State Seal Industry Links
Daily InformationIndustry LinksLegal Documents

go_searchsite.gif (1592 bytes)

Questions?  Comments?  Contact Us!
Site Tips or "How Do I.....?"Home

Access for People with Disabilities Consumer Info
Complaint Form
About CPUC
What's New on the CPUC Site
News Room
Phone ListingInfo for Consultants
Job Opportunities


What are EMFs?

Electric and Magnetic fields are invisible lines of force that surround any electrical device.  Electric fields are produced by voltage and increase in strength as the voltage increases.  The electric field strength is measured in units of volts per meter (V/m).  Magnetic fields result from the flow of current through wires or electrical devices and increase in strength as the current increases.  Magnetic fields are measured in units of gauss (G) or tesla (T).  Most electrical equipment has to be turned on, i.e., current must be flowing, for a magnetic field to be produced.  Electric fields, on the other hand, are present even when the equipment is switched off, as long as it remains connected to the source of electric power.

Electric fields are shielded or weakened by materials that conduct electricity (including trees, buildings, and human skin).  Magnetic fields, on the other hand, pass through most materials and are therefore more difficult to shield.  Both electric and magnetic fields decrease as the distance from the source increases.

For more information about the technical and health-related aspects of EMFs, please the see the Department of Health Services EMF Program.

Current Issues By Industry
Current Issues in the Electric IndustryCurrent Issues in the Environmental IndustryCurrent Issues in the Gas IndustryCurrent Issues in the Telecommunication Industry