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 AerobiologiaJournal Prestige (SJR): 0.673 Citation Impact (citeScore): 2Number of Followers: 4      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1573-3025 - ISSN (Online) 0393-5965 Published by Springer-Verlag  [2658 journals]
• Evaluating inaccurate pollen concentrations caused by turbulence using
passive sampler

Abstract: Abstract Understanding the atmospheric concentration of pollen (which is one of the most common vectors of allergens) is necessary to determine the atmospheric allergen level. Airborne pollen concentrations were predominantly evaluated using volumetric and gravitational particle samplers. However, no previous studies have successfully shown whether these sampling methods can be used to evaluate actual airborne pollen concentrations. In this study, the relationship between wind speed and sampling efficiency was investigated to determine whether the influence of ambient wind speed on sampling efficiency was significant. To this end, the influence of wind speed was analyzed by comparing a volumetric sampler and a gravitational sampler. The experimental results indicate that an increase in the wind speed results in an increase in the sampling efficiency of the gravitational sampler because of fluctuations in the turbulence. Our simulation shows that when pollen is entrained in the turbulence, the changes in the wind speed, turbulence amplitude, and turbulence length influence the deposition rate of pollen on the gravitational sampler. These influences can be explained by the turbulence vibration model. These results show the inadequacy of existing evaluation methods, not only for pollen deposition data, but also for all types of bioaerosol deposition data.
PubDate: 2021-10-06

• Analysis of allergenic pollen data, focusing on a pollen load threshold
statement

Abstract: Abstract Airborne allergenic pollen affects a significant part of the population and the information on pollen load is a valuable tool for public health prevention. The messages should be provided in a form easily understandable for the population. The study provides new insight for the categorisation of pollen load by defining thresholds solely from aerobiological data. Using the long-term airborne pollen data of Corylus, Alnus, Betula, Poaceae, and Artemisia have been evaluated the regionality of pollen concentrations in Lithuania. SPIn and peak values of the main pollen season highlighted as regionality indicators. The largest differences between stations were found in the cases of Corylus and Artemisia. The principle enabling a group of pollen concentrations into levels has been analysed based on retrospective aerobiological data of five pollen types. Thresholds were determined by employing the lowest peak value of the pollen season and applying the 25% principle for selected pollen types. The results were verified by performing associations of defined thresholds with retrospective morbidity data of allergic rhinitis and allergic asthma in Lithuania. Determined pollen thresholds can be used in epidemiological studies requiring associations with pollen concentration. Thresholds could also complement air quality information by integrating pollen load data into public messages or contribute to the development of mHealth systems.
PubDate: 2021-09-29

• ‘Pollen potency’: the relationship between atmospheric pollen counts
and allergen exposure

Abstract: Abstract Pollen allergies are responsible for a considerable global public health burden, and understanding exposure is critical to addressing the health impacts. Atmospheric pollen counts are routinely used as a predictor of risk; however, immune responses are triggered by specific proteins known as allergens, which occur both within and on the surface of the pollen grain. The ratio between atmospheric pollen counts and allergen concentrations (‘pollen potency’) has been shown to be inconsistent, with potentially important implications for pollen monitoring practice. Despite this, there has been no previous synthesis of the literature and our understanding of the factors that influence pollen potency remains poor. We conducted a scoping review with the aim of deriving a current understanding of: (a) the factors that influence pollen potency; (b) its variation through time, between taxa and by location; and (c) the implications for pollen monitoring practice. Our synthesis found that pollen potency is highly variable within and between seasons, and between locations; however, much of this variability remains unexplained and has not been deeply investigated. We found no predictable pollen potency patterns relating to taxon, geography or time, and inconclusive evidence regarding possible driving factors. With respect to human health, the studies in our synthesis generally reported larger associations between atmospheric allergen loads and allergy symptoms than whole pollen counts. This suggests that pollen potency influences public health risk; however, the evidence base remains limited. Further research is needed to better understand both pollen potency variability and its implications for health.
PubDate: 2021-09-20

• Comparison of Alternaria spore levels between two areas within the same
city (Salamanca, Middle West Spain)

