certain risks to consumers. As national standards for mobile phone radiation have not yet been issued, mobile phone manufacturers rarely take the initiative to send mobile phones for inspection. At present, most mobile phones in the market have not passed the relevant national tests, and are only self-inspected by the manufacturers. The manufacturer's self-inspection is not only a spot check. The items of the spot check are focused on the quality of the mobile phone. Rarely, there are tests including SAR. In the current mobile phones on the market, the relevant parameters of the mobile phone radiation can not be found in the manual.

The previous "radiation door" incident of a famous international mobile phone manufacturer made people discover that many mobile phones that did not meet European and American standards have drilled holes in Chinese standards and became hot products in major mobile phone stores. This makes consumers worry that although the non-compliance with European and American standards does not mean that the radiation of this mobile phone will endanger human health, mobile phones with high radiation are always disturbing. ^[5]

1. Regulations on electromagnetic radiation protection GB8702-88

2. Local exposure limit of electromagnetic radiation for mobile phones GB21288-2007

3. Guidelines for the management of radiation environmental protection. Electromagnetic radiation monitoring instruments and methods HJ / T 10.2-1996

4. Limits of public exposure control in the electromagnetic environment (advice) revised GB8702-88

5. Electromagnetic exposure to the human body from wireless communication devices used for handheld and body wear-Human models, instruments and procedures Part 1: S AR evaluation procedures for handheld wireless communication devices used near the ear (frequency range 300MHz ~ 3GHz) YD / T 1644.1-2007

6. SAR Measurement Requirements for 100MHz to 6GHz (KDB865664, Federal Communicantions Commission Office of Engineering and Technology)

7. China Tyre Lab: Research Report on Mobile Phone Electromagnetic Radiation

8. China Tyre Lab: Research Report on Base Station Electromagnetic Radiation

9. Research on the Brain Temperature Rising Caused by Mobile Phone Radiation, Zhao Zhihua, Information Technology, No.8, 2008

10. Simulation study of human body's absorbed dose from mobile phone, Wang Manzhu, Journal of University of Electronic Science and Technology of China, No.2, 2008

11. Calculation of safe distance for mobile phone and base station far-field radiation, Yao Lijie, Safety and EMC, Issue 3, 2012

12. Introduction of SAR Standards for Mobile Phones in Different Countries and Analysis of SAR Value Data, Shi Ying, Environmental Engineering, Volume 29 Supplement 2011 ^[6]

    gossip:

    1. Don't sleep with your cell phone;

    2. When answering a call, the microphone will be a hand grenade away from your mouth;

    3.Alternatively use mobile phones on both sides of the head;

    4. Try to hang your mobile phone around your waist and use a Bluetooth headset to make and receive calls ...

    the truth:

    We live in radiant universe

    There are more and more radiation sources in our living space, and the electromagnetic environment is becoming more and more complicated. Even if you think mobile phone radiation is harmful to your health and you do nt use it, that s the same way you ca nt avoid the radiation of radio waves. In a dense radiation environment, the power of your mobile phone is insignificant. No less than a hand user, just as meaningless as quitting in a smoky smoking room, unless you have the ability to shut down all base stations or stay away from crowds in uninhabited places. ^[7]

    Many people are struggling to find a cure for dementia, but many are not necessarily effective. A recent study found that contact with a cell phone may help prevent dementia. The research conducted in mice proved that long-term exposure to electromagnetic waves from mobile phones can prevent or even reverse Alzheimer's disease.

    The findings are published in the journal Alzheimer's Disease. Gary Arendas, a researcher at the University of South Florida in the United States, said: "This study surprised us by discovering that mouse contact with mobile phones in early adulthood can help protect memory and prevent the symptoms of dementia. This is even more surprising. Shockingly, the electromagnetic waves generated by mobile phones can actually reverse the memory deficits of older mice with Alzheimer's. "

    Researchers said they found that beta-amyloid deposits in their brains were significantly reduced when elderly mice with Alzheimer's disease were exposed to the electromagnetic waves generated by mobile phones. Brain plaques formed by abnormal Beta-amyloid deposits are a major feature of Alzheimer's disease, which is why most treatments target this protein. The researchers said the study could also allow scientists to separate the effects of cell phone exposure on memory from the effects of other lifestyle factors such as exercise and diet on memory.

