What is a battery EMF

Potential health effects from exposure to electromagnetic fields 2015 update

context - An electromagnetic field (EMF) is a physical field that is generated by stationary, rotating or moving electrically charged particles. EMFs occur naturally, but they are also a by-product of electrical devices and new technologies.

The ubiquity of these new technologies (including laptops, cell phones, induction hobs and WiFi) has raised concerns about how exposure to EMF could affect our health.

Latest update: September 8, 2009

1. Introductory explanations on electromagnetic fields

1.1 The term "electromagnetic field" (EMF) is often used as a generic term; actually encompassing, however, quite different frequency ranges, which differ considerably in terms of both physical and biological aspects. EMF include static magnetic fields (SMF) and static electric fields (SEF), extremely low frequency (ELF), 1Hz - 300Hz, and intermediate frequency (IF) electric fields ( EF) and magnetic fields (MF), 300Hz - 100kHz, as well as electromagnetic fields of the radio frequency (English: RF - radio frequency), 100kHz - 300GHz.

Up to the RF (radio frequency) range, electric and magnetic fields can be viewed independently of one another, while in the RF range they are firmly coupled to one another like chain links.

In the ELF range, EF and MF can stimulate nerve and muscle cells, whereas in the RF range, energy absorption (heating) is responsible for possible biological effects. The intermediate frequency range is characterized by the fact that the cell stimulation effect diminishes while the heating is not yet effective. Static MF, static EF, MF and EMF can be of natural origin, such as the static magnetic field of the earth or static electric fields caused by friction (which can be observed when stripping off clothing, which generates the smallest electrical surges). Lightning strikes generate broadband electromagnetic fields that extend from the low frequency range (NF range) to the RF range. The activity of the sun is an important natural source of high frequency electromagnetic fields.

The technical use of electricity mainly causes sinusoidal alternating fields, which occur in the LF range (e.g. railways, household appliances, power lines), in the intermediate frequency range (e.g. energy-saving lamps, electronic monitoring of department store items and in the RF range (e.g. transmission antennas, mobile telecommunications devices, Microwave ovens) can be generated.

Static magnetic fields of technical origin are created by permanent magnets in magnetic clips or other closures, e.g. B. in necklaces, underwear, handbags or holders use, or by electrical direct current in battery-operated devices. Extremely strong static magnetic fields are used in some workplaces and in magnetic resonance imaging (MRI) in medicine. More...

1.2 The present SCENIHR report assessed the latest scientific studies in order to assess whether exposure to EMF can induce harmful effects. It takes into account all approaches from laboratory tests carried out on subjects, animals (including lifelong exposure over several generations), tissue and cell cultures, as well as epidemiological studies with parts of the population exposed to EMF in daily life by comparing cases with control groups (case-control studies) or by analyzing the health of population groups (cohort studies). More...

1.3 In the preparatory phase of its opinion, SCENIHR carried out public consultations by making the preliminary opinion available on the Internet for comments and contributions from February 4 to April 16, 2014. In addition, a public hearing was held in Athens on March 27, 2014, which was attended by 57 organizations. As a result of the public consultation, 186 comments on various chapters of the opinion were submitted and carefully considered in the revision of the draft opinion. More...

2. What are the sources of exposure to radio frequency fields?


Wireless local area computer networks use radio frequency fields
Photo credit: Ramzi Mashisho

Radio or radio frequency (RF) fields range from 100 kHz to 300 GHz. In today's society, they have many uses. Well-known sources include radar, television and radio transmitting antennas, various radio services and telecommunications services, as well as devices such as microwave ovens or portable devices such as cell phones or tablets.

Since the field strength decreases rapidly with increasing distance from the source, devices worn close to the body are characterized by very inhomogeneous fields to which only a limited part of the body is exposed. However, fields from more distant sources are almost homogeneous and therefore lead to whole-body exposure. As a result, existing regulations limit both local and whole-body exposure. Among the many sources, radio transmitters in close proximity or directly on the body have become the main source of exposure for many people. For brain tissue in particular, the cell phone used on the ear remains the main source of exposure. However, since the first generation of cell phones, the technology aimed to reduce the transmission power of cell phones through various methods. In addition, hands-free systems significantly reduce the energy absorbed by the head. More...

