Comparative analysis of airborne fungal spore distribution in urban and rural environments of Slovakia.

Monitoring airborne fungal spores is crucial for public health and plant production since they belong to important aeroallergens and phytopathogens. Due to different land use, their concentration can differ significantly between urban and rural areas. We monitored their spectrum and quantity on two geographically close sites with a different degree of urbanisation: Bratislava City and Kaplna Village in Slovakia, located 38 km apart. We recorded the spectrum of airborne fungal spores over a year and confirmed the microscopic results by amplicon-based metagenomic analysis. The main spore season of the most frequent genera lasted over a week longer in Kaplna, but its intensity was approximately two-fold higher in Bratislava. This can be possibly connected to the microclimatic conditions of the urban area (especially wind speed and heat island effect) and the lesser use of fungicides. Cladosporium was the dominant genus on both sites, influencing the intensity most significantly. Through statistical analysis of the influence of meteorological parameters on airborne fungal spore levels, we identified a significant relationship with temperature, while the impact of other parameters varied depending on the spore type and release mechanism. Our results show the differences in airborne fungal spore levels between urban and rural areas and highlight the necessity for more monitoring stations in various environments.

Moss spores: overlooked airborne bioparticles in an urban environment.

Moss spores are present in aerobiological samples, but their low representation, lack of known allergenic properties, and difficult identification have led to their being overlooked by aerobiologists so far. The data about their presence in the atmosphere and the factors that influence them are, however, important from the biodiversity conservation point of view, since they give us information about their ability to spread to new habitats. In this pilot study, we analysed their presence in the atmosphere of Bratislava city, Slovakia (2018-2023), using Burkard volumetric sampler, and determined the most significant factors influencing its temporal distribution. The size category of 13-18 µm was the most represented in the samples. Environmental factors influenced the daily spore concentrations and the characteristics of the whole spore season. The start of the Main Spore Season (MSS) depended mainly on the temperatures in November-January, initiating earlier growth of sporophytes in the following year, while the intensity of the MSS was influenced by high humidity in April, stimulating the formation of spores in sporangia. The daily concentration of airborne moss spores was mostly influenced by the actual temperature and wind speed, promoting the release and dispersal of spores, and precipitation lowering their levels due to the "wash-out" effect, although no intradiurnal pattern was observed. More data from other locations is needed to determine the role of atmospheric spore transport for the conservation of moss species facing anthropogenic climatic change.

Long-term pollen season trends of Fraxinus (ash), Quercus (oak) and Ambrosia artemisiifolia (ragweed) as indicators of anthropogenic climate change impact.

The ongoing climatic change, together with atmospheric pollution, influences the timing, duration and intensity of pollen seasons of some allergenic plant taxa. To study these influences, we correlated the trends in the pollen season characteristics of both woody (Fraxinus, Quercus) and herbaceous (Ambrosia) taxa from two pollen monitoring stations in Slovakia with the trends in meteorological factors and air pollutants during the last two decades. In woody species, the increased temperature during the formation of flower buds in summer and autumn led to an earlier onset and intensification of next year's pollen season, especially in Quercus. The increase of relative air humidity and precipitation during this time also had a positive influence on the intensity of the pollen season of trees. The pollen season of the invasive herbaceous species Ambrosia artemisiifolia was prolonged by increased temperature and humidity during the summer and autumn of the same year, which extended the blooming period and delayed the end of the pollen season. From the studied air pollutants, only three were found to correlate with the intensity of the pollen season of the studied taxa, CO - positively and SO2 and NO2 - negatively. It is important to study these long-term trends since they not only give us valuable insight into the response of plants to changing conditions but also enable the prognosis of the exacerbations of pollen-related allergenic diseases.

Environmental impacts on intraspecific variation in Ambrosia artemisiifolia genome size in Slovakia, Central Europe.

The quantity of DNA in angiosperms exhibits variation attributed to many external influences, such as environmental factors, geographical features, or stress factors, which exert constant selection pressure on organisms. Since invasive species possess adaptive capabilities to acclimate to novel environmental conditions, ragweed (Ambrosia artemisiifolia L.) was chosen as a subject for investigating their influence on genome size variation. Slovakia has diverse climatic conditions, suitable for testing the hypothesis that air temperature and precipitation, the main limiting factors of ragweed occurrence, would also have an impact on its genome size. Our results using flow cytometry confirmed this hypothesis and also found a significant association with geographical features such as latitude, altitude, and longitude. We can conclude that plants growing in colder environments farther from oceanic influences exhibit smaller DNA amounts, while optimal growth conditions result in a greater variability in genome size, reflecting the diminished effect of selection pressure.

Temporal variation of allergenic potential in urban parks during the vegetation period: a case study from Bratislava, Slovakia.

Park greenery represents an oasis for urban residents; however, during the flowering period of trees that produce allergenic pollen grains, these areas threaten individuals suffering from seasonal allergic respiratory diseases. In this study, we evaluated the temporal distribution of the allergenic potential of three most important urban parks in Bratislava over the vegetation period, using a modification of the Urban Green Zone Allergenicity Index (IUGZA) and Individual-Specific Allergenic Potential Index (IISA) designed as a running index - rIUGZA and rIISA. We found that rIUGZA gives better information for park management and revitalization, since it considers the potential size of woody plants, while rIISA, considering the actual size of the vegetation, provides more relevant information for pollen-allergy sufferers. Based on rIISA, the allergenic potential was highest in May for the Grassalkovich Garden (formal baroque garden) and Janko Král Park (English landscape park) and in April for the Medic Garden (repurposed baroque garden). We also found differences in the duration of the period of increased allergenic potential in these parks, ranging from 1 to 3 months. Based on the total annual sums of rIISA, we found the highest allergenic potential in the Medic Garden and lowest in the Janko Král Park. This variance is caused mainly by the different density of trees and percentage of allergenic species. The biggest contributors to the allergenic potential were Platanus, Acer and Tilia. Based on the information on temporal variation of the allergenic potential during the vegetation period provided by the running indices, it is possible to improve the planning of park revitalization based on the flowering period of allergenic species and provide better information to the pollen-allergy sufferers for minimizing the allergenic effect of urban green areas on their health during a particular month.

Impact of meteorological parameters and air pollutants on airborne concentration of Betula pollen and Bet v 1 allergen.

The intensity of birch pollen season is expressed by seasonal pollen integral (SPIn, the sum of the mean daily pollen concentration during the birch pollination period) and the amount of Bet v 1 allergen released per birch pollen grain expressed by pollen allergen potency (PAP). Betula pollen and Bet v 1 allergen were simultaneously measured in the air of Bratislava from 2019 to 2022 by using two Burkard traps (Hirst-type and cyclone) in order to evaluate the causes of the seasonal variation in the SPIn and PAP levels. The highest SPIn (19,975 pollen/m3) was observed in 2022 and the lowest one (1484 pollen/m3) in 2021. The average daily PAP level (4.0 pg Bet v 1/pollen) was highest in 2019 and lowest (2.5 pg Bet v 1/pollen) in 2020. We found that seasonal variation in SPIn was associated mainly with the changes in environmental conditions during the pre-season period, whereas the year-to-year variation in PAP levels was attributed to environmental conditions during both pre- and in-season periods. Our results indicate that rainy weather in June 2020 and cold overcast weather in January‒February 2021 resulted in low SPIn in 2021. On the other hand, dry weather in June 2021 and warm weather in January‒February 2022 resulted in high SPIn in 2022. The low average daily PAP level in 2020 was associated with (1) low levels of gaseous air pollutants in March, when the ripening of pollen takes place; (2) an earlier start of the birch main pollen season (MPS); and (3) dry weather during the MPS. On the other hand, high PAP level in 2019 was associated with higher levels of air pollutants in March and during the MPS.

Temporal variation in the spectrum and concentration of airborne microalgae and cyanobacteria in the urban environments of inland temperate climate.

