Interactive effects in 60‐HZ electric‐field exposure systems

Abstract

The level of exposure of laboratory animals to 60-Hz electric fields is commonly specified in terms of the unperturbed field strength present before the introduction of experimental subjects and their cages. In the research reported in this paper, rats were housed in two parallel rows in 12.4 cm x 25.1 cm x 10.2 cm high plastic cages resting on the lower electrode of a parallel-plate exposure system, and the actual perturbed electric fields experienced by an experimental animal were investigated. The most important results are: 1) Reducing the spacing between the exposure electrodes from 8.7 to 1.7 times the height of a singly exposed rat model, while maintaining a constant unperturbed field strength, resulted in a 15% increase in the electric field at the highest point on the surface of the body and a 10% increase in the short-circuit current of the model. 2) For multiple animal exposures, increases of 10% in both the field at the highest point of the body and the short-circuit current were observed when the electrode spacing was reduced from 8.7 to 2.6 times the height of a rat. 3) Plastic cages caused 1--6% reductions in the electric field at the surface of the body, except very near the cage walls, where enhancements of more than 20% were observed. 4) When 16 rats were simultaneously exposed, the short-circuit current, IS, of an individual subject of weight W (in g), that was surrounded on all sides by other rats of weight W, was reduced from the short-circuit current, IU, measurement with the same subject individually exposed as follows: during a 12 h light (sleeping) cycle, IS/IU = 1.00 -- 0.0173W 1/2; during a 12 h night (awake) cycle, IS/IU = 1.00 -- 0.0136W 1/2.

Endocrinological effects of strong 60‐Hz electric fields on rats

“…by Kaune [1981]. Averaged over the duration of the exposure, effective field It has been shown that electric fields experienced by a rat exposed in the Effective field strengths for adult male rats as a function of age are given strengths for the 30-and 120-day exposures reported in this paper are 68 and 64 kV/m, respectively.…”

Electrical parameters in 60-Hz biological exposure systems and their measurement :

“…The parallel plate spacing should be sufficiently large in order to avoid significant perturbation of the surface charge distribution on the top plate by the presence of the animal [19]. The measurements of Kaune [20] indicate that a model animal in the shape of a hemi -ellipsoid on the bottom plate does not significantly interact with the top plate charge distribution when the height of the hemi -ellipsoid is as much as 28% of the plate spacing.…”

“…The influence of plastic enclosures on the field distribution at the surface of a test animal has been studied by Kaune [20].…”

Exposure chamber for determining the biological effects of electric and magnetic fields on dairy cows

“…However, since the dimensions of the exposure chamber are generally not much larger than those of the exposed animals, the field distortion may be much larger [Kaune, 1981].…”