18 Int. J. Environment and Pollution, Vol. 46, Nos. 1/2, 2011 Copyright © 2011 Inderscience Enterprises Ltd. A system for assessment of climatic air pollution levels in Bulgaria: description and first steps towards validation Dimiter Syrakov*, Valery Spiridonov, Maria Prodanova and Andrey Bogatchev National Institute of Meteorology and Hydrology, Bulgarian Academy of Sciences, 66 Tzarigradsko Chausee, Sofia 1784, Bulgaria E-mail: dimiter.syrakov@meteo.bg E-mail: valery.spiridonov@meteo.bg E-mail: maria.prodanova@meteo.bg E-mail: Andrey.Bogatchev@meteo.bg *Corresponding author Nikolai Miloshev and Kostadin Ganev Geophysical Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl.3, Sofia 1113, Bulgaria E-mail: miloshev@geophys.bas.bg E-mail: kganev@geophys.bas.bg Eleni Katragkou, Dimitrios Melas, Anastasia Poupkou and Kostas Markakis Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, 54 124 Thessaloniki, Greece E-mail: katragou@auth.gr E-mail: melas@auth.gr E-mail: poupkou@auth.gr E-mail: kmarkak@auth.gr Roberto San Jose and Juan Luiz Pérez Computer Science School, Technical University of Madrid, Campus de Montegancedo – Boadilla del Monte-28660, Madrid, Spain E-mail: roberto@fi.upm.es E-mail: JuanPerez@fi.upm.es