- Does EMF have immediate adverse effects on our health?
- When a person is exposed to EMF, the electrical component does not penetrate into the body, while magnetic component does. This magnetic field is capable of inducing electric field and currents inside the body. When a person is exposed to EMF several hundred times stronger than the EMF in an ordinary living environment, the EMF may have effects that disturb the functions of important organs and systems, such as nerves, muscles or heart.
In addition, EMF of approximately 100 kHz or higher frequencies could have thermal action that changes the body physiological activity.
- Do even weak EMFs accumulate in our body when exposed for a long time?
- In general, electromagnetic waves, such as gamma rays, X-rays, and other radioactive rays, accumulate in the human body. It is said, however, that extremely low frequency (ELF) EMF, such as 50 and 60 Hz generated from power utilities and high frequency EMF (radio waves) used for telecommunications, do not accumulate.
☆ WHO Fact Sheet 182 - Physical Properties and Effects on Biological Systems.(Backgrounder June 2007)
- If we live under transmission lines for a long time, does it adversely affect our health?
- It is thought that the electric field component of EMF generated from transmission lines does not adversely affect human health. Some epidemiological studies reported that if children are continuously exposed to a magnetic field averaging 0.4 μT or stronger, the incidence of childhood leukaemia could double. However, biological research has not indicated any repeatable results of such an adverse effect.
Based on these results, WHO Fact Sheet 322 (Exposure to extremely low frequency fields) states: " Thus, on balance, the evidence related to childhood leukaemia is not strong enough to be considered causal….. A number of other adverse health effects have been studied for possible association with ELF magnetic field exposure. These include other childhood cancers, cancers in adults, depression, suicide, cardiovascular disorders, reproductive dysfunction, developmental disorders, immunological modifications, neurobehavioral effects and neurodegenerative disease. The WHO Task Group concluded that scientific evidence supporting an association between ELF magnetic field exposure and all of these health effects is much weaker than for childhood leukaemia."
- I plan to buy a house near transmission lines? Is this OK?
- The intensity of a magnetic field is up to 20 μT at one meter above the ground directly beneath transmission and distribution lines and up to 4 μT or so on the border between the premises of a substation and ordinary land. No short-term magnetic field effects are anticipated because these values are smaller than the values stipulated in the guidelines for limiting exposure to electromagnetic fields (100 μT for 50 Hz frequency and 83 μT for 60 Hz frequency) from the International Commission on Non-Ionizing Radiation Protection (ICNIRP).
Living under such a place for a long time, however, you need to consider probable health effects from a long-term viewpoint.
According to WHO Fact Sheet 322 (Exposure to extremely low frequency fields) published in June 2007, data pooled for epidemiological studies indicate a consistent pattern that log-term exposure to ULF magnetic fields exceeding 0.3 to 0.4 μT would double the incidence of childhood leukaemia. However, the fact sheet concludes that no strong causal relation is suggested since the survey method had problems-the survey objects were biased; there was no biophysical mechanism; and most of the animal studies indicated no effects.
Furthermore, Fact Sheet 322 concludes that although much research was conducted on childhood cancers other than childhood leukaemia, adult cancers, depression, suicide, cardiovascular disorders, reproductive dysfunctions, developmental disorders, immunological modification, neurobehavioral effects, and neurodegenerative disorders, scientific evidence supporting an association between ELF magnetic field exposure and all of these health effects is much weaker than for childhood leukaemia.
This still does not mean that health effects from long-term exposure have been completely disproved. In science, proving that no health effects exist is theoretically impossible, but you can read the WHO's conclusion mentioned above as that health effects are extremely low.
☆ Download PDF file of WHO Fact Sheet 322 (Exposure to extremely low frequency fields).(Backgrounder June 2007)
☆ Download PDF file of WHO Environmental Health Criteria No. 238 (Extremely Low Frequency Fields).
- Do EMFs generated from PCs and TVs affect reproduction or foetuses? Is there any relation between such devices and eye problems?
