Electromagnetic Energies in Man’s Immediate Environment

Abstract

The increased utilization of electric energy in man’s immediate environment raises the urgent question of whether such energy might not cause changes, perhaps even radical ones, in human living conditions. High-voltage transmission lines in particular may seem menacing to the layman and generate fears that their presence, especially near homes, may have adverse effects on health. But health questions are raised not only by high-voltage lines for 50- or 60-Hz power current and 16 ²/₃ Hz railway current (in central Europe), but also by electric railways themselves (15,000 V, 16 ²/₃ Hz), for very strong currents arise in the overhead contact lines at irregular intervals, combined with a return current which may flow over paths other than the rails. Because these rails are not specifically insulated from the gound, substantial stray currents may arise at points many kilometers distant from the rails (Fig. 12-1). Household power current, to which modern man must live in close proximity, is yet another factor, even though the voltages in this case are substantially lower (110 V, 220 V or 380 V). Other sources of electromagnetic fields, such as telephones, radios, television sets, etc., will be disregarded for the time being.