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