- WHO Fact Sheet 201 (Video Display Units (VDUs) and Human Health) published in July 1998 concludes: "These studies have failed to demonstrate any effects on reproductive process due to EMF emitted from VDUs. Cataracts and other eye diseases were not found to have any link with VDU work."
⇒ Reference document:
☆ Download PDF file of WHO Fact Sheet 201 (Video Display Units (VDUs) and Human Health).(Backgrounder May 2006)
- Does an IH stove adversely affect people nearby?
- Besides 50 and 60 Hz EMF (ELF) generated from the power supply circuit of the IH stove, electric current is also flowing on the coil that generates 20 to 90 kHz intermediate frequency EMF to heat pots and pans for cooking. This frequency band range is suggested as 27 μT in the guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP).
IH stoves have rapidly become popular in recent years. Research data on intermediate frequency EMF being used for such stoves are limited, compared with those on low and high frequency EMF. Although further research is necessary, no research results have been reported so far that such intermediate frequency EMF adversely affects health.
A survey of measurements of 10 Hz to 400 kHz EMF generated from home electric appliances in 2007 in accordance with the international measurement standards (IEC 62233) by the Association for Electric Home Appliances, a foundation in Japan, indicates that the measurement results were lower than the limit values.
⇒ Reference document:
☆ Download PDF file of WHO Information Sheet (Intermediate Frequencies (IF)).
- Do microwave ovens adversely affect people nearby?
- A microwave oven generates 2.45 GHz EMF (micro wave) that is efficient for heating food products. When water molecules absorb microwave energy, they evaporate, resulting in heat for cooking. When the microwave oven is turned off, no microwave energy remains inside the oven or in the food product. It is important to know that microwave energy is heating the entire volume of the product, while in conventional cooking the heat goes from outside to inside.
Microwave energy absorbed in the human body generates heat within the organs. When an organ, like an eyeball, in which only a small quantity of blood is circulated and whose temperature control is weak, or when organs, like testicles, which are sensitive to temperature, are exposed to a very strong microwave, the organs may have heat damage. However, heat damage occurs only when the human body is exposed for a long time to EMF whose value is far higher than those in the surroundings of the microwave oven. In an ordinary usage environment, no person is exposed to such strong EMF. Hence, it is thought that EMF generated from microwave ovens used in homes do not effect health.
Microwave ovens are designed, without fail, to confine microwaves in the oven, generating microwaves only when the switch is on and the door closed.
☆ Download PDF file of WHO Information Sheet (Microwave Ovens).
- Does a base station for mobile phone adversely affect residents living nearby for a long time?
- WHO Fact Sheet No. 304 (Base stations and wireless technologies) states: "Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations cause adverse health effects."
Concerning effects of high frequency EMF (radio waves) on the human body, the Telecommunications Technology Council of Japan submitted a report in June 1990 on the "Guidelines for protecting the human body in using radio waves" and a report in April 1997 on "How to protect the human body in using radio waves" (collectively called the " Radiofrequency Radiation Protection Guidelines") to the Ministry of Internal Affairs and Communications. In response, the Ministry enacted the Enforcement Regulations of the Radio Law in October 1999 and the Wireless Facility Regulations in June 2002, introducing the Radiofrequency Radiation Protection Guidelines.
Telecommunications carriers are required to operate their base stations for mobile phones within the radio wave intensity defined in the standard values in accordance with the Radiofrequency Radiation Protection Guidelines. Shielding fences are also built around the antennas of base stations for mobile phones that exceed the standard value so that people are kept away.
The intensity of radio waves at a place some 200 m distant from a base station becomes 1/1,000 the intensity of the standard value.
☆ Download PDF file of WHO Fact Sheet No. 304 (Base stations and wireless technologies).(Backgrounder May 2006)
- Does the static magnetic field, generated from railways and the bullet train, adversely affect our health?
- You may experience a temporal sensation, such as dizziness, nausea, or magnetic phosphenes when you move around in a very strong static magnetic field. However, neither railways nor bullet trains generate such a strong static magnetic field. Hence, it is thought that the static magnetic field from railways and the bullet train does not affect human health.
