| Mobile phone radiation and health concerns have been | | | | observed. The physiological significance or biological |
| raised since the 1990s, especially following the | | | | relevance of some the reported changes were |
| enormous increase in the use of wireless mobile | | | | questioned by the authors themselves (e.g., "Taken |
| telephony throughout the world (as of August 2005, | | | | together, the results of the REFLEX project were |
| there were more than 2 billion users worldwide). This is | | | | exclusively obtained in in vitro studies and are, |
| because mobile phones use electromagnetic waves in | | | | therefore, not suitable for the conclusion that RF-EMF |
| the microwave range. These concerns have induced a | | | | exposure below the presently valid safety limits |
| large body of research (both epidemiological and | | | | causes a risk to the health of people"). A comment by |
| experimental, in non-human animals as well as in | | | | Boulder (2005) on these results questions "whether the |
| humans). Concerns about effects on health have also | | | | positive findings were more common than expected |
| been raised regarding other digital wireless systems, | | | | from random chance (false positive rates from cellular |
| such as data communication networks. | | | | genotoxicity tests can be as high as 20%)." |
| The results, so far, have been controversial: the | | | | The communications protocols used by mobile phones |
| majority of epidemiological studies have not found any | | | | often result in low-frequency pulsing of the carrier |
| clear indication of short and medium term health | | | | signal. These low frequencies are similar to those that |
| hazards. On the other hand there is extensive literature | | | | exist in the electrical oscillations of the human body, |
| on so-called non-thermal effects of weak microwave | | | | specifically the alpha and delta brain waves. Non-linear |
| radiation on biological tissue in animal models or in-vitro, | | | | interactions could theoretically result when resonances |
| including affecting the growth of certain tumors, cell | | | | are created when the brain is subjected to mobile |
| death, increased permeability of the blood-brain barrier, | | | | phone radiation, in a manner similar to that observed |
| DNA damage and others, which suggest the possibility | | | | when light strobing induces photosensitive epilepsy in |
| of adverse health effects in humans. | | | | susceptible individuals. No experimental results have |
| Part of the radio waves emitted by a mobile telephone | | | | indicated this theoretical possibility, however. These and |
| handset are absorbed by the human head; the radio | | | | other non-thermal effects are summarized in (Hyland, |
| waves emitted by a GSM handset, for example, can | | | | 2000). |
| have a power of up to 2 watts, and an analog phone | | | | Other researchers have argued that the so-called |
| in the USA (probably very few in use today) can have | | | | "non-thermal effects" could be reinterpreted as a |
| 3.6 watts, as in the old large mobile phone units installed | | | | normal cellular response to an increase in temperature. |
| in cars. Other digital mobile technologies, such as | | | | The noted German biophysicist Roland Glaser, for |
| CDMA and TDMA, have today lower rates, under 1 | | | | example [6] has argued that there are several |
| watt. The average radiation rate of cellphones in some | | | | thermoreceptor molecules in cells, and that they |
| countries is regulated and it is mandatory to inform the | | | | activate a cascade of second and third messenger |
| consumers about it (usually printed in the battery | | | | systems, gene expression mechanisms and production |
| compartment). In some systems the cellphone and the | | | | of heat shock proteins in order to defend the cell |
| base station check reception quality and signal strength | | | | against metabolic cell stress cause by heat. The |
| and the power level is increased or decreased | | | | increases in temperature that cause these changes |
| automatically, within the above limits, such as inside | | | | are too small to be detected by studies such as |
| buildings or vehicles, etc. | | | | REFLEX, which base their whole argument on the |
| The rate at which radiation is absorbed by the human | | | | apparent stability of thermal equilibrium in their cell |
| body is measured by the Specific Absorption Rate | | | | cultures. |
| (SAR), and its maximum levels for modern handsets | | | | Several reports by national and international experts |
| have been set by governmental regulating agencies in | | | | have been published in the last 3 years, examining the |
| many countries. In the USA, the FCC has set a SAR | | | | scientific evidence provided so far for possible |
| limit of 1.6 W/kg, averaged over a volume of 1 gram of | | | | detrimental effects of the use mobile handsets. For |
| tissue, for most parts of the body. (SAR values are | | | | example: |
| heavily dependent on the size of the averaging | | | | AGNIR REPORT 2003: "Overall the evidence for RF |
| volume. Without information about the averaging | | | | field effects on cognitive functions in humans is |
| volume used comparisons between different | | | | inconsistent and inconclusive (...) The biological evidence |
| measurements can not be made.) | | | | suggests that RF fields do not cause mutation or |
| Thermal effects | | | | initiate or promote tumor formation and that the |
| One well-understood effect of microwave radiation is | | | | epidemiological evidence overall do no suggest causal |
| dielectric heating, in which any dielectric material (such | | | | associations between exposure to RF fields in |
| as living tissue) is heated by rotations of polar | | | | particular from mobile phone users and the risk of |
| molecules induced by the electromagnetic field. In the | | | | cancer. Exposure levels for those living near to mobile |
