Pollen concentration of invasive tree of heaven (Ailanthus altissima) on the Northern Great Plain, Hungary

In areas where the tree of heaven (Ailanthus altissima) appears and multiplies, the original vegetation degrades and transforms. The invasive tree of heaven is also of great importance in urban environments, where it causes building damage, static problems and endangers utilities. Ailanthus pollen concentration was measured during the 3-year period (2016-2018) at three county capitals (Szolnok, Debrecen, Nyíregyháza) of the Northern Great Plain, Hungary (JászNagykun-Szolnok county, Hajdú-Bihar county and Szabolcs-Szatmár-Bereg county), with a 7-day Hirst-type (Burkard) pollen trap. The highest total pollen count of A. altissima was measured in all three years in Nyíregyháza (1114 pollen m-3 in 2016; 788 pollen m-3 in 2017; 635 pollen m-3 in 2018), while the lowest values were measured in Szolnok in all three years (99 pollen m-3 in 2016; 78 pollen m-3 in 2017; 93 pollen m-3 in 2018). In Debrecen, the annual total pollen concentration varied between 109-127 pollen grains m-3 in the studied period. The extent of the prevalence of A. altissima can be deduced from its pollen concentrations. For this purpose, multi-year pollen data is displayed on a map in which areas characterized by different pollen concentrations are represented by colour codes. Pollen monitoring provides information on the size of A. altissima stands and provides a basis for proposals and plans for measures to control this invasive tree species and mitigate the damage caused by it

Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe

Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown−no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen−virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations.</p