The International Commission on Non-Ionizing Radiation Protection (ICNIRP) reviewed its Guidelines on Limits of Exposure to Static Magnetic Fields in March 2009. According to the guidelines, the exposure limit to the public is set to 400,000 μT (= 400 mT)
⇒ Reference document:
☆ Download PDF file of ICNIRP Fact Sheet (Guidelines on limits of exposure to static magnetic fields).
☆ Download PDF file of ICNIRP Guidelines (Guidelines on limits of exposure to static magnetic fields).
- I have heard that there is a causal relation between EMF and electromagnetic hypersensitivity (EHS). Is this true?
- WHO Fact Sheet No. 296 states in its conclusions: "EHS is characterized by a variety of non-specific symptoms that differ from individual to individual. The symptoms are certainly real and can vary widely in their severity. Whatever its cause, EHS can be a disabling problem for the affected individual. EHS has no clear diagnostic criteria and there is no scientific basis to link EHS symptoms to EMF exposure. Further, EHS is neither medical diagnosis, nor is it clear that it represents a single medical problem."
⇒ Reference document:
☆ Download PDF file of WHO Fact Sheet No. 296 (Electromagnetic Hypersensitivity).(Backgrounder December 2005)
- Are there any reports that show a causal connection between those who have occupational exposure to electromagnetic fields and disease?
- There is no such a report.
The international guideline value (ICNIRP) is 1,000μT for those who are engaged in maintenance of electric power equipment such as transmission lines. The survey of health effects in working environment was conducted long time ago, but there were no health effect.
The maintenance work near a broadcasting tower and antenna of mobile phone base station is done with stopping electric waves.
Doctors and nurses engaging in MRI diagnosis are exposed to fairly strong static magnetic fields. However, when work is done appropriately, the exposure amount up to 8 tesla (T) is acceptable.
Welding workers work with wrapping a code around their bodies. They are exposed to strong magnetic fields, as a large current flows through the code. However, no health effect has been reported according to the result of the labor environment survey.
- Does the electromagnetic wave produced by optical lines have any adverse effect on health?
- The optical lines transmit optical signals instead of electric signals. Types of light used for optical communication are infrared light to visible light which exist in nature. The output of light is very small and light does not leak from the cable.
- Does far-infrared ray emitted from heating appliances have any adverse effect on health?
- Infrared light is one type of electromagnetic waves as with sunlight. Far-infrared ray has a longer wavelength among red light and has an effect of reaching deep inside the body. You feel warm when you are exposed to far-infrared ray. This is the same reason why you feel warm when you are exposed to sunlight.
- When I use an optical mouse for PC, I sometimes feel uncomfortable with my hand. Is this an effect of electromagnetic waves?
- Optical mouse radiates infrared light. It has very high frequency and is within the range of optical waves. The cause of your uncomfortable feeling is not the effect of electromagnetic waves, but may be bodily heat stored in your hand as a result of holding a mouse for a prolonged time, or there may be other causes.
- Does infrared light emitted from remote controllers of television sets and others have any adverse effect on health?
- Remote controllers for TV sets and other equipment use infrared light, which is one type of electromagnetic waves. As its output is small and the effect is extremely weak, it does not have any adverse effect on health.
- Do electromagnetic fields of magnetic necklaces have any adverse effect on health?
- In 2006, the World Health Organization (WHO) released the risk evaluation report of static electromagnetic fields (Fact Sheet No.299 “Static Electric Fields and Magnetic fields”). The report says they could not classify it regarding cancer risk, because there were almost no results of epidemiological study.
☆ WHO Fact Sheet No.299 “Static Electric Fields and Magnetic fields” (Japanese translation) PDF file download
- Do electromagnetic fields of potential therapeutic devices have any adverse effect on health?
