Allergenic Ambrosia pollen grains in the air of some Polish cities in 2019

Ambrosia is regarded as the most dangerous allergy-related plant posing a considerable threat to human health with its highly allergenic pollen. In Europe, there are 4 Ambrosia species originating from North America; they most often colonize ruderal habitats and agricultural fields. The aim of the study was to compare Ambrosia pollen seasons in 9 cities located in different parts of Poland in 2019. Aerobiological tests were conducted in Bialystok, Bydgoszcz, Lublin, Olsztyn, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, and Wroclaw. The investigations were carried out with the volumetric method using Burkard or Lanzoni pollen samplers. The 98% method was used to determine the duration of the pollen season. The earliest onset of the pollen season was recorded in Szczecin (August 7^th) and Sosnowiec (August 9^th), whereas the latest beginning was noted in Wroclaw (August 22^nd) and Bydgoszcz (August 21^st). The longest pollen season was recorded in Sosnowiec (52 days) as well as Lublin and Szczecin (50 days), while the shortest pollen season was noted in Wroclaw (10 days). The highest mean daily concentrations of Ambrosia pollen grains were recorded in Sosnowiec (104 P/m³) and Wroclaw (77 P/m³), whereas the lowest value was obtained in Szczecin (18 P/m³). Peak days were noted mostly during the last 10 days of August. The highest value of Ambrosia annual pollen sum was reported from Sosnowiec (326) and Lublin (310), while the lowest sum was noted in Szczecin (69). The multimodal course of the graph presenting the pollen seasons in the analysed cities and literature data indicate that the pollen originated not only from local sources but also from long-distance transport. The highest risk of Ambrosia pollen-induced allergy in sensitive subjects was demonstrated in Lublin, Piotrkow Trybunalski and Warsaw. The concentration of Ambrosia pollen in the air of the analysed Polish cities was substantially lower than the values indicated by measurement stations located in other parts of Europe.