The health impacts of the LED lighting

Focus on the light-emitting diodes

The first visible spectrum LED was created in 1962, emitting only very low-intensity light. The first light-emitting diodes have been used several years in electronics as weak, monochromatic light sources for indicator or warning lights. The blue diode was invented in the 1990s, followed by improvements that made it possible to use it in new and important applications, mainly for lighting and for television and the computer screens. The first white LEDs appeared on the market gradually, particularly for domestic lighting, and have now become increasingly powerful. The light-emitting diodes are now commonly used as normal light sources in various lighting systems: traffic lights, portable lighting, vehicle lights and domestic room lighting, for example.

As a result of their low energy consumption, the market for LEDs is expanding rapidly. They are used in a growing number of sectors for a wide range of applications, including the following examples:

Signposting: traffic lights, city lighting, road and traffic safety (automobile lights), warning lights...
Lighting at home and in the workplace: torches and headlamps, lighting units, spotlights, decorative lighting (spotlights, arrays, decorative strings of electrical lights, etc.), lighting for operating theatres and dentists’ chairs...
Medical or beauty applications: llamps for light-therapy applications, for medical or beauty treatment...

What exactly do we know about the health effects of the LED lighting?

Health effects of the lighting systems using light-emitting diodes

In October 2010, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) published its expert appraisal on the health issues surrounding lighting systems using LEDs.

The light-emitting diodes sold on the market are mainly characterized by the high proportion of blue in the white light emitted and their very high luminance (“brightness”). Indeed, the blue light is a component of white light like that emitted by the sun, or by a conventional light bulb, which is composed of the colours of the rainbow. Then, the issues of most concern identified by the Agency concern the eye due to the toxic effect of blue light and the risk of glare.

Risk related to blue light

The blue light emitted by the LED is pervasive. Thus, the photochemical risk associated with blue light — therefore recognised as being harmful and dangerous for the retina, as a result of cellular oxidative stress — depends on the accumulated dose to which the person has been exposed. Three populations have been identified as either particularly sensitive to the risk or particularly exposed to blue light: children and aphakics persons (with no crystalline lens), patients suffering from certain eye diseases (e.g. age-related macular degeneration, ARMD) and populations particularly exposed to LEDs (certain categories of workers: those installing lighting systems, theatre and film industry professionals…).

However, the European photobiological safety standard concerning the photobiological safety of lamps (NF EN 62471, December 2008, defined by the International Commission on Illumination - CIE and the International Electrotechnical Commission - IEC), applying to lamps and devices using lamps, recommends exposure limits for radiation from these light sources. It considers all of the photobiological hazards that may affect the eye (thermal and photochemical hazards) and defines 4 risk groups:

risk group 0 (no risk). Without risk.
risk group 1 (low risk). The product does not present a risk of exposure limits in normal conditions of use.
risk group 2 (moderate risk). The reflex to look away from the lamp is enough to limit risk.
risk group 3 (high risk). The product may present a risk even for momentary or brief exposure.

Are LED lights bad for your eyes?

No, for the general public, lighting sources do not exceed risk groups 0 (no risk) or 1 (low risk). A guarantee of quality delivered by the TÜV Rheinland certificate, an internationally recognized reference laboratory.

Risk related to glare

Two types of glare have been identified:

discomfort glare, due to the brightness of the fixtures and differences in contrast, results in an instinctive desire to look away from a bright light source or difficulty in seeing a task.
disability glare, due to the the interreflection of light within the eyeball and the brightness of the fixtures, reduces the contrast between task and glare source to the point where the task cannot be distinguished. When glare is so intense the vision is completely impaired.

Therefore, for outdoor lighting concerning the discomfort glare, the LED fixtures must comply with the European standard NF EN 12464-1 ("Lighting of workplaces – Part 1: indoor workplaces").

Bibliography

French Agency for Food, Environmental and Occupational Health & Safety (2010, October 25). Lighting systems using light-emitting diodes: health issues to be considered [online]. Retrieved from https://www.anses.fr/en/system/files/PRES2010CPA14EN.pdf.