- In Japan, home medical devices including potential therapeutic devices are subject to a screening based on the medical device certification. When you use these devices for therapeutic purposes, you are exposed to electromagnetic fields. On the other hand, you obtain benefits from using them. In any case, please strictly observe contraindication/prohibition matters for the device specified by each manufacturer. For example, those with the cardiac pacemaker should be careful.
- Do electromagnetic fields of AC magnetic induction therapy apparatuses have any adverse effect on health?
- In Japan, magnetic induction therapy apparatuses are subject to the medical device approval screening based on the Pharmaceutical Affairs Act and the compliance inspection based on the Electrical Appliance and Material Safety Act. To use them safely and properly, please make sure to read instruction manual and do not do contraindication/prohibition matters.
In principle, the World Health Organization (WHO) does not conduct a risk assessment for medical purposes. Because, you use a therapeutic device with the purpose of using it, and you will benefit from doing so.
- Is the safety secured against exposure to radiation (electromagnetic waves in broader meaning) with medical testing equipment, such as MRI, CT, and X-ray?
- MRI and CT are used for diagnosis, and X-ray is used for diagnosis and treatment. CT equipment emits X-ray from all directions, and MRI equipment is diagnostic equipment using direct current magnetic fields. They are based on different principles. The World Health Organization (WHO) does not cover radiation and electromagnetic waves generated in medical practice. The reason is that you can choose whether you use them or not and which equipment to use. For example, CT has a benefit of detecting cancer, but has a risk of developing cancer. Whether you use it or not is your choice.
On the other hand, there are restrictions for working environment of healthcare professionals.
- Do electromagnetic fields of MRI (Magnetic Resonance Imaging) have any adverse effect on health?
- Electromagnetic fields generated by MRI are called static magnetic fields. It is said their strength is up to 2 to 3 tesla (T). The limit value for occupational exposure specified by the international guidelines for static magnetic fields (ICNIRP) is 2 tesla (T). Therefore, there are some cases in which the exposure exceeds this level.
However, this exposure is for medical practice, and MRI has a benefit of medical diagnosis. Therefore, it is not covered by the scope of health effect of WHO, as they consider that a benefit of assisting diagnosis offsets a possible risk of exposure to electromagnetic fields.
If a body of a patient moves in the static magnetic fields, the induced current flows through the body. This is similar to the situation of short-time effect of commercial frequency magnetic fields. Therefore, WHO recommends avoiding generation of induced current as much as possible by moving the patient’s body slowly.
- Do electrostatic fields and static magnetic fields have any adverse effect on health?
- Only one effect on the human body of electrostatic fields in normal living environment is discomfort associated with discharge phenomenon of a static electric shock when air is dry. On the other hand, it is not clear whether an exposure to static magnetic fields of a few millitesla (mT) has any adverse effect on health or not, as there is not the sufficient number of quality research. The guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) specify a limit of exposure for general public. The strength of magnetic fields is 400 millitesla. There is no chance of encountering such a strong magnetic field in normal living environment.
- I saw the article that said a librarian got sick in the library where the Electronic Article Surveillance (EAS) equipment is installed. Is it the effect of electromagnetic fields?
- We visited the library to have an interview about the incident. They said air-conditioning system had been turned off in the reception area of the library at the time of the incident. After they turned on air-conditioning system and improved circulation of air by installing a desk fun, the patient felt better.
- Do the electromagnetic waves (electric waves) radiated from Tokyo Skytree have any adverse effect on health?
- The electromagnetic waves (electric waves) from Tokyo Skytree are also regulated by the Radio Act based on the electric wave protection guidelines. The Fact Sheet No.304 “Base Stations and Wireless Technologies” released by the World Health Organization (WHO) concluded that there is no scientific basis for adverse effect on health by weak radio frequency from wireless networks, considering the investigation results collected in the past.
☆ Fact Sheet No.304 “Base Stations and Wireless Technologies” (Japanese translation) PDF file download
- Do the electromagnetic waves (electric waves) from an amateur radio tower have any adverse effect on health?
- In the Fact Sheet No.304 “Electromagnetic fields and Public Health: Base Stations and Wireless Technologies,” the World Health Organization (WHO) expresses their view that electric waves emitted from mobile phone base stations and radio communication do not have adverse effect on health.
☆ Fact Sheet No.304 “Base Stations and Wireless Technologies” (Japanese translation) PDF file download
- Does a TV tower give any adverse effect on health of those who are living near it?
- There were the reports that said broadcasting towers had adverse effect on health in Australia, Great Britain, Korea and Germany. However, the result of the recent reproductive experiment denied the effect.
- Many men put their mobile phones in the pants pocket. Does it have any adverse effect on health?
- The maximum output of a mobile phone is around 1W. This level of the output is not considered to give any thermal effect.
- I sometimes have headache or feel sick after I talked on the mobile phone for long a long time. Is it an effect of electromagnetic waves (electric waves)?
- There is no scientific basis for electromagnetic waves (electric waves) of mobile phones causing symptoms such as headache and sick.
While you use a mobile phone for a long time, the phone and your ear contact each other and your ear is pressed by the phone. Also, you get tired after listening with one ear for a long time. These conditions are considered to be a cause of the symptoms. The effect on the human body of high-frequency waves emitted from mobile phones is thermal effect, but it is not assumed to be a cause of discomfort. Rather, heat release is prevented when the mobile phone contacts your ear for long time and also heat is generated by the battery of mobile phone. These conditions are considered to bring about discomfort.
- Do the electromagnetic waves (electric waves) emitted from mobile phones and smart phones have any adverse effect on health?
- High-frequency electromagnetic waves (electric waves), which are used by mobile phones, have a health effect due to heat. To prevent it, international guidelines and electric wave protection guidelines are stipulated.
As to the relation between mobile phones and brain tumors, the largest epidemiological studies ever were conducted in many countries including Japan. According to the result of the international interphone studies in 2010, the increase in risk of glial tumors was not confirmed. The fact sheet of the World Health Organization (WHO) had the same conclusion.
On the other hand, the International Agency for Research on Cancer (IARC) classified it as Group 2B, “Probably carcinogenic to humans” in 2010. However, IARC evaluated only the possibility of carcinogenic property, and did not conduct other evaluations. Therefore, WHO plans to evaluate the health risk comprehensively, such as health effects other than cancer and dose-response relationship (whether the impact has increased depending on usage), in 2016.
- Do electromagnetic fields of all-electric home have any adverse effect on health? I am wondering whether I should use electricity or gas.
- An all-electric home is the home that uniformly uses electricity as energy used inside home for hot-water supply, cooking, heating and cooling, etc. If you use electricity, the magnetic fields are generated as with home electric appliances. We would suggest that you had better make a decision on which energy to use considering factors other than electromagnetic fields also, such as economy and safety.
- I use an electric blanket, carpet and sheet while sleeping. Do the electromagnetic fields of these have any adverse effect on health?
- If you worry, we would suggest you to warm up an electric blanket beforehand and turn off power just before going to bed for children. For adult, you need not take extra attention, because the proof that shows the relation between health effect and exposure to magnetic fields is weaker than that for childhood leukemia.
- Do the electromagnetic fields generated from home electric appliances have any adverse effect on health? What is a safe distance?
- There is no standard for safe distance. However, the strength of magnetic fields emitted from home electric appliances is sufficiently lower than the limit for exposure to magnetic fields provided by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) (200μT at frequency of 50Hz and 60Hz).
The strength of magnetic fields is proportional to the magnitude of electrical current and inversely proportional to the distance from the source (if the distance is doubled, the magnetic fields is four times smaller). Therefore, even if multiple home electric appliances are used in the normal living condition, the total exposure is not considered to exceed the limit for exposure to magnetic fields specified in the ICNIRP guidelines.
If you can’t help worrying, we have one suggestion. The more distance you keep from home electric appliances in use and their supply cables, the less you are exposed to magnetic fields.
