Wireless electronic devices and health
Encyclopedia
The World Health Organization
has acknowledged that electromagnetic field
s (EMFs) are influencing the environment (but not people), and that some people are worried about possible effects. In response to public concern, the World Health Organization established the International EMF Project in 1996 to assess the scientific evidence of possible health effects of EMF in the frequency range from 0 to 300 GHz. They have stated that although extensive research has been conducted into possible health effects of exposure to many parts of the frequency spectrum, all reviews conducted so far have indicated that exposures are below the limits recommended in the ICNIRP
(1998) EMF guidelines, covering the full frequency range from 0–300 GHz, and do not produce any known adverse health effect.
International guidelines on exposure levels to microwave
frequency EMFs such as ICNIRP limit the power levels of wireless devices and it is uncommon for wireless devices to exceed the guidelines. These guidelines only take into account thermal effects, as nonthermal effects have not been conclusively demonstrated. The official stance of the Health Protection Agency
is that “[T]here is no consistent evidence to date that WiFi and WLANs adversely affect the health of the general population”, but also that “...it is a sensible precautionary approach...to keep the situation under ongoing review...”.
(125 mW) for Power Class 4 to 33 dBm
(2W) for Power class 1, a wireless router can range from a typical 15 dBm
(30 mW) strength to 27 dBm
(500 mW) on the high end.
Wireless routers can be located significantly farther away from users' heads than a mobile phone, resulting in far less exposure overall. The Health Protection Agency
(HPA) claims that if a person spends one year in a Wi-Fi hotspot, they will receive the same dose of radio waves as if they had made a 20-minute call on a mobile phone. Nevertheless, the same is not true of Wi-Fi enabled laptops, which are not as far away.
The HPA also acknowledges that due to the mobile phone's adaptive power ability, a DECT cordless phone's radiation could actually exceed the radiation of a mobile phone. The HPA explains that while the DECT cordless phone's radiation has an average output power of 10 mW, it is actually in the form of 100 bursts per second of 250 mW, a strength comparable to some mobile phones.
equipment is designed to work within predefined standards. Wireless access points are also often close to humans, but the drop off in power over distance is fast, following the inverse-square law
. However, wireless laptops are typically used close to humans. WiFi has been anecdotally linked to electromagnetic hypersensitivity
, e.g., in Toronto, Canada schoolchildren as well as staff workers of France National Library.
The HPA's
position is that “...radio frequency (RF) exposures from WiFi are likely to be lower than those from mobile phones.” It also saw “...no reason why schools and others should not use WiFi equipment.” In October 2007, the HPA launched a new “systematic” study into the effects of WiFi networks on behalf of the UK government, in order to calm fears that had appeared in the media in a recent period up to that time". Dr Michael Clark, of the HPA, says published research on mobile phones and masts
does not add up to an indictment of WiFi.
also uses the microwave frequency spectrum in the range of 2.4 GHz to 2.4835 GHz. The radiated output power of Bluetooth
devices varies between 1 and 100 mW, and can operate continuously or sporadically (on demand), so total exposure to EMF radiation is quite variable. Bluetooth devices have not been linked with any health issues.
in the microwave and radio spectrum is used in a number of practical devices for professional and home use, such as:
In addition, electrical and electronic devices of all kinds emit EM fields around their working circuits, generated by oscillating currents. Humans are in daily contact with computers, video display monitors
, TV screens, microwave ovens, fluorescent lamps, electric motors of several kinds (such as washing machines, kitchen appliances [like electric can openers, blenders, and mixers], water pumps, etc.) and many others. A study of bedroom exposure in 2009 showed the highest ELF-EF from bedside lights and the highest ELF-MF from transformer devices, while the highest RF-ELF came from DECT cordless phones and outside cellphone base stations; all exposures were well below International Commission on Non-Ionizing Radiation Protection
(ICNIRP) guideline levels. The highest typical daily exposure, according to a study of 2009, came from cellphone base stations, cellphones and DECT cordless phones, with the highest exposure locations in trains, airports and buses. The typical background power of electromagnetic fields in the home can vary from zero to 5 milliwatts per meter squared. Long-time effects of these electromagnetic fields on human and animal health are still unknown.
