As the use of LEDs for lighting becomes more widespread and LED objects multiply, the Anses (French national agency for food, environmental and occupational health safety) has published an update of its 2010 report on the health effects of LEDs in the light of the new scientific knowledge available. The Agency confirms the toxicity of blue light on the retina and highlights the effects of disrupting biological rhythms and sleep linked to 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 LED devices with the highest blue light content, especially for children, and reducing light pollution as much as possible in order to protect the environment.
In the context of energy saving policies and the withdrawal of traditional lamps (incandescent lamps and conventional halogen lamps) from the lighting market, LEDs are experiencing a considerable expansion due to their energy efficient performance. Thus, in a few decades, the exposure of the population to blue light has increased significantly, especially in the evening with artificial lighting or screens rich in blue light. Indeed, LEDs, due to their technological specificity, can emit a light rich in short wavelengths, known as "blue-rich", and a more intense illumination than other light sources, which can induce effects on human health as well as on the environment.
At the very beginning of the deployment of this technology, the first assessment by Anses underlined the toxicity of blue light for the retina in LED lighting and recommended that the regulatory and normative framework be adapted. As a result, for domestic lighting, only LED lamps in risk groups 0 or 1 (in accordance with the NF-EN-62471 photobiological safety standard) are currently accessible to the general public. The most risky lighting (groups 2 and 3) is reserved for professional use under conditions that guarantee the safety of workers.
Today, the 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 light from LEDs highlighted.
The new scientific data supports the 2010 finding that blue light is toxic to the eye and can lead to impaired vision. They show short-term phototoxic effects from acute exposure and long-term effects from chronic exposure, which increase the risk of age-related macular degeneration (AMD). Warm white" LED household lighting is indistinguishable from traditional lighting and has a low risk of phototoxicity. On the other hand, other types of LED lighting, such as torches, car headlights, decorations or toys, may emit particularly high blue light levels and belong to risk group 2, but they are not covered by the current regulation.
Furthermore, the report highlights that even very low exposure to blue-rich light in the evening or at night disrupts biological rhythms and therefore sleep. The Anses stresses that computer screens, smartphones and tablets in particular are major sources of blue light and children and adolescents, whose eyes do not fully filter blue light, are a particularly sensitive population.
The expertise also shows that a high proportion of LED lamps show significant variations in light intensity. Certain populations such as children, adolescents and professionals could be more sensitive to the potential effects induced by this light modulation: headaches, visual fatigue, accidental risk, etc.
Develop regulations and better inform the public about the risks associated with exposure to blue light.
In view of the results of its expertise, the Anses issues a series of recommendations to limit the population's exposure to blue-rich light. The Agency recalls the importance of favouring "warm white" domestic lighting (colour temperature below 3000 K). In order to prevent the effects of disruption of biological rhythms, it recommends limiting the exposure of populations, and in particular children, to blue-rich light from LED screens (mobile phones, tablets, computers, etc.) before bedtime and during the night.
In addition, the Anses recommends that the regulatory framework for all LED systems be changed and in particular to
restrict the availability of LED objects to the general public to those of photobiological risk group 0 or 1;
limiting the light intensity of motor vehicle headlights, while ensuring road safety
minimising the level of temporal modulation of light emitted by all light sources (lighting, displays, LED objects).
On the other hand, concerning 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 very variable. Moreover, their effectiveness in preserving circadian rhythms has not yet been proven. The Anses encourages the establishment of standards defining the performance criteria of protective equipment against blue light.
An impact on biodiversity and the environment.
As regards the environment, the available studies mainly concern artificial light at night in general and not specifically LEDs. Regardless of the ecosystem studied, scientific knowledge converges in showing 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 strengthened to limit light pollution, while ensuring the safety of people.