Despite their non-negligible representation among the airborne bioparticles and known allergenicity, autotrophic microorganisms-microalgae and cyanobacteria-are not commonly reported or studied by aerobiological monitoring stations due to the challenging identification in their desiccated and fragmented state. Using a gravimetric method with open plates at the same time as Hirst-type volumetric bioparticle sampler, we were able to cultivate the autotrophic microorganisms and use it as a reference for correct retrospective identification of the microalgae and cyanobacteria captured by the volumetric trap. Only in this way, reliable data on their presence in the air of a given area can be obtained and analysed with regard to their temporal variation and environmental factors. We gained these data for an inland temperate region over 3 years (2018, 2020-2021), identifying the microalgal genera Bracteacoccus, Desmococcus, Geminella, Chlorella, Klebsormidium, and Stichococcus (Chlorophyta) and cyanobacterium Nostoc in the volumetric trap samples and three more in the cultivated samples. The mean annual concentration recorded over 3 years was 19,182 cells*day/m3, with the greatest contribution from the genus Bracteacoccus (57%). Unlike some other bioparticles like pollen grains, autotrophic microorganisms were present in the samples over the course of the whole year, with greatest abundance in February and April. The peak daily concentration reached the highest value (1011 cells/m3) in 2021, while the mean daily concentration during the three analysed years was 56 cells/m3. The analysis of intra-diurnal patterns showed their increased presence in daylight hours, with a peak between 2 and 4 p.m. for most genera, which is especially important due to their potential to trigger allergy symptoms. From the environmental factors, wind speed had a most significant positive association with their concentration, while relative air humidity had a negative influence.

Co-occurrence of airborne biological and anthropogenic pollutants in the central European urban ecosystem.

The interactions between organic and inorganic air pollutants, enhanced by the impact of weather parameters, may worsen the respiratory allergy symptoms in allergy sufferers. Pollen grains and fungal spores belong to some of the most crucial aeroallergens. Other allergenic bioparticles in the atmospheric microbiome can include microalgae, fern spores and mites. In this study, we evaluated if and to what extent air pollutants and weather parameters drive the daily variation in airborne concentrations of broad spectrum of bioparticles (pollen grains, fungal spores, microalgae, fern spores and invertebrates) in the air of Bratislava over 3 years, 2019-2021. Air samples were collected using a Hirst-type volumetric sampler. Based on the results of Spearman's correlation analysis, air temperature seems to be the most influential meteorological factor, positively associated with the concentration of all types of bioparticles at assemblage level, even though the association with microalgae was negative. Wind speed, known to have a diluting effect on most airborne particles, appears to be the most influential for microalgae, as their concentration in the air increases along with rising wind speed. Considering air pollutants, correlation analysis revealed that as the daily concentrations of ozone, PM10, CO and/or NO2 increased, so did the levels of most types of analysed bioaerosols at the assemblage level. Regarding that bioparticles may act as carriers for inorganic particles and amplify their allergenic impact, a concomitant increment in the airborne concentration of both organic and inorganic pollutants poses a threat to allergy sufferers in the study area. The concentration of microalgae, on the other hand, decreases with rising levels of CO, NO2 and PM10; thereby, their synergistic effect on allergy sufferers is negligible. Based on our findings, we suggest that the response of pollen and fungal spore concentration to environmental conditions should be investigated at the taxon, not the assemblage level, as each pollen/spore taxon has a different pattern in response to meteorological parameters and air pollutants.

Bioaerosols on the atmospheric super highway: An example of long distance transport of Alternaria spores from the Pannonian Plain to Poland.