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
has acknowledged that electromagnetic field
Electromagnetic field
An electromagnetic field is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction...
s (EMFs) are influencing the environment (but not people), and that some people are worried about possible effects. In response to public concern, the World Health Organization established the International EMF Project in 1996 to assess the scientific evidence of possible health effects of EMF in the frequency range from 0 to 300 GHz. They have stated that although extensive research has been conducted into possible health effects of exposure to many parts of the frequency spectrum, all reviews conducted so far have indicated that exposures are below the limits recommended in the ICNIRP
International Commission on Non-Ionizing Radiation Protection
The International Commission on Non-Ionizing Radiation Protection is an international commission specialized in non-ionizing radiation protection. The organization's activities include determining exposure limits for electromagnetic fields used by devices such as cellular phones..ICNIRP is an...
(1998) EMF guidelines, covering the full frequency range from 0–300 GHz, and do not produce any known adverse health effect.
International guidelines on exposure levels to microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
frequency EMFs such as ICNIRP limit the power levels of wireless devices and it is uncommon for wireless devices to exceed the guidelines. These guidelines only take into account thermal effects, as nonthermal effects have not been conclusively demonstrated. The official stance of the Health Protection Agency
Health Protection Agency
The Health Protection Agency, or, in Welsh, Yr Asiantaeth Diogelu Iechyd is a statutory corporation. It is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards...
is that “[T]here is no consistent evidence to date that WiFi and WLANs adversely affect the health of the general population”, but also that “...it is a sensible precautionary approach...to keep the situation under ongoing review...”.
Exposure difference to mobile phones
Users of wireless devices are typically exposed for much longer periods than for mobile phones and the strength of wireless devices is not significantly less. Whereas a mobile phone can range from 21 dBmDBm
dBm is an abbreviation for the power ratio in decibels of the measured power referenced to one milliwatt . It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form...
(125 mW) for Power Class 4 to 33 dBm
DBm
dBm is an abbreviation for the power ratio in decibels of the measured power referenced to one milliwatt . It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form...
(2W) for Power class 1, a wireless router can range from a typical 15 dBm
DBm
dBm is an abbreviation for the power ratio in decibels of the measured power referenced to one milliwatt . It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form...
(30 mW) strength to 27 dBm
DBm
dBm is an abbreviation for the power ratio in decibels of the measured power referenced to one milliwatt . It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form...
(500 mW) on the high end.
Wireless routers can be located significantly farther away from users' heads than a mobile phone, resulting in far less exposure overall. The Health Protection Agency
Health Protection Agency
The Health Protection Agency, or, in Welsh, Yr Asiantaeth Diogelu Iechyd is a statutory corporation. It is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards...
(HPA) claims that if a person spends one year in a Wi-Fi hotspot, they will receive the same dose of radio waves as if they had made a 20-minute call on a mobile phone. Nevertheless, the same is not true of Wi-Fi enabled laptops, which are not as far away.
The HPA also acknowledges that due to the mobile phone's adaptive power ability, a DECT cordless phone's radiation could actually exceed the radiation of a mobile phone. The HPA explains that while the DECT cordless phone's radiation has an average output power of 10 mW, it is actually in the form of 100 bursts per second of 250 mW, a strength comparable to some mobile phones.
Wireless LAN
Most wireless LANWireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...
equipment is designed to work within predefined standards. Wireless access points are also often close to humans, but the drop off in power over distance is fast, following the inverse-square law
Inverse-square law
In physics, an inverse-square law is any physical law stating that a specified physical quantity or strength is inversely proportional to the square of the distance from the source of that physical quantity....
. However, wireless laptops are typically used close to humans. WiFi has been anecdotally linked to electromagnetic hypersensitivity
Electromagnetic hypersensitivity
Idiopathic environmental intolerance attributed to electromagnetic fields is a set of claims of adverse medical symptoms purportedly caused by exposure to electromagnetic fields. Other terms for IEI-EMF include electromagnetic hypersensitivity , electrohypersensitivity, electro-sensitivity, and...