    The study looked at 96 mice, including both treated mice that gradually developed Alzheimer's and normal mice. The mice were exposed to the electromagnetic waves generated by their phones twice a day for an hour for 7 to 9 months. The mouse didn't wear a handset, and no mouse had a small cell phone near its ear. Its cage is located around a fixed antenna that generates mobile phone signals. The distance between each mouse and the antenna and the electromagnetic waves it contacts are the same, and the level of electromagnetic waves they contact is the same as the level of electromagnetic waves generated by a cell phone that humans put in their ears for communication.

    Researchers say that if rats with Alzheimer's disease begin to come into contact with electromagnetic waves emitted by mobile phones shortly after adulthood, their cognitive abilities will be protected by electromagnetic waves before the memory decline becomes apparent. If older mice with Alzheimer's touch this signal, their memory deficits will improve. Researchers write that more importantly, the memory of normal mice has also improved greatly after exposure to mobile phones for several months.

    Researchers said that normal mice showed signs of improved memory after several months of contact with a cell phone, suggesting that humans may have similar effects after several years of contact with a cell phone. However, they also issued a warning: "We must be very careful when judging the results of our mobile phone use and exposing humans to electromagnetic waves." The researchers concluded that the discovery may mean that exposure to electromagnetic fields is a prevention and treatment of human dementia. Is an effective, harmless and drug-free method. ^[10]

    Twenty years ago, analog mobile phones (commonly known as Big Brother) were only affordable by a few rich people. Due to cost considerations, base stations could not be built too much. In order to ensure signal quality, only mobile phones with a high radiant power of 1.3 watts could be designed. Digital mobile phones are very popular, and their maximum design power does not exceed 0.6 watts. Although the radiated power has been reduced, due to the large number of households, their security issues have also received more extensive attention than before. There are endless stories about the harmful effects of mobile phone radiation on the human body. For example, compared with those who do not use mobile phones, the incidence of brain tumors and cancers is higher, memory loss, and pregnant women are more likely to have abortions. Suggestions for using your phone safely, such as hanging your phone around your waist and using Bluetooth headsets to make and receive calls, alternately using your phone on both sides of your head, do nt put your phone next to your pillow when you sleep, and use a cell phone anti-radiation film.

    Whether mobile phone radiation is harmful to human health has been a hot issue in global academic research for many years, and hundreds of scientific research results have shown that the use of mobile phones has nothing to do with the incidence of brain tumors and cancer. List some of the more important studies: The Swedish National Institute of Occupational Diseases, through a study of 905 adult mobile phone users, published research results in the international literature on occupational and environmental health in April 2006, saying that the use of mobile phones does not increase brain tumors Incidence. The London Cancer Research Society and three British universities conducted a four-year follow-up study of 966 brain tumor patients and 1,716 healthy people. A research report was published in January 2006, and the conclusion was that the use of mobile phones and the incidence of brain tumors Nothing. Danish scientists conducted a 21-year follow-up study of 420,000 mobile phone users, and ABC News published their findings on December 5, 2006, stating that cell phone radiation has nothing to do with cancer incidence. According to Japanese news in December 2008, Tokyo Women's Medical University compared 322 brain cancer patients using mobile phones with 683 healthy people and found that using mobile phones has nothing to do with the incidence of brain cancer. The United Nations International Health Organization stated on January 4, 2002 that the use of mobile phones has nothing to do with the risk of brain tumors.

    The fact that mobile phone radiation is not harmful to human health has been the mainstream view in the international academic community, but some experts have different opinions. In March 2005, a federal court in Maryland, USA, initiated a complaint against the mobile phone industry because they did not guarantee consumption. The prosecutor was protected from unsafe radiation, and the prosecution cited the opinion of a professor of bioengineering at the University of Washington, saying that cell phone radiation could harm human DNA and could cause benign tumors. However, all claims that the sound of mobile phone radiation, including this professor, is harmful to human health, are not based on scientific theory, and have not been confirmed by experimental results. They are just hypotheses.

    Although the general public does not understand electromagnetics and biology, it is still generally considered that mobile phone radiation is harmful. In 2006, a Russian experiment was carried out on the Internet, and a raw egg was placed in the middle of two mobile phones. After 65 minutes of talking, the egg was cooked, and even some foreign websites said that it can be cooked in 3 minutes. People are very burdened and their brains are cooked like eggs. Those with a little electromagnetic knowledge will know that the power of mobile phones is far lower than that of microwave ovens, and it is impossible to produce such a strong thermal effect as microwave ovens. Some people in China have repeated this experiment and proved that raw eggs are not only undercooked, even the temperature is simply Nothing changed, the Russian experiment was just a funny scam.

