Are mobile/cellular phones harmful to health is a question which has been frequently put forth by many , but few would have got the REAL answers.Many answers have also come forth supported by ’facts’(as claimed) and statistics. I do not promise to provide the answer to the question, but would share my knowledge without using much of technical jargon.
Firstly, let us understand what are microwaves - since these form the basis of every wireless communication device What are Microwaves? microwaves are a form of electromagnetic radiation. as are X-rays, gamma rays, ultraviolet, visible light, radio waves, and radar. Electromagnetic radiation is an electric and magnetic disturbance, a wave that transports energy from a source to a receiver without the actual transfer of material. Microwaves have high frequencies, about 300megahertz to 300gigahertz or more, (which correspond to wavelengths of 100 cms or less) and happen to be strongly absorbed by the human body and by moist foods. The absorption of the microwaves by any object would depend on the size of the atoms which make up the object. Depending on their size, each atom/molecules, different freqencies are absorbed by them. Frequency at which the absorption is the maximum, is termed as its resonant frequency.
Secondly let us understand how a microwave oven works. A microwave oven can be considered as a transmitter, which transmits microwaves at a frequency of 2450 mega hertz into a container inside which the food to be cooked is placed. The resonant frequency of water, which consititute a major part of the item to be cooked, is very close to this frequency. Hence the water molecules vibrate, producing heat, which cooks the food. The maximum heating occurs at a distance which corresponds to quarter the wavelength from the antenna which transmits the microwave.(for those who have studies microwaves, this is obvious and those who have not may accept it without trying to authenticate this)
Let us now come to the matter which is under discussion - cellular phones. Cellular phones use microwave frequncies. Various bands of frequencies are used depending on the type of service used. For example the GSM phones use the frequencies near 830, 900, 1740 and 1900 MHz. Let us consider only the 900 MHz band for our discussion. This has a quarter wavelength of approximately 7.5 cms. Hence the maximum heating takes place at a distance of 7.5 cms from the antenna. Cell phone users may try to identify the organ which is at this distance from the cell phone antenna and do not be surprised if you find your brains there.
Does this imply that the brain would be ’cooked’ during cell phone usage? The answer is partly yes, partly no, partly I dont know. The brain constitues about 70% water, but the resonant frequency of water molecules is at about 2450 MHz and drops rapidly on either sides of this frequency. Hence the heating at cell phone operating frequency is quite less. However the heating of oxygen atoms, which are also present are not less!!! Does it mean the brain will be ’cooked’ slowly?
Fortunately the power transmitted by the cell phones is quite less to cause any considerable damage. However the effects due prolonged usage might cause damage to the brain cells. The next question which may arise is that since we have been using microwaves for years (radio stations, TV stations etc), aren’t we living in a oven and what additional damage could be caused by the cell phones? One property of electromagnetic waves is that its power at any point varies inversely as the cube its distance from its source. To put it simple terms if the power received at a point which is 10 kms away from the transmitter is 8 units, the power received at 20 kms is just 1 unit. Hence we receive a fraction of power from these sources. However, though the cell phones transmit only less power, they are very close to our bodies and the effective power received by the body is quite high. We were never carrying any radio stations near our heads, but we are carrying the cell phones close to our heads!!!! By reducing the usage of cellular phones also we do not succeed in limiting the radiation since the phones are in contact with the base station towers even when you are not talking!!
Are we safe if we use hands free devices? The answer again is partly yes and partly no. If a cell phone is carried near the hip while using a hands free devices, the exposure is not reduced, but is transferred to other organs like kidneys!! How can we reduce the risk? The best solution is not to use the cell phones, but it would’t be possible for many. We cannot throw away the comforts brought about by technological advancements. Some of the implementable solutions are
(a) Avoid placing the cellular phone around the waist and in the trouser pockets for obvious reasons.
(b) Use of radiation shields
(c) Reuction of cellular phone usage
(d) DO NOT GIVE YOUR CELL PHONE TO BABIES(the absorption rate is higher in children for microwaves)
(e) Use of land line phones as much as possible