During the last 30 years, there has been a remarkable devel opment and increase in the number of processes and devices that utilize or emit non-ionizing radiant energies such as micro waves, a form of electromagnetic wave energy and ultrasound representative of mechanical vibration. These energies are used in all sectors of our society for military, industrial, telecommunications, medical, and consumer applications. More recently, the use of ultrasound in biology and medicine has been considerably expanded. These increases in sources of non ionizing radiant energy have resulted in growing...