, e.g., in Toronto, Canada schoolchildren as well as staff workers of France National Library.
The HPA's
Health Protection Agency
The Health Protection Agency, or, in Welsh, Yr Asiantaeth Diogelu Iechyd is a statutory corporation. It is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards...
position is that “...radio frequency (RF) exposures from WiFi are likely to be lower than those from mobile phones.” It also saw “...no reason why schools and others should not use WiFi equipment.” In October 2007, the HPA launched a new “systematic” study into the effects of WiFi networks on behalf of the UK government, in order to calm fears that had appeared in the media in a recent period up to that time". Dr Michael Clark, of the HPA, says published research on mobile phones and masts
Radio masts and towers
Radio masts and towers are, typically, tall structures designed to support antennas for telecommunications and broadcasting, including television. They are among the tallest man-made structures...
does not add up to an indictment of WiFi.
Bluetooth
BluetoothBluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...
also uses the microwave frequency spectrum in the range of 2.4 GHz to 2.4835 GHz. The radiated output power of Bluetooth
Bluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...
devices varies between 1 and 100 mW, and can operate continuously or sporadically (on demand), so total exposure to EMF radiation is quite variable. Bluetooth devices have not been linked with any health issues.
Other devices
Radio frequencyRadio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
in the microwave and radio spectrum is used in a number of practical devices for professional and home use, such as:
- DECTDigital Enhanced Cordless TelecommunicationsDigital Enhanced Cordless Telecommunications , usually known by the acronym DECT, is a digital communication standard, which is primarily used for creating cordless phone systems...
and other cordless phonesCordless telephoneA cordless telephone or portable telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station...
operating at a wide range of frequencies - Remote controlRemote controlA remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...
devices for opening gates, etc. - Portable two-way radioRadioRadio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
communication devices, such as walkie-talkies - Wireless securitySecuritySecurity is the degree of protection against danger, damage, loss, and crime. Security as a form of protection are structures and processes that provide or improve security as a condition. The Institute for Security and Open Methodologies in the OSSTMM 3 defines security as "a form of protection...
(alarm) systems - Wireless security video cameras
- Radio links between buildings for data communication
- Baby monitorBaby monitorA baby monitor, also known as a baby alarm, is a radio system used to remotely listen to sounds made by an infant. The transmitter unit, equipped with a microphone, is placed near to the child. It transmits the sounds the baby makes by radio waves to a receiver unit with a speaker carried by, or...
s - Smart meterSmart meterA smart meter is usually an electrical meter that records consumption of electric energy in intervals of an hour or less and communicates that information at least daily back to the utility for monitoring and billing purposes. Smart meters enable two-way communication between the meter and the...
s for electric energy
In addition, electrical and electronic devices of all kinds emit EM fields around their working circuits, generated by oscillating currents. Humans are in daily contact with computers, video display monitors
Computer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
, TV screens, microwave ovens, fluorescent lamps, electric motors of several kinds (such as washing machines, kitchen appliances [like electric can openers, blenders, and mixers], water pumps, etc.) and many others. A study of bedroom exposure in 2009 showed the highest ELF-EF from bedside lights and the highest ELF-MF from transformer devices, while the highest RF-ELF came from DECT cordless phones and outside cellphone base stations; all exposures were well below International Commission on Non-Ionizing Radiation Protection
International Commission on Non-Ionizing Radiation Protection
The International Commission on Non-Ionizing Radiation Protection is an international commission specialized in non-ionizing radiation protection. The organization's activities include determining exposure limits for electromagnetic fields used by devices such as cellular phones..ICNIRP is an...
(ICNIRP) guideline levels. The highest typical daily exposure, according to a study of 2009, came from cellphone base stations, cellphones and DECT cordless phones, with the highest exposure locations in trains, airports and buses. The typical background power of electromagnetic fields in the home can vary from zero to 5 milliwatts per meter squared. Long-time effects of these electromagnetic fields on human and animal health are still unknown.
External links
- WiFi information at the UK Health Protection AgencyHealth Protection AgencyThe Health Protection Agency, or, in Welsh, Yr Asiantaeth Diogelu Iechyd is a statutory corporation. It is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards...