Shift work, which is related with a disturbance of the synchronization of internal biological processes in the human body with the natural circadian rhythm, has been associated with a number of diseases. Since the identification of a new non-visual photoreceptive mechanism that is active in the regulation of physiological processes, the influence of light on circadian rhythms has been studied under laboratory conditions. To gain a better understanding of a possible association between shift work and health risks, the investigations of the actual personal light exposure in field studies are of great importance. In this study, dosimetric data on actual light exposure and activity of the shift and day-working nurses will be measured for three separate weeks during different seasons. With the aim to identify characteristic features in the light exposure of that profession, the data will be captured by body-worn detectors both inside and outside working hours. Subsequently, the measurement results will be evaluated on the basis of a new approach for the analysis of such light exposure patterns, which is based on the method of exponential moving average.
Unit 2.2 "Physical Agents"