    The potential harm of mobile phone radiation to human health is mainly the harmful thermal effect caused by the absorption of radiant energy by human tissues. The international standard for examining the harm of mobile phones to human health is SAR, that is, the absorption rate of the mobile phone's radiant energy by the user's head. The US standard is 1.6 W / kg, the European standard is 2.0 W / kg. The source of this standard is an industrial standard made in the early last century to protect the health of workers of wireless transmitting equipment. At that time, the safety of non-ionizing radiation was insufficiently understood, and the standards were more stringent. In fact, even if receiving more powerful non-ionizing low-frequency radio wave radiation for many years, there has never been any adverse effect on health, and there has never been any report of someone affecting health due to radiation.

    The domestic media has been speculating on SAR standards since 2006, and public opinion tends to formulate more stringent domestic standards. This view is one-sided, let alone talk about whether mobile phone radiation is harmful to the human body, even if it is to reduce the amount of human body radiation, setting stricter standards may well be self-defeating. Assume that the standards are more stringent and the radiated power of mobile phones is reduced. In order to ensure the quality of calls, communication companies need to build more and denser base stations. The radiated power of base stations is much larger than a single mobile phone, and the distance between users and base stations will be more Recently, the amount of radiation received may not only have not decreased, but increased. Moreover, the cost of building more base stations will be shared in our telephone bill.

    Mobile phone radiation is harmful to human health, and safety recommendations based on harmful assumptions are meaningless and even ridiculous. Stores that sell cellphone anti-radiation film are priced at ten yuan each. It is said that it can effectively reduce the radiation on the head after being affixed. The radio wave radiation of the mobile phone is omnidirectional, and it is not easy to control its radiation. In the scientific research, an electromagnetic shielding room with a cost of more than 100,000 yuan is usually used. A radiation protection film of 10 yuan is impossible to play any role. Taking a step back, assuming that the radiation is effectively attenuated, can we still make a phone call?

    Some experts suggest that you can use a Bluetooth headset to connect your phone to your waist to make a call. Keeping your phone 1 meter away from your brain can reduce more than half of the radiation, and even some can reduce 99%, although the radiation energy will increase with distance. Accelerated attenuation, but it will never reach this level, otherwise, can there be a signal at a distance of two or three meters from the mobile phone? Can the signal be transmitted to the base station several kilometers away? The fact is that no matter if you place your mobile phone near your head or your waist, the communication effect is the same, and there is basically no difference in the amount of radiation to your head. In addition, because you are afraid of radiating the mobile phone and hurting your brain, you place the mobile phone near your waist, so why not be afraid of hurting your kidney? The brain is good, and the skull is protecting it, which can play a certain shielding role, the kidney does not have it.

    The public's panic about radio wave radiation is a common phenomenon. It is the same at home and abroad. An American expert concluded on the basis of speculation and assumptions in 1979 that children living near high-voltage lines may have the risk of developing leukemia due to radiation. This increase to three times the average has aroused widespread concern across the United States, and the United States has consumed up to $ 25 billion in social costs over the next 20 years. The National Academy of Sciences published the results of a three-year study in 1996, arguing that the high-voltage environment was not related to the incidence of leukemia. The National Cancer Institute published a similar conclusion in 1997 after seven years of research involving 1,200 people. In a lawsuit involving high-voltage lines and leukemia that attracted national attention, the court hired 16 top experts, including six Nobel Prize winners who received physics, pathology, biochemistry, and medicine, respectively. The conclusions they gave also The same high-voltage environment has nothing to do with the incidence of leukemia, and finally calmed down the farce. In fact, the expert who claims that the high-voltage line is more susceptible to leukemia, the statistics may be true, but there is no real cause-and-effect relationship. The mainstream view in academia believes that families living near the high-voltage line are usually poor, which leads to leukemia. The higher rate is due to its poor living and sanitary conditions, and has nothing to do with the high-voltage line itself.

    The penetration rate of mobile phones is very high. Even if some mobile phone users are found to have a brain tumor, it also indicates that it is caused by mobile phone radiation. For example, the annual incidence of brain tumors in the United States is about 6/100 00, and there are 6,000 mobile phone users in the United States. Cases of brain tumors are normal. Even after significantly exceeding 6000, it cannot be concluded that the incidence of brain tumors will increase the incidence of brain tumors. Similar to the example of high-voltage lines, people who frequently use mobile phones tend to work compared with people who do not use mobile phones. It is stressful with interpersonal relationships, fast-paced life, and more emotional tension, which may be caused by these factors and has nothing to do with the use of the mobile phone itself. Developed countries such as Europe, the United States, and Japan have conducted hundreds of statistical studies and found that the incidence of mobile phone users is not abnormal compared with non-mobile phone users, indicating that the possibility that "mobile phone radiation will increase the incidence of brain tumors" does not exist. .

    The public in China has a very interesting view on electromagnetic radiation. It is generally believed that radio wave radiation is harmful to the human body, but magnetic field radiation is beneficial to the human body. Magnetized cups, magnetic therapy pants, magnetic therapy pillows, magnetic therapy slippers and other so-called health products Very common in the market. The claim that magnetic fields are beneficial to the human body is also baseless. Fang Zhouzi once wrote "Can magnetic therapy really cure diseases?" ", Thoroughly analyzed and exposed the magnetic therapy scam. CCTV's 3.15 party in 2009 also revealed this scam. For this scam that has been around for many years, it can only be said that the voice of the authoritative media is too late. Recognizing the magnetic therapy scam does not require much deep expertise. It can be done only by questioning spirit and common sense. Many docks and factories have magnetic hoisting machines. When the hoisting machine is powered on, it generates strong magnetic force and can weigh up to tons. The iron plates and containers are sucked up. Hoisting workers work in such a strong magnetic environment all year round. The radiated magnetic strength is tens of thousands of times that of magnetic therapy products. It has never caused any health problems because of this. Could a small magnet be useful?

    During the period of resistance to the United States and aid of the DPRK, a 10-watt radio station in Zhongnanhai could talk to Pyongyang. If such a radio station is used, it may not reach even 30 kilometers, because the number and power of wireless devices have increased rapidly in recent decades.

    Carcinogenic

    A large study on the relationship between the use of mobile phones and cancer released its findings this week, but the interpretation of the research results by different media is quite different.

    The British "Daily Telegraph" believes that the study "found that people who use cell phones for more than one and a half hours a day for 10 years are more likely to develop brain cancer." For the same research report, the French news agency AFP said that the study showed "there is a clear link between the use of mobile phones and brain cancer."

    British Nature staff reviewed the controversial research report.

    What kind of research is this? I haven't heard it before?

    The research is an international collaborative study called I NTERPHONE, conducted by the International Agency for Research on Cancer, a member of the World Health Organization (WHO) in Lyon, France. This is a case control study in which researchers interview people with various types of cancer and ask about their cell phone usage. It was compared with data obtained from interviews with similar people who did not have the cancer.

    Mobile phones emit low-level wireless electromagnetic waves, and people are concerned about whether they will affect health. This study hopes to confirm whether using mobile phones increases the risk of two types of brain cancer, which are gliomas (glioma ) And meningioma. The study involved 2,708 patients with gliomas and 7,658 patients with meningioma, and 7,658 controls.

    The study involved 13 countries, some of which have previously been published, but the latest paper published in the International Journal of Epidemiology is the first to integrate the findings of all 13 countries. The research received funding from some mobile phone companies, but the INTERPHONE project has complete scientific independence, which can guarantee the scientific rigor of this research.

    What did the study find?

    Unfortunately, the results of the study did not give very straightforward conclusions. The study said, "Overall, no signs of increased use of mobile phones have been found to increase the risk of gliomas and meningiomas."

    Regular cell phone use actually seems to reduce the risk of cancer. But the 10% of those who used their mobile phones for the longest time seemed to be 40% more likely to develop gliomas. However, the study states that there are reasons to suspect this apparent association.

    So can using a mobile phone protect us from cancer or make us carcinogenic?

    The study found that the average mobile phone user s risk of developing gliomas and meningioma appears to have dropped by about 20%, but Anthony Swerdlow, an epidemiologist at the London Cancer Institute in the UK who participated in the study, said the study itself Design issues are likely to affect research results. He said that there is evidence that those who refuse to serve as the control group are those who do not use mobile phones, which indicates that when selecting people in the control group without cancer, the number of people who use mobile phones is relatively large, and the proportion is skewed. In the actual population, people without cancer should have more talented people who do not use mobile phones. "The proportion of people using mobile phones in the control group is too high."

