Sources and Intensity

Glossary

EMFs

electric and magnetic fields

HV

high-voltage

kV

kilovolt (unit of measurement used for HV lines;
1 kV = 1 000 volts)

V/m

volt per metre (unit of measurement used for electric fields)

µT

microtesla (unit of measurement used for magnetic fields;
1 µT = 1 millionth of a tesla)

Magnetic Field Calculations

The height of overhead transmission lines varies considerably, depending on whether measurements are made near a tower (where lines are at their highest point) or mid-way between two towers (where lines are lowest). For this reason, magnetic field calculations are based on the conductors' average distance from the ground. Furthermore, for all types of lines, magnetic field strengths are measured at one metre from the ground.

For household appliances such as stoves, television sets and hair dryers, the magnetic field values are taken from Electric and Magnetic Fields Associated with the Use of Electric Power, Questions & Answers, published in June 2002 by the National Institute of Environmental Health Sciences.