Among the many features considered with various source of lighting, health issues rarely come up. In many of my previous articles at www.ledtubes8.com, I have enlisted numerous reasons why LEDs are eventually the best solutions for lighting. In comparison with other forms of artificial light, LEDs always win over, as they are cheaper in the long run, more energy-saving than any other form of light, more eco-friendly, and more durable.
The most obvious issue with light – let that be natural or artificial source – is flickering. Even sun light can flicker under shady circumstances (among trees for instance), and strangely that would mean a health risk too, for those suffering from photosensitive epilepsy.
It is significant to differentiate between visible and invisible flicker of the light though. With artificial sources of light, we have to examine both forms and their hazards to health. The extent of the flicker depends on the frequency of light. Visible flicker is typically between 3-70 Hz of frequency, though what we classically define as flickering light is below 40 Hz. Normally, no form of artificial light should fall into this range, however we probably all have experienced flickering fluorescent tubes, as well as incandescent lights. Visible flicker of any light is a danger for those suffering from photosensitive epilepsy, but also autism. The stroboscopic effect also damages the eyes, and we simply do not see well in this light (we cannot identify edges sharply, motions seems slower, etc).
Both incandescent lights and fluorescents operate at the standard 50/60 Hz, which is the frequency of the alternating current electricity supply, depending on the region. To avoid visible flickering, fluorescent tubes use an additional ballast to double this frequency, but with the aging lamp, the frequency will gradually drop. Fluorescent lights also flicker when lighting up, as the gas included needs time to heat up.
With LEDs, visible flicker should never happen. The light turns on instantly, and without flicker; and operates at minimum 120 Hz frequency. Only a few occasions of flickering LED light were reported so far: obviously malfunctioning light – but that you should always get rid of; some electronic devices can manipulate the frequency of light, also flicker can occur with dimming. Dimming of any form of light may lead to flicker though, since the frequency of light reduces with any form of dimming (analogue or PWM).
Invisible flicker can also be hazardous to our health. Even though the human eye can rarely detect the flicker of the light over the frequency of 70 Hz, it still might affect health. Strained eyes, headaches, even migraines have been reported due to low quality light, or hardly visible flicker. The sources are low-frequency lights of incandescent or fluorescent forms, or televisions and monitors. LED lighting, operating at high frequency, simply does not cause any of the above-mentioned problems.
Other, more obvious advantages of LED lighting are its noiseless running, there is no humming sound during its operation. There are no poisonous substances are included in the LEDs, so their disposal is safe and eco-friendly. Fluorescent lights are very dangerous on the other hand, since they contain mercury, a poisonous substance. Many argue that properly used fluorescents are no danger to the user, however if they break, it is best to leave the spot for four hours, and this can mean a real threat for those who regularly install these lights. LEDs are also recyclable, unlike other forms of lighting.
The heat, emitted by LEDs is so little, that they are safe to the touch, even after several hours of operation. LEDs also do not emit UV radiation (unlike fluorescents), so they are safe for desktop and task lights from a short distance.
According to the findings of one of the recent researches by NASA LEDs are not only safe to our health, but can be beneficiary for it. The original aim of the research was to find fast ways of growing plants in space during long-term expeditions. Results included that deep photon infrared form of LED lighting increases energy inside the cells, so its therapeutic use is possible for speeding up healing in cells (for deep wounds or recreation after tumor operations), but the light is also used for cosmetic purposes, like rejuvenating aging skin. Whatever is true of rejuvenation, early issues of LED lighting dangerous to health is far from reality.
