Abstract: | Establishing safe exposure levels for microwave irradiation is important since new, more powerful emitters are developed and the potential for accidental exposure is increasing. Analysis of the behavior of exposed laboratory animals has proven to be an accurate and repeatable metric for assessing the effects of microwave irradiation. Determining the specific absorption rate (SAR) at which an animal will cease an ongoing behavior has proven useful in the development of safe exposure levels for humans. Behaviors that have been used are simple tasks, and the point at which behavior changes significantly or ceases has often been referred to as “work stoppage.” The tasks have been used to evaluate the overwhelming effects of heating produced by microwave irradiation. Both whole‐body exposures and partial‐body exposures with hotspots have been evaluated. Recent studies have suggested that microwave effects on specific cognitive aspects of behavior such as attention, learning, memory, discrimination, and time perception may occur at SAR levels far below the SARs needed to cause work stoppage. New research studies are underway to evaluate microwave‐induced cognitive effects. Bioelectromagnetics 20:64–74, 1999. Published 1999 Wiley‐Liss, Inc. |