POWER-LINES AND THE GEOMAGNETIC-FIELD

The metric of prime interest in power line epidemiological studies has been AC magnetic intensity. To consider also possible geomagnetic inv olvement, the orientation of a long straight power line is examined re lative to a uniform geomagnetic field (GMF) with dip angle alpha. An e xpression is derived for the component of the total GMF that is parall el, at an elevation beta, to the circuital magnetic field that surroun ds the line. This component is a function of the angles alpha and beta , the total geomagnetic intensity B-T, and the angle theta between the axis of the power line and magnetic north. Plotting these geomagnetic parameters for known leukemia residences allows one to test for possi ble ion cyclotron resonance or other GMF interactions. This approach, in principle, is an easy addition to existing or planned studies, beca use residential access is not required to obtain local values for alph a, beta, theta, and B-T. We recommend including these parameters in th e design of epidemiological studies examining power line fields and ch ildhood leukemia. (C) 1995 Wiley-Liss, Inc.