Are Led Lights Safe For Human Health?
- May 06, 2019
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A light-emitting diode (LED) is a semiconductor device that emits optical radiation when an electric current passes through it. Most LEDs emit a narrow band of wavelengths ranging from infrared (at a wavelength of approximately 1000 nanometers) to ultraviolet (about 300 nanometers). LEDs are used in remote controls; security lighting; screens for phones, tablets and computers; TV sets; light pointers; home lighting; outdoor lighting; street and garden lighting; traffic signals and increasingly in the automotive industry, to name just some of the applications.
LED lights are up to 90% more energy efficient than incandescent (glowing) light bulbs and last much longer than conventional light sources, making them much more economical and environmentally friendly. They also do not suddenly burn out, leaving people in the dark, but slowly lose their brightness over time. In addition, their flexible size and shape makes it possible to adapt their use to suit various needs. Unlike incandescent light sources, LED emitters are cool. However, in the last several years there are more and more questions about the influence of LED lighting on your health.
Blue Light Benefits (It's not all bad!)
Despite all of the buzz around blue light being a hazard, it is important to remember that the health risks of blue light are very specific to overexposure during evening hours.
In fact, blue light is an essential part of our circadian rhythms, as exposure during the morning and daylight hours provides an indication to our bodies that it is daytime and time for us to be alert.
The best way to maintain regular, healthy and appropriate exposure to blue light is to utilize natural daylight as much as is possible. Of course, many of us live in locations that do not have access to natural daylight for a variety of factors - whether they are architectural, climactic, or geographical.
Preliminary research indicates that a lack of exposure to blue light can have detrimental health effects. Health conditions such as SAD (Seasonal Affective Disorder) have been suggested to be caused by a lack of exposure to natural light, especially common during winter months.
Emit Optical Radiation
LED lights emit optical radiation that could only in certain circumstances potentially damage the eyes and skin depending on several variables that have to be taken into account. These variables include the spectrum (or wavelength distribution) of the LED light source, the intensity of the lighting (especially in the blue-band), the duration of exposure, the health of the eye and how someone is looking at the LEDs – staring at them without blinking or actively moving the eyes, and looking at them straight-on or in their peripheral vision.
Any exposure to optical radiation from LEDs, however, is likely to be insignificant compared with exposure to natural light outdoors. The primary source of optical radiation is the sun. Other types of lighting, like regular lightbulbs, also expose people to optical radiation, which is just part of the electromagnetic spectrum that is divided into radio wave, microwave, terahertz (or sub-millimetre) radiation, optical radiation (infrared (IR), the visible light (VIS), ultraviolet (UV)), X-rays and gamma rays.
The human eye is exposed to high levels of natural and artificial sources of optical radiation of different spectra and intensities over a lifetime. A lifetime of this combined exposure to optical radiation may contribute to degenerative eye diseases, such as age-related macular degeneration.
Health risks of flickering
LEDs are more energy-efficient and can help towards commitments to lower carbon emissions from electricity generation. Yet flicker has proved a problem, as it did before in the case of fluorescent lighting.
Flicker can be bad for your health. Even if it is so fast that you can’t see it and are unaware of it, it can cause headaches and eyestrain and interfere with the control of eye movements. Most lamps flicker between bright and dim but the flicker from LEDs changes almost instantly between bright and black.
This means that sometimes people can see a trail of the same image of a lamp repeated one after the other, every time their eyes move across it. This pattern is particularly noticeable with the LED tail lights of cars, but it can sometimes be seen with LED room lights.
Even without the backing of significant medical or scientific research to back it up, it is hard to argue for any positive health benefits of flicker - it is simply not a natural way for humans to be exposed to light. Natural daylight, candles, and even (most) incandescent bulbs provide a steady stream of light without any flicker. Especially for populations that are sensitive to flicker - such as the elderly and those with certain medical conditions - flicker is an issue that is always best avoided.
When available, look for LED bulbs with a flicker free designation, along with a flicker percentage below 5%, flicker index less than 0.02.
When possible, avoid the use of dimmers altogether, as they introduce an additional risk factor when it comes to flicker. If dynamic brightness control is essential, avoid "dimmable" LED bulbs.
Is LED lighting harmful to your health?
In fact, this is overrated. LED lighting has fewer disadvantages than most other lighting. The only source that can win in the health effects of LED bulbs is the old-fashioned incandescent bulb, but it has withdrawn from the market. In addition, LED bulbs are getting better and better, and all fixtures put safety requirements on the color and intensity of the lights after 2012. You can start replacing old bulbs with LEDs to ensure better health!