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August 5, 1992

Electromagnetic Pulse and Its Effects

Author Affiliations

From the Board of Trustees, American Medical Association, Chicago, Ill.

JAMA. 1992;268(5):639-641. doi:10.1001/jama.1992.03490050087032

ELECTROMAGNETIC pulse (EMP) is an electromagnetic phenomenon that results when a thermonuclear device or weapon explodes above the earth. Resolution 14, adopted at the June 1988 Annual Meeting of the House of Delegates of the American Medical Association (AMA), requested that the AMA evaluate the risk to US hospitals from EMP and recommend steps to counter the threat. This report, Report P of the Board of Trustees, is a response to that request.

THE NATURE OF EMP  When a thermonuclear bomb explodes, a tremendous amount of energy is released; about half of it is kinetic, one third is thermal, and the remainder is in the form of ionizing radiation. About one thousandth to one millionth part of the total energy consists of gamma radiation, which produces "Compton recoil electrons," a fundamental cause of EMP.1-3There are two basic types of EMP, a relatively slow electromagnetic pulse called "magnetohydrodynamic" EMP