Description: Narrow-leafed ash ( Fraxinus angustifolia ) is a common polygamous tree growing on the banks of rivers in the western Mediterranean region. Pollination occurs during winter, and the tree’s pollen is among the most abundant during that season. This work aims to relate the phenology of pollen shedding, source tree distribution, meteorology and airborne pollen occurrence for the species. Aerobiological sampling was conducted in Badajoz (south-western Spain) using a Hirst volumetric sampler over 24 years (1993–2016). Trees were geo-localized in a circle 500 m in diameter surrounding the pollen sampler. During the last two periods, pollination phenology was studied in 10 specimens, five in the surroundings of the pollen station and five 3 km apart, at a frequency of 3–4 days on average. Moreover, a detailed analysis of pollen occurrence was conducted for these two periods. Daily data for the whole period and hourly data over the last 2 years were used, including pollen monitoring and meteorology. A comparison was made between pollen occurrence and source distribution. The main pollen season lasted on average 53 (28–75) days. Average values were less than 10 grains m −3 , except for two periods of 23–24 grains m −3 . Daily data and hourly data correlation with meteorology showed different signs in correlation analysis. Hourly analysis showed that the maximum concentration occurred just after noon. Most pollen was recorded at an average temperature of 9 °C. Analysis of pollen sources and pollen occurrence showed a close relationship between predominant wind directions and tree distribution. Peaks of phenology were not coincident with pollen peaks. No trends in pollination were found. Non-homogeneous distribution of pollen sources for Fraxinus angustifolia provided a suitable tool to demonstrate that wind direction plays a relevant role when aerobiological data are interpreted according to source distribution. A limitation in phenology analysis and aerobiological data was noted in the narrow-leafed ash species.

Description: We report on the determination of the spore concentration and the species composition of the airborne fungi in selected caves of the Tatra Mountains, Poland. The following caves were surveyed: Mylna, Obłazkowa, Mroźna, Zimna and Naciekowa. The sampling was carried out in July 2015 and in January 2016. The aeromycological analyses were performed with the impact method, using the Air Ideal 3P apparatus and potato dextrose agar (PDA, Biocorp) culture medium. In the course of the July 2015 analysis, 17 species of fungi were isolated and 11 species were isolated in January 2016. In Mylna and Naciekowa caves, the dominant species were Cladosporium cladosporioides and Stachybotrys cylindrospora . In Obłazkowa cave, Rhizoctonia predominated and in Zimna cave—the colonies of the yeast-like fungi, along with S. cylindrospora . In Mroźna cave, Penicillium notatum was the most abundant taxon. In the winter time, in the majority of the caves Penicillium spp. predominated, with the exception of Mroźna and Naciekowa caves where Aspergillus niger was dominant. We propose that aeromycological monitoring be performed regularly in the following caves: Mroźna, Naciekowa and Zimna.

Description: Members of Cupressaceae and Taxaceae are known to release large amounts of highly allergenic pollen grains into the atmosphere, which are responsible for the onset of pollinosis in many countries throughout the world. In addition to pollen grains, their pollen sacs produce orbicules, which are submicron particles reported to carry allergens and which are potentially able to reach much further down the respiratory tract than pollen grains. Previous research has postulated the presence of orbicules in the atmosphere; however, direct observations have not yet been reported. The aim of this research was to provide the first direct evidence that Cupressaceae orbicules are released into the atmosphere by detecting them in daily aerobiological samples. We observed pollen sacs, pollen grains, and orbicules of nine species of Cupressaceae using scanning electron microscope (SEM). We then used a light and confocal microscope, to examine daily aerobiological samples. Under SEM, we measured the orbicule size (0.494–0.777 µm) and detected unknown nanometric particles (130–200 nm). Under the light microscope, aerobiological samples showed clusters of stained dots surrounding the pollen grains of Cupressaceae. Under the confocal microscope, the same clusters were resolved into submicron particles with the same autofluorescence as the pollen grains. These features enabled us to identify them as orbicules. We believe that our findings help to explain the onset of pollinosis and allergic asthma related to Cupressaceae pollen grains in many countries, even before pollen grains are actually detected or after they are no longer observed in aerobiological monitoring samples.

