Very high concentrations of birch pollen in the air of selected Polish cities in 2022 - clinical implications.

Introduction: In the Polish population, the most common cause of allergic rhinitis (AR) in the spring is birch pollen.

Aim: The aim of this study was to assess the basic characteristics of the birch pollen season in selected cities in central and northern Poland including Warsaw, Piotrkow Trybunalski, and Bydgoszcz in 2022, considering their clinical implications.

Material and method: Pollen monitoring was conducted using the volumetric method with the Hirst-type continuous volumetric sampler. Measurements were taken in 7-day cycles, and the microscopic analysis was performed for each 24-hour period. Results During the studied period, birch pollen posed a threat in the 2nd and 3rd decades of April and the 1st and 2nd decades of May. The birch pollination intensity was reflected by the very high values of maximum average daily pollen concentration 4102 pollen/m3 in Warsaw, 4389 pollen/m3 in Piotrkow Trybunalski, 3832 pollen/m3 in Bydgoszcz and the sum of the average daily pollen concentrations (i.e. Annual Pollen Integral, APIn) from 32439 in Bydgoszcz to 37638 in Warsaw, and long periods of exposure to high concentrations (2930 days).

Conclusions: The pollen season 2022 is part of an alternating 2-year cycle of the birch pollen season intensity. The variability of parameters describing the dynamics of pollen seasons over years makes it necessary to monitor information on the pollen concentration in the air during the pollen season, both by the patients with inhalant allergy and their physicians.