Effects of Grounding on Body Voltage and Current in the Presence of Electromagnetic Fields.

OBJECTIVES The aim of this study was to determine if grounding in the presence of electromagnetic fields (EMFs) encountered in a normal housing environment produces harmful currents in the human body. DESIGN This study had a test-retest design, with duration of 5-15 min per participant. PARTICIPANTS There were 50 participants, of whom 23 were males aged 12-77 years (Mage ± standard deviation = 50.5 ± 19.5 years) and 27 were females aged 13-79 years (Mage ± standard deviation = 45.9 ± 19.0 years). INTERVENTION Each participant was instructed to touch a lamp on a desk with his or her left hand, then to move the hand away from the lamp (first one foot away and then three feet) while his/her body voltage was measured. Each participant was then grounded and instructed to repeat the same hand movements. Current was also measured during the grounded retest. OUTCOME MEASURES The measured parameters were alternating current (AC) body voltage and current generated from contact or proximity to a lamp and other appliances situated on top of a desk. RESULTS AC body voltage was reduced by an average of 58-fold when participants were grounded compared with when they were not grounded. AC currents generated during grounding were several orders of magnitude lower than the accepted minimum level of perception. CONCLUSION Normal levels of EMFs existing in houses are too low to produce harmful currents when a person is grounded.