Basic physics: why we can recieve radio signal inside a close room?
the answer to this question is also the answer why whatever tons of shit you quote from the net is rubbish.
seeing your ignorance and strong belief in all these nonsensical rubbish is exact the reason why there is a need to introduce science early in school.
http://www.popsci.com/science/article/2010-02/disconnected
The Man Who Was Allergic to Radio Waves
Your cellphone does not in itself cause cancer. But in the daily sea of radiation we all travel, there may be subtler dangers at work, and science is only just beginning to understand how they can come to affect people like Per Segerbäck so intensely
By James Geary Posted 03.04.2010 at 11:39 am 83 Comments
Per Segerbäck’s Nearly Electricity-Free Home The photographer shot on film, using daylight, to avoid setting off Segerbäck’s hypersensitivity. Jonathan Worth
Per Segerbäck lives in a modest cottage in a nature reserve some 75 miles northeast of Stockholm. Wolves, moose and brown bears roam freely past his front door. He keeps limited human company, because human technology makes him physically ill. How ill? On a walk last summer, he ran into one of his few neighbors, a man who lives in a cottage about 100 yards away. During their chat, the man's cellphone rang, and Segerbäck, 54, was overcome by nausea. Within seconds, he was unconscious.
Segerbäck suffers from electro-hypersensitivity (EHS), which means he has severe physical reactions to the electromagnetic radiation produced by common consumer technologies, such as computers, televisions and cellphones. Symptoms range from burning or tingling sensations on the skin to dizziness, nausea, headaches, sleep disturbance and memory loss. In extreme cases like Segerbäck's, breathing problems, heart palpitations and loss of consciousness can result.
A cellphone has to be in use -- either making or receiving a call, or searching for a signal, when radiation levels are highest -- for it to have this kind of effect on Segerbäck. Phones that are on but neither sending nor receiving usually don't produce enough radiation to be noticeable. But it's not the sound of the phone that sets him off. Once, while on a sailboat with friends, he recalls, he was on the front deck when, unknown to him, someone made a call belowdecks. Headache, nausea, unconsciousness. When Segerbäck is within range of an active cellphone (safe distances vary because different makes and models produce different radiation levels), he experiences the feeling that there is "not enough room in my skull for my brain."
Sweden is the only country in the world to recognize EHS as a functional impairment, and Segerbäck's experience has been important in creating policy to address the condition. Swedish EHS sufferers -- about 3 percent of the population, or some 250,000 people, according to government statistics -- are entitled to similar rights and social services as those given to people who are blind or deaf. Today, local governments will pay to have the home of someone diagnosed with EHS electronically "sanitized," if necessary, through the installation of metal shielding.
SEA OF RADIATION
Electromagnetic fields (EMFs) are inescapable. We are constantly exposed to them, mostly in the form of either extremely low-frequency (ELF) radiation from things like domestic appliances and power lines or radio-frequency (RF) radiation from things like cellular and cordless phones, telecom antennas, and TV and radio transmission towers. Our bodies even produce faint EMFs of their own, from the electrical activity in the brain and heart.
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Science, Feature, cancer, cell phones, cellphone radiation, EHS, electromagnetic radiation, EMF, ericsson, extreme low-frequency radiation, March 2010, melatonin, national cancer institute, radiation, radio, radio waves
Ionizing radiation -- the kind produced by x-rays, CT scans and nuclear bombs -- can do terrible damage to the body. It is classified as a carcinogen. But ELF and RF are types of non-ionizing radiation, which is thought to be nearly harmless. Non-ionizing radiation isn't powerful enough to break molecular bonds, so it cannot directly cause the cellular damage that leads to disease. This type of radiation is everywhere. "We are bathed in a sea of non-ionizing radiation," says John Boice, a professor of medicine at Vanderbilt University School of Medicine and scientific director of the International Epidemiology Institute, a biomedical research firm in Rockville, Maryland.
This sea, most scientists agree, is harmless. Cellphones are safe and conditions like EHS cannot exist, they argue, because the EMFs involved are too weak to have any health effect. The non-ionizing radiation from cellphones has almost no known influence on the human body. In fact, the only universally recognized effect of non-ionizing radiation is a very minor heating of nearby tissue. The Federal Communications Commission sets EMF limits for cellphones -- measured as "specific absorption rates" (SARs) -- below which significant heating does not occur. Segerbäck's symptoms and those of other EHS sufferers, according to many researchers, may be either misdiagnosed or imaginary. Some experts suggest that people like Segerbäck perhaps suffer from a psychological disorder, or that their cases may illustrate the "nocebo" effect, in which the expectation that something will make you sick actually does make you sick. A review published last year in the journal Bioelectromagnetics found no evidence that hypersensitive individuals had an improved ability to detect EMFs, and the study found evidence of the nocebo effect in those same people.
