LIGHTING AND HEALTH: CASE STUDY IN RETAIL STORES

5 LabVitrus ABSTRACT Despite the decades of research, it was only in 2002 that David Berson discovered the connection between light and a third type of photoreceptor in the retina and this was the missing link in the description of the mechanism of biological effects controlled by the light and dark cycle. This discovery revolutionized the research on the spectrum, the intensity, the duration and the type of light that affects biological responses. This work addresses the issue of non-visual impacts of human exposure to light, in an attempt to relate the quality of lighting design to health, comfort, and well-being of female retail store employees. The sample for the cross-sectional study was randomly established with female volunteers. Three groups of ten employees each were selected: street retail stores with outside contact and daily working hours (9 a.m. to 6 p.m.), shopping mall retail stores with no window facing outside, with daily working hours (9 a.m. to 6 p.m.) and evening working hours (2 p.m. to 10 p.m.). Assessment of lighting considered the occurrence of glare, color appearance of light, flexibility, and possibility of lighting control by employees. The tools to assess well-being and health were psychometric scales internationally validated by the psychiatric field to measure depression, anxiety, and stress symptoms. Assessment of sleep conditions and analysis of the activity/rest rhythm was carried by a wrist monitor with attached luximeter and the analysis of the body temperature rhythm was made by a temperature sensor, to which each participant was submitted for five consecutive days. The lighting pattern's influence on the circadian system was verified by measuring saliva melatonin and cortisol levels. The degree of satisfaction of employees and their preferences regarding work environment lighting were surveyed by applying questionnaires. Data were analyzed using Pearson correlations, ANOVA, and stepwise regression. The study concludes that it is necessary to review the stores' lighting design strategies, to seek new guidelines able to solve the possible conflicts between light oriented to sell products and that which considers the store as a workplace. The results indicates that the improper choice of fixtures and poor lighting design, can actually have negative consequences for health and also for work performance and well beingFirst paragraph