At a time when the use of LEDs for lighting is becoming more widespread, and LED objects are becoming more and more common, the Anses (France's national agency for food, environmental and occupational health and safety) has published an update of its 2010 report on the health effects of LEDs, based on new scientific knowledge. The Agency confirms the toxicity of blue light on the retina, and highlights the disruptive effects on biological rhythms and sleep associated with exposure to blue light in the evening or at night, particularly via screens and especially for children. The Agency therefore recommends limiting the use of the most blue-light-intensive LED devices, especially for children, and reducing light pollution as much as possible to protect the environment.
Against a backdrop of energy-saving policies and the withdrawal of traditional lamps (incandescent lamps and conventional halogen lamps) from the lighting market, LEDs are experiencing considerable expansion due to their energy-efficient performance. In the space of just a few decades, public exposure to blue light has risen sharply, particularly in the evening, with artificial lighting and screens rich in blue light. LEDs, by virtue of their technological specificity, can emit light rich in short wavelengths, known as "blue-rich" light, and more intense illumination than other light sources, which can have effects on both human health and the environment.
At the very beginning of the deployment of this technology, Anses' first expert report highlighted the toxicity to the retina of the blue light present in LED lighting, and recommended adapting the regulatory and standards framework. As a result, for domestic lighting, only LED lamps in risk groups 0 or 1 (in accordance with photobiological safety standard NF-EN-62471) are currently available to the general public. The highest-risk lighting (groups 2 and 3) is reserved for professional use under conditions that guarantee worker safety.
Today, Anses is publishing a new report covering all LED systems and taking into account all the scientific data acquired since 2010.
New effects of blue LED light highlighted.
The new scientific data confirm the 2010 findings on the toxicity of blue light for the eye, which can lead to impaired vision. They show short-term phototoxic effects linked to acute exposure, and long-term effects linked to chronic exposure, which increase the risk of age-related macular degeneration (AMD). Warm white" LED lighting in the home is indistinguishable from traditional lighting, and presents a low risk of phototoxicity. On the other hand, other types of LED lighting, such as flashlights, car headlights, decorations or toys, can emit particularly rich blue light and fall into risk group 2, but are not covered by current regulations.
The report also highlights the fact that even very low levels of exposure to blue-rich light in the evening or at night can disrupt biological rhythms and thus sleep. Anses points out that computer screens, smartphones and tablets in particular are major sources of blue-rich light, and children and teenagers, whose eyes do not fully filter blue light, are a particularly sensitive population.
Expertise also shows that a high proportion of LED lamps exhibit significant variations in light intensity. Certain populations, such as children, teenagers and professionals, could be more sensitive to the potential effects induced by this light modulation: headaches, visual fatigue, accident risk, etc.
Develop regulations and better inform the public about the risks associated with exposure to blue light.
Based on the results of its assessment, Anses is issuing a series of recommendations to limit public exposure to blue-rich light. The Agency reminds us of the importance of choosing "warm white" domestic lighting (color temperature below 3,000 K). To prevent disruption of biological rhythms, it recommends limiting exposure of the general public, and children in particular, to blue-rich light from LED screens (cell phones, tablets, computers, etc.) before bedtime and during the night.
In addition, Anses recommends that the regulatory framework applying to all LED systems be developed, and in particular that :
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restrict the availability of LED objects to the general public to those in photobiological risk group 0 or 1;
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limit the light intensity of vehicle headlights, while ensuring road safety;
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minimize the level of temporal modulation of light emitted by all light sources (lighting, screens, LED objects).
On the other hand, with regard to the means of protection available to the general public, such as treated lenses, protective glasses or specific screens, the Agency stresses that their effectiveness against the effects of blue light on the retina is highly variable. Moreover, their effectiveness in preserving circadian rhythms has not yet been proven. Anses encourages the establishment of standards defining the performance criteria of protective equipment against blue light.
Impact on biodiversity and the environment.
As far as the environment is concerned, available studies focus mainly on artificial light at night in general, and not specifically on LEDs. Regardless of the ecosystem studied, scientific knowledge consistently shows an increase in mortality and an impoverishment of the diversity of animal and plant species studied in environments lit at night, including by LED lighting. The Agency recommends that regulations be tightened to limit light pollution, while ensuring the safety of people.