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To save energy, the European directives from the
Eco-design of Energy Using Products (2005/32/CE)
have recommended the replacement of incandescent
lamps by more economic devices such as Light
Emitting Diodes (LEDs).
However, the emission spectrum of these devices is
enriched in blue radiations, known to be potentially
dangerous to the retina.
Recent studies showed that light exposure
contributes to the onset of early stages of
age-related macular degeneration (AMD).
Now researchers investigate, in albinos and
pigmented rats, the effects of different exposure
protocols.
Twenty-four hours exposure at high luminance was
compared to a cyclic (dark/light) exposure at
domestic levels for 1 week and 1 month, using
different LEDs (Cold-white, blue and green), as well
as fluorocompact bulbs and fluorescent tubes.
Behind the phototoxicity of LED bulbs, a culprit:
blue light. "White light, whether natural or
artificial, actually combines rays of different
colors, each corresponding to a specific wavelength"
explains Alicia Torriglia, who supervised this work
with Professor Behar-Cohen.
Each light source - LEDs, fluorescent tubes or
compact fluorescent bulbs - combines different
colors in varying proportions and the potential
toxicity of each of them on the retina depends both
on the intensity of light and the wavelengths that
compose it.
The rays corresponding to the blue light are more
energetic than the others. They are also known to be
more deleterious for equivalent exposure times and
light intensities.
"Thanks to our observations, we have shown that the
light emitted by LEDs produces two parallel toxic
phenomena: apoptosis, but also a second form of cell
death, necrosis, and necrosing causes a cell to
damage its neighbors. This explains why the toxicity
of blue light is higher than that of other
wavelengths ".
The data suggest that the blue component of the
white-LED may cause retinal toxicity at occupational
domestic illuminance and not only in extreme
experimental conditions, as previously reported.
It is important to note that the current regulations
and standards have been established on the basis of
acute light exposure and do not take into account
the effects of repeated exposure.
THE FRENCH AGENCY FOR FOOD, ENVIRONMENTAL AND
OCCUPATIONAL HEALTH & SAFETY
Maisons-Alfort, 19 October 2010
Conclusions concerning the risk related to
blue light
"...The arrival of LEDs on the lighting market
for the general public is an unprecedented
development: it is the first time that sources
classified in Risk Group 2 have become accessible to
the general public, for use in the home and, most
importantly, with no indication of the risk.
The same LED considered individually or integrated
in a lighting system could be assigned to different
Risk Groups depending on the evaluation distance
imposed by the NF EN 62 471 standard.
As the technology behind LED lighting evolves
over the next few years, lighting performance is
likely to improve considerably.
The risks associated with exposure to LED-based
lighting systems are therefore likely to increase as
the radiance increases..." (Link...)
See also
LED products billed as eco-friendly contain toxic
metals, study finds (2013-05-20)
Link...
How does light affect our brain’s performance?
(2014-04-24)
Link...
Blue light may fight fatigue around the clock
(2014-02-14)
Link...
Smartphones use can affect your sleep (2014-01-24)
Link...
Like coffee, blue light keeps night drivers alert
(18/12/2012)
Link...
For more information
Neuroscience
Light-induced retinal damage using different light
sources, protocols and rat strains reveals LED
phototoxicity
Link...
Inserm - Institut national de la santé et de la
recherche médicale
Link...
anses
Lighting systems using light-emitting diodes (LEDs):
health issues to be considered
Link...
LED – light-emitting diodes
Health effects of lighting systems using
light-emitting diodes (LEDs)
Link...
Complete report available only in French
Link...
OPINION OF THE FRENCH AGENCY FOR FOOD, ENVIRONMENTAL
AND OCCUPATIONAL HEALTH & SAFETY
in response to the internally-solicited request
entitled:
“Health effects of lighting systems using
light-emitting diodes (LEDs)”
Link...
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