Electromagnetic Fields

People often ask "What are electric and magnetic fields?" Electric and magnetic fields together are referred to as electromagnetic fields, or EMFs. Electric and magnetic fields are invisible areas of energy that surround electric devices. JEA power lines, electrical wiring and electrical equipment all produce EMF. There are two main categories of EMFs:

• Higher-frequency EMFs includes x-rays and gamma rays. These EMFs can damage DNA or cells directly
• Low- to mid-frequency EMFs includes magnetic fields from electric power lines such as those from JEA, appliances, radio waves, microwaves, infrared radiation and visible light. These EMFs are not known to damage DNA or cells directly

Electric fields are produced whether or not a device is turned on, whereas magnetic fields are produced only when current is flowing, which usually requires a device to be turned on. Power lines produce magnetic fields continuously because current is always flowing through them. Electric fields are easily shielded or weakened by walls and other objects, whereas magnetic fields can pass through buildings, living things, and most other materials.

Exposure to Electric or Magnetic Fields

Electric Fields

A person standing directly under a high-voltage transmission line may feel a mild shock when touching something that conducts electricity. These sensations are caused by the strong electric fields from the high-voltage electricity in the lines. They occur only at close range because the electric fields rapidly become weaker as the distance from the line increases.

Magnetic Fields

Magnetic fields can induce the flow of weak electric currents in the body. However, such currents are estimated to be smaller than the measured electric currents produced naturally by the brain, nerves and heart.

More Information About EMFs

• For information about EMFs and cancer, visit the National Institute of Environmental Health Sciences (NIEHS) website
• For information about workplace exposure to EMF, visit the Occupational Safety and Health Administration website
• For information about power lines and other sources of EMF, visit the U.S. Environmental Protection Agency website
• For information about EMF and public health, visit the World Health Organization website