Research on EMFs and LED lights
As with information about EMFs generally, information about EMFs and LEDs is very scant.
Creating Healthy Homes suggests that the only reason LEDs could produce EMFs is with the creation of ‘dirty electricity,’ which some LEDs allegedly produce depending on their configuration and wiring setup. They write that, “If an LED bulb has a switched mode power supply, it usually produces dirty electricity but not always. [The] problem with switched mode power supplies is that they reduce voltage and convert from AC to DC by squaring off the sine wave of 60 Hz AC electricity, thereby producing harmonics of dirty electricity as a side effect. These harmonics then radiate off circuits in your walls running throughout the house and from AC power cords that you plug into outlets.”
Another site, from the Electromagnetic Fields by B. Blake Levitt that, “Light Emitting Diode (LED) bulbs are far cleaner [and] emit no EMFs.‘ But later on their page, they write that “LEDs are extremely low EMF; they do have a small transformer which reduces the voltage to the device, although electriCLEAR uses ‘line-voltage’ LEDs which have no transformer and are truly zero EMF.”
Another source I found about the LED-EMF connection was Natural News, which is not a site I use as a reference very often as they tend toward alarmist. They state that, “LEDs […] do not create EMF dirty electricity–” which is the opposite of what these other sources claim.
With the exception of Natural News, most of the information about the EMF-LED connection is that the ‘research’ comes from sites that are offering services related to such topics.
LED EMF test results
|MF Reading in milligauss(mG)||2”||12”||24”|
|Power OFF||0.25 mG Average||–||–|
|Halo EL-405827 Full Bright||0.80 mG||0.25 mG||–|
|Halo EL-405827 Dimmed||0.30 mG||0.25 mG||–|
|Cree CR 4E-15 Full Bright||0.65 mG||0.25 mG||–|
|Cree CR 4E-15 Dimmed||0.33 mG||0.25 mG||–|
|Lutron DVCC-153P-WH||2.72 mG||0.70 mG||0.25mG|
MF from LED Lights Analysis
The dimmer appears to produce the strongest and largest magnetic field, starting at 2.0 mG and not receding to background levels until 24 inches away.
Compared to an incandescent lamp, which does not generate additional EM waves on its own but creates an alternate electromagnetic field with the same frequency of the AC voltage, an LED lamp has much more EM noise because of the frequency omponents introduced by the rectifier.
The effect of an LED lamp with a simple rectifying circuit is noticeable, the EMF is still of low frequency but can reach several hundreds Hz or even few kHz.