Alder pollen concentrations in the air during snowfall

Abstract

The focus of our study was airborne alder pollen because it is one of the main causes of inhalant allergies in many countries in the Northern Hemisphere. The main research setback was pollen concentrations during snowfall. Analyses from a 21-year database showed that the hourly patterns of occurrence of airborne Alnus pollen during snowfall differ. Snowfall can cause a decrease in pollen concentrations in the air that may persist for several hours. However, during the snowfall period of 2018, an increase in pollen concentrations was observed. High temperatures during the days preceding snowfall stimulate thermal currents, and pollen could become airborne. During snowfall, airborne pollen grains are supposedly washed out of the atmosphere and numerous pollen grains are deposited on the snow surface. Hypotheses about the long-distance transport of pollen have also been verified. Back-trajectory analysis has revealed that air masses from Belarus and Ukraine were transported to Rzeszow. We found that the influence of snowfall on pollen concentrations is ambiguous and individuals prone to allergies also notice symptoms on days with snowfall and temperatures below zero.

A comprehensive aerobiological study of the airborne pollen in the Irish environment

“…From further examination of the monthly correlation, a notable decline in temperature was noted following June/July when most pollen types were in decline. This supports previous findings that temperature dependence decreases following peak pollen season (Khwarahm et al, 2014 ). In 2018 a notable increase in temperature dependence was seen in September during which most pollen types were in steady decline, representing a period of resuspension (Rojo et al, 2020 ).…”

“…As a result, the expected release of arboreal pollen in late March was significantly reduced as was the summer release of Poaceae pollen. This corroborates results from similar studies where colder temperatures during early spring were linked to a delay and reduction in arboreal pollen release (Emberlin et al, 2002;Kasprzyk & Borycka, 2019) and a reduction in summertime Poaceae concentrations (Makra et al, 2012). A study by Emberlin et al (1999) observed a comparable correlation between the soil temperature in early spring and the abundance of grass pollens released during the following summer, corroborating the increased Poaceae pollen concentrations seen for the 2019 season.…”

“…Temperatures at the start of the year have been shown to play an important role in initiating the onset of the pollen season for spring flowering plants (Emberlin et al, 2002 ). As such, this strong positive correlation is representative of pre-peak season correlations seen in other studies (Khwarahm et al, 2014 ; Piotrowska & Kaszewski, 2012 ).…”

“…The correlation analysis identified a positive correlation between air temperature and proliferation of arboreal pollen such as for Alnus , Betula , Corylus in Dublin and Quercus in Carlow. The importance of temperature on pollen production is well established in the literature (Emberlin et al, 1993 ; Frenguelli et al, 1991 ; Khwarahm et al, 2014 ; Norris-Hill, 1997 ). These arboreal pollens also negatively correlated with relative humidity coinciding with similar findings found in previous studies (Pérez-Badia et al, 2011 ; Puc, 2012 ).…”

“…Sun duration and global radiation were also observed to positively impact many arboreal and herbaceous pollen taxa, particularly during 2019. The importance of sun duration and global radiation for pollen release and production has been highlighted in the literature (Gioulekas et al, 2004 ; González-Fernández et al, 2021 ; Khwarahm et al, 2014 ). This is particularly true for grass and herb pollen types (Çakir & Doğan, 2020 ; de La Guardia et al, 1998 ; Myszkowska, 2012 ).…”