Environmental Biophysics Branch; Summary Statement

At the present time, the research programs of the Environmental Biophysics Branch cover essentially two areas-nonionizing radiation (microwaves) and noise (auditory and nonauditory effects). Two new programs-the biological effects of light and molecular biophysics-will be started in the very near future. It is the aim of scientists working in the microwave program to develop new microwave exposure systems and to determine the effect of microwave exposure on human health. An important aspect of their research is the development of microwave delivery systems which permit exposure of suitable test systems to continuous wave, pulsed wave and modulated wave radiation of known field characteristics. Other efforts are directed towards the development of instrumental and analytical dosimetric techniques as well as the evaluation of the electrical properties of biological materials. In the health effects area, they are studying the biophysical mechanisms of the interaction of continuous wave, pulsed and modulated 1-10 GHz microwave radiation with biological samples at cellular and molecular levels and are evaluating the effects of continuous wave and pulsed 2.45 GHz microwave radiation on embryonic development and reproductive functions of exposed animals. They are also examining the effects of continuous wave and pulsed 2.45 GHz microwave radiation on the development of the immunological response in animals and investigating the effect of continuous wave pulsed and modulated 1-10 GHz microwave radiation on central nervous system functions and behavior in animals. Studies on the biological effects of 2.45 GHz radiation on a variety of in vitro systems (DNA, mouse embryos, rabbit erythro-cyte, rat lymphocytes) have failed to reveal any significant changes in the irradiated systems other than those that could be directly attributable to thermal heating. However, a small decrease in fertility has been observed when male quails that had been exposed in ovo to microwaves were mated with either control or exposed females. Other research, undertaken by contract, involves an examination of the effects of microwaves, electrical fieldl and magnetic field exposure on biological rhythms in rats; on conditioned behavior in primates ; and on urinary excretion of various metabo-lites and other indicators of neurohormone secretion. These studies may help answer questions about possible health effects of radiation from high voltage lines. Also being studied by contract are the effects of chronic exposure to low levels of microwaves. This is a particularly important aspect of microwave research, since data on long-term effects are needed for the formulation of microwave radiation safety …