The health hazards posed by the non-ionizing Radio-Frequency (RF) and microwave radiation are discussed in relation to transmission, absorption, resonance, thermal effects and indirect effects. The interaction with the normal human body, patients with implants, children and monkeys are detailed so as to highlight the correlation of material properties of skin, fat, tissues, bones and muscles with the nature of radiation these are exposed to. The aspect of occupational and general public exposure to continuous as well as pulsed radiation in the near field and far field domains is looked into with respect to the short-term and fatigue effects. Standards and safety regulations of the developed countries and the acceptable levels of exposure are outlined, along with some ground realities on the actual levels of exposure. The Indian scenario, with the advent of telecommunication boom, faces more problems demographically, due to multiple exposures. The need for Indian standards on public health and safety regulations in telecommunications is spelt out with emphasis on the necessity for evolving a science policy in this regard.

The radiation abundant in nature and man-made is classified into many types. The types of man-made radiation are listed in Tables 1a and 1b, along with their respective domain frequencies and wavelengths. Of these, the frequency domain from 1 Hz to 300 GHz is of great interest to us as the entire gamut of the telecommunication range, starting from the AM radio and extending up to the telemetry waves, X band and W band microwaves, falls within this range. Because of their widespread use in telecommunications, their widespread interaction with the human body assumes significance.

The Radio-Frequency (RF) waves, microwaves and the millimeter waves used for telemetry and cooking are categorized as non-ionizing as they do not have sufficient quantum energy to ionize an atom, meaning they cannot eject electrons from an atom or molecule to produce a positively charged core or ion. The threshold for ionization occurs somewhere in the ultraviolet range. However, in the RF and microwaves range, the radiation just contributes to the random molecular motion, which can be described as thermal energy. As an indirect effect of the heating phenomenon, chemical changes are likely to occur in the human body (Nave and Nave, 1985). To have a physiological effect, the energy of the radiation must be absorbed. To be absorbed, there must be quantum energy level pairs which match the photon energy of the radiation. Further, the dielectric constant of the material must also be high in order to absorb the radiation to which it is exposed. A low dielectric constant for the material means good transmission, low loss, low capacitance and low absorption of the radiation (Tummala Rao, 2001). Similarly, a high relative permittivity (the real part and not the imaginary part of a complex function describing it) provides an antithetical effect. Hence, in general, a good capacitance, absorption, energy storage and high loss of energy of radiation are found in high dielectric constant materials with a high relative permittivity.

Interaction of Radio-Frequency and Microwave Radiation with the Human Body, Microwaves, Human interaction, Composite materials, Standards/Regulations, Science policy, dielectric constant, relative permittivity, telecommunications, charged core, ionize an atom, eject electrons .