| case of a person using a cell phone, most of the | | | | phone base stations are extremely low and the |
| heating effect may occur in the head surface, causing | | | | evidence suggests that they are unlikely to pose a risk |
| its temperature to increase by a fraction of a degree. | | | | to health." |
| The level of temperature increase is an order of | | | | SWEDISH RADIATION PROTECTION AUTHORITY |
| magnitude less than that obtained during the exposure | | | | REPORT 2002 [8]: "No significant associations have |
| of the head to direct sunlight. The brain's blood | | | | been seen between all brain tumors combined and |
| circulation easily disposes of excess heat by | | | | phone use, with relative risks ranging from 0,9 to 1,3 (...) |
| instantaneously increasing local blood flow. However, | | | | Subgroup analyses showed no consistent pattern of |
| the cornea of the eye does not have this temperature | | | | increased risk. It was considered that it was not |
| regulation mechanism. Premature cataracts are known | | | | biologically plausible that exposure to RF fields could |
| as an occupational disease of engineers who work on | | | | increase the risk of cancer. The studies conducted so |
| high power radio transmitters at similar frequencies. | | | | far have ruled out with a reasonable certainty that |
| Due to the low power of mobile phones, cataracts | | | | mobile phones cause cancer." |
| have not been reported to occur in users of these. | | | | Electromagnetic hypersensitivity syndrome |
| It has been claimed that some parts of the human | | | | Many users of mobile handsets have reported feeling |
| head are more sensitive to damage due to increases | | | | several unspecific symptoms during and after its use, |
| in temperature, particularly in anatomical structures with | | | | such as burning and tingling sensations in the skin of |
| poor vasculature, such as nerve fibers. More recent | | | | the head and extremities, fatigue, sleep disturbances, |
| results from a Swedish scientific team at the | | | | dizziness, loss of mental attention, reaction times and |
| Karolinska Institute (Lonn, Ahlbom, Hall and Feychting) | | | | memory retentiveness, headaches, malaise, |
| have suggested that continuous use of a mobile phone | | | | tachycardia (heart palpitations) and disturbances of the |
| for a decade or longer can lead to a small increase in | | | | digestive system. Some researchers, implying a causal |
| the probability of getting acoustic neuroma, a type of | | | | relationship, have named this syndrome as a new |
| brain tumor. The increase was not noted in those who | | | | diagnostic entity, EHS or ES (electrosensitivity). The |
| used phones for less than 10 years. The study has | | | | World Health Organization prefers to name it |
| been criticized for possible problems in data analysis | | | | "idiopathic environmental intolerance", in order to avoid |
| such as recall bias. However, another study conducted | | | | the implication of causation. This entity is quite |
| by the Swedish National Institute for Working Life | | | | controversial, because albeit identified in unmistaken |
| supported an increased risk of "malignant tumors on | | | | terms by the patients who affirm to suffer from it, in |
| the side of the head the phone is used." [2] Such long | | | | some cases in such a radical way that they avoid |
| term heavy use involved phones of older higher power | | | | using cellphones, it has not been recognized as a |
| analog designs that were first introduced to Sweden in | | | | separate clinical entity by most medical researchers. |
| 1984, earlier than many other countries. | | | | Two recent literature reviews, however, one reviewing |
| Non-thermal effects | | | | 13 published papers in 2003 and 2004, and another |
| In December 2004 a pan-European study named | | | | reviewing 31 papers published before 2004, have |
| REFLEX, involving 12 collaborating laboratories in | | | | concluded that there is no scientific evidence for a |
| several countries showed some compelling evidence | | | | causal relationship between the reported clusters of |
| of DNA damage of cells in in-vitro cultures, when | | | | symptoms and exposure to microwave radiation used |
| exposed between 0.3 to 2 watts/kg. This overlaps | | | | in cellphones, well below the safety standards. A |
| with the level of radiation typically emitted by digital cell | | | | workshop conducted by the WHO in Prague in 2004 |
| phones of around 0.2 to 1 watt/kg. There were | | | | also reached the same conclusions, viz., that 1) |
| indications, but not rigorous evidence of other cell | | | | reported symptoms are very unspecific and could |
| changes, including damage to chromosomes, | | | | have other causes; 2) there is no causal association |
| alterations in the activity of certain genes and a | | | | demonstrated between exposure and symptoms, 3) |
| boosted rate of cell division. The results of this study | | | | that patients who display those symptoms should be |
| run contrary to many similar studies that were | | | | medically examined for alternative explanations and |
| conducted before and showed no increase in DNA | | | | causes, including psychiatric/psychological ones (since |
| damage. . | | | | they are typical manifestations of stress and other |
| According to a recent (2004) review published by the | | | | somatization/psychosomatic causes), and that the |
| UK National Radiation Protection Board (Z J | | | | environment where they work or live should be |
| Sienkiewicz and C I Kowalczuk ), "the effects reported | | | | assessed in order to discover other factors at work |
| by the REFLEX project do not appear to have been | | | | that could explain the symptoms; and 4) lowering the |
| seen consistently (...) Overall these inconsistencies do | | | | safety limits for handset radiation (SAR levels) will not |
| not suggest that robust responses have been | | | | affect the situation. |