1. Department of Public Health, Medical School, University of Patras, 26500 Patras, Greece
2. School of Environment & Life Sciences, University of Salford, Manchester M5 4WT, UK
3. Department of Hygiene and Epidemiology, Medical School, University of Athens, 11527 Athens, Greece
4. Department of Production and Management Engineering, Faculty of Engineering, Demokritos University of Thrace, 67100 Xanthi, Greece