Characterisation of Tilia pollen seasons in 2018-2019

Literature reports suggest that Tilia pollen exhibits low or moderate allergenicity. The aim of the study was to compare the pollen seasons of this taxon in seven Polish cities in 2018 and 2019. The aerobiological research stations were located in Bialystok, Cracow, Lublin, Piotrkow Trybu-nalski, Sosnowiec, Szczecin, and Warsaw. Aerosol samples were collected with the volumetric method using Burkard or Lanzoni pollen samplers. The length of the pollen season was determined using the 95% method. The earliest onset of the Tilia pollen season was noted in Cracow in both years of the study. In 2018, it began already in May. The highest concentrations of lime pollen grains were recorded in Lublin, whereas the lowest values were reported from Bialystok and Cracow. The maximum daily Tilia pollen concentration was recorded in most of the measurement sites between June 6th and June 11th in 2018 and between June 16th and June 24th in 2019. The annual pollen grain sum in both study years was the highest in Lublin (971, 844), whereas the lowest values were noted in Bialystok (85, 102) and Cracow (111, 75). The concentrations of Tilia pollen in Lublin in 2018 and 2019 were several times higher than the mean values recorded in this city in 2001–2017. The allergen index calculated for Tilia trees growing in the centre of Lublin indicates a moderate allergenic threat posed by the pollen of this taxon to the residents of the city.