Betula and Populus pollen counts and meteorological conditions in Szczecin, Poland

The aim of the study was to analyse a relationship between the meteorological conditions and the pollen counts of selected allergenic taxa (Betula spp., Populus spp.) in the air of Szczecin city (north western Poland) in 2001. Apart from the individual rhythm of plant pollination, weather conditions are considered the most important factors determining the dispersion and content of pollen in the air. The meteorological parameters analysed were the minimum, maximum and average values of air temperature, relative humidity, solar radiation and wind speed. The beginning and end of a season were established by the 98 % method. The concentration of birch pollen in the air in 2001 was very high, the pollen season started in the third decade of April and lasted till the 10 May. The highest airborne concentration of 3,712 grains in 1 m(3) per 24 h was noted at the beginning of May on a sunny day with strong wind, and air temperature above 20 degrees C. The concentration of poplar pollen in 2001 was low. The pollen season started from the beginning of April and lasted till the beginning of May. The maximum concentration of airborne poplar pollen of 222 grains in 1 m(3) per 24 h was observed in the third decade of April and was preceded by several days with low temperature (1- 2 degrees C), rain, snowfalls and strong wind. A positive and statistically significant correlation was found between the air temperature and the birch pollen concentration, while a similar but negative correlation was found for poplar pollen.