Evaluation of interactions of electric fields due to electrostatic discharge with human tissue

Electrostatic discharges (ESDs) produce in the human tissue very strong electric fields of short duration. Possible biophysical interactions are evaluated by comparing the fields in subcutaneous fat/skin to the thresholds for peripheral nerve stimulation, and by computations of membrane potential and electric fields in cytoplasm of a typical cell in bone marrow. It is found that a 4-A peak ESD event is capable of stimulation of nerves located in subcutaneous fat of the lower arm of the hand eliciting a spark, with tens of kV/m and pulse duration of ~80 ns. For the same ESD event, the transmembrane potential (TMP) reaches 32 mV with a pulse duration of ~200 ns (half-width duration). The electric field in the cytoplasm of a bone marrow cell changes from about 8.8 kV/m to-2 kV/m in about 200 ns.