rathirak nguon's List: Electro Magnetic Fields

• Electromagnetic fields
• Electromagnetic fields

• Electromagnetic field

• The electromagnetic field is a physical field produced by 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. It is one of the four fundamental forces of nature (the others are gravitation, the weak interaction, and the strong interaction). The field propagates by electromagnetic radiation; in order of increasing energy (decreasing wavelength) electromagnetic radiation comprises: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

• Structure of the electromagnetic field

   

  The electromagnetic field may be viewed in two distinct ways.

   

   

  [edit] Continuous structure
• Discrete structure

• Dynamics of the electromagnetic field

   

  In the past, electrically charged objects were thought to produce two types of field associated with their charge property. An electric field is produced when the charge is stationary with respect to an observer measuring the properties of the charge, and a magnetic field (as well as an electric field) is produced when the charge moves (creating an electric current) with respect to this observer. Over time, it was realized that the electric and magnetic fields are better thought of as two parts of a greater whole — the electromagnetic field.

• Health and safety

   

  The potential health effects of the very low frequency EMFs surrounding power lines and electrical devices are the subject of on-going research and a significant amount of public debate. In workplace environments, where EMF exposures can be up to 10,000 times greater than the average, the US National Institute for Occupational Safety and Health (NIOSH) has issued some cautionary advisories but stresses that the data is currently too limited to draw good conclusions.^[2]

   

  The potential effects of electromagnetic fields on human health vary widely depending on the frequency and intensity of the fields. For more information on the health effects due to specific parts of the electromagnetic spectrum, see the following articles with details of possible dangers (MRI) and some currently unfounded fears (mobile phones):

   
   
  • Static electric fields: see Electric shock
   
  • Static magnetic fields: see MRI/Safety for one of the few applications in which magnetic fields are strong enough to have safety implications
   
  • Extremely low frequency (ELF): see Power lines/health concerns
   
  • Radio frequency (RF): see Electromagnetic radiation and health
   
  • Light: see Laser safety
   
  • Ultraviolet (UV): see Sunburn
   
  • Gamma rays: see Gamma ray
   
  • Mobile telephony: see Mobile phone radiation and health

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• Are EMFs Hazardous to Our Health?

• Can electromagnetic fields (EMF) from power lines, home wiring, airport and military radar, substations, transformers, computers and appliances cause brain tumors, leukemia, birth defects, miscarriages, chronic fatigue, headaches, cataracts, heart problems, stress. nausea, chest pain, forgetfulness, cancer and other health problems?

  Numerous studies have produced contradictory results, yet some experts are convinced that the threat is real.

  Dr. David Carpenter, Dean at the School of Public Health, State University of New York believes it is likely that up to 30% of all childhood cancers come from exposure to EMFs. The Environmental Protection Agency (EPA) warns "There is reason for concern" and advises prudent avoidance".

• EPA Says the Threat Is Real

  By 1990, over one hundred studies had been conducted worldwide. Of these, at least two dozen epidemiological studies on humans indicated a link between EMFs and serious health problems. In response to public pressure, the Environmental Protection Agency IEPA) began reviewing and evaluating the available literature.

• How Do I Measure EMFs?

  A Gauss is a common unit of measurement of magnetic field strength. A Gauss meter is an instrument which measures the strength of magnetic fields. Inside a Gauss meter there is a coil of thin wire, typically with hundreds of turns. As a magnetic field radiates through the coil, it induces a current, which is amplified by the circuitry inside the Gauss meter.

• Power Lines

  An enormous amount of electricity is created at power generating stations and sent across the country through wires that carry high voltages. All power lines radiate electromagnetic fields. The question is: how much are the

  power lines near YOUR home radiating? The amount of EMFs coming from a power line depends on its particular configuration. Power companies know which power line configurations are best for reducing EMFs but most don't feel the evidence supports costly changes in the way they deliver electricity.

  Substations

  A substation is an assemblage of circuit breakers, disconnecting switches and transformers designed to substations have been blamed for causing cancer clusters among nearby residents. Paul Brodeur wrote about several such cancer clusters in the July 9, 1990 issue of the New Yorker Magazine.

  Transformers

  A key component of a utility's electrical distribution network depends upon numerous, small transformers mounted on power poles. A transformer looks like a small metal trash can, usually cylindrical.

• Home Wiring

  If your home has high EMF readings, it is important to determine the sources of the EMF so that remedial action can be taken, if possible. Many times a particular room will have a higher EMF reading. Check to see if the electricity is coming into the house on the wall outside that room. When this is the case, it is usually a good idea to block off that room and only use it for storage purposes.

