First comparison of symptom data with allergen content (Bet v 1 and Phl p 5 measurements) and pollen data from four European regions during 2009–2011 Katharina Bastl a, ⁎, Maximilian Kmenta a,b , Anna-Mari Pessi c , Marje Prank d , Annika Saarto c , Mikhail Sofiev d , Karl-Christian Bergmann e , Jeroen T.M. Buters f,g , Michel Thibaudon h , Siegfried Jäger a , Uwe Berger a a University Department of Ear, Nose and Throat Diseases, Medizinische Universität Wien, Austria b Department of Paleontology, Universität Wien, Austria c University of Turku, Turku, Finland d Finnish Meteorological Institute, Helsinki, Finland e Charité, Allergy-Centre-Charité, Klinik für Dermatologie, Venerologie und Allergologie, Berlin, Germany f ZAUM — Center of Allergy & Environment, Helmholtz Zentrum München/Technische Universität München, Munich, Germany g CK-CARE, Christine Kühne Centre for Allergy Research and Education, Davos, Switzerland h RNSA (Réseau National de Surveillance Aérobiologique), Brussieu, France HIGHLIGHTS • Allergen content is currently a main suspect for having a direct impact on symptoms. • Measurements of main allergens (Bet v 1/ Phl p 5) explain peaks in the symptom load. • A direct pattern between the symptom level and the allergen content was not found. • A focus on the development and onset of allergy symptoms is needed in monitor- ing. GRAPHICAL ABSTRACT abstract article info Article history: Received 26 August 2015 Received in revised form 4 January 2016 Accepted 4 January 2016 Available online xxxx Editor: D. Barcelo Background: The level of symptoms in pollen allergy sufferers and users of the Patient's Hayfever Diary (PHD), does not directly reflect the total amount of pollen in the air. It is necessary to explain the symptom load and thus the development of allergic symptoms and to determine which environmental factors, besides the pollen load, influence variables. It seems reasonable to suspect allergen content because the amount of allergen varies throughout seasons and regions and is not always correlated with the total pollen amount. Methods: Data on the allergen content of ambient air (Bet v 1 and Phl p 5) from 2009 until 2011 was used to com- pare the respective pollen and symptom loads for study regions in Austria, Germany, France and Finland. Results: Our findings suggest that allergen amount (Bet v 1/Phl p 5) has a strong but regionally dependent impact on the symptom load of pollen allergy sufferers. Peak symptom loads can be traced with peak allergen loads. The influence of other important aeroallergens should also be assessed during the pollen season. Keywords: Allergen content Bet v 1 Science of the Total Environment 548–549 (2016) 229–235 Abbreviations: HIALINE, EU-funded project called Health Impacts of Airborne Allergen Information Network; IgE, immunoglobulins E; PHD, Patient's Hayfever Diary; SLI, symptom load index. ⁎ Corresponding author. E-mail address: katharina.bastl@meduniwien.ac.at (K. Bastl). http://dx.doi.org/10.1016/j.scitotenv.2016.01.014 0048-9697/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv