Birch pollen grains without cytoplasmic content in the air of Szczecin and Bialystok

Birches, due to their wide ecological amplitude are components of almost all woodland communities from very dry dune pine forests to mires, from poor to fertile ash-elm carrs and also birch pollen has the potential to be transported long distances from one region to another. This paper presents course of the pollen season and comparison of the concentrations of birch pollen grains with and without cytoplasmic content in Szczecin and Bialystok. Measurements were performed by the volumetric method (Burkard and Lanzoni pollen samplers). Pollen season was defined as the period in which 98% of the annual total catch occurred. Seasonal Pollen Index (SPI) was estimated as the annual sum of daily average pollen concentrations. The pollen season of birch started in Szczecin and Bialystok at the beginning of the April and lasted to the half of May. However total pollen was two times higher in Bialystok than in Szczecin. The maximum values of seasonal pollen count occurred in the middle of April in both cities. The risk of pollen allergy was high in Szczecin and Bialystok, and threshold values of allergy symptoms’ occurrence were exceeded during the whole birch pollen season. Statistically relevant correlations between wind speed, particulate matter and birch total pollen, and also between the pollen concentration without cytoplasmic content were observed. Also, southern air circulation from Africa was noted. These coexisting factors indicate the appearance of long range transport of birch pollen from southern Europe in 2016.