• Computers

  Computers are a complicated subject. Know this: EMFs radiate from all sides of the computer. Thus, you must not only be concerned with sitting in front of the monitor but also if you are sitting near a computer or if a computer is operating in a nearby room.

• Electric Blankets and Waterbeds

  Electric blankets create a magnetic field that penetrates about 6-7 inches into the body. Thus it is not surprising that an epidemiological study has linked electric blankets with miscarriages and childhood leukemia.

  This pioneering work was performed by Dr. Nancy Wertheimer and Ed Leeper, who originally discovered that magnetic fields were linked to childhood leukemia. Similar health effects have been noted with users of many electric blankets and waterbed heaters will emit EMFs even when turned off.

• Electric Clocks

  Electric clocks have a very high magnetic field, as much as 5 to 10 mG up to three feet away. If you are using a bedside clock, you are probably sleeping in an EMF equivalent to that of a powerline Studies have linked high rates of brain tumors with chronic exposure to magnetic fields, so it is wise to place all clocks and other electrical devices (such as telephones and answering devices) at least 6 feet from your bed.

• Additional Radiation Info:

  Eyeglass frames should ideally be made from plastic with no wires in them, otherwise they can serve as an antenna to focus the radio and cellular phone waves directly into your brain.

  What EMF Level Is Safe?

  There's a heated debate as to what electromagnetic field (EMF) level is considered safe. Since the experts have not come to an consensus, you'll have to decide for yourself... Many government and utility documents report the usual ambient level of 60-Hz magnetic field to be 0.5 mG.

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• Classical Electrodynamics

• Electromagnetic Fields

• What are electromagnetic fields?

• Electromagnetic Fields

• electromagnetic field (EMF)

• An electromagnetic field, sometimes referred to as an EM field, is generated when charged particles, such as electrons, are accelerated. All electrically charged particles are surrounded by electric fields. Charged particles in motion produce magnetic fields. When the velocity of a charged particle changes, an EM field is produced.
• Electromagnetic fields were first discovered in the 19th century, when physicists noticed that electric arcs (sparks) could be reproduced at a distance, with no connecting wires in between. This led scientists to believe that it was possible to communicate over long distances without wires. The first radio transmitters made use of electric arcs. These "spark transmitters" and the associated receivers were as exciting to people in the early 20th century as the Internet is today. This was the beginning of what we now call wirelesscommunication.

• Harmful Cell Phone EMF Radiation Linked to Brain Cancer, Infertility & More Health Dangers

•        

  Media centre

                  

  	WHO > Programmes and projects > Media centre > Fact sheets

             

  Main content

     

  printable version           Fact sheet N°227
• Ultraviolet radiation: solar radiation and human health

• Reduce electro magnetic field EMF radiation  from Mobile phone computer and other office / home appliances with BIOPRO protection

• Mobile Phone Radiation Harms DNA, New Study Finds
• MUNICH/AMSTERDAM (Reuters)   - Radio waves from mobile phones harm body cells and damage DNA in laboratory   conditions, according to a new study majority-funded by the European Union,   researchers said on Monday. The so-called Reflex study, conducted by 12   research groups in seven European countries, did not prove that mobile   phones are a risk to health but concluded that more research is needed   to see if effects can also be found outside a lab.
• After being exposed to electromagnetic fields that are typical for mobile   phones, the cells showed a significant increase in single and double-strand   DNA breaks. The damage could not always be repaired by the cell. DNA carries   the genetic material of an organism and its different cells.
   
    "There was remaining damage for future generation of cells," said project   leader Franz Adlkofer.
   
    This means the change had procreated. Mutated cells are seen as a possible   cause of cancer.

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• Mobile phones 'alter human DNA'

• Mobile phone radiation and health
• Mobile phone radiation and health concerns have been raised, especially following the enormous increase in the use of wireless mobile telephony throughout the world (as of August 2005^[update], there were more than 2 billion users worldwide). Mobile phones use electromagnetic radiation in the microwave range, and some^[1] believe this may be harmful to human health. These concerns have induced a large body of research (both epidemiological and experimental, in non-human animals and in humans). Concerns about effects on health have also been raised regarding other digital wireless systems, such as data communication networks.

• The World Health Organization, based upon the consensus view of the scientific and medical communities, states that health effects (e.g. headaches) are very unlikely to be caused by cellular phones or their base stations,^[2][3] and expects to make recommendations about mobile phones in October 2009.^[4]

   

  However, some national radiation advisory authorities, including those of Austria,^[5] France,^[6] Germany,^[7] and Sweden^[8] recommended to their citizens measures to minimize exposure. Examples of the recommendations are:

• Overall health risks

   

  Many scientific studies have investigated possible health effects of mobile phone radiations. These studies are occasionally reviewed by some scientific committees to assess overall risks. The most recent assessment was published in 2007 by the European Commission Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). It concludes from the available research that no significant health effect has been demonstrated from mobile phone radiation at normal exposure levels:

• Health hazards of handsets

   

   

  [edit] Radiation absorption

   

   

   

   

  

   Calculated specific absorbed radiation (SAR) distribution in an anatomical model of head next to a 125 mW dipole antenna. Peak SAR is 9.5 W/kg averaged over a 1 mg cube. (USAF/AFRL).