- Do we need not worry about the effect of electromagnetic fields when electric transmission lines are buried in the ground?
- Even if electric transmission lines are buried in the ground, electromagnetic fields still exist. Because the underground transmission lines are buried with placing insulated cables closely each other, there is an effect of reducing magnetic fields. On the other hand, the distance between the cables and people on the ground is closer compared to when the transmission lines are overhead, and the magnetic fields increase. Therefore, we cannot really say whether the magnetic fields of buried transmission lines increase or decrease.
- I live surrounded by multiple home electric appliances. What is the comprehensive exposure to electromagnetic fields?
- The strength of magnetic fields generating from most home electric appliances is about a few percent of the values specified in the guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). When you use multiple appliances, you need to add this percent value to judge whether the sum exceeds 100% or not. The possibility that comprehensive exposure would exceed the values of the ICNIRP guidelines is considered to be extremely low.
- Does exposure to low-frequency magnetic fields for long time have any adverse effect on health other than childhood leukemia?
- According to the Fact Sheet No.322 “Exposure to extremely low frequency fields” released by World Health Organization (WHO) in June 2007, many studies were made about the effect of extremely low frequency fields on childhood cancer other than childhood leukemia, cancer of adult, depression, suicide, heart and vascular diseases, reproductive dysfunction, developmental anomaly, immunologic variation and neurobehavior, as well as heurodegenerative disease. However, any proofs to show a causal relation between exposure to magnetic fields and development of disease are weaker than that for childhood leukemia. This does not mean that the effect of long-term exposure on health is completely denied (in the world of science, it is theoretically impossible to prove that there is completely no effect on health), but we can interpret that the possibility of adverse effect on health is extremely low.
☆ Fact Sheet No.322 “Exposure to extremely low frequency fields” (Japanese translation) PDF file download
- I have heard that the birth rate of girl increases if we are exposed to low-frequency electromagnetic fields for a long time. Is that true?
- There are some studies of laboratory animals to investigate sex distribution at birth depending on a level of exposure to electromagnetic fields to understand the effect on reproduction. No difference in sex distribution was found. There is almost no study on human.
- I have heard that childhood leukemia may develop as a result of exposure to low-frequency magnetic fields for a long time. Is that true?
- According to the Fact Sheet No.322 “Exposure to extremely low frequency fields” released by World Health Organization (WHO) in June 2007, the analysis based on pooled data of multiple epidemiology studies shows a consistent pattern that developing childhood leukemia were doubled due to long-term exposure to extremely low frequency magnetic fields exceeding 0.3 to 0.4 microtesla (μT). However, the fact sheet concluded that it was not so strong as to be regarded as a causal relation as a whole for the following reasons: there were problems with the research method such as a bias of survey samples; there is no biological mechanism; most of the studies of animals did not show the existence of effect.
☆ Fact Sheet No.322 “Exposure to extremely low frequency fields” (Japanese translation) PDF file download
- If low frequency magnetic fields have a nervous stimulating effect, don’t they have any adverse effect on health?
- It is impossible for science to prove “perfect safety” in general terms, the guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) determines a guideline value of 200 microtesla (μT) with five-time reduction coefficient from the borderline threshold to develop flash light, when considering magnetic flash light that is the most sensitive reaction of nerve stimulation. The level of magnetic fields to which we are exposed in normal living environment is several tenths to several hundredth times smaller than that. Therefore, even if there are a lot of external magnetic fields, which are far smaller than the threshold, they are not likely to cause nervous stimulation from an electrophysiology point of view.
- If we are exposed to very strong low frequency magnetic fields, what kind of symptoms do we experience?
- Intrinsically, our bodies are carrying an electric current generated by physiological nervous activity and muscle movement. When we are exposed to very strong low frequency magnetic fields (50Hz, 60Hz) of 1,000 microtesla(μT) or more, magnetophosphene phenomenon occurs. When it occurs, we feel light around our eyes. The phenomenon itself does not have any direct health effect on human. However, as we feel uncomfortable when it occurs, it serves as a basis for the exposure protection guidelines in the sense of avoiding the phenomenon.
