2011 - Daylight Symposium
OFFICE WORKERS’ DAILY EXPOSURE TO LIGHT AND ITS INFLUENCE ON SLEEP QUALITY AND MOOD by Sylvia Hubalek
Institution for Statutory Accident Insurance and Prevention
To study the amount of light entering the eye and its effects on office workers, measurements were taken from 23 office workers over a period of seven consecutive days. Two parameters of visible light were recorded: (i) illuminance and (ii) irradiance of the blue spectral component. Every evening before going to bed, a questionnaire had to be filled out, containing scales relating to the mood dimensions of pleasure and arousal, questions about the previous night’s sleep and a rough time table with information about the person’s whereabouts during the day. The exposure to light on workdays is regular but it varies strongly on days off. No evidence could be provided for the influence of age, sex or seasonal affective disorder (SAD) scores on the daily exposure to light of office workers. The amount of light entering the eye during the day appears to have a positive impact on sleep quality the following night. Pleasure and arousal were not significantly associated with daily light exposure.
Sylvia Hubalek studied architecture and environmental engineering at TU Munich. After graduation in 2000, she started to work at Ebert-Ingenieure in Munich where her responsibilities included planning, consulting and simulation in the field of daylight and artificial lighting. While working full time, she continued her education at TU Ilmenau where she attended a programme on “Light Application”under the supervision of Prof. Dr. Dietrich Gall. As of autumn 2003, she was employed as a Scientific Assistant at ETH Zurich, Switzerland. She initially worked at the Institute of Hygiene and Occupational Physiology under the supervision of Prof. Dr. Dr. Helmut Krueger. In autumn 2005, she transferred to the Centre for Organizational and Occupational Sciences under the supervision of Prof. Dr. Theo Wehner. At ETHZ she was involved in environmental ergonomics with her supervisor Dr. Christoph Schierz. In addition to providing consulting services for lighting at workstations and managing training courses for students, she did research on “Light and Humans”. The results were included in her PhD thesis and other publications. Since May 2007, she has been working at the Institution for Statutory Accident Insurance and Prevention (Berufsgenossenschaft), where she is involved in occupational accident prevention. She is a member of TC 3-46 “Research Roadmap for Healthful Interior Lighting Applications” at CIE.