    Similarly, Swerdlow finds that among the 10% of people who use their mobile phones for the longest time, some people report that the use of mobile phones is "unbelievable", such as using mobile phones for 12 hours a day.

    A study of the effectiveness of the data collection methods used by the INTERP HO NE project found that asking participants how many calls they made was more accurate than asking them how long they used their mobile phones. When using phone calls for analysis, the top 10% showed no signs of increased cancer risk.

    What did you find from previous research?

    Some animal and cell studies have clearly shown an increased risk of cancer after cell phone radiation, but these findings are difficult to replicate.

    Patricia McKinney, an epidemiologist at the University of Leeds who participated in the British branch of the INTERP HONE project, believes that "in general, biological and cellular tests are not convincing because there is no consistent evidence or can explain the mechanism by which this happens".

    Human studies should say that there is no link between cell phone use and cancer. Swerdlow said a Swedish team found that cell phone use increased the risk of cancer, but he also said that it was "outliers in the data."

    In addition, although mobile phones have become ubiquitous, the total number of brain tumor reports that have been counted has not increased since the phones were first used.

    The question remains unanswered?

    This is undoubtedly the case, and even the researchers involved in the project have not fully agreed on the significance of their work. Some researchers have clearly suggested that cell phones should be used with caution and that people should restrict their use.

    McKinney said, "We haven't reached a complete conclusion. We feel that we are on the side of most people who think that mobile phones are not risky."

    In addition, INTERP HONE only investigated the use of mobile phones by adults, and could not provide any information on whether children use mobile phones are at risk. Whether children use mobile phones poses risks is a more controversial topic.

    Similarly, due to the time limit of the study, the study did not provide any data on whether the use of mobile phones for more than 15 years would bring risks. The study stated that "the possible effects of frequent use of mobile phones for a long time require more research."

    So what is the causal relationship between mobile phone use and cancer?

    No connection has been established.

    Swerdlow said, "Evaluating whether the epidemiological survey reflects causality has a unified evaluation standard. The results of this study failed to meet this evaluation standard and did not show whether there was a causality" ^[11]

    Regarding the idea that "mobile phone radiation will increase the chance of developing brain tumors", some oncologists said that there is no relevant scientific basis for this conclusion.
    Park Hao-zhe, deputy director, chief physician and director of neurosurgery of Liaoning Cancer Hospital, said that glioma is a common intracranial tumor. Compared with other intracranial tumors, the incidence of glioma is not particularly prominent. Clinically, there have been cases of gliomas receiving radiation therapy, and experiments have shown that short-term concentrated radiation exposure can induce brain tumors, but this does not mean that long-term radiation by mobile phones can cause brain tumors. On the one hand, the radiation of mobile phones is not radiation, but microwaves, and the human body receiving microwaves can only cause thermal effects such as burns locally, and cannot produce the consequences after being irradiated by radiation.
    In addition, the value of cell phone radiation is very small, and the radiation to induce brain tumors is concentrated and large.
    According to Park Hao Zhe, some foreign institutions have conducted surveys on 30,000 people, mainly studying the relationship between cell phone radiation and brain tumors. The results of the investigation showed that the occurrence of brain tumors has nothing to do with mobile phone radiation, and the claim that exposure to mobile phone radiation increases the risk of brain tumors is not scientifically based.
    Park Hao-chek believes that from the results of surveys on the health effects of mobile phone radiation at home and abroad, it is safe for people to use mobile phones in contact with mobile phone radiation.
    With the development of mobile phone production technology, the radiation generated by the use of mobile phones will become smaller and smaller, and in life, people are exposed to radiation from the surrounding environment anytime, anywhere, and mobile phone radiation appears insignificant. Therefore, Park Hao-che believes that there is no need to worry too much about the harm of mobile phone radiation, and the health impact of mobile phone radiation is very limited.

    Regarding the statement that "mobile phone radiation has a greater impact on children", Park Hao-che believes that it is possible that children are more sensitive to mobile phone radiation based on the consideration that children's skulls are thinner than adults and are not completely closed.
    Whether it is an adult or a child, exposure to mobile phone radiation can only cause local thermal effects at most, because the radiation value is very small and cannot reach the ability to penetrate the brain. Park Hao-che reminded that it is necessary to use mobile phones sparingly, such as not using mobile phones for a long time, especially children, and not leaving mobile phones by your side while sleeping.

