Electro
Magnetic
Radiation
A comprehensive overview of EMR field types, sources, measurement units, and health-relevant exposure categories.
Explore Fields →01 / What Is EMF?
Electromagnetic fields (EMF) are emissions of energy in the form of traveling electromagnetic fields. Extremely low frequency (ELF) fields exist as fields only and do not radiate significantly. As the frequency of an electromagnetic field increases, more and more of the energy is radiated outward from its source.
Frequency Spectrum
Static & Air Ionization
Ionization converts atoms to ions by adding or removing charged particles. The ideal air ion ratio is 5:4 (Neg:Pos). Synthetic materials — plastics, polyester, acrylic finishes — disrupt this natural balance and increase static electricity. Natural alternatives include wood, cotton, wool, lime, casein, and linseed oil finishes.
DC Magnetic Fields
The Earth generates a natural DC magnetic field. Man-made sources include steel trusses, concrete reinforcement, metal piping, metal bed frames, box springs, and metal window or door frames. These materials become magnetized and distort the local DC field.
02 / AC Electric Fields
Electric fields exist between two surfaces or conductors at different voltages. Even with no devices switched on, voltage-carrying wiring inside walls produces AC electric fields in living and sleeping areas. Common sources include household wiring, overhead power lines, lamp and device cables, and charging adapters.
In sleeping areas, the wiring inside walls can produce meaningful electric field exposure even when circuit breakers are off — the field is driven by voltage, not current.
03 / Body Voltage (BV)
Body Voltage is the AC potential induced in the human body by surrounding AC electric field sources. It is an indication of electric field exposure — not a direct measurement of the fields themselves — but serves as a useful diagnostic tool, particularly for sleeping area assessments.
04 / AC Magnetic Fields
Alternating magnetic fields occur wherever AC current is flowing through a completed circuit. Unlike electric fields which exist from voltage alone, magnetic fields require current to be present — something must be "turned on."
Sources include: electric wiring, alarm clocks, dimmer switches, CFL and LED lighting ballasts, power supplies, transformers, motors, cable TV wiring, and outdoor power lines. Average residential exposure is typically below 1.0 mG.
05 / Radio Frequency & Microwaves
High-frequency radiation spans from approximately 30 kHz (radio wave region) up to 300 GHz (microwave region). RF radiation is emitted intentionally by transmitters, and also inadvertently by electronic equipment and electrical wiring.
Radio Waves
Long wave, AM radio, short wave radio, FM radio, TV broadcast stations. Generally lower power density at residential distances.
Microwaves
Radar, cellular networks, Wi-Fi, wireless access points, smart meters, and microwave ovens. Often the dominant RF source in modern homes and offices.
The unit of electromagnetic waves is given as either field strength (V/m or A/m) or power density (µW/cm² or mW/m²).
Harmonics/Noise
Harmonics are distortions of the normal 60 Hz electrical current waveform — whole-number multiples of the input frequency (120 Hz, 180 Hz, 300 Hz, etc.) generally produced by nonlinear loads such as variable-speed motors, switch-mode power supplies, LED drivers, solar inverters, and compact fluorescent lighting.
