Urban-centric lighting is the research topic of an Urban Lighting Task Group, promoted by CICAT, the Spanish Lighting Industry Cluster, and was created to carry out an innovation project of applied research about the influence of exterior lighting in human health. The project that we want to share in Healthy City Design International 2023 is a collaborative effort between companies of the lighting industry ecosystem, an applied research project aimed to foster innovation and share knowledge between the academia, the institutions, the independent consultants, the designers and the industry. The research project is being carried out by a task group formed by professionals from different companies in the form of a real-world experience in public space. Such methods and technologies are an application of evidence-based knowledge in the field of artificial lighting for the sake of health and well-being. There is also a fundamental source of awareness that comes from social sciences about how the built environment design promotes well-being, or else constitutes a hazard for health. The starting point of this search for innovation in lighting for the public realm is the will to address the challenges that contemporary and future urban spaces are facing. These challenges are the direct consequence of the need for healthier, more sustainable, less polluting, and more inclusive urban spaces, and affect the work of all the professionals that design and plan for the public realm. The main purpose of this project is to evaluate and discriminate the objective parameters that will define the lighting design and its features, choosing among the available technological innovation those that are properly grounded on scientific evidence. At the same time, there is research and innovation that come from disciplines such as ecology, environmental psychology, critical urban studies, and sociology, that are strictly necessary to nurture with sense and meaning design decisions in the urban realm. They have given the knowledge for establishing critical approaches such as gender perspective and environmental justice awareness, among others. Such approaches should be included in the toolset for the building of a complete methodological framework following a holistic concept of health and well being. This why we need to identify and evaluate inclusive lighting strategies on urban space, to avoid those that drive in an unequal or unjust result for reason of gender, race, age, or socio-economic status. From the biological perspective, the framework must apply the knowledge and scientific evidence about the non-visual effects of lighting on mental and physical health and has the parameters that involve this interaction identified and quantized. This effects on health and behavior have been studied and demonstrated on humans, animals, insects, and plants, so there is a founded consciousness about the harmful effects of light at night on living organisms.

1. PROJECT APPROACH: TACTICAL URBAN
INTERVENTION METHODOLOGY
Urban-Centric Ligh ng: Applying innova on
in public ligh ng for the healthy and inclusive city.
Alberto Barberá Duelo, Ligh ng Designer. Anoche Ligh ng Design
Andrea Padré, Cluster Manager. CICAT
The experimental lighting is installed in Parc del Molinet since the summer of 2022.
This is a green public space just by the Besòs Riverside Park, a natural frontier
between the cities of Barcelona and Santa Coloma de Gramanet, a town of medium-
low-income population. The restoration of the Besòs riverbanks has reclaimed a
natural space that is now a successful asset for the neighbours. The park was built
and is currently owned and maintained by AMB (Area Metropolitana de Barcelona) in
the late 90’s. AMB is the public administration of the metropolitan area of Barcelona, a
large urban conurbation made up with 36 municipalities. A supra-local institution that,
among other attributions, manages, plans, and makes urban and mobility projects at
a metropolitan level. AMB and its technical team has collaborated and integrated into
the Task Group to develop and execute the prototype, and now is the owner of the
installation.
The installation consists of luminaires with double LED emission, that provide a
tunnable spectrum for the light, controlled by sensors in a closed and autonomous
bluetooth network that works unmonitored. Equivalent Daylight Illuminance (MEDI)
is the parameter that we have chosen to guide the spectral contents of the resultant
mixed-spectrum.
This project is a collaborative effort between private companies and public
institutions, aimed to foster innovation and share knowledge between the
academia, the institutions, the lighting designers and the industry. The
research is conducted to the implementation of a real-world experimental
intervention on urban space applying innovative techniques and developing
the required technological solutions, from prototyping lighting fixtures to the
deployment of wireless, bluetooth-based control networks for regulating the
system and managing sensor data. The objective is to develop an evidence-
based methodological framework to assess and minimize the effects on health
of public lighting and light pollution, that cause sleep disorders and circadian
misalignments.
Psychosocial health effects are also considered in the approach. The
perspective of social well-being is based on human-space interaction dynamics.
Affection, subjective perception of trust, sense of belonging, among others, are
successful indicators for such values. Perception of safety is another indicator
that is commonly associated with light at night. This fact causes a gender bias
in accesibility and inclusivity in urban space. In this sense, a holistic approach
to health in the urban environment has therefore to include the intersectional
feminist perspective.
URBAN-CENTRIC LIGHTING TASK GROUP
CICAT is a Lighting Cluster, an organisation that aims to
promote innovation in lighting and is formed by companies
from the lighting industry ecosystem.
URBAN-CENTRIC LIGHTING is a Task Group focused in
innovation research in the field of urban lighting.
