MOBILE PHONES, CELLPHONE TOWERS, AND THEIR NEED
A cellular phone or a cellphone or a mobile phone is a phone that works on the basis of a radio link present in a geographical area.
A cellphone tower is a telephonic site where equipment related to electronic communication is placed, usually in a location at a great height, so as to create a cellular network without any obstructions. 
Cellphone towers operate at the radiowave frequency, and emit non-ionizing radiation which cannot enter the DNA of tissues due to low energy.
The main purpose of constructing a cellphone tower is to ensure the existence of a cellular network, transmission of communication signals, and process all these signals so as to create an efficient and receptive communication area. 
Specific Absorption Rate (SAR) 
On exposure to a radio frequency electromagnetic field, the rate at which energy is absorbed by the human body and its tissues is the Specific Absorption Rate (SAR). The transmission levels of radiation emitted by a cellphone are measured in terms of Specific Absorption Rate.
SAR is defined as the power absorbed per mass of body tissue. The units of SAR are Watts per Kilogram (W/kg).
In order to measure SAR of a mobile phone, the phone is placed near the head. SAR is then measured at that location in the head where the absorption rate is measured at its maximum peak.
There is no fixed "safe" SAR value for mobile phone devices. However, the lower the SAR value, the better.
Different countries have different standards for permissible SAR levels -
• USA - 1.6 W/kg or below
• European Union - 2 W/kg
• India - Follows US SAR standards. All mobile phones are required to have a hands-free mode so as to reduce transmission of mobile phone radiation to the head.
HEALTH EFFECTS OF CELLPHONE RADIATION
According to the WHO, mobile phone radiation is classified as "possibly carcinogenic". It is placed in Group 2B on the International Agency for Research on Cancer scale. In other words, mobile phone radiation could be a risk factor for carcinogenicity. However, the long-term health effects of mobile phone usage need to be studied in greater detail. 
Approximately, around 20-80% of radiation emitted by a cellphone penetrates to a distance of about two inches into the adult brain.
The side-effects of cellphone radiation exposure are as follows - 
1. Blurry vision
4. Memory Loss
5. DNA changes
6. Birth Defects
7. Metabolic Disorders
8. Hormonal Imbalances
Other than the possible risk of carcinogenicity and the above-mentioned side-effects, the major health effects of exposure to cellphone radiation are as follows - 
1. Radiation emitted by mobile phones could have an adverse impact on the functioning of certain cells, such as gene expression, protein activation, and cellular communication and signaling.
2. Radiowaves emitted by mobile phones may increase the permeability of the blood brain barrier.
3. Studies have shown that long-term usage of mobile phones causes low sperm count and other infertility issues in men.
4. Although the WHO regards mobile phone radiation to be "possibly carcinogenic", however, the evidence for the existence of a direct link between mobile phone radiation and cancer is debatable.
5. Upon exposure to radiofrequency radiation (RFR), it was observed that a decline in cognitive functioning occurred in male subjects.
6. Some users have reported hypersensitive reactions to electromagnetic radiations after mobile phone usage. The signs of these hypersensitive reactions include fatigue, dizziness, headache, stress, palpitations, etc.
7. It has been found that even the presence of a weak radiation field emitted by a cellphone has the capacity to affect brain activity levels by altering levels of brain glucose.
8. Usage of cellphones during pregnancy can increase the chances of the foetus developing ADHD.
9. Usage of mobile phones close to surgically-implanted artificial medical devices such as pacemakers, defibrillators, etc. can interfere with the functioning of these devices.
10. Usage of mobile phones (even in "hands-free" mode) while driving can act as a distraction, and increase chances of road accidents.
11. Use of mobile phones for more than five years is associated with an increased risk of acoustic neuroma, and the risk of developing the disease increased with increased usage of cellphones.
PROTECTION FROM CELLPHONE RADIATION
Some countries issue advisories to their citizens regarding the usage of cellphones so as to minimize the effects of radiation emitted by them - 
1. While using the cellphone for verbal communication, ensure usage of hands-free sets or a bluetooth device so as to minimize the exposure of radiation to the head
2. When not in usage, cellphones should be kept away from the body
3. Even from a safety perspective, do not use cellphones in vehicles.
4. Usage of mobile phones by children should be monitored so as to minimize exposure to radiation as much as possible.
5. Use text messaging (short messaging service) instead of calling as a means to communicate using a cellphone so as to minimize exposure of radiation to the brain.
6. Use cellphones with minimal SAR levels - the lower, the better.
7. Use a scientifically-proven EMF protection device which offers protection from cellphone radiation, and minimizes its impact on the body.
8. Use cellphones in airplane mode as far as possible. The airplane mode cuts off all wireless communication and transmission, and the impact of cellphone radiation is minimized to a great extent.
9. While sleeping, maintain a distance of at least six inches between the cellphone and your head to minimize exposure to radiation.
10. For verbal communication purposes, toggle the use of a cellphone by alternatively keeping the phone away from the head for speaking, and bringing the phone near the head only for listening.
11. Use the cellphone only when the signal strength is at its maximum. Weak signal strength means that the phone will emit more radiation in order to increase its signal strength.
12. Do not use the cellphone in enclosed places such as vehicles, elevators, or other places containing metallic devices. Cellphones draw more power and emit greater radiation in the presence of metal.
13. At home, try to use the wired landline phone as far as possible to minimize exposure to radiation.
14. When not required, turn off all "wireless" communication connectivity in the cellphone such as the wifi connection, Bluetooth, etc.
Related Youtube Video
 http://www.youtube.com/watch?v=v7wCeuSqm34 (Cell Phone Radiation Safety Tips With Dr Sanja Gupta on Anderson Cooper)
http://www.youtube.com/watch?v=lKXzHW9qMKE (Dr. Oz on Cell Phones and Your Health)
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