RT Journal Article T1 Diurnal pattern of Poaceae and Betula pollen flight in Central Europe A1 Suarez-Suarez, Mariel A1 Costa-Gómez, Isabel A1 Maya-Manzano, Jose M. A1 Rojo Úbeda, Jesús A1 Hentges, François A1 Porcsin, Ildiko A1 Sarda-Estève, Roland A1 Baisnée, Dominique A1 Schmidt-Weber, Carsten A1 Buters, Jeroen AB In Central Europe the most common allergies are provoked by grass or birch pollen allergens. We determined the intra-daily behavior of airborne pollen grains of grasses (Poaceae) and birch (Betula ssp.) in Central Europe, based on data obtained from a network of automatic pollen monitors over Europe (www.pollenscience.eu). Our aim was to determine the time of day when the lowest concentrations occur, to provide allergic individuals the optimal time to ventilate their homes. The study was carried out in three Central European capitals, Berlin (Germany), Paris-Saclay (France), and Luxembourg (Luxembourg), as well as in eight stations in Germany (Altötting, Feucht, Garmisch-Partenkirchen, Hof, Marktheidenfeld, Mindelheim, Munich and Viechtach). The diurnal rhythm of these eleven locations was analyzed for either the complete, first week, peak week, peak day and last week of the pollen season. The data studied were reported as pollen/m3 measured in 3 h periods. Stations were classified as city, semi-populated or countryside areas using land-use and population density criteria.Grass pollen has a more pronounced diurnal rhythm than birch pollen concentrations. A significant difference was observed when comparing day (6–21 h) versus night (21–6 h) for all stations. No difference was detected between city and countryside for both pollen types, although for Poaceae a longer period of maximum concentrations was observed in big cities and higher day/night-time differences were registered in the countryside (6.4) than in cities (3.0). The highest pollen concentrations were observed between 9 and 18 h for grass, but the rhythm was less pronounced for birch pollen. For allergic individuals who want to bring in fresh air in their homes, we recommend opening windows after 21 h, but even better early in the morning between 6 and 9 h before pollinations (re)starts. PB Elsevier SN 0048-9697 YR 2023 FD 2023-11-20 LK https://hdl.handle.net/20.500.14352/112447 UL https://hdl.handle.net/20.500.14352/112447 LA eng NO Mariel Suarez-Suarez, Isabel Costa-Gómez, Jose M. Maya-Manzano, Jesús Rojo, François Hentges, Ildiko Porcsin, Roland Sarda-Estève, Dominique Baisnée, Carsten Schmidt-Weber, Jeroen Buters, Diurnal pattern of Poaceae and Betula pollen flight in Central Europe, Science of The Total Environment, Vol 900, 2023, 165799, https://doi.org/10.1016/j.scitotenv.2023.165799. DS Docta Complutense RD 16 abr 2025