NIF effects of artificial light on the well-being of
humans, which is still used in the working and
residential areas, could be damaging to health.
In particular, the availability on the market of
light sources with cool colour temperature,
unknowingly used during evening hours, can
phase shift the correct human circadian rhythm.
Just as the use of modern backlit screens with
white LEDs, which have a fair amount of light
radiation content of short wavelength, can be
harmful to the normal sleep cycle 3,4,5 . It is for
this reason that recently the manufacturers of
operating systems for these devices have
introduced a feature that can be activated to
automatically reduce the blue light component
emitted from the display from dusk to dawn.
In this mode of operation, the screens acquire
a warm white due to the decrease of the blue
light component.
Position of international bodies
In this context the CIE has taken a cautious
stance, because after the publication of a first
technical report 6 , which presented the first
studies useful to understand how lighting could
be introduced into architectural projects,
optimal for vision and for physiological and
behavioural stimulation, a subsequent
publication 7 came out where a new research
path for the identification of a healthy lighting
in interiors was proposed. In the latter,
however, the fact that the light that enters the
eyes also has physiological and psychological
effects other than vision, is seen as scientifically
accepted data. Great emphasis is laid on the
fundamental importance of artificial lighting
in relation to well-being, but also on the need
for further research in this area. The aspects that
should be deepened by the research concern
the fundamental processes, the patterns of daily
exposure to light, the analysis of longer
exposure times, the relationship between
lighting design applications and the natural
differences between individuals. In addition,
the JTC9 Joint Technical Committee is working
on the preparation of the recommendation
CIE system for Metrology of ipRGC influenced
light response 8 where to define the spectral
sensitivity functions, quantities and metrics,
and to describe the ability of light to stimulate
five types of photoreceptors, S cones, M cones,
L cones, rods and ipRGC, which can contribute
to the NIF effects of light in humans.
Other national and supranational bodies have
published in recent years recommendations that
provide the first scientific and applicative
guidelines for evaluating NIF effects. So it
happened in the USA, with the recommendation
on the relationship between light and health of
human beings 9 and with the norm that defines
the lighting guidelines for hospitals 10 . Also in
Germany a standard has been published that
defines and quantifies some NIF effects of light 11 .
In Europe there is the CEN/TC 169 Technical
Committee within which the working group
WG13 Non-visual effects of light on human
beings operates, who has already published
a technical report 12 that could in fact anticipate
the possible contents of the CIE-JT9 CIE system
for Metrology of ipRGC influenced light response.
In this technical report, metrics are proposed
that can be used to evaluate the lighting on
the human eye compared to the possibility
of generating NIF effects.
The International Association of Lighting Designer
(IALD), by its nature close to the evidence and
requirements of professional practice, has
published a white paper 13 in which the theme of
a holistic lighting design aimed at the objectives
of Human Centric Lighting is introduced. Among
these objectives the theme of circadian lighting
plays a central role, among other topics, such as
LED innovation, flicker, photobiological safety of
light, colour rendering index and the regulatory
situation in the sector. In this article the topic is
presented starting from the scientific researches
of the sector but maintaining a strong applicative
and informative connotation. It is noted that,
with the advent of LEDs, industries have
gradually proposed new products for circadian
lighting or more generally for the well-being of
people in interior spaces. Still, the use of these
products should not be considered equivalent to
a miraculous medicine, but rather a new, more
flexible lighting tool and able, potentially, to
better adapt to the design and end-users needs,
becoming an interesting perspective for lighting
designers in the very near future. However, it is
emphasized that any benefit can only derive
from a correct use of the products, that is on
condition that they are properly installed and
used in order to perform not only a useful
function to the vision but also to the well-being.
The risk to consider is that improper use could
produce potentially harmful health effects.
But this consideration is even more true for other
types of technological products, or products
of the food sector which are misused or excessive
in industrialised countries. Based on these
observations, the IALD provocatively asked if
medical knowledge and skills will be needed for
the lighting designers of the future, stating that
the designer should rather be responsible and
always informed about the scientific and
technological innovations of the sector and about
the new rules and recommendations presented
by international bodies.
Production area
At the beginning of the new millennium, on the
basis of the first researches on the relationship
between artificial lighting and individual
well-being, some companies began to introduce
lighting products for interior spaces, defined
as biodynamic, designed to synchronize the
human circadian cycle 14,15,16 . Yet, those early
experiences were based on linear fluorescent
lamps, inadequate to be used to achieve
circadian lighting, both for their size and for
other technical reasons. Over the past decade
these biodynamic products have largely gone
out of production because of high costs and
management difficulties, but mainly because
they were not understood and accepted
by designers and users. At the same time,
companies in the sector have been committed
to metabolizing the new LED technology, that
is the products that have gradually, increasingly,
replaced the other artificial light sources. The
LEDs are photo electronic components and the
manufacturers, working in the
electromechanical sector for decades, had
to acquire additional skills in the electronics
sector 17 . This process, which was essential
for the survival of the companies themselves,
absorbed most of the resources available for
research and development, effectively relegating
the circadian issue into the background.
Today the situation has changed radically.
The LEDification process has reached a stage
of maturity in which the fundamental question
is no longer how to adopt the new solid-state
lighting technology, but it is to explore all
possible lighting applications that allow to
exploit its full potential. The LightingEurope
association, representing more than a thousand
companies in the lighting industry in the
European Union, declares as basic four areas
of research and development: LEDification,
Intelligent Lighting Systems, Human Centric
Lighting and Circular Economy.
The term LEDification refers to the pathway with
which LEDs have gradually replaced traditional
light sources such as incandescent lamps,
halogen lamps, gas discharge lamps and
fluorescent lamps in recent years. The LEDs
enable energy efficient solutions and, at the
same time, they allow us to improve the quality
of light. New operators, coming from the
electronics sector, are entering this market.
This process has also changed the total value
chain in the lighting products sector. In fact,
lighting fixture manufacturers can now integrate
LED light sources directly into the luminaires
and in many cases there is no longer a physical
separation between the light source and the
lighting fixture. In addition, the products life
cycle has been extended compared to traditional
light sources. Finally, the lighting systems can
and should become easier to configure and
install, to be called smart lighting.
As illustrated, the introduction of LED technology
is moving the lighting products from analog to
digital, creating the new concept of Intelligent
Lighting System (ILS). The ILS are part of an
interconnected system. Since the lighting can
be structured as connected ecosystems in the
buildings design phase both of new buildings
and redevelopment, it can be fitted into the
backbone of an intelligent building. Lighting
is an autonomous system from an operational
point of view but connected to other building
«Lighting can energize, promote relaxation, positively influence mood
and increase the level of subjective alertness and cognitive performance,
but also improve the sleep-wake cycle. In other words, lighting
can support human’s health, well-being and performance,
combining the benefits of a correct vision with the biological
and emotional ones of light»
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LUCE 326 / RICERCA