[1] Med Univ Wien, Univ Klin Hals Nasen & Ohrenkrankheiten, Vienna, Austria
[2] Aristotle Univ Thessaloniki, Dept Mech Engn, Informat Syst & Applicat Grp, GR-54006 Thessaloniki, Greece
[3] Finnish Meteorol Inst, Air Qual Res, FIN-00101 Helsinki, Finland
[4] Charite, Dept Dermatol & Allergy, D-13353 Berlin, Germany