Referred to as EMF, the fields of energy surrounding electric power wires and other current-carrying devices.

Electric power lines, household wiring, and appliances all carry electric current. Since the late 1970s, concerns have been raised about the link between electric and magnetic fields, the invisible lines of force that surround all electrical devices, and cancer. Alternating current (AC), the form of electric power used in the United States, produces fields that induce weak electric currents in objects that conduct electricity, including humans. Direct current, the form of current produced by batteries, is unlikely to induce electric current in humans. The currents induced by AC fields have been the focus of most research on how EMFs may affect human health.

Some studies in epidemiology (studies with humans to understand the cause and progression of disease) have suggested a possible link may exist between...