2.1 For handheld cell phones, RF exposure is mostly limited to the region of the body that is closest to the antenna. Cordless telephones They also emit radio waves, but because the base stations are closer to the handsets, they are much weaker. The same applies wireless computer networks (WLAN)More...

2.2 In order to be able to work effectively, antennas radiate from Cellular antenna locations and Transmission towers in characteristic spatial patterns. As a result, the distance measured in the vicinity of the antenna is an unsuitable equivalent for the exposure height. More...

2.3 In the medicine the EMF used are strong enough to produce a stimulating or healing effect for diagnosis and therapy. More...

2.4 The European Union has also recommended safety limits for exposure to RF fields. For hand-held cell phones, these limit values ​​are specified with regard to the specific energy absorption rate for both local, i.e. partial, and whole-body exposure. Today's telephones emit much less energy than the recommended limit value. Other wireless devices that are used indoors, such as cordless phones and wireless computer networks, also generate radio waves, but exposure from these sources is generally lower than that from cell phones. For antennas that transmit radio signals, most people are only exposed to a very small fraction of the recommended limit because the field strength decreases sharply with increasing distance. More...

3. Can cell phones cause cancer?


There are more than 7 billion cell phones in use in the world.
Photo credit: Juha Blomberg

3.1 In recent years, many studies using different scientific approaches have investigated whether radio or radio frequency (RF) fields, particularly those from cell phones, could cause cancer.

Epidemiological studies of cell phone users have focused on cancer of the head and neck area because these tissues are most exposed to the RF fields emitted by handsets. So far, most of the studies available do not show an increased risk of brain tumors. In addition, they do not indicate an increased risk of other cancers of the head and neck area.

Some studies raised questions about an increased risk for heavy cell phone users of some specific tumors (glioma and acoustic tumor). Other recent epidemiological studies did not confirm such an association. Furthermore, data from cancer registries in some countries do not give any indications of an increase in these brain tumors since the introduction and massive use of cell phones and deny this assumption.

Epidemiological studies do not indicate an increased risk of other malignant diseases, including cancers in children. More...

3.2 Further evidence of the absence of a carcinogenic effect was provided by a large number of adequately conducted experimental studies that examined whether radio frequency fields could cause cancer. More...

3.3 Studies assessing the harmful potential of radio frequency fields have not confirmed such an effect. Other possible endpoints were also explored, such as cell death, gene expression, or cell proliferation; however, most of the investigations did not discover any effects. More...

4. Can cell phones or base stations trigger headaches or other health effects?


Cellular antennas
Photo credit: Pyb

4.1 Some people attribute non-specific health symptoms such as headache, fatigue and dizziness to radio frequency (RF) fields. Such complaints have raised concerns that certain individuals are much more sensitive to EMF than others. This is a phenomenon called "Idiopathic Environmental Intolerance to Electromagnetic Fields" (IEI-EMF), also known as "Electromagnetic Hypersensitivity". Studies carried out since the previous report in 2009 reinforce the conclusion at the time that there is no evidence that EMF exposure via mobile phones is causally related to these symptoms.

Instead, current evidence suggests that there may be a nocebo effect (negative placebo effect); H. Effects can be based on the sheer belief that something is harmful than the alleged cause itself. There is actually no scientific evidence that people - be it so-called sensitive groups or healthy control groups - are able to perceive radio frequency fields better than one is might expect by accident. More...

4.2 Because cell phones are used near the head, there are concerns that they could affect the brain. There is evidence that radio frequency exposure may have a weak impact on brain activity, sleep, learning, memory and behavior, but there is still no evidence of health relevance. However, the present results deserve further research on the subject. More...

4.3 Based on recent studies in humans and animals, the new SCENIHR opinion concluded that radio frequency fields do not have adverse effects on reproduction and development as long as exposure does not generate heat. More...

4.4 The only epidemiological study that looked at cell phone use and brain tumors in children and adolescents showed no association.

There is still no substantiated evidence of any other health impact. More...

