Analysis of body hair movement in ELF electric field exposure — For mechanism of seasonal change in perception threshold

For the study of biological effects of ELF electric field, a theoretical and experimental study was conducted on the body hair movement in electric field exposure. First, the dielectric constant of body hair was measured, and its dependence on relative humidity was demonstrated. Then, the electric force and the movement of hair were formulated. After the reasonability of equations was verified in experiments, the property of the electric force was examined. The dependence of the electric force on the dielectric constant of hair has been proved through the analysis of hair movement. The perception threshold in electric field exposure was measured. It became significantly low when the relative humidity increased from 50% to 90%. With these results, we could complete the cause-result chain to explain the seasonal variation of the detection threshold of ELF electric field.