   

   

   

  Part of the radio waves emitted by a mobile telephone handset are absorbed by the human head. The radio waves emitted by a GSM handset, can have a peak power of 2 watts, and a US analogue phone had a maximum transmit power of 3.6 watts. Other digital mobile technologies, such as CDMA2000 and D-AMPS, use lower output power, typically below 1 watt. The maximum power output from a mobile phone is regulated by the mobile phone standard it is following and by the regulatory agencies in each country.
• One well-understood effect of microwave radiation is dielectric heating, in which any dielectric material (such as living tissue) is heated by rotations of polar molecules induced by the electromagnetic field. In the case of a person using a cell phone, most of the heating effect will occur at the surface of the head, causing its temperature to increase by a fraction of a degree. In this case, the level of temperature increase is an order of magnitude less than that obtained during the exposure of the head to direct sunlight. The brain's blood circulation is capable of disposing of excess heat by increasing local blood flow. However, the cornea of the eye does not have this temperature regulation mechanism and exposure of 2-3 hours' duration has been reported to produce cataracts in rabbits' eyes at SAR values from 100-140W/kg, which produced lenticular temperatures of 41°C.^{[verification needed][15]} Premature cataracts have not been linked with cell phone use, possibly because of the lower power output of mobile phones.

• Mobile phones and cancer

   

  In 2006 a large Danish study about the connection between mobile phone use and cancer incidence was published. It followed over 420,000 Danish citizens for 20 years and showed no increased risk of cancer.^[29] The German Federal Office for Radiation Protection (BfS) consider this report as inconclusive.^[3

• Health hazards of base stations

   

  Another area of worry about effects on the population's health have been the radiation emitted by base stations (the antennas on the surface which communicate with the phones). This is because, in contrast to mobile handsets, it is emitted continuously and is more powerful at close quarters. On the other hand due to the attenuation of power with the square of distance, field intensities drop rapidly with distance away from the base of the antenna. Base station emissions must comply with ICNIRP guidelines of a maximum power density of 4.5 W/m² (450 microwatts/cm²) for 900 MHz and 9 W/m² (900 microwatts/cm²) for 1800 MHz.^[56] These guidelines are set for heating, which is the only understood mechanism of electromagnetic fields on biological tissue. The ICNIRP guidelines are distrusted by some.^[57]

• Occupational health hazards

   

  Telecommunication workers who spend time at a short distance from the active equipment, for the purposes of testing, maintenance, installation, etc. may be at risk of much greater exposure than the general population. Many times base stations are not turned off during maintenance, because that would affect the network, so people work near "live" antennas.

• Safety standards and licensing

   

  In order to protect the population living around base stations and users of mobile handsets, governments and regulatory bodies adopt safety standards, which translate to limits on exposure levels below a certain value. There are many proposed national and international standards, but that of the International Commission for Non-Ionizing Radiation Protection (ICNIRP) is the most respected one, and has been adopted so far by more than 80 countries. For radio stations, ICNIRP proposes two safety levels: one for occupational exposure, another one for the general population. Currently there are efforts underway to harmonise the different standards in existence.^[71]

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• Video comment by Dr Patrick Dixon on research showing possible health risks from heavy exposure to mobile phone radiation. Risks probably very small in normal use.
• 2.5 times risk of brain tumours from phone radiation in humans? Early Alzheimers disease from destroyed brain cells? Reports showing no health risk at all? Each month we see more reports about mobile phone radiation effects - but what does it actually mean for you and me? Is there really a health risk? Here is a common-sense personal view from a physician and parent of four children who is also a major user of wireless devices of all kinds.

• Warning: Using a mobile phone while pregnant can seriously damage your baby

• Electromagnetic radiation and health
• Electromagnetic radiation and health

• CAN RADIATION FROM ALL ELECTRICAL WIRING, EQUIPMENT, POWER LINES, SUBSTATIONS   AND EVEN BATTERY OPERATED ITEMS AFFECT OUR BIOPHYSICAL AND BIOLOGICAL BODIES,   DAMAGE, ALTER OUR DNA AND LEAD TO ILLNESS AND DISEASE?

• Mobile phone risk to kids