Alternaria spores are pathogenic to agricultural crops, and the longest and the most severe sporulation seasons are predominantly recorded in rural areas, e.g. the Pannonian Plain (PP) in South-Central Europe. In Poland (Central Europe), airborne Alternaria spore concentrations peak between July and August. In this study, we test the hypothesis that the PP is the source of Alternaria spores recorded in Poland after the main sporulation season (September-October). Airborne Alternaria spores (2005-2019) were collected using volumetric Hirst spore traps located in 38 locations along the potential pathways of air masses, i.e. from Serbia, Romania and Hungary, through the Czech Republic, Slovakia and Ukraine, to Northern Poland. Three potential episodes of Long Distance Transport (LDT) were selected and characterized in detail, including the analysis of Alternaria spore data, back trajectory analysis, dispersal modelling, and description of local weather and mesoscale synoptic conditions. During selected episodes, increases in Alternaria spore concentrations in Poznan were recorded at unusual times that deviated from the typical diurnal pattern, i.e. at night or during morning hours. Alternaria spore concentrations on the PP were very high (>1000 spores/m3) at that time. The presence of non-local Ambrosia pollen, common to the PP, were also observed in the air. Air mass trajectory analysis and dispersal modelling showed that the northwest part of the PP, north of the Transdanubian Mountains, was the potential source area of Alternaria spores. Our results show that Alternaria spores are transported over long distances from the PP to Poland. These spores may markedly increase local exposure to Alternaria spores in the receptor area and pose a risk to both human and plant health. Alternaria spores followed the same atmospheric route as previously described LDT ragweed pollen, revealing the existence of an atmospheric super highway that transports bioaerosols from the south to the north of Europe.

Seasonal variation in the allergenic potency of airborne grass pollen in Bratislava (Slovakia) urban environment.

The Phl p 5 allergen of the plant species Phleum pratense is considered one of the most crucial grass pollen allergenic molecules inducing respiratory allergies. In this study, we evaluated seasonal variation in the concentration of both grass pollen and Phl p 5 allergens as well as the ratio allergen/pollen (pollen potency) in the air of Bratislava during two consecutive years, 2019-2020. These 2 years differed in terms of air pollution, as COVID-19 lockdown in spring 2020 considerably improved air quality in the study area. Air samples were collected using a Hirst-type sampler for pollen detection and the cyclone sampler for aeroallergen detection. In 2020, we observed 80.3% higher seasonal pollen integral, probably associated with the longer pollen season duration, however, 43.6% lower mean daily pollen potency than in 2019. The mean daily pollen value was 37.5% higher in 2020 than in the previous year, while the mean daily allergen value was 14.9% lower in 2020. To evaluate the relationship between the amount of pollen or allergen in the air and selected meteorological factors and air pollution parameters, we used multiple regression analysis. Regarding weather factors, precipitation and relative humidity were significantly associated with pollen and/or allergen concentration, though these associations were negative. Atmospheric pollutants, especially CO, NO2 and O3 were significantly associated with pollen and/or allergen levels. The associations with CO and O3 were positive, while the association with NO2 was negative. Our results indicate that for grasses, an air pollutant that has a significant positive relationship to the ratio of allergen/pollen is nitrogen dioxide.

Relationship between Poaceae pollen and Phl p 5 allergen concentrations and the impact of weather variables and air pollutants on their levels in the atmosphere.

The sensitization to grass pollen is a known problem in European countries. Phl p 5 is an important allergen recognized by the majority of grass sensitized individuals. In this study, we evaluated daily variation in airborne Poaceae pollen and Phl p 5 allergen concentrations to determine whether airborne pollen concentrations alone are sufficient to reflect the actual allergenic potential of the air. The relationships between the mentioned pollen and allergen concentrations and associated environmental variables were also examined. The airborne particles were collected during the Poaceae flowering season in Bratislava in 2019. Pollen sampling was performed using a Hirst-type sampler, while a cyclone sampler was used for the aeroallergen capturing. Allergenic molecules were quantified by ELISA assay. The associations between pollen and allergen concentrations showed that these two variables are positively correlated; however, the correlation was not significant. We observed the concurrent occurrence of airborne pollen and allergen peaks on the same day. Nevertheless, during some days of the pollen season, the allergen concentrations did not correspond to the airborne pollen values. Moreover, the days with low pollen concentration but high pollen potency and vice versa were observed. The effect of selected environmental variables on daily pollen and allergen concentrations was evaluated through Spearman's correlation analysis. Of all meteorological variables considered, air temperature, precipitation, and relative air humidity were significantly correlated with airborne pollen and/or allergen concentrations. The association with air temperature was positive, while the negative association was observed with precipitation and relative air humidity. Among the atmospheric pollutants, O3 and PM10 were significantly and positively associated with both pollen and allergen concentrations, whereas CO and PM2.5 were significantly and positively associated only with pollen concentration.