The cellphone industry's position on the subject is clear. "The peer-reviewed scientific evidence has overwhelmingly indicated that wireless devices do not pose a public-health risk," says John Walls, vice president of public affairs at CTIA -- The Wireless Association, the international industry body. "In addition, there is no known mechanism for [EMFs] within the limits established by the FCC to cause any adverse health effects." A host of major institutions -- including the U.S. Food and Drug Administration, the International Commission on Non-Ionizing Radiation Protection (ICNIRP), the American Cancer Society and the World Health Organization -- agree with this assessment. (Although the ICNIRP says scientific assessment of the health aspects of wireless devices should continue as the technology becomes more widespread.)
Boice points out that data from cancer registries, such as the National Cancer Institute's SEER program, shows that brain-cancer rates haven't gone up since the early 1990s. The trends are also relatively flat from the mid-1970s to the early 2000s in Denmark, Finland, Norway and Sweden, where cellphones have been in use longer than in the U.S. If cellphones were causing brain cancer, an obvious uptick in reported cases would be expected. "If you look at the totality of biological and experimental studies," Boice says, "the vast amount of evidence is that there is no association between cellphones and malignancies."
Signal Strength: Cellphones are one of a number of household items that give off electromagnetic radiation Davvi.com
Your cellphone gives off radiation largely through the antenna when you make and receive calls and when it searches for a signal.
Cellphones operate in the radio-frequency range of the spectrum, along with radar and FM radio broadcasts.
Daily life exposes us to radiation from many sources, and electromagnetic fields vary [the circled number is the median field strength]. The combined effect is difficult to determine.
Cont'd
Go to the site to read the rest of the story
http://en.wikipedia.org/wiki/Electromagnetic_radiation_and_health
Electromagnetic radiation and health
From Wikipedia, the free encyclopedia
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Electromagnetic radiation can be classified into two types: ionizing radiation and non-ionizing radiation, based on its capability of ionizing atoms and breaking chemical bonds. Ultraviolet and higher frequencies, such as X-rays or gamma rays are ionizing, and these pose their own special hazards: see radiation and radiation poisoning. Non-ionizing radiation, discussed here, is associated with electrical and biological hazards.
Contents
1 Types of hazards
1.1 Electrical hazards
1.2 Fire hazards
1.3 Biological hazards
2 Positions of governments and scientific bodies
2.1 World Health Organization
2.2 Health Canada
2.3 U.S. military definition
3 Electric power transmission
3.1 Mitigation
3.2 Leukemia and cancer
3.2.1 Suggesting no significant link
3.2.2 Suggesting a significant link
3.2.3 Other findings
3.2.4 UK SAGE report
4 Mobile telephones
5 See also
6 References
7 External links
Types of hazards
Electrical hazards
Strong radiation can induce current capable of delivering an electric shock to persons or animals. It can also overload and destroy electrical equipment. The induction of currents by oscillating magnetic fields is also the way in which solar storms disrupt the operation of electrical and electronic systems, causing damage to and even the explosion of power distribution transformers,[1] blackouts (as in 1989), and interference with electromagnetic signals (e.g. radio, TV, and telephone signals).[2]
Fire hazards
Extremely high power electromagnetic radiation can cause electric currents strong enough to create sparks (electrical arcs) when an induced voltage exceeds the breakdown voltage of the surrounding medium (e.g. air). These sparks can then ignite flammable materials or gases, possibly leading to an explosion.
This can be a particular hazard in the vicinity of explosives or pyrotechnics, since an electrical overload might ignite them. This risk is commonly referred to as HERO (Hazards of Electromagnetic Radiation to Ordnance). MIL-STD-464A mandates assessment of HERO in a system, but Navy document OD 30393 provides design principles and practices for controlling electromagnetic hazards to ordnance.
On the other hand, the risk related to fueling is known as HERF (Hazards of Electromagnetic Radiation to Fuel). NAVSEA OP 3565 Vol. 1 could be used to evaluate HERF, which states a maximum power density of 0.09 W/m² for frequencies under 225 MHz (i.e. 4.2 meters for a 40 W emitter).
Biological hazards
The best understood biological effect of electromagnetic fields is to cause dielectric heating. For example, touching or standing around an antenna while a high-power transmitter is in operation can cause severe burns. These are exactly the kind of burns that would be caused inside a microwave oven.
