CONSIDERATIONS FOR HUMAN EXPOSURE STANDARDS FOR FAST-RISE-TIME HIGH-PEAK-POWER ELECTROMAGNETIC PULSES

Development of new emitter systems capable of producing high-peak-powe r electromagnetic pulses with very fast rise times and narrow pulse wi dths is continuing. Such directed energy weapons systems will be used in the future to defeat electronically vulnerable targets. Human expos ures to these pulses can be expected during testing and operations. De velopment of these technologies for radar and communications purposes has the potential for wider environmental exposure, as well. Current I EEE C95.1-1991 human exposure guidelines do not specifically address t hese types of pulses, though limits are stated for pulsed emissions. T he process for developing standards includes an evaluation of the rele vant bioeffects data base. A recommendation has been made that human e xposure to ultrashort electromagnetic pulses that engender electromagn etic transients, called precursor waves, should be avoided. Studies th at purport to show the potential for tissue damage induced by such pul ses were described. The studies cited in support of the recommendation were not relevant to the issues of tissue damage by propagated pulses . A number of investigations are cited in this review that directly ad dress the biological effects of electromagnetic pulses. These studies have not shown evidence of tissue damage as a result of exposure to hi gh-peak-power pulsed microwaves. It is our opinion that the current gu idelines are sufficiently protective for human exposure to these pulse s.