Abstract: Abstract The purpose of this study is to contribute to the knowledge about fungal spores in the atmosphere of the city of Salamanca (Middle West Spain), through the comparative study of Alternaria spore levels in two different sampling points within the same city. The study was done in terms of seasonal and hourly distribution and the possible influence of the main meteorological parameters on their atmospheric concentrations. The sampling was carried out from 17 February 2014 to 16 February 2016, both included, with two Hirst-type volumetric spore trap samplers, in two buildings in the city: one in a semi-urban environment, on the outskirts of the city, and the other in the city centre, 1.4 km apart. After the two years of sampling, the total annual values of Alternaria varied very little concerning the location of the samplers. The maximum values coincided in the two spore traps during 2014–2015 on the same day with similar amounts, whereas in 2015–2016 the difference was more noticeable both in date and amount. In the study of the seasonality of Alternaria's atmospheric distribution, there were no differences in the length of the main spore season nor the number of days with health risk levels (concentrations above 100 spores/m3). With regard to correlations, the analyses carried out between daily concentrations in both samplers obtained highly significant and positive results. The influence of meteorological parameters on spore levels, showed a positive effect of temperature and sunshine, as well as a negative one for humidity and rainfall.
PubDate: 2021-09-12

• On the measurement uncertainty of Hirst-type volumetric pollen and spore
samplers

Abstract: Abstract Hirst-type volumetric spore traps are used across the globe and are the current standard instrument for monitoring pollen. While they suffer from various issues related to sampling, measurement, and human error, they are, nevertheless, relatively cost-efficient and robust instruments that have been in use for decades. They are also the only reference against which newer instruments can be directly evaluated and it is thus important to understand and quantify all errors to make fair comparisons. Here, we investigate the variability across three Hirst-type traps run in parallel for three months during the main pollen season in Payerne, Switzerland. A variety of temporal resolutions is studied. Overall, daily average values show median relative differences of 16% for total pollen (inter-quartile range (IQR) = 8–32%) and between 23 and 67% for the top three taxa considered. The values are identical for total pollen when only concentrations > 10 pollen grains/m3 are considered, but decrease notably for the individual taxa investigated, with median relative differences ranging 14–30%. At the 2-hourly resolution, there is considerably more variability between the three samplers, with median relative differences of 42% for total pollen (IQR = 20–88%) and 62–120% for the top three taxa, respectively. Again, when the lowest concentrations are not included, these differences decrease somewhat to 40% for total pollen (IQR = 19–78%) and 41–56% for the top three taxa, respectively. Observations of low concentrations below 10 pollen grains/m3 therefore have a large impact on the measurement uncertainty: for daily average total pollen concentrations there are differences of over 100% between the three samplers, and for individual taxa differences reach up to 200%, the maximum value possible in terms of pairwise comparisons.
PubDate: 2021-09-12

• Characterisation of pollen seasons in Iceland based on long-term
observations: 1988–2018

Abstract: Abstract This paper describes a long-term (1988–2018) data series from pollen monitoring in two locations in Iceland: Akureyri and Reykjavík. Our data showed a low diversity of airborne pollen present in the aeroplankton of Iceland. We showed that Betula spp. and Poaceae can be considered the main pollen allergens in Iceland. Both Betula spp. and Poaceae pollen seasons in Iceland are characterised by a late onset compared to continental Europe. Betula spp. seasons are further characterised by a longer duration and low SPI and peak values. Icelandic Poaceae seasons are shorter, but have SPI and peak values comparable to those recorded in continental Europe. We recorded no synchronisation in the intensity of pollen production between our monitoring sites in Iceland, and our data do not confirm the existence of repeatable cycle (bi- or triennial) of high and low pollen production in Betula spp. Statistically significant trends towards increasing SPI values were recorded in Reykjavík (Betula spp.) and Akureyri (Poaceae).
PubDate: 2021-09-01