    With the rapid development of society, mobile communication electromagnetic radiation has gradually become the focus of public opinion. The public's doubts and concerns about electromagnetic radiation continue to appear on the Internet and the media. Relevant Chinese government agencies and mobile communication operators are actively carrying out electromagnetic radiation management, standard formulation and daily monitoring, and gradually opening up new channels for communication with the public to protect the public's health and right to know.

    Many people have many misunderstandings when using mobile phones. For example, they always like to walk around when they are using mobile phones, and answer calls in the corner. Frequently moving the location will cause the strength of the mobile phone signal to fluctuate, and the mobile phone is always transmitting radio waves to the transmitting station, increasing the radiation of the mobile phone. When using a mobile phone in a corner, the signal is poor, which will increase the power of the mobile phone and increase the radiation intensity. For the same reason, using a mobile phone in a small, closed environment such as an elevator will also increase its radiation intensity. ^[12]

    So far, scientists have different views on the long-term effects of mobile phones on humans, especially the human brain. Scientists in Sweden and Germany have said that radiation from mobile phones may heat up human tissues, increasing the risk of brain tumors among users. The UK's National Radiation Protection Board released a report last month that more and more test results have proved that the use of mobile phones may cause harm to human health. Therefore, taking "preventive measures" is a wise choice for users, especially children under 16 years of age who have not yet fully developed their brains.

    Because there is no unified method and procedure for measuring the radiant energy of mobile phones in the world so far, the measurement results of various manufacturers do not recognize each other, users are at a loss, and they do not know whether their mobile phones are dangerous. This standard developed by the International Electrotechnical Commission addresses these two issues. However, there is no specific standard for the amount of radiation ("radiation absorption ratio") in this standard. ^[13]

    Will cell phone radiation cause cancer?

    For now, the possibilities are very low.

    First of all, two concepts need to be clarified here, ionizing radiation and non-ionizing radiation. It is also electromagnetic radiation. The difference between the two is the intensity of the radiation and whether it can produce ionization (that is, release one or several electrons from atoms, molecules or other bound states).

    Radiation energy is strong, and can produce ionizing radiation, which is ionizing radiation; otherwise, it is non-ionizing radiation.

    Ionizing radiation: direct damage to DNA, risk of carcinogenesis

    Including the following 3 types:

    Nuclear radiation: Atomic bombings, nuclear leaks in Japan's Fukushima and the former Soviet Union can cause large-scale nuclear radiation.

    Medical instruments: CT, enhanced CT (PET-CT), and X-ray are all sources of ionizing radiation. Therefore, it is highly not recommended that non-high-risk groups do CT or enhanced CT every year for anti-cancer physical examination.

    Natural radioactive sources: There are many natural radioactive elements in nature. They are widely found in stones, soil and air. Therefore, it is recommended to buy marble flooring through formal channels. If conditions permit, it is best to test it to ensure safety.

    Non-ionizing radiation: not enough to cause genetic mutations and not cause cancer

    The electromagnetic radiation generated by the mobile phones, televisions, computers, microwave ovens, routers, satellite receivers, etc. that we are in daily contact with are all non-ionizing radiation. So far, there is not enough effective evidence to prove that non-ionizing radiation common in life can cause cancer.

    Whether it is a "brush party" who puts a cell phone next to a pillow, a housewife who uses a microwave oven to heat meals, or a worker who is in close contact with a transmission tower, their cancer risk will not increase significantly.

    In 2011, the World Health Organization classified mobile phone electromagnetic radiation as a "2B" carcinogen, but the "2B" carcinogen means "limited evidence of carcinogenicity to humans and insufficient evidence of carcinogenicity to experimental animals; or There is insufficient evidence for carcinogenicity in humans and sufficient evidence for carcinogenicity in laboratory animals. "

    In other words, for human beings, putting a mobile phone by the pillow while sleeping may only cause cancer. Exactly how likely this is, we need follow-up observations, and there is no need to be too panic.

    Is there a health hazard when the phone is placed on the pillow?

    Have.

    Having said that, although the consequences of putting a mobile phone on the pillow are not as severe as we think, Chunyujun still recommends that electronic products such as mobile phones and Ipads be far away from themselves before going to bed. The reason is that being able to touch the mobile phone at your fingertips can make you indulge and fall asleep, which leads to insomnia and lack of sleep, which affects the next day's work or study efficiency, and also adversely affects health.

    If you stare at the screen for a long time, you may be prone to dry eyes and fatigue. If you play with your phone for a long time in the dark, you may also increase the risk of glaucoma.