Description: In this study, a Tauber pollen trap was used in the urban area of Shijiazhuang to monitor continuously the outdoor air pollen from 2007 to 2011. The trap was emptied at regular intervals (typically 15 days). The results show that airborne pollen assemblages are generally similar each year among 2007–2011 and are responsive to the flowering times of plants, being dominated by pollen from woody plants in the spring and by pollen from herbaceous plants in summer and autumn. Two peak pollen influx periods, especially for the main allergenic pollen taxa, are seen, one between early March to early June and a second between late August to early October. During the four seasons, the main pollen taxa are Juglans , Artemisia , Platanus , Populus , Chenopodiaceae, Urtica  +  Humulus , Rosaceae, Pinus , Poaceae, Cereals, Quercus, and Betula , and all taxa other than Rosaceae were confirmed by relevant studies to be allergenic pollen taxa. RDA analysis of pollen influx and meteorological factors shows that in spring, temperature and humidity have significant effects on the pollen influx of woody plants; in summer, humidity and precipitation have significant negative effects on pollen influx of herbaceous plants; in autumn, temperature, water vapor pressure, and precipitation have a significant positive influence on herbaceous pollen influx; in winter, there were no significant correlations between airborne pollen influx and meteorological factors. The results reveal the dispersion patterns of airborne pollen and provide an important reference to appropriate construction of urban green systems and the reliable reduction in regional pollinosis.

Description: Relationships between meteorological factors and airborne pollen concentrations at high altitudes are virtually unknown. We used cross-correlation analyses to test the relationships between daily variation in meteorological factors (i.e. temperature, humidity and wind speed) and airborne pollen concentration, diversity (number of families and Shannon and Simpson diversity indices) and evenness (Pielou index) in an Apennine high-altitude site (Gran Sasso Massif, 2117 m elevation). In contrast to patterns observed at low altitudes, the temperature had a negative correlation with pollen abundance and diversity, whereas humidity had a positive correlation. The unexpected negative correlations with temperature can be explained with the particular position of our sampling site. Wind speed was positively correlated with pollen diversity and abundance in the short term, which can be explained by the fact that higher wind speed promotes both primary emission of pollen from the anthers and subsequent re-suspension. Evenness and wind speed were negatively correlated in the short term because of the different response of different species to meteorological conditions. In the longer term, the average concentrations of the various taxa tend to reach similar values, leading to increased values of diversity. Our finding of a decrease in pollen emission with increasing temperature has important implications for the study of the impacts of global change on high-altitude plant communities. We also detected a high abundance of Cupressaceae/Taxaceae pollen, a reflection of the expansion of thermophilic species, such as Juniperus, due to climate change.

Description: Numerous studies have focused on occupational and indoor environments because people spend more than 90% of their time in them. Nevertheless, air is the main source of bacteria in indoors, and outdoor exposure is also crucial. Worldwide studies have indicated that bacterial concentrations vary among different types of outdoor environments, with considerable seasonal variations as well. Conducting comprehensive monitoring of atmospheric aerosol concentrations is very important not only for environmental management but also for the assessment of the health impacts of air pollution. To our knowledge, this is the first study to present outdoor and seasonal changes of bioaerosol data regarding an urban area of Poland. This study aimed to characterize culturable bacteria populations present in outdoor air in Gliwice, Upper Silesia Region, Poland, over the course of four seasons (spring, summer, autumn and winter) through quantification and identification procedures. In this study, the samples of bioaerosol were collected using a six-stage Andersen cascade impactor (with aerodynamic cut-off diameters of 7.0, 4.7, 3.3, 2.1, 1.1 and 0.65 μm). Results showed that the concentration of airborne bacteria ranged from 4 CFU m −3 , measured on one winter day, to a maximum equal to 669 CFU m −3 on a spring day. The average size of culturable bacterial aerosol over the study period was 199 CFU m −3 . The maximal seasonally averaged concentration was found in the spring season and reached 306 CFU m −3 , and the minimal seasonally averaged concentration was found in the winter 49 CFU m −3 . The most prevalent bacteria found outdoors were gram-positive rods that form endospores. Statistically, the most important meteorological factors related to the viability of airborne bacteria were temperature and UV radiation. These results may contribute to the promotion and implementation of preventative public health programmes and the formulation of recommendations aimed at providing healthier outdoor environments.