• Fungi in the indoor air of critical hospital areas: a review

Abstract: Abstract Invasive fungal infection is an important cause of mortality and morbidity in neonates, especially in low-birthweight neonates. The contribution of fungi in the indoor air to the incidence of mucocutaneous colonization and to the risk of invasive fungal infection in this population is uncertain. This review aimed to identify and to summarize the best available evidence on the fungal contamination in the indoor air of critical hospital areas with an emphasis on pediatric/neonatal ICUs. Publications from 2005 to 2019 were searched in the databases Scientific Electronic Library Online (SciELO), US National Library of Medicine National Institutes of Health Search (PubMed), and Latin American Caribbean Health Sciences (LILACS). Descriptors in Health Sciences (DeCS) were used. Research papers published in Portuguese, English, and Spanish were included. Twenty-nine papers on all continents except Australia were selected. The results showed that the air mycobiota contained several fungal species, notably Aspergillus, Penicillium, Cladosporium, Fusarium, and yeast (Candida) species. The selected papers point out the risks that fungi pose to neonates, who have immature immune system, and describe simultaneous external factors (air humidity, seasonality, air and people flow, use of particulate filters, and health professionals’ hand hygiene) that contribute to indoor air contamination with fungi. Improving communication among health professionals is a great concern because this can prevent major health complications in neonates, especially in low-birthweight neonates. The results reinforced the need to monitor environmental fungi more frequently and efficiently in hospitals, especially in neonatal ICUs.
PubDate: 2021-09-01

• A systematic review of threshold values of pollen concentrations for
symptoms of allergy

Abstract: Abstract Pollen threshold values used in public warning systems are intended to inform people of the risk of developing allergy symptoms. However, there is no consensus about which pollen concentrations provoke allergy symptoms. The aim of this systematic review was the evaluation of studies investigating the relationship between pollen concentrations (alder, ash, birch, hazel, mugwort and ragweed) and the number of cases in which participants visited a doctor, drug consumption and allergy symptoms. This systematic literature review is registered in PROSPERO (CRD42019112369). A PubMed search was applied and enriched by consultation with experts and a snowball strategy. The included studies were checked for risk of bias (RoB), and extensive data were extracted and compared. Of 511 studies, 22 were eligible according to the previously established inclusion criteria, and 17 from these showed a low RoB. The strongest evidence was reported for ash (Fraxinus) pollen, where an increase of number of doctor’s visits at an interquartile range (IQR) of 18–28 grains/m3 was detected by three studies. Five studies about birch (Betula) pollen showed a threshold value of 45 grains/m3 for increased drug consumption. The evidence of a threshold value was limited for alder (Alnus), hazel (Corylus), mugwort (Artemisia) and ragweed (Ambrosia) pollen. The inconsistent results concerning all types of pollen, except ash pollen, can be the result of multiple factors, e.g., age, gender, allergen content of pollen and individual sensitivity. These influencing factors should be investigated more closely in future research.
PubDate: 2021-09-01

• Characterization of bioaerosols in and around a landfill site in Delhi

Abstract: Abstract The present study was carried out to estimate the spatiotemporal variation of fungal bioaerosols, in and around a landfill site in Delhi. The sites were deep in the landfill to nearby residential areas. Fungal bioaerosol sampling was done with the help of Anderson six stage viable cascade impactor on monthly basis for one year from June 2015 to May 2016 at seven different sites in and around the landfill site. The entire sampling period was classified in five different seasons, viz., winter, spring, summer, monsoon and autumn, characteristic of Delhi. It was observed in monsoon season concentration was maximum at most of the sites while lowest during autumn season. Contrary to this, it was also found that concentrations of fine fraction of bioaerosols were significantly high even during autumn at sites deep in the landfill while low in the residential areas near landfill. As such no significant pattern was observed with the coarse fraction of fungal bioaerosols. Typical relations of fungal concentration with the meteorological parameters were also observed. It was noticed that concentration was directly related to temperature and wind speed while inversely related to humidity. Fine and coarse fractions of bioaerosols showed a very good and positive relationship with each other. Among the eight fungal genera identified from the samples of Okhla landfill sites, Penicillium, Aspergillus and Rhizopus were found in abundance at all the seven sites in all the five seasons. Alternaria and Fusarium were found in abundance in spring, summer and winter seasons whereas Cladosporium in autumn and winter. Aspergillussps was present in all the five seasons.
PubDate: 2021-09-01

