Mobile phones and health

Mobile phone radiation and health concerns have beenobserved. The physiological significance or biological
raised since the 1990s, especially following therelevance of some the reported changes were
enormous increase in the use of wireless mobilequestioned 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 isexclusively obtained in in vitro studies and are,
because mobile phones use electromagnetic waves intherefore, not suitable for the conclusion that RF-EMF
the microwave range. These concerns have induced aexposure below the presently valid safety limits
large body of research (both epidemiological andcauses a risk to the health of people"). A comment by
experimental, in non-human animals as well as inBoulder (2005) on these results questions "whether the
humans). Concerns about effects on health have alsopositive 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: theThe communications protocols used by mobile phones
majority of epidemiological studies have not found anyoften result in low-frequency pulsing of the carrier
clear indication of short and medium term healthsignal. These low frequencies are similar to those that
hazards. On the other hand there is extensive literatureexist in the electrical oscillations of the human body,
on so-called non-thermal effects of weak microwavespecifically 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, cellare 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 possibilitywhen 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 telephoneindicated this theoretical possibility, however. These and
handset are absorbed by the human head; the radioother non-thermal effects are summarized in (Hyland,
waves emitted by a GSM handset, for example, can2000).
have a power of up to 2 watts, and an analog phoneOther 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 installednormal cellular response to an increase in temperature.
in cars. Other digital mobile technologies, such asThe noted German biophysicist Roland Glaser, for
CDMA and TDMA, have today lower rates, under 1example [6] has argued that there are several
watt. The average radiation rate of cellphones in somethermoreceptor molecules in cells, and that they
countries is regulated and it is mandatory to inform theactivate a cascade of second and third messenger
consumers about it (usually printed in the batterysystems, gene expression mechanisms and production
compartment). In some systems the cellphone and theof heat shock proteins in order to defend the cell
base station check reception quality and signal strengthagainst metabolic cell stress cause by heat. The
and the power level is increased or decreasedincreases in temperature that cause these changes
automatically, within the above limits, such as insideare 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 humanapparent stability of thermal equilibrium in their cell
body is measured by the Specific Absorption Ratecultures.
(SAR), and its maximum levels for modern handsetsSeveral reports by national and international experts
have been set by governmental regulating agencies inhave been published in the last 3 years, examining the
many countries. In the USA, the FCC has set a SARscientific evidence provided so far for possible
limit of 1.6 W/kg, averaged over a volume of 1 gram ofdetrimental effects of the use mobile handsets. For
tissue, for most parts of the body. (SAR values areexample:
heavily dependent on the size of the averagingAGNIR REPORT 2003: "Overall the evidence for RF
volume. Without information about the averagingfield effects on cognitive functions in humans is
volume used comparisons between differentinconsistent and inconclusive (...) The biological evidence
measurements can not be made.)suggests that RF fields do not cause mutation or
Thermal effectsinitiate or promote tumor formation and that the
One well-understood effect of microwave radiation isepidemiological evidence overall do no suggest causal
dielectric heating, in which any dielectric material (suchassociations between exposure to RF fields in
as living tissue) is heated by rotations of polarparticular from mobile phone users and the risk of
molecules induced by the electromagnetic field. In thecancer. Exposure levels for those living near to mobile
case of a person using a cell phone, most of thephone base stations are extremely low and the
heating effect may occur in the head surface, causingevidence 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 ofSWEDISH RADIATION PROTECTION AUTHORITY
magnitude less than that obtained during the exposureREPORT 2002 [8]: "No significant associations have
of the head to direct sunlight. The brain's bloodbeen seen between all brain tumors combined and
circulation easily disposes of excess heat byphone 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 temperatureincreased risk. It was considered that it was not
regulation mechanism. Premature cataracts are knownbiologically plausible that exposure to RF fields could
as an occupational disease of engineers who work onincrease 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, cataractsmobile 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 humanMany users of mobile handsets have reported feeling
head are more sensitive to damage due to increasesseveral unspecific symptoms during and after its use,
in temperature, particularly in anatomical structures withsuch as burning and tingling sensations in the skin of
poor vasculature, such as nerve fibers. More recentthe head and extremities, fatigue, sleep disturbances,
results from a Swedish scientific team at thedizziness, 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 phonetachycardia (heart palpitations) and disturbances of the
for a decade or longer can lead to a small increase indigestive system. Some researchers, implying a causal
the probability of getting acoustic neuroma, a type ofrelationship, have named this syndrome as a new
brain tumor. The increase was not noted in those whodiagnostic entity, EHS or ES (electrosensitivity). The
used phones for less than 10 years. The study hasWorld 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 conductedthe implication of causation. This entity is quite
by the Swedish National Institute for Working Lifecontroversial, because albeit identified in unmistaken
supported an increased risk of "malignant tumors onterms by the patients who affirm to suffer from it, in
the side of the head the phone is used." [2] Such longsome cases in such a radical way that they avoid
term heavy use involved phones of older higher powerusing cellphones, it has not been recognized as a
analog designs that were first introduced to Sweden inseparate clinical entity by most medical researchers.
1984, earlier than many other countries.Two recent literature reviews, however, one reviewing
Non-thermal effects13 published papers in 2003 and 2004, and another
In December 2004 a pan-European study namedreviewing 31 papers published before 2004, have
REFLEX, involving 12 collaborating laboratories inconcluded that there is no scientific evidence for a
several countries showed some compelling evidencecausal relationship between the reported clusters of
of DNA damage of cells in in-vitro cultures, whensymptoms and exposure to microwave radiation used
exposed between 0.3 to 2 watts/kg. This overlapsin cellphones, well below the safety standards. A
with the level of radiation typically emitted by digital cellworkshop conducted by the WHO in Prague in 2004
phones of around 0.2 to 1 watt/kg. There werealso reached the same conclusions, viz., that 1)
indications, but not rigorous evidence of other cellreported 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 ademonstrated between exposure and symptoms, 3)
boosted rate of cell division. The results of this studythat patients who display those symptoms should be
run contrary to many similar studies that weremedically examined for alternative explanations and
conducted before and showed no increase in DNAcauses, including psychiatric/psychological ones (since
damage. .they are typical manifestations of stress and other
According to a recent (2004) review published by thesomatization/psychosomatic causes), and that the
UK National Radiation Protection Board (Z Jenvironment where they work or live should be
Sienkiewicz and C I Kowalczuk ), "the effects reportedassessed in order to discover other factors at work
by the REFLEX project do not appear to have beenthat could explain the symptoms; and 4) lowering the
seen consistently (...) Overall these inconsistencies dosafety limits for handset radiation (SAR levels) will not
not suggest that robust responses have beenaffect the situation.