THE URBAN CHALLENGES that the project is assuming
include:
- designing healthy and restorative spaces,
- that will serve as common places for interaction,
- applying the ecological and feminist perspective on urban
space planning,
- working for an equitable and just access to technology
and well-beign improvements.
The health effects of ARTIFICIAL LIGHT AT NIGHT are
studied and drive the design decisions.
Lighting for the healthy and restorative city:
Defining a urban lighting framework
for health, inclusion and wellbeing
CASE STUDY: PARC DEL MOLINET (SANTA
COLOMA DE GRAMENET)
STRATEGIES FOR IMPLEMENTATION
The experimental framework has demonstrated in the practice that a positive cost-
benefit balance can be obtained by the implementation of existing, affordable lighting
technology, and the application of empirical evidence-based design decisions and
strategies.
The outcomes regarding urban health are:
- An overall significant reduction of light emission (light pollution). An idle mode is
created with reduced light levels when the space is not used (no sensor input) or
during curfew hours.
- A total elimination of circadian disruption risk by Artificial Light at Night in
outdoor environment. In idle mode the maximum ambient melanopic EDI is 1 lux,
and during activation is less than 10 lux measured at the vertical plane at 1.2m,
following the recommendations by Brown, et al. (2022).
This represents a planning methodology that is able to anticipate and verify the
health effect of urban lighting in the field and in the studio, and that can inform the
manufacturers about the best strategies to develop lighting product for a healthy
urban environment. It is also a powerful tool for developing comprehensive and
effective lighting policies adressed to urban health.
VISIBILITY STRATEGY : Outdoor lighting planned for perceived safety is commonly
associated with higher light levels than those recommended minimum values listed in
the standards. Focusing in visual confort and a nuanced space rendering, while assuring
a correct perception, reduces the overall energy reducing the overall light level and its
uniformity. Information is better read in contrasted visual displays, so a better uniformity
does not assure the best strategy to reduce risk. A visually rich and balanced lighting
promotes well-being and helps in building the restoration effect of a urban space.
CIRCADIAN STRATEGY : KUMUX Spectral Optimisation Software is the tool that has
been used to advance and simulate the biological response in humans to the balanced
blend of 2 different LED light sources, with different spectral content, in order to advance
the biological effect that the prototypes will produce in terms of human circadian
disruption.
TECHNOLOGY STRATEGY : Advanced lighting control is being implemented through
wireless bluetooth networks, that allow to light dimming, spectral blending and sensor-
controlled operation. Due to the technology’s distributed intelligence, networks are
self-sufficient and don’t require external monitoring. This setup is specially suitable
for planning installation retrofitting at a reasonable cost, with no additional electrical
infrastructure.
ECO-SOCIAL HEALTH STRATEGY : Lighting is reduced when sensors don’t report
occupancy, resulting in an overall reduction of light emission. This energy emission
reduction is the best strategy to minimize light pollution. Control over the light levels is
facilitated to the user by the activation of identified motion sensors, that provide with a
20-minute lapse of white light of better color rendering for a more comfortable use of
space.
CONCLUSSIONS AND FUTURE STEPS
It is possible to characterize and design lighting environments and lighting spectra that uses
scientific evidence on the non-visual photoreception to reinforce human health, sleep, well-being
and performance using the Standard CIE S 026:2018. Human physiological responses to light
can be anticipated by the corresponding Equivalent Daylight Illuminance (melanopic EDI),
that uses the relative spectral sensitivity of cones, rods and ipRGC. We have referred to Brown
et al. (2022) recommendations for establishing light exposures that prevent the activation of
non-visual responses.
The Light / Dark cycle is the
main synchroniser of the internal
biological clock, controlling the
production of melatonin, a hormone
that is synthesized in the pineal
gland only in the pressence of
darkness.
Image: Kvetnoy, Int J Mol Sci 2022
A prototype set of lighting fixtures developed on purpose for the
project, have been set to use two pairs of combinations: a mix of
PC-Amber and 3000K LED arrays, and 2200K and 3000K LED
arrays are mounted in standard urban fixtures.
APPLYING METRICS FOR PREVENTING
CIRCADIAN EFFECTS
A: Melanopic Action Spectrum
B: Weighed Spectral Power Distribution
Brown TM, Brainard GC, Cajochen
C, Czeisler CA, Hanifin JP, Lockley
SW, et al. (2022) Recommendations
for daytime, evening, and nighttime
indoor light exposure to best support
physiology, sleep, and wakefulness
in healthy adults. PLoS Biol 20(3):
e3001571.
Project Pictures:
Lighting intervention in Parc del Molinet (Santa Coloma de
Gramenet, Barcelona). This urban green space is managed by
AMB (Area Metropolitana de Barcelona), the public institution
that takes care of strategical infrastructure and land planning in
the metropolitan region of Barcelona.