• Bioaerosols in public and tourist buses

Abstract: Abstract Public bus system worldwide transports daily more than 34 million people; therefore, air quality inside buses is an important urban air pollution issue. Airborne microbiological composition and abundance was examined inside five different fuel type buses (diesel (EURO IV and EURO V), hybrid diesel (HD), compressed natural gas (CNG), hybrid natural gas (HCNG) and electric vehicle (EV)) from Barcelona bus system, inside and outside the tourist bus and different periods of campaigns (summer: May–September and winter: November–March). Quantitative PCR was used to quantify total bacteria, Penicillium/Aspergillus and Cladosporium sp. and Kinetic Chromogenic Limulus Amebocyte Lysate (LAL) Assay for endotoxins. The targeted 16S rRNA genes were amplified and sequenced to asses bacterial community composition and biodiversity. Regarding the targeted microorganisms, the results showed low bioaerosol concentrations, being fungi and endotoxins below the detection limit, although bacterial airborne has a geometric average of 103 equivalent E. Coli genomes/m3. Airborne bacterial community biodiversity showed that Actinobacteria and Proteobacteria were the most abundant Phylum in the different sampled buses and in the two seasons (summer: May–September and winter: November–March). While regarding to genera taxonomic category, the different fuel type buses presented a high overlap degree, being Cutibacterium the most abundant and Paracoccus the one only detected inside. The different seasons showed that the different taxonomic genera decrease from summer: May–September to winter: November–March and in this case Paracoccus was the most abundant. Overall, biodiversity inside buses is greatly affected by the presence of humans inside, but also by the outdoor sources at the moment of the sampling, and the seasonal period, more than the type of bus.
PubDate: 2021-09-01

• Airborne sub-pollen particles from rupturing giant ragweed pollen

Abstract: Ragweed pollen is a prevalent allergen in late summer and autumn, worsening seasonal allergic rhinitis and asthma symptoms. In the atmosphere, pollen can osmotically rupture to produce sub-pollen particles (SPP). Because of their smaller size, SPP can penetrate deeper into the respiratory tract than intact pollen grains and may trigger severe cases of asthma. Here we characterize airborne SPP forming from rupturing giant ragweed (Ambrosia trifida) pollen for the first time, using scanning electron microscopy and single-particle fluorescence spectroscopy. SPP ranged in diameter from 20 nm to 6.5 μm. Most SPP are capable of penetrating into the lower respiratory tract, with 82% of SPP < 1.0 μm, and are potential cloud condensation nuclei, with 50% of SPP < 0.20 μm. To support predictions of the health and environmental effects of SPP, we have developed a quantitative method to estimate the number of SPP generated per pollen grain ( $${n}_{\mathrm{f}}$$ ) based upon the principle of mass conservation. We estimate that one giant ragweed pollen grain generates 1400 SPP across the observed size range. The new measurements and method presented herein support more accurate predictions of SPP occurrence, concentration, and air quality impacts that can help to reduce the health burden of allergic airway diseases. Graphic abstract Rupturing ragweed pollen releasing cellular components (right), viewed by an inverted light microscope.
PubDate: 2021-09-01

• Efficiency of bioaerosol samplers: a comparison study

Abstract: Abstract Bioaerosols, including bacteria and fungi, are ubiquitous and have been shown to impact various organisms as well as biogeochemical cycles and human health. However, sample collection poses a challenge for aeromicrobiologists and can determine the success of a study. Establishing a standard collection procedure for bioaerosol sampling could help advance the field. We tested the efficiency (number of organisms collected and DNA yield per unit time) of three sampling devices: a membrane filtration device, a liquid impinger, and a portable electrostatic precipitator bioaerosol collector. We compared the efficiency of these three devices for both culture-dependent studies, by enumerating colony forming units (CFUs), and culture-independent studies, by extracting and quantifying total DNA. Our results show that the electrostatic precipitator collected microorganisms significantly more efficiently than the membrane filtration and liquid impingement in both types of studies over the same time interval. This is due to the high flow rate of the device. This work is important and timely because aeromicrobiology is currently restricted by long sampling times and  risk of evaporation, desiccation, or freezing during sample, which increases with sampling times.  Fieldwork convenience and portability of instruments are an additional challenge for sampling. Using a sampler that can overcome these technical hurdles can accelerate the advancement of the field, and the use of a lightweight, battery-powered, inexpensive, and portable bioaerosol collection device could address these limitations.
PubDate: 2021-09-01