Summer storms and their effects on the spectrum and quantity of airborne bioparticles in Bratislava, Central Europe.

A thunderstorm is a risk factor for severe respiratory allergy or asthma attacks in patients suffering from pollen/spore allergy. This study aimed to investigate the changes in the spectrum and quantity of pollen and fungal spores in the air of Bratislava during summer storms as well as the impact of selected environmental parameters on these changes. Pollen/spore samples were collected using a Burkard volumetric aerospore trap during summer 2016. To identify those types of pollen/spores that may harm human health during the storm episodes, we analysed how the concentration of individual bioparticles in the air changed during pre-storm/storm/post-storm periods. The effect of environmental variables on the concentration of selected pollen/spore types was evaluated through Spearman's correlation analysis. The results of our study suggest that thunderstorm-related respiratory allergy symptoms in the study area may be caused by (1) spores of Myxomycetes, the airborne concentration of which increases due to an increase in wind speed during the pre-storm period; (2) ruptured pollen and Diatripaceae spores, the concentration of which increases due to increase in precipitation and relative air humidity, respectively, during the storm period; and (3) spores of Fusarium and Leptosphaeria, the concentration of which increases due to increase in precipitation and air temperature, respectively, during the post-storm period.

High Ambrosia pollen concentrations in Poland respecting the long distance transport (LDT).

High Ambrosia pollen concentrations in Poland rather rarely come from the local sources. The aim of this study was to define the temporal and spatial differences of the high Ambrosia pollen concentrations by creating models for the pollen transport from the distant sources. This study was thought to determine the direction of the air masses inflow into Poland, carrying Ambrosia pollen, from areas of the bordering countries with the pollen concentrations higher than iSTOTEN_n Poland. Pollen and meteorological datasets at 8 monitoring sites in Poland, and daily pollen concentrations at 11 sites in the Czech Republic, 5 sites in Slovakia and 3 sites in Ukraine were analysed recently. Days with concentrations ≥10 Pollen/m3 and concurrent meteorological situations were analysed in great deal. The HYSPLIT model was applied to compute backward trajectories up to 4 days backward (96 h) and at three altitudes: 20, 500 and 1000 m above ground level (a.g.l.). High pollen concentrations occur most frequently when the air masses inflow into Poland from southerly (S, SE, SW, 44%) and easterly (E, 6%) directions and in no advection situations (25%). In years with the highest frequency of days over 10 Pollen/m3, the prevailing directions of the pollen influx into Poland were from the South (2004-2006, 2008, 2011) but in one year (2014) from the East. Trajectories for the studied period show that air masses come most frequently from Slovakia and the Czech Republic. Sometimes, the Ambrosia pollen transport happens from Ukraine.

Intradiurnal variation of predominant airborne fungal spore biopollutants in the Central European urban environment.

Fungal spores are an important cause of allergic respiratory diseases worldwide. However, little is known about the intradiurnal pattern of spore concentrations of different fungal spore types in the air of the urban area. In this study, we evaluated bihourly variation in spore concentration of eight predominant fungal spore types in the atmosphere of Bratislava city (Agrocybe, Alternaria, Cladosporium, Coprinus, Exosporium, Epicoccum, Ganoderma, Leptosphaeria) with the aim to understand the relationships between the spore concentrations against associated environmental variables. Spore samples were collected using a Hirst-type volumetric aerospore trap from January to December 2016. Alternaria, Cladosporium, Epicoccum and Exosporium peaked during the daytime period between 10:00 and 16:00, while for Agrocybe, Ganoderma, Coprinus and Leptosphaeria, the nighttime peaks (20:00 and 04:00) were observed. Effect of a complex of environmental variables on bihourly concentrations of selected airborne fungal spore taxa was evaluated through multiple regression analysis. Air temperature, wind speed, sunshine duration and precipitation were positively associated with daytime spore types, while the association with nighttime spores was negative. In contrast, relative air humidity influenced negatively Exosporium daytime spore type but positively the Leptosphaeria nighttime spore type. Moreover, a circadian cycle of light and darkness was considered as an important predictor of nighttime spore levels. Among the atmospheric pollutants, PM10 was positively associated with all analysed daytime spores, while except for Leptosphaeria, O3 was negatively associated with nighttime spore types. NO2 and PM10 had mixed effects on nighttime spore levels. In general, air temperature, PM10 and wind speed were environmental parameters with great influence on airborne fungal spore concentration, being present in eight, seven and four regression models, respectively. Constructed regression models which the best explained variation in fungal spore concentrations were those for Ganoderma (R2 = 0.38) and Alternaria (R2 = 0.31).

