It is a common misconception that cell phone usage causes cancer. The cell phone signals are basically electromagnetic signals and mobile phones are low-powered radiofrequency transmitters, operating at frequencies between 450 and 2700 MHz with peak powers in the range of 0.1 to 2 watts. The well-known electromagnetic spectrum is shown below for reference.
When human body is exposed to powerful electromagnetic radiation like X- rays and Gamma rays, the radiation causes to break chemical bonds and ionise molecules in the cell DNA structure pulling out electrons. The damaged DNA replicates defectively and unwanted cells are accumulated , the condition we call it as Cancer or Tumour. But, the cell phone radiation is not powerful enough to either break chemical bonds or to ionize the tissues. When such low radiation incidents on any object , the electrons in the object are jiggled by the transfer of energy from the radiation and the heat is produced. Even the intensity of radiation is increased , the energy per photon remains same (according quantum theory) and cannot ionise human tissues. In fact, Infrared radiation emitted in candle flame is more powerful than cell phone signal! If it is true that low energy radiation like microwaves or cell signals causes cancer, then by now, many would have suffered from tumours due to constant exposure to radio broad casting waves which are being transmitted from long back. The radio waves are more or less similar to low power mobile signals. Actually, every day we are exposed to cosmic radiation from space and sunlight which contains more powerful ultraviolet radiation , still, we are able to bear them successfully. WHO also agreed that there is no substantial evidence of cancer caused due to exposure to cell phone radiation. WHO stated regarding the health effects of mobile phone radiation :
“A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. To date, no adverse health effects have been established as being caused by mobile phone use.”
Too much usage of cell phone may cause negligible temperature rise in brain or any other organs of body due to heat produced by the radiation. The radiation is mostly absorbed by the skin and other superficial tissues and the internal organs are not directly exposed. The mobile phone radiation, by its very nature of electromagnetic properties, is not powerful enough to be carcinogenic. However, due to increase of cell phone towers in large numbers, and the health hazards of long term usages is not yet conclusive (as the usage multiplied from 1990 onwards only in the world), radio frequency exposure limits in terms of SAR are set for safe usage.