Diurnal variation of chosen airborne pollen at five sites in Poland

The aerobiological investigations were carriedout at five sites located in different climaticand geobotanical regions in Poland. The diurnalperiodicity of Alnus, Betula, Secale,Poaceae, Urtica, and Artemisia wasstudied during two successive years. The taxawere chosen on the basis of pollen grainabundance and allergenity. The pollen wascollected with a Burkard spore trap. Twelvetransversal transverses of microscope slidescorresponding to two-hour periods wereanalysed. The diurnal variations ofPoaceae, Alnus and Betula were irregularand varied between sites and years; highconcentrations were observed at different hoursof the day and night. Diurnal concentrations of Secale, Urtica and Artemisia hadonly one maximum in the middle of the day,constant between sites and years. The lowestconcentrations were observed between eveningand early morning. There was no close relationbetween the time of the liberation ofAlnus, Betula and Poaceae pollen and thetime of the maximum pollen counts. There was aseveral hour delay observed between the timeof Secale pollen liberation and maximumconcentration of airborne pollen.