DESCRIPTION: This proposal outlines a series of studies using a state-of-the-art in vitro EMF exposure facility to examine, systematically, the effects of 60 Hz EMF exposure on the stress response of cultured human cells. The potential induction of the cellular stress response by 60 Hz EMF will be addressed in a simple series of experiments, with, as integral to their design, specifications for the remote addition of stress-inducing reagents to cell cultures within the exposure field. Quantitative comparisons of sham-exposure versus EMF-exposure will be made in a blinded experimental design. Several endpoints will be followed in response to EMF exposure alone and in combination with known stress-inducing treatments by oxidants or heavy metals. Immunological assays will be used to detect the induction of heat shock protein (HSP) expression for members of each of four major families of human HSP. In a separate set of experiments, a brief pre-treatment with a low-level oxidant stress will be followed by a much higher toxic insult and cell survival will be followed. The potential effects of 60 Hz EMF exposure on the stress response to either phase of these experiments will be determined. All together, these experiments will serve to thoroughly document the ability of 60 Hz EMF to induce a stress response in cultured human cells, and will aid in assessing the extent of risk to whole animals.