Grass pollen season in selected cities of Poland in 2019

The pollen of grass is the primary trigger of pollen allergies during the summer months. It causes some of the most severe and difficult-to-treat symptoms. During the flowering of grass, over 90% of patients allergic to grass pollen suffer from allergic conditions. The symptoms caused by grass pollen allergens appear in some patients after exceeding the concentration of 20 grains in m3 of air. The aim of this study was to compare Poaceae pollen seasons in 2019 in 11 cities located in different regions of Poland. Pollen monitoring was conducted in Bialystok, Bydgoszcz, Sosnowiec, Lublin, Olsztyn, Szczecin, Piotrkow Trybunalski, Warsaw, Opole, Zielona Gora and Wroclaw. Airborne pollen was monitored by the volumetric method using Burkard or Lanzoni pollen samplers. Pollen season length was determined by the 98% method, where the start of the season was defined as the date when 1% of the seasonal pollen total was trapped and the end of the season as the date, when 99% of the seasonal pollen total was reached.The pollen season start date was recorded earliest in Zielona Gora (April 27^th), latest in Szczecin (May 25^th). The highest grass pollen concentration values were found in Lublin, Piotrkow Trybunalski and Warsaw, whereas the lowest ones in Bialystok. The annual grass pollen sum was highest in Lublin (4715 pollen grains), whereas it was lowest in Bialystok (1256 pollen grains). A relatively high pollen count was also recorded in Warsaw (4106 pollen grains) and Zielona Gora (4077 pollen grains). The longest grass pollination season was recorded in Zielona Gora (139 days) and the shortest in Szczecin (110 days). In the remaining measuring points, grass pollen in the air maintained from 112 to 131 days. The highest grass pollen allergen risk occurred in Lublin, Olsztyn and Zielona Gora and the lowest in Bialystok.