Above: Animation of a half-wave dipole antenna radiating radio waves, showing the electric field lines. The antenna in the center is two vertical metal rods connected to a radio transmitter (not shown). The transmitter applies an alternating electric current to the rods, which charges them alternately positive (+) and negative (−). Loops of electric field leave the antenna and travel away at the speed of light; these are the radio waves. In this animation the action is shown slowed down enormously. — from Wikipedia.
Standard Building Biology evaluation guidelines recommend levels of exposure of 0.0003 uW/cm2 in the radiofrequency range, or 0.0030 mW/m2 (unit of measurement used on this website, milliwatts per meter squared).
The guidelines define RF radiation levels according to the expertise and experience of the Building Biology Institute, FOR SLEEPING AREAS, as follows:
Radio frequency (RF including microwaves) safety readings in the home (especially in sleeping areas where we spend most of our time):
- No Concern – less than 0.10 μW/m2 (microwatt per meter squared)
- Slight Concern – 0.10 – 10 μW/m2
- Severe Concern – 10 – 1000 μW/m2
- Extreme Concern – greater than 1000 μW/m2
Converted to milliwatts per meter squared (measurements used in the readings on this website):
- No Concern – less than .0001 mW/m2 (< 0.0001 milliwatt per meter squared)
- Slight Concern – .0001 – .0100 mW/m2
- Severe Concern – .0100 – 1 mW/m2
- Extreme Concern – > 1.0 mW/m2 (greater than 1 milliwatt per meter squared)
Measured in field strength with ground potential, shown in Volts per meter (V/m):
- No Concern – less than 1 V/m
- Slight Concern – 1-5 V/m
- Severe Concern – 5-50 V/m
- Extreme Concern – greater than 50 V/m
Health and EMF expert, Magda Havas, PhD., agrees that (especially for children) outdoor microwave radiation levels should not exceed one (1) milliwatt per meter squared, and indoor areas should not exceed .00100 mW/m2.