5. Conclusions on cell phones and radio frequency fields


Few studies have looked at the effects on children

Extensive research has been carried out in recent years into how the radio frequency fields generated by cell phones could affect human health. There have been many different scientific approaches such as laboratory tests on cells, tissues, animals and human volunteers, as well as epidemiological studies in the population.

Overall, the epidemiological studies on EMF exposure from radio frequencies used by mobile phones did not show an increased risk of brain tumors.In addition, they do not indicate an increased risk of other cancers of the head and neck area, neither in adults nor in children.

Research has found no evidence that exposure to radio frequency fields below existing safety limits could cause self-reported non-specific symptoms such as headache and dizziness. Current findings tend to suggest that there is a nocebo effect (negative placebo effect); H. Rather, effects can be based on the sheer belief that something is harmful than on the alleged cause itself.

Some studies have looked at potential health effects in children to explain the increasing popularity of cell phones among adolescents and to raise concerns that children may be more vulnerable to EMF. No adverse effects on reproduction and development were found. More...

6. Intermediate frequency (IF) fields, for example from induction furnaces


CRT screens generate fields in the medium frequency range
Photo credit: Anissa Thompson

6.1 "Intermediate frequencies" range from 300 Hz to 100 kHz. These are lower than radio frequencies and higher than extremely low frequencies such as those from electrical power supplies. The term intermediate frequency range comes from the fact that it lies on the border of the ranges of two known interaction mechanisms. It is characterized by the fact that the cell stimulation effect decreases while the heating is not yet effective. Technologies that generate intermediate frequency fields have become more numerous in recent years; these include Induction ovens and induction chargers. IF fields are also used by medical devices and are generated by industrial processes, e.g. B. welding generated. More...

6.2 Recognized biological effects in the lower ZF range are nerve stimulation and at the upper end of the ZF range, energy absorption. Little data are available on the exposure of individuals to IF fields. There are few specific studies on this. No epidemiological studies have been carried out. With regard to the expected increase in occupational IF exposure, SCENIHR recommends more experimental studies on biomarkers and health effects in workers. More...

7. Extremely low frequency (ELF) fields, for example from power lines and household appliances


High voltage lines generate fields in the low frequency range
Photo credit: Miguel Saavedra

7.1 Extreme low-frequency (ELF) magnetic fields and electric fields are those below 300 Hz. Extreme low-frequency (ELF) magnetic fields occur, for example, with alternating current (AC) in high-voltage lines, cables and household appliances. Other important sources of ELF magnetic fields are transformers, welders, and trains. ELF electric fields are particularly strong in the vicinity of high-voltage overhead lines. The field strengths of both ELF magnetic fields and ELF electric fields decrease rapidly with distance from the source. This means that devices close to the body cause inhomogeneous fields and thus only partial exposure of the body, while sources that are further away such as overhead lines generate almost homogeneous fields and consequently the entire body is exposed to them. More...

7.2 In areas that are open to the public, exposure to ELF fields is below the existing limit value. Directly under a high-voltage line, for example, the strength of the electric field can reach close to the safety limit value without exceeding it, whereas the magnetic fields do not reach the limit values ​​for a long time.

At home, both electric and magnetic fields are strongest in the vicinity of electrical appliances; the strongest magnetic fields are found right next to kitchen machines and drills. More...

7.3 The latest studies confirm earlier results of a statistical link between childhood leukemia and magnetic fields, e.g. B. of high-voltage lines. The interpretation of these reports remains difficult, however, because no mechanisms have been found that could explain these results. Also, the epidemiological evidence is not supported by other scientific approaches or approaches such as in vivo or in vitro Laboratory tests supported.

The association with childhood leukemia remains a single result because epidemiological studies of other cancers in children or adults do not show a consistent association with any other cancer. More...

7.4 As in the case of radio frequency fields, "electrosensitivity" is an issue that also arises when exposed to ELF fields. Overall, the available studies do not provide convincing evidence for a causal relationship between exposure to ELF magnetic fields and the self-reported unspecific symptoms.

Only a few epidemiological studies on neurodegenerative diseases have surfaced since the last statement. They do not support the previous conclusion that ELF magnetic field exposure could increase the risk of developing Alzheimer's disease or other neurodegenerative diseases, including dementia. More...

