Laboratory of Environmental Biophysics: Summary Statement

The objectives of the nonionizing radiation research program are as follows: (1) to develop microwave exposure systems for bioeffects research; (2) to develop and test techniques for measuring microwave energy absorption; (3) to determine the effect of microwaves on isolated nerve preparations; (4) to determine how 2450 MHz microwave radiation interacts with biological systems at all levels; (5) to study the effect of long-term exposure of experimental animals to 915 MHz and 2450 MHz microwave radiation on their CNS and behavior; (6) to ascertain the effect of 60 Hz fields firom high voltage transmission lines on the CNS of mammals. During the past year a waveguide system for exposing isolated nerves to microwave radiation has been fabricated and tested. In addition, a 2450-MHz absorber-lined horn system has been modified to permit exposure of pregnant mice. Equipment has also been built to measure the colonic temperature of mice during microwave exposure. Studies on the biological effects of 2450 MHz radiation on a variety of in vitro systems has failed to reveal any significant changes in the irradiated systems other than those that could be directly attributable to heating. However, a small decrease in fertility was observed when male quail that had been exposed in ovo to microwaves were mated with either control or exposed females. One of the most important areas in nonionizing radiation research is the effect of prolonged low level exposure to microwaves. The long-term effects of the exposure of rats to 915 MHz and 2450 MHz is currently the subject of investigation by two contractors. Preliminary results suggest that exposure of pregnant rats to 915 MHz radiation does not alter the relative numbers of viable offspring and stillborns. Studies on the long-term effects of microwave exposure on the CNS and behavior of rats are still ongoing. The effect of longterm exposure of rats to 60 Hz fields is the subject of a third contract.