Urbanisation is leading to an increase in outdoor lighting technologies in cities, which can disrupt wildlife habitats in urban greenery and alter their natural biological, physiological, and behavioural rhythms. Despite the flexibility of LED lighting technology, it is not being used effectively in practise to minimise ecological disturbances while providing sufficient illumination for people. A PRISMA review of 31 papers on lighting using contemporary LED sources and wildlife species revealed that lighting parameters were inadequately described to (1) characterise the relationship between assessed ecological impacts and light properties and (2) adjust properties of contemporary lighting technologies to reduce such impacts on animals. The authors suggest strengthening interdisciplinary collaborations for informed sustainable development by establishing common procedures and methods to ensure the transferability of research outcomes to practical applications.

This is the third part of a three-part technical report about the Uppsala testbed part of the NorDark research project. The earlier two reports contain the corresponding information based on the existing outdoor lighting installed at the testbed site in Sävja, Uppsala (Dincel, 2023; Dincel, 2024). Part One discussed the method and procedure of collecting data as well as illuminance and luminance levels by hand-held and HOBO sensor devices under different sky and weather conditions. Part Two complemented the first part by including spectral power distribution (SPD) and correlated colour temperature (CCT) values of the same conditions recorded by hand-held spectrometer devices and wearable LYS button sensors. This part focuses on outlining the measured results of illuminance and spectral properties after an outdoor lighting intervention was implemented at the site. The post-intervention measurements described here were conducted on specific days within a timeframe during the period of November 2023 and January 2025.

Modern lifestyles increasingly involve indoor activities, which entails considerations for ensuring sufficient light exposure for circadian entrainment and overall well-being. At higher latitudes, where daylight hours are limited in winter, environmental factors such as snow cover may enhance light exposure through its high reflectance. This study investigates the potential effects of snow cover on human biology and behavior in an urban population in Uppsala (59.9° North), Sweden between December and February. Forty-five individuals were monitored for one week when there was snow cover and another week without snow cover by using actigraphy, diaries, and collection of morning saliva melatonin samples. Our findings suggest that indoor dwellers at northern latitudes struggle to obtain adequate natural light exposure to sustain mood and alertness during December and January. However, snow cover increases morning light exposure, lowers melatonin levels, and enhances alertness and activity throughout the day. On the other hand, snow cover had minimal influence on sleep-wake cycles, sleep quality, and daytime mood ratings.

Reducing light pollution and promoting sustainable lighting practices require new tools that integrate environmental, social, and technical considerations in design processes. Urban Digital Twins are emerging as powerful instruments for this purpose, enabling integrated evaluation of lighting impacts on both people and ecosystems. This paper presents an exploratory evaluation of NorDark-DT, a recently developed urban digital twin designed to support the sustainable planning of lighting infrastructure in green urban areas. This exploratory assessment was conducted with master’s students engaged in lighting design practices. Participants performed two task-oriented exercises of planning and comparing lighting configurations after-dark for a site in Uppsala, Sweden. Results show that NorDark-DT effectively facilitates the exploration of alternative lighting solutions within realistic green urban area contexts and encourages reflection on issues such as light pollution, biodiversity, and ecological preservation. Nevertheless, further improvements are required to enhance the user interface, expand analytical capabilities, strengthen integration with professional lighting software, and optimize performance for varying hardware setups. Beyond professional practice, the tool also proved valuable for educational purposes by promoting interdisciplinary collaboration and broadening students’ understanding of sustainability in lighting design. Overall, this study provides an initial step in a usability assessment of NorDark-DT, confirming its potential to support environmentally responsible, socially aware, and well-informed lighting interventions.

The prevailing implementation and usage of contemporary lighting technologies and design practices in cities have created over-illuminated built environments. Recent studies indicate that exposure to electric lighting effects formed through spatial characteristics has visual, physiological, and behavioural effects on both humans and non-humans, such as wildlife. In order to gain a better understanding of the impact that electric lighting has on space and different organism groups, a comprehensive literature review was conducted applying PRISMA 2020 systematic review guidelines. Results of the searches from various databases, such as Web of Science, PubMed and Scopus, identified 5260 related studies. A total of 55 papers connected to four themes: (1) urban morphology; (2) human visual impressions; (3) ecological impacts; and (4) design approaches and methods were analysed with a focus on urban morphology. The review provided the following general findings: lighting properties alone are inadequate to depict visual impressions of pedestrians, patterns formed through light interacting with spatial characteristics can contribute to understanding how spaces are visually perceived and help characterising the exposure of wildlife organisms to potential disturbances.

This is the second part of a technical report related to the NorDark research project complementing the information in report part one that was published previously (Dincel, 2023). This document outlines the spectral properties of the measured results, such as the spectral power distribution (SPD) and related metrics, for example, the correlated colour temperature (CCT). The measurements were conducted in Sävja, Uppsala, for a specific day and timeframe during the period of November 2022 and February2023. In the first part of the technical report, the information, method and procedure of collecting data related to the measured illuminance and luminance levels on site are presented. This second part of the technical report complements the first part by including an overview summary of the gathered data including SPD and CCT at the horizontal ground and vertical eye level measurements recorded by hand-held spectrometer devices and wearable LYS button sensors. The work was conducted as part of the interdisciplinary research project NorDark.

First part of the technical report outlines the procedures and summary information of the measured results of illuminance and luminance levels conducted in Sävja, Uppsala for specific day and timeframe during the period of November 2022 and February 2023. This report provides a step-by-step overview of the process of defining the project site, the light measurement locations, the development of a light measurement protocol, and the results of the light measurements as well as computer simulations. The first part of the technical report includes horizontal ground and vertical eye level illuminance (lux) measurements. The work was conducted as part of the interdisciplinary research project NorDark.