This heating effect varies with the power and the frequency of the electromagnetic energy. A measure of the heating effect is the specific absorption rate or SAR, which has units of watts per kilogram (W/kg). The IEEE[3] and many national governments have established safety limits for exposure to various frequencies of electromagnetic energy based on SAR, mainly based on ICNIRP Guidelines,[4] which guard against thermal damage.
There are publications which support the existence of complex biological effects of weaker non-thermal electromagnetic fields (see Bioelectromagnetics), including weak ELF magnetic fields[5][6] and modulated RF and microwave fields.[7] Fundamental mechanisms of the interaction between biological material and electromagnetic fields at non-thermal levels are not fully understood.[8]
A 2009 study at the University of Basel in Switzerland found that intermittent (but not continuous) exposure of human cells to a 50 Hz electromagnetic field at a flux density of 1 mT (or 10 G) induced a slight but significant increase of DNA fragmentation in the Comet assay.[9] However that level of exposure is already above current established safety exposure limits.
Positions of governments and scientific bodies
World Health Organization
In May 2011, the WHO's International Agency for Research on Cancer published a review of the evidence on health risks of EMF, and concluded that there was limited evidence that cellphone users might be at increased risk of glioma and acoustic neuroma, and that there was inadequate evidence of any other health risks posed by EMF.[10][11] This "possibly carcinogenic" classification was often misinterpreted, meaning only "that there is very little scientific evidence as to the carcinogenicity of cell phone use".[12]
Health Canada
"There is no conclusive evidence of any harm caused by exposures [to electric and magnetic fields] at levels found in Canadian homes and schools, including those located just outside the boundaries of power line corridors."[13]
U.S. military definition
In Federal Standard 1037C, the United States government adopts the following definition:
Electromagnetic radiation hazards (RADHAZ or EMR hazards): Hazards caused by a transmitter/antenna installation that generates electromagnetic radiation in the vicinity of ordnance, personnel, or fueling operations in excess of established safe levels or increases the existing levels to a hazardous level; or a personnel, fueling, or ordnance installation located in an area that is illuminated by electromagnetic radiation at a level that is hazardous to the planned operations or occupancy. These hazards will exist when an electromagnetic field of sufficient intensity is generated to: (a) induce or otherwise couple currents or voltages large enough to initiate electroexplosive devices or other sensitive explosive components of weapon systems, ordnance, or explosive devices; (b) cause harmful or injurious effects to humans and wildlife; (c) create sparks having sufficient magnitude to ignite flammable mixtures of materials that must be handled in the affected area. —Department of Defense Dictionary of Military and Associated Terms
Electric power transmission
The preponderance of evidence suggests that the low-power, low-frequency, electromagnetic radiation associated with household current does not constitute a short or long term health hazard, and whilst some biophysical mechanisms for the promotion of cancer have been proposed (such as the electric fields around power lines attracting aerosol pollutants[14][15]), none have been substantiated. [16][17][18][19][20][21] Nevertheless, some research has reported correlation with a number of adverse health effects, although controversy can include whether observed correlation implies causation. These include, but are not limited to, childhood leukemia,[16] adult leukemia,[22] neurodegenerative diseases (such as amyotrophic lateral sclerosis),[23][24][25] miscarriage,[26][27][28] and clinical depression.[citation needed]
Mitigation
One response to the potential dangers of overhead power lines is to place them underground. The earth and enclosures surrounding underground cables prevent the electric field from radiating significantly beyond the power lines, and greatly reduce the magnetic field strength radiating from the power lines, into the surrounding area.[29] However, the cost of burying and maintaining cables at transmission voltages is several times greater than overhead power lines.[30]
Leukemia and cancer
Suggesting no significant link
In 1997 the National Cancer Institute (NCI) released a report published in the New England Journal of Medicine, the result of a seven-year epidemiological investigation. The study investigated 638 children with acute lymphoblastic leukemia (ALL) and 620 controls and concluded that their study provided "little evidence that living in homes characterized by high measured time-weighted average magnetic-field levels or by the highest wire-code category increases the risk of ALL in children."[31] Following the report, the US Department of Energy disbanded the EMF Research and Public Information Dissemination (RAPID) Program, saying that its services were no longer needed.[32]
In 2005, the Canadian Federal-Provincial-Territorial Radiation Protection Committee said, "The outcome of a recently conducted pooled analysis of several epidemiological studies shows a two-fold increase in the risk of leukemia in children living in homes, where the average magnetic field levels are greater than 0.4 microtesla (4 milligauss). [However,] it is the opinion of [this committee] that the epidemiological evidence to date is not strong enough to justify a conclusion that EMFs in Canadian homes, regardless of locations from power lines, cause leukemia in children."[33]