7.5 For some other diseases, recent results show no effect of ELF fields on fertility in humans. Effects on cardiovascular disease are considered unlikely. More...

8. Static magnetic fields, for example from battery-operated devices and high-voltage direct current overhead lines


Magnetic resonance imaging uses static magnetic fields
Photo credit: Kasuga Huang

8.1 Static magnetic fields, such as those generated by permanent magnets, do not oscillate and therefore have no frequency (0 Hz). Artificial static magnetic fields arise wherever electricity in the form of direct current (DC) is used, for example in some trains, trams, subways, but also in the emerging high-voltage direct current overhead lines for long distances and in devices operated by (battery) direct current. Static magnetic fields can also come from permanent magnets worn on the body, such as those used for necklaces or bra closures. Very strong static magnetic fields are used in imaging processes in medicine, for example in MRI (magnetic resonance tomography). More...

8.2 In principle, static magnetic fields can induce forces in biological molecules and cell components which - such as hemoglobin - have magnetic properties. Fast movements in very strong static magnetic fields can induce relevant internal body electrical field strengths with acute consequences such as dizziness and nausea. Overall, however, there is no consistent evidence of persistent, harmful effects due to short-term exposure of up to a few Tesla. In summary, the newly reported results therefore do not offer any reason to change the risk assessment of exposure to static magnetic fields already presented in the previous statement.

A number of new technologies, such as MRI, use combinations of different EMFs that require further research. More...

9. Are there any health effects from combined exposure to different EMFs or from simultaneous exposure to other substances?

The few available studies too combined exposure various EMFs do not provide sufficient information for a risk assessment. Regarding one simultaneous exposure by ELF or RF with various chemical or physical substances, inconsistent results in the form of an increase or even a decrease in the effects of some chemicals or physical substances have been observed in some cases. Further research is recommended to clarify the role of EMF in such effects. More...

10. Conclusions on the health effects of electromagnetic fields

10.1 Overall, the epidemiological studies for RF EMF-Exposure to radio frequencies used by mobile phones does not increase the risk of brain tumors. In addition, they do not indicate an increased risk of other cancers of the head and neck area.

There is no evidence that self-reported non-specific symptoms such as headache or fatigue are related to exposure to radio frequency fields. More...

10.2 Due to the scarce data on intermediate frequency (IF) fields, the assessment of the health risks of short-term exposure to strong IF fields is based on recognized biological effects at lower and higher frequencies. Correct assessment of the potential health effects of long-term exposure is important as certain workplaces are increasingly exposed to such fields. More...

10.3 The new epidemiological studies are in line with previous reports of an association of childhood leukemia with exposure to magnetic fields such as power lines. However, no mechanisms have been found and there is no support from other scientific approaches such as in vivo or in vitro Laboratory tests that could explain these results. Together with the weaknesses of the epidemiological studies, it is not possible to interpret the cause. New epidemiological studies of neurodegenerative diseases published since the last opinion do not support the earlier conclusion that exposure to ELF magnetic fields could increase the risk of developing Alzheimer's disease or other neurodegenerative diseases, including dementia. In addition, they do not provide any evidence of harmful effects on pregnancy and do not show any effect of ELF fields on human fertility.

Overall, the available studies do not provide convincing findings for a causal relationship between exposure to ELF magnetic fields and the self-reported unspecific symptoms. More...

10.4 New applications of very strong static magnetic fields, used alone or in conjunction with other fields, will require a risk assessment for occupational exposure, for example at workplaces near MRI scanners. Overall, there is no consistent evidence of persistent, harmful effects due to short-term exposure of up to a few Tesla. More...

10.5 The few studies available on combined exposure to various EMFs do not provide sufficient information for a risk assessment. Simultaneous exposure to ELF or RF with different chemical agents or physical substances leads to inconsistent results in the form of an increase or decrease in the effect. Therefore, and due to the limited amount of research available and the range of protocols used, it is not possible to draw definitive conclusions, particularly with regard to their relevance to human carcinogenicity under real exposure conditions. More...

10.6 The opinion identifies a number of areas for which information on health effects is either sparse or insufficient; or the information does not match enough to allow an assessment of the theoretical health effects. More...