Concomitant Occurrence of Desert Dust, Fungal Spores and Anthropogenic Air Pollutants During Long Distance Transport of Ragweed Pollen

Background: The atmospheric pathway of ragweed pollen from Southeastern to Northern Europe often passes through highly industrial mining district in Southern Poland (Silesia region) considered as one of the most polluted area in EU. It is hypothesized that air pollutants released over Silesia might be uplifted, mixed with pollen, and concomitantly transported further North to less polluted regions. Methods: The monitoring of ragweed pollen and fungal spores was conducted between 2005-2015 in Poznań, Poland and Budapest, Hungary by 7-days volumetric traps of Hirst design. Following mean daily air pollutant levels have been extracted from the Polish Inspectorate for Environmental Protection database: carbon monoxide (CO), sulphur dioxide (SO2), nitrogen dioxide (NO2), and particulate matter (PM2.5 and PM10). The pathways of air masses with ragweed pollen to Poznań have been calculated using HYSPLIT model. Results: During the episodes of long-distance transport (LDT) of ragweed pollen to Poland the concentration of potentially health-risk air pollutants, i.e., PM10, and SO2 have also significantly increased. The analysis revealed that PM10 released over Silesia might reach Northern Poland during LDT episodes. In particular LDT episodes the high fraction of PM10 were associated with the transport of desert dust, that may originated from both Sahara desert and Ukrainian steppe. In addition, during LDT episodes the concentration of other allergenic biological particles, i.e. Alternaria and Cladosporium spores have also markedly increased. Conclusions: We suggest that the LDT episodes of ragweed pollen are much more hazardous and clinically important than it was suspected, as they are related to elevated levels of anthropogenic and natural air pollutants (including fungal spores and desert dust)