- Do we need not consider health effect of electric fields?
- Effect of electric fields on the human body has been studied since fifties. As a result, the World Health Organization (WHO) concluded that there is no essential health problem with extremely low frequency electric fields if they are at the level general public encounter normally.
- Which has more adverse effect on our health in the low frequency electromagnetic fields, electric fields or magnetic fields?
- If a very strong electric field exists, human detect it and feel discomfort. However, as the electric field itself is shielded on the surface of living body and does not enter into the body (the case of induced current caused by electric fields is excepted), it gradually lost researchers’ attentions as a research object. Therefore, explanations about the strength of low frequency electromagnetic fields and the health effect on the human body are about the magnetic field.
The exposure protection guidelines for electric fields are stipulated in order to prevent discomfort and effect of the current induced by the electric fields as well as the magnetic fields.
- I would like to know what I should bear in mind when building a new house in order to prevent electromagnetic fields from giving adverse effects on health.
- We need not pay extra attention to electromagnetic fields that exist in living environment.
However, if you want to reduce the effect of electromagnetic fields because you can not dispel concerns about them, one effective way is not to place a bed of child near the house wiring so as to reduce a risk of exposure to magnetic fields from house wiring. Another option is to warm up an electric blanket beforehand and turn off the power just before going to bed.
- I am concerned about the fact that they conclude there is no effect of electromagnetic fields on health even though medical science is in the process of developing.
- There is no perfect score in science. Because we need to confirm we do not made a wrong judgment when evaluating a risk, we carefully judge whether there is a causal relation between exposure to electromagnetic fields and health effect based on nine standards called Bradford-Hill criteria.
Of course, science is not perfect and there may be new discoveries in the future. In such cases, we are to evaluate a risk to make a judgment.
- When I attended the lecture sessions on electromagnetic fields, etc., I heard that some country recognized that electromagnetic fields were harmful. Is that true?
- There is no such a case in which any government including the government of Japan announced formally that electromagnetic fields we are exposed to in normal living environment have adverse effect on health. The World Health Organization has the same view.
- I saw books that said electromagnetic fields have adverse effect on human body. Is that true?
- Studies of electromagnetic fields had various results: some say electromagnetic fields are harmful to the human body and some say not. International organizations, such as the World Health Organization, verify these results from various viewpoints, and evaluate whether they are harmful or not.
On the other hand, there are some books that tend to create a story connecting opinions that electromagnetic fields are dangerous. Based on the detailed review of scientific papers that was conducted recently, WHO concluded that they could not confirm health effect of exposure to low-level electromagnetic fields based on the proofs they currently have.
- I have heard that electromagnetic fields have an adverse effect on the heart. Is that true?
- If you do not have any artificial organ, including a cardiac pacemaker, in your body, you have no problem in normal living environment.
- I have heard that electromagnetic fields give an adverse effect on cells when they pass through a gene of the cell. Is that true?
- Among electromagnetic fields, ultraviolet ray, X-ray and γ-ray, which are ionizing radiation and have higher frequencies than light ray, may destroy cells when passing through the cells. Therefore, they are used in the extremely strict control system.
However, electromagnetic fields do not have such strong energy as to destroy cells even if they pass through the cells.
- Why the health effect of electromagnetic fields is evaluated by frequency level?
- Because actions of electromagnetic fields on the living body are classified into two types depending on frequency level of electromagnetic fields. Dividing point is around 100 kilohertz (kHz). Dominating action of each type are:
・Less than 100 kilohertz (kHz): mainly stimulating action due to the generation of induced current
・More than 100 kilohertz: mainly thermal action
- I have heard that children’s use of cellular phones is restricted in foreign countries.
- There is a movement toward restriction of children’s use of cellular phones in Europe. It is not because of the existence of risk. It is just a precautionary measure. While the use of mobile phone is safe for children, it is not clear whether it would present a risk after a long time use at the current stage.