Expansion and aerobiology of Ambrosia artemisiifolia L. in Slovakia.

INTRODUCTION AND OBJECTIVE: The invasive alien species Ambrosia artemisiifolia cause environmental, agronomical and medical problems in many regions of the world, including Slovakia. The purpose of this study was to survey the spread and distribution of this species in Slovakia and to analyse its airborne pollen pattern. MATERIALS AND METHODS: To evaluate the spatiotemporal dynamics of Ambrosia invasion in the territory of Slovakia, herbarium specimens, published databases and field investigations were considered. Aerobiological sampling was based on the analysis of pollen records at five aerobiological stations in Slovakia. For Bratislava and Banská Bystrica Monitoring stations, trends in Ambrosia pollen seasons were determined using Mann-Kendall test and Sen's slope estimator. RESULTS: Since the first record of A. artemisiifolia in Slovakia, the number of its colonies and its spread rate has increased considerably, and the colonisation of this species has been successful mainly in the south-western part of the country. Highest airborne pollen counts were recorded in Nitra, Trnava and Bratislava Monitoring Stations situated in the areas most infested by A. artemisiifolia in Slovakia. However, high pollen counts were also noted in Banská Bystrica and Kosice Monitoring Stations situated in areas where the source species was less abundant. During the study period, the number of days on which the pollen concentration exceeded the threshold of sensitivity increased significantly (+1.33 days/year) in Banská Bystrica, whereas the peak value decreased significantly (-13.37 pollen/year) in Bratislava. CONCLUSION: The number of the populations of A. artemisiifolia has increased considerably in recent years. Besides the most infested areas, high airborne pollen counts were also recorded in territories where the plant species was less abundant. During the study period, the intensity of Ambrosia pollen seasons decreased in Bratislava, probably due to changes in land-use practices, while the increasing trend in the pollen seasons intensity in Banská Bystrica mainly reflects the situation in the ragweed-infested remote areas due to long-range pollen transport.

Influence of airborne pollen counts and length of pollen season of selected allergenic plants on the concentration of sIgE antibodies on the population of Bratislava, Slovakia.

INTRODUCTION AND OBJECTIVE: The association between airborne pollen counts or duration of pollen season and allergy symptoms is not always distinguished. The purpose of this study was to examine the correlation between pollen exposure (annual total pollen quantity and main pollen season length) of selected allergenic plants in the atmosphere of Bratislava, and concentration of allergen-specific immunoglobulin E (sIgE) in serum of patients with seasonal allergy during 2002-2003. MATERIALS AND METHODS: The concentration of pollen was monitored by a Burkard volumetric pollen trap. At the same time, 198 pollen allergic patients were testing to determine the values of sIgE antibodies against selected pollen allergens; a panel of 8 purified allergens was used. RESULTS: The highest percentages of sensitization were detected for Poaceae and Ambrosia pollen allergens. The most abundant airborne pollen types were Urticaceae, Betula, Populus, Fraxinus, Pinus and Poaceae. The length of the pollen season varied. The longest pollen season was that of the Plantago - 105 days, and the shortest, Corylus - 20 days. A significant correlation was found between annual total pollen quantity and median sIgE values, especially in 2002. CONCLUSIONS: A strong and significant positive correlation was observed between pollen counts, excluding Betula, and sIgE levels in both analysed years. The correlation was weaker and negative in the case of length of pollen season and sIgE values.