European Aeroallergen Network (EAN): a key tool to analyze the birch pollen season in Europe

Abstract Background The European Aeroallergen Network (EAN) is a Europe-wide, noncommercial network for the standardized collection and analysis of pollen and fungal spores. It plays a central role in the research and prevention of inhalation allergies, such as the widespread birch pollen allergy. The EAN database facilitates international research, clinical studies, and the provision of daily pollen information by virtue of its extensive, quality-assured, long-term data. Methods The EAN database is a Java-based, two-stage web application with TLS-secured data transmission. Authorized users are permitted to upload pollen measurement data, analyze it, and make it available to others within the framework of scientific collaborations. The functionality of the database was examined through the utilization of four distinct application examples, with measurement stations located in three Austrian cities (Graz, Innsbruck, and Vienna) serving as the experimental setting: (1) calculation of base statistics for seasonal characterization, (2) completeness report for quality control, (3) comparison graphics for showing interannual differences, and (4) European maps based on pollen data from several hundred European pollen traps for the spatial visualization of pollen loads. Results The EAN data show that the 2025 birch pollen season began about 2 weeks later and was less intense than that of 2024. A decline in total pollen counts and peak concentrations was observed at all measuring stations, indicating a shift between mast and nonmast years. Completeness analyses were conducted to provide information on data quality and to facilitate the identification of missing periods. Comparative graphs illustrated annual and location-dependent differences in exposure, while European maps visualized the seasonal progression and long-range transport of birch pollen. Conclusion The results highlight the scientific and practical importance of the EAN database for allergy research, clinical studies, and pollen information services. The system was developed to promote international comparability, quality control, and forecasting. Furthermore, the EAN database is a valuable resource for aerobiological and climate research. The long-term records of aerobiological data reveal trends in flowering times, pollen concentrations, and mast years, as it has been shown for the birch pollen season in the present study. Consequently, these records can serve as biotic indicators of climate change.