Monday, December 30, 2002		Feature

JUST by their basic operation, cellphones have to emit a small amount of electromagnetic radiation. Cellphones emit signals via radio waves, which comprise radio frequency (RF) energy, a form of electromagnetic radiation.

A lot of talk going on whether or not cellphones emit enough radiation to cause adverse health effects. The concern is that cellphones are often placed close to or against the head during use, which puts the radiation in direct contact with the tissue in the head. There’s evidence supporting both sides of the argument.

Source

When talking on a cellphone, a transmitter takes the sound of voice and encodes it onto a continuous sine wave. Cellphones have low-power transmitters in them. Most car phones have a transmitter power of 3 watts. A handheld cellphone operates on 0.75 to 1 watt of power. The position of a transmitter inside a phone varies depending on the manufacturer, but it is usually in close proximity to the phone’s antenna. The radio waves that send the encoded signals are made up of electromagnetic radiation propagated by antenna. The function of an antenna in any radio transmitter is to launch the radio waves into space; in the case of cellphones, a receiver in the cellphone tower picks up these waves.

Electromagnetic radiation is made up of waves of electric and magnetic energy moving at the speed of light, according to the Federal Communications Commission (FCC). All electromagnetic energy falls somewhere on the electromagnetic spectrum, which ranges from extremely low frequency (ELF) radiation to X-rays and gamma rays. When talking on a cellphone, most users place the phone against the head. In this position, there is a good chance that some of the radiation will be absorbed by human tissue.

Health risks

All cellphones emit some amount of electromagnetic radiation. Given the close proximity of the phone to the head, it is possible for the radiation to cause some sort of harm. What is being debated in the scientific and political arenas is just how much radiation is considered unsafe, and if there are any potential long-term effect of cellphone radiation exposure.

There are two types of electromagnetic radiation: Ionising radiation and non-ionising radiation.

On its Website, the FDA states: "The available scientific evidence does not demonstrate any adverse health effects associated with the use of mobile phones." However, that doesn’t mean that the potential for harm doesn’t exist. Radiation can damage human tissue if it is exposed to high levels of RF radiation, according to the FCC.

The added concern with non-ionising radiation, the type of radiation associated with the cellphones, is that it could have long-term effects. Although it may not immediately cause damage to tissue, scientists are still unsure about whether prolonged exposure could create problems. This is especially sensitive issue today, because most persons are using cellphones than ever before.