الفهرس 
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Abstract
The mobile phone is a modern-day invention, which has managed to
reach many parts of the world enabling telecommunications across areas where it was not possible before. The use of mobile phones is now so extensive that in some countries the number of phone subscriptions outnumbers the population.
Although these devices have proved to be life saving in certain circumstances (e.g., after accidents) and helped improve the quality of life in some sectors concerns continue to be raised about potential adverse health impacts associated with their use. These range from cancer and cognitive deficiencies to subjective effects, such as a feeling of warmth around the ear used, headache and fatigue.
As mobile phones are generally held close to the head during use, one of the concerns widely expressed has been that the radiofrequency (RF) waves emitted during use might lead to an increase in brain cancer risk and adversely affect hearing.
Technically speaking, mobile phones emit electromagnetic radiation radiofrequency, RF) that is essentially non-ionizing (frequencies between 300 MHz and 300GHz). Mobile phones communicate by transmitting radio waves through a network of fixed antennas called base stations. The specific absorption rate (SAR) measures the energy dose that subjects exposed to RF absorb and is expressed in power (watts) by tissue mass (kilograms) {W/Kg}. Effects of this dose deposition by use of cellular phones, however, take long to manifest. In some cases, this duration may by 10 years or more.
A large number of studies have been performed over the last two decades
to assess whether mobile phones pose a potential health risk, a significant
number of these studies has mostly looked for an association between brain
tumors, hearing problems and mobile phone use. based on these studies suggest
no significant adverse effects in the initial years after cell phone use. There is
suggestion of possible significant effects after 10 years.
Summary
97
Short-term effects:
Tissue heating is the principal mechanism of interaction between
radiofrequency energy and the human body. At the frequencies used by mobile
phones, most of the energy is absorbed by the skin and other superficial tissues,
resulting in negligible temperature rise in the brain or any other organs of the
body. The hearing system is in the closest proximity to the device This may lead to
relatively high energy deposition in the ear compared to other parts of the body, so
that hearing is potentially the most affected target of thermal and non-thermal effects.
To date, research has not been able to provide support for a causal relationship
between exposure to electromagnetic fields and short-tem effects of auditory
system.
Long-term effects:
Epidemiological research examining potential long-term risks from
radiofrequency exposure has mostly looked for an association between brain
tumours and mobile phone use. However, because many cancers are not
detectable until many years after the interactions that led to the tumour, and
since mobile phones were not widely used until the early 1990s, epidemiological
studies at present suggest that they need more time to confirm there results.
However, results of many studies suggested that long-term use of mobile phones
may lead to high frequency hearing loss and increased risk of acoustic neuroma after
10 years of mobile phone use. It is concluded that the possible effects of long-term
heavy use of mobile phone would require further investigation. Cell phone
technology too is rapidly advancing and it is claimed that the electromagnetic
exposure is progressively less with newer phones.
Summary
98
For those of us who feel concerned with the issue, it may be appropriate to
observe the following precautions:
1) Use the cell phone whenever it is really needed, for most routine work and casual
talks, use the regular landline connection.
2) Discourage children from excessive use of cell phones.
3) Whenever possible, use a wired ear piece connected to the cell phone.
4) Avoid cell phone use when the signal is weak.
5) Consider alternating between left and right ear while talking on cell phone.