Proceedings of the 12 th International Conference on Protection and Restoration of the Environment Editors: A. Liakopoulos, A. Kungolos, C. Christodoulatos, A. Koutsopsyros ISBN 978-960-88490-6-8 1166 Indoor illumination in tertiary sector and human health. A review N.G.Katsikas 1 , S.A. Dedegkika 2 , C.S.Psomopoulos 1 , K.D.Mardikis 1 , G.Ch.Ioannidis 1 1. T.E.I. Piraeus, Dept. of Electrical Engineering,250 Thivon str & P.Rali Ave,Gr-12244, Egaleo, Greece 2. Attikon University Hospital, 2 nd Neurological Clinic, Rimini 1,Gr-12462, Chaidari, Grrece Corresponding author’s e-mail: katsikas.n@gmail.com,Tel +30 2109711737, Fax: +30 2109711737 Abstract Illumination is one of the basic parameters affecting indoor environment quality. Effects on human health due to improper illumination have been observed in the tertiary sector. The main observed problems concern perception and behavior issues and changes in the human circadian system, as well as other effects. This work presents a review of a number of studies conducted in the field and summarizes the results from different research groups. Experimental results, investigating the role of the light colors in the behavior of human, will be presented. These results concerns classrooms in schools where it was observed that the lack of proper light quality creates an irrelevant speech, with additional result the improper monitoring and concentration of the students. The effect of poor artificial lighting on hospital staff and patients’ progress, concerning different categories of people in terms of mood and perception, are also presented. Moreover, the effect of blue light in people during sleep and the negative impacts of the applied specified range of light in humans are outlined according to recent studies. Several cases, regarding LEDs illumination, is also presented showing that this type of light affects the employment efficiency since it is commonly used in the typical working environment. This paper is focused mainly on the tertiary sector due to the existence of specific regulations that can be easily checked and applied. Keywords Indoor illumination and health, LEDs lighting, indoor environment quality, circadian system, quality of lighting, human behavior and light 1. INTRODUCTION Since the beginning of last century, artificial lighting has started playing a critical role in modern’s world development. Tertiary sector has known a rapid growth in such short time, a 24 hour a day non stopping machine. People working in 24 hour shifts have never thought of the impacts of light on their health. The circadian clock allows a normal Melatonin (MLT) production between 2 and 4 am, a time where a person should be sleeping but also a time that many people is demanded to be awake on night shifts. Night shift workers work under constant high levels of bright lighting with a significant impact on melatonin production. Melatonin is a hormone produced by the human body. It is a protective, oncostatic and antioxidant hormone which under exposure on night time lighting has been proven to be suppressed. Many researches have shown that bright lighting alerts and awakens the human body to work under better and more focused rhythms compared to a more relaxed low temperature lighting [1]. Studies have been performed on lighting’s impacts in education institutes such as schools and colleges, where brighter lighting (>500lx) showed more positive effects on performance and alertness than a low standard lighting (300lx). However, illuminance is not the only factor that impacts on human health and behavior. Correlated Color Temperature (CCT) on different levels (3000K-12000K) also generates positive effects on student’s performance, physical growth and psychological outcomes. On the other hand, if lighting is not installed carefully there is a danger to create pollution, known as lighting pollution. This can be observed at night on gas stations, malls and other commercial places which are using HID lamps. This kind of lighting is based more on