Description: Metabarcoding is a promising DNA-based method for identifying airborne pollen from environmental samples with advantages over microscopic methods. Sample preparation and DNA extraction are of fundamental importance for obtaining an optimal DNA yield. Currently, there is no standard procedure for these steps, especially for gravimetric pollen samplers. Therefore, the aim of this study was to develop protocols for processing environmental samples for pollen DNA extraction and for metabarcoding analysis and to assess the efficacy of these protocols for the taxonomic assignment of airborne pollen collected by gravimetric (Tauber trap) and volumetric (Hirst-type trap) samplers. Protocols were tested across an increasing complexity of samples, from pure single-species pollen to environmental multi-species samples. A short fragment (about 150 base pairs) of the chloroplast trn L gene was amplified using universal primers for plants. After PCR amplification, amplicons were Sanger-sequenced and taxonomic assignment was accomplished by comparison with a custom-made reference database including chloroplast DNA sequences from most of the anemophilous taxa occurring in the study area (Trentino, northern Italy), representing 46 plant families. Using the classical morphological pollen analysis as a benchmark, we show that DNA metabarcoding is efficient and applicable even in complex samples, provided that protocols for sample preparation, DNA extraction, and metabarcoding analysis are carefully optimized.

Description: Fungal spores are normal components of external environments. They have been reported to be associated with human, animal and plant diseases causing primary and opportunistic infections. Cladosporium is commonly the most frequently isolated genus from air samples, and its species are considered mainly saprophytic, but there is a wide variety of taxa that can cause adverse effects on human and animal health and also on plants. In this work, we aimed to record Cladosporium spores frequency of isolation in northern Argentinean Patagonia and to perform a molecular characterization based on actin gene complemented with EF1α and ITS genes. The ability of the pathogens to cause disease in pip fruits of Packham’s Triumph and Abate Fetel pears and red delicious apples was determined. Results confirmed Cladosporium spores as the main genera isolated from air samples, and the molecular characterization revealed the existence of 11 species in this region grouped in C. cladosporioides and C. herbarum complexes. Pathogenicity tests revealed that Cladosporium sp. cause disease on fruit. Abate Fetel was the most susceptible to infection. These results compose the first study in Argentina in respect of identification at species level of airborne Cladosporium spores, and furthermore, it is the first report in northern Patagonia and the high valley of Río Negro productive region. This knowledge can help farmers to take preventive measures in order to avoid biological damage.

Description: The composition of fungal biota and air quality of five traditional subterranean wine cellars and one store building of a modern wine production facility were examined in the Tokaj wine region (northeastern Hungary). Air samples were collected with SAS IAQ sampler onto PDA, MEA and RBA. Strains representing morphotypes were isolated from colonies formed on agar plates from either air or surface samples. The internal transcribed spacer (ITS) region of the rRNA gene cluster was amplified with primers ITS1 and ITS4. Altogether 90 morphotypes were isolated, 48 and 12 strains (43 species) from the air and surfaces, respectively. The number of spore-forming species generated high diversity of indoor fungi and differences between the cellars’ fungal compositions; however, their dominant species were proved to be the same. Among the isolated strains Penicillium spp. were the most frequent. The walls of cellars were covered by colonies of Zasmidium ( Cladosporium ) cellare often referred to as a noble mold. Even so, this mold has been found only at a small concentration in the air samples (10–30 CFU/m 3 ). The walls of the modern store were free of molds. Diversity of fungi of the examined wine cellars was influenced by environmental conditions to a certain degree, such as elevation (height above sea level), age, reconstruction time of cellars, indoor ethanol concentration and the number of chimneys. The location of cellars poorly influenced the concentration of fungi of the air inside cellars, contrary to outdoors where the air of the municipal area contained more CFUs than that of rural spaces.

Description: Forecasting daily airborne pollen concentrations is of great importance for management of seasonal allergies. This paper explores the performance of the pollen calendar as the most basic observation-oriented model for predicting daily concentrations of airborne Ambrosia , Betula and Poaceae pollen. Pollen calendars were calculated as the mean or median value of pollen concentrations on the same date in previous years of the available historic dataset, as well as the mean or median value of pollen concentrations of the smoothed dataset, pre-processed using moving mean and moving median. The performance of the models was evaluated by comparing forecasted to measured pollen concentrations at both daily and 10-day-average resolutions. This research demonstrates that the interpolation of missing data and pre-processing of the calibration dataset yields lower prediction errors. The increase in the number of calibration years corresponds to an improvement in the performance of the calendars in predicting daily pollen concentrations. However, the most significant improvement was obtained using four calibration years. The calendar models correspond well to the shape of the pollen curve. It was also found that daily resolution instead of 10-day averages adds to their value by emphasising variability in pollen exposure, which is important for personal assessment of dose-response for pollen-sensitive individuals.