Light profoundly impacts many aspects of human physiology and behaviour, including the synchronization of the circadian clock, the production of melatonin, and cognition. These effects of light, termed the non-visual effects of light, have been primarily investigated in laboratory settings, where light intensity, spectrum and timing can be carefully controlled to draw associations with physiological outcomes of interest. Recently, the increasing availability of wearable light loggers has opened the possibility of studying personal light exposure in free-living conditions where people engage in activities of daily living, yielding findings associating aspects of light exposure and health outcomes, supporting the importance of adequate light exposure at appropriate times for human health. However, comprehensive protocols capturing environmental (e.g., geographical location, season, climate, photoperiod) and individual factors (e.g., culture, personal habits, behaviour, commute type, profession) contributing to the measured light exposure are currently lacking. Here, we present a protocol that combines smartphone-based experience sampling (experience sampling implementing Karolinska Sleepiness Scale, KSS ratings) and high-quality light exposure data collection at three body sites (near-corneal plane between the two eyes mounted on spectacle, neck-worn pendant/badge, and wrist-worn watch-like design) to capture daily factors related to individuals’ light exposure. We will implement the protocol in an international multi-centre study to investigate the environmental and socio-cultural factors influencing light exposure patterns in Germany, Ghana, Netherlands, Spain, Sweden, and Turkey (minimum n=15, target n=30 per site, minimum n=90, target n=180 across all sites). With the resulting dataset, lifestyle and context-specific factors that contribute to healthy light exposure will be identified. This information is essential in designing effective public health interventions.

The European Partnership of Metrology, on behalf of EURAMET, is conducting a global field campaign to quantify human exposure to visible and ultraviolet (UV) light, thereby supporting the future development of improved personal light dosimeters and guiding evidence-based luminaire design. This initiative leverages personal daily-light measurements collected both indoors and outdoors across six geographically diverse sites on multiple continents. By systematically capturing how much light reaches the human eye and identifying key spectral components necessary for optimal illumination, these data will inform refined practical recommendations for advanced indoor lighting solutions. Through ongoing field data collection, the project aims to raise awareness among manufacturers, designers, and end-users, ensuring the widespread adoption of adequate, well-balanced light environments. This paper presents the Spanish contribution to the consortium’s overall goals, highlighting the methodology employed, preliminary insights, and the potential impact on future lighting practices.

Personal light exposure is a modifiable component of the health exposome, but its everyday determinants remain poorly understood. We conducted an observational, harmonised, multi-country wearable study of ocular light exposure in 191 adults across nine sites in Sweden, the Netherlands, Germany, Spain, Turkey, Costa Rica, and Ghana, comprising 1,480 participant-days. Participants wore calibrated light loggers near the corneal plane and at chest level and completed repeated contextual assessments. Average daytime exposure remained below recommended melanopic levels, with adherence varying by site, daily phase and photoperiod. Exposure generally increased with latitude despite greater year-round sunlight at lower latitudes, consistent with behavioural filtering through shade-seeking, indoor living or heat avoidance. Individual and activity-level differences explained more variation than site. Daylight access, outdoor activity and micro-environment were the strongest correlates. These findings support personalized, context-sensitive light interventions and establish ocular light exposure as a measurable exposomic factor relevant to health.

This research aims to address the housing deficit in Honduras, with a focus on the Central District. This is a complex issue exacerbated by the effects of climate change and the shortcomings of traditional construction methods. The research centres on analysing the vernacular architecture of the Lenca indigenous people, as it is considered a source of profound knowledge regarding bioclimatic and sustainable solutions. This study employs a structured research methodology comprising several stages: an ethnographic review of building traditions; an analysis of local climatic conditions; and the execution of detailed dynamic energy simulations using Design Builder software. The experimental stage has validated the significantly higher thermal performance and energy efficiency of Lenca vernacular-inspired housing typologies compared to contemporary conventional alternatives. Based on these findings, the chapter presents an innovative model of progressive social housing that systematically integrates traditional construction principles with the functional and programme-related needs of today's society. Finally, the research concludes with an argument for crucial policy reforms, an update to existing building regulations and the active promotion of local materials and craftsmanship. It suggests that these measures are vital for developing housing solutions that are culturally appropriate, resilient to climate variations, and energy efficient. This would offer a tangible way to address the nation's housing deficit and substantially improve the quality of life of its most vulnerable populations.

Indoor radon concentrations have become a significant health concern due to their long-term deleterious effects on the lungs. Radon exposure is a leading cause of lung cancer, especially among non-smokers, making it critical to understand the risk factors associated with radon presence. This article evaluates radon levels in a single-family house located to the northwest of Madrid. The study was conducted during both summer and winter seasons, which are the predominant periods for this region. The research aims to analyze the varying radon concentrations observed during these seasons, considering factors such as ventilation, seasonal temperature differences, and the specific construction materials used in the house. The accumulation of radon can be influenced by the permeability of the building’s foundation, materials, and the effectiveness of natural ventilation systems. In winter, reduced ventilation can lead to higher radon levels due to the sealing of windows and doors to retain heat, while summer conditions may provide more opportunities for ventilation, potentially reducing concentrations. This study examines how these factors interact, exploring the relationship between indoor air quality and radon levels. Measurements before and after ventilation renewal are included to assess any changes in radon concentrations. The findings aim to provide a better understanding of the behavior of radon in residential settings and offer practical recommendations for mitigating its health risks, especially in homes with poor ventilation and specific construction characteristics. Ultimately, the results could guide strategies for improving indoor air quality and reducing radon exposure in similar homes.