The World Health Organization issued a fact sheet, No. 322, in June, 2007 based on the findings of a WHO work group (2007), the IARC (2002) and the ICNIRP (2003), which reviewed research conducted since the earlier publication. The fact sheet says "that there are no substantive health issues related to ELF electric fields at levels generally encountered by members of the public." For ELF magnetic fields, the fact sheet says, "the evidence related to childhood leukaemia is not strong enough to be considered causal", and "[as regards] other childhood cancers, cancers in adults, ... 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. In some instances (i.e., for ... breast cancer) the evidence suggests that these fields do not cause them."[16]
According to Dr. Lakshmikumar at the National Physical Laboratory, India, a direct, causal, link between RF radiation and cancer (including leukemia) would require one to be "willing to discard Planck's Law… and the entire body of quantum physics." [34]
In 2010, Maslanyj et al., applying the Bradford-Hill criteria to available evidence, considered the application of low-cost exposure reduction measures as appropriate precautionary responses to "small and uncertain public health risks". Even after pooling all the data, they found it fell short of establishing "strength of association, dose-response relationship, biological plausibility and coherence, and analogy". They recognised that controversy would continue so long as other interpretations of the data were possible.[35]
Suggesting a significant link
In 2001, Ahlbom et al. conducted a review into EMFs and Health, and found that there was a doubling in childhood leukemia for magnetic fields of over 0.4 µT, but said that that it "... may be partly due to bias. This is difficult to interpret in the absence of a known mechanism or reproducible experimental support."[36]
In 2002 a study by Michelozzi et al. found a relationship between leukemia and proximity to the Vatican Radio station transmitters although "the study has limitations because of the small number of cases and the lack of exposure data."[37]
In 2005 Draper et al. found a 70% increase in childhood leukemia for those living within 200 metres (656 ft) of an overhead transmission line, and a 23% increase for those living between 200 and 600 metres (656 and 1,969 ft). The authors concluded that "the relation may be due to chance or confounding." The authors considered it unlikely that the increase from 200 m to 600 m is related to magnetic fields as they are well below 0.4 µT at this distance.[38] Bristol University (UK) has published work on a theory that could account for this increase, and would also provide a potential mechanism, being that the electric fields around power lines attract aerosol pollutants.[15]
Other findings
The World Health Organisation issued Factsheet No. 263 in October 2001 on ELF (Extremely low frequency) EMFs and cancer. It said that they were "possibly carcinogenic", based primarily on IARC's similar evaluation with respect to childhood leukemia. It also said that there was "insufficient" data to draw any conclusions on other cancers.[39] The WHO later noted that result had been based on evidence which was "weakened by methodological problems" and that "on balance, the evidence related to childhood leukaemia is not strong enough to be considered causal."[16]
In 2007, the UK Health Protection Agency produced a paper showing that 43% of homes with magnetic fields of over 0.4 µT are associated with overground or underground circuits of 132 kV and above.[40]
UK SAGE report
The UK Department of Health set up the Stakeholder Advisory Group on ELF EMFs (SAGE) to explore the implications and to make recommendations for a precautionary approach to power frequency electric and magnetic fields in light of any evidence of a link between EMF and childhood leukemia. The first interim assessment of this group was released in April 2007 [1], and found that the link between proximity to power lines and childhood leukemia was sufficient to warrant a precautionary recommendation, including an option to lay new power lines underground where possible and to prevent the building of new residential buildings within 60 m (197 ft) of existing power lines. The latter of these options was not an official recommendation to government as the cost-benefit analysis based on the increased risk for childhood leukemia alone was considered insufficient to warrant it. The option was considered necessary for inclusion as, if found to be real, the weaker association with other health effects would make it worth implementing.[41]
Mobile telephones
Main article: 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, there were more than 2 billion users worldwide). Mobile phones use electromagnetic radiation in the microwave range, and some[42][unreliable medical source?] believe this may be harmful to human health.[43] These concerns have induced a large body of research (both epidemiological and experimental, in non-human animals as well as in humans).[44][45] 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 or promotion of cancer) are unlikely to be caused by cellular phones or their base stations,[46][47] and expects to make recommendations about mobile phones in the third quarter of 2010 at the earliest, or the first quarter of 2011 at the latest[48][dated info].
