The electromagnetic spectrum is a scale of frequencies (or alternatively, a continuous scale of wavelengths) defining the entire range of electromagnetic radiation. The scale extends from the lowest frequency (corresponding to the longest wave length) through to the highest frequency (corresponding to the shortest wave length).  There is an inverse relationship between frequency and wave length.  The electromagnetic spectrum is divided into frequency ranges (for example, ultraviolet, visible light, infrared, radiofrequency, and extremely low frequency) according to their actual use, their physical properties and their potential health effects.

The spectrum is generally categorized into two principal electromagnetic radiation types: non-ionizing radiation and ionizing radiation.

The Electromanetic Spectrum

The energy embodied in electromagnetic radiation depends on the frequency (or wave length) and/or amplitude (height) of the electromagnetic fields.  The different frequencies of electromagnetic radiation are usually represented on a scale known as the electromagnetic radiation spectrum.

This scale may be divided into two main ranges, according to the amount of energy of the electromagnetic radiation, by frequencies: ionizing and non-ionizing radiation. This classification expresses the ability or non-ability of the radiation to cause changes in the physical structure of the atoms or molecules of matter.

Over the past few years there has been much controversy regarding the effects of non-ionizing radiation on cells and on living organisms.  Scientists studying the effects of non-ionizing radiation on health have proposed a number of possible mechanisms through which radiation may affect the living body:

• Thermal effects (heating)

Non-ionizing radiation may react with biological tissues through a variety of mechanisms.  As far as we know today, non-ionizing radiation is unable to directly affect genetic material (DNA) because its energy level is not high enough to destroy the bonds between atoms and molecules of body cells.

The word radiation usually refers to electromagnetic radiation.  Electromagnetic radiation is energy that spreads through space or through various types of matter in the form of waves.  Radiation is emitted by many different sources that are man-made (e.g. antennas/base stations) or natural (e.g., the sun). Electromagnetic radiation is a combination of electric and magnetic fields – electromagnetic fields – created by charges and electric currents.  Electromagnetic radiation is described by physical attributes that include frequency, wave length and indicating the intensity of radiation. Matter absorbs electromagnetic radiation in the form of tiny particles of energy called photons.  In this manner, in our visual system, cells in the retina of the eye absorb photons of visible light , and translate them into images.  The magnitude of absorption of electromagnetic radiation by matter depends both on the attributes of the electromagnetic radiation and on those of the absorbing matter.

Like adults, children are exposed to a wide range of environmental agents that may be harmful to health; these include air pollutants, toxins in water and food, chemicals (pesticides, mercury, lead), as well as noise and environmental radiation (UV radiation, radiofrequency radiation, radiation from the electric grid, etc.). The nature of the environmental agent, the timing of exposure and the degree of exposure determine the risk of developing diseases.

Pregnant women are defined as a population at risk mainly because of the developing fetus.  The fetus growing in the mother's uterus receives its nourishment and oxygen from her, and it is sensitive to various environmental agents to which the mother may be exposed during the pregnancy.

No research has been reported on the effect of non-ionizing radiation on patients suffering from chronic diseases.  It is therefore advisable to act according to the precautionary principle and educated use of devices that emit non-ionizing radiation.

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