• Airborne pollen trends in Tétouan (NW of Morocco)

Abstract: Abstract Trends of the airborne annual pollen integral (APIn) and pollen season of principal woody and herbaceous plants in Tétouan were analysed over a 10-year monitoring period (2008–2017). Pollen was continuously sampled by means of a 7-day recording volumetric pollen trap by Burkard. Pollen trends were analysed by using Mann–Kendall tests and Sen’s slope. Aerobiological data were correlated with temperature and rainfall. A significant decreasing trend in annual minimum temperature was revealed together with significant decreasing trends in the APIn observed for Cupressaceae, Cannabis, Parietaria, Pinus and Quercus, this being highly significant for Cupressaceae and Pinus. On the contrary, the seasonal intensity of Mercurialis, Morus and Olea showed nonsignificant trends. Besides this, 77% of the studied pollen types showed a tendency to decreasing the peaks value, these trends being significant for Cupressaceae (−204.67 pollen/ m3 per year) and Pinus (−14.33 pollen/ m3 per year). The end of the Quercus pollen season showed a marked tendency to occur earlier across the years (−4.5 days/year) and the start day of Cannabis, Cupressaceae, Pinus and Poaceae to occur later (+ 7.13, 2.33, 1.67 and 2.5 day/year, respectively), shortening the duration of the respective pollen seasons but not with a significant trend. Regarding the association between the pollen season intensity and meteorological parameters, six pollen types showed at least one statistically significant coefficient correlation. The decreasing and significant trend in the intensity of the APIn diminishes also the exposure to airborne pollen for allergic sufferers, having implications in the field of public health. Decreasing trends in annual minimum temperature and the general lack of significant trends and correlation coefficients between the parameters of the pollen season of different pollen types and monthly mean temperatures and rainfall suggest that interannual variability in the data is due to human interventions, deforestation, fires and the opposite response of some species to warming in Fall/Winter and Spring, and this could be the reasons for the observed behaviour in the pollen season.
PubDate: 2021-09-01

• Estimating the allergenic potential of urban green areas in the city of

Abstract: Abstract Urban green spaces offer large environmental, social, and economic benefits for the population. However, when species that compose it are chosen, its allergenicity is not usually considered, which poses a risk to the population with pollinosis. In this work, the potential allergenicity index (IUGZA) of five urban parks in the city of Madrid (Spain) has been calculated, in order to assess their allergenic potential and to identify the species that most contribute to increasing it. The results show that three of the parks register an index value sufficient high to cause adverse reactions in the exposed population. The most contributing species to the index value are London plane (Platanaceae family), horse chestnut (Sapindaceae family), pines and cedars (Pinaceae family), and various species of the Cupressaceae family. Some parks showed a relationship between tree density and percentage of species with high or very high potential allergenicity value (VPA), with the IUGZA. A relationship between grass coverage and the percentage of contribution to the value of the index has been observed. These studies can guide managers in the selection of species with low allergenicity and management practices in order to minimize the effects on allergic citizens.
PubDate: 2021-09-01

• Characteristics of airborne microbial community in Hefei, eastern China,
under a good quality in mid-spring

Abstract: Abstract Whether airborne microbial community can be affected by air quality in a short time has been controversial. To study the relationships between the hub bacteria, fungi, and air quality will allow to better understand the mechanism of microbial community change. Total suspended particulate samples were collected to explore the microbial community by metagenome sequencing. Results showed that the bacterial richness and diversity showed a weak uptrend with the increase in air quality index (AQI). The bacterial community was relatively stable, and its minor change was more likely to be caused by AQI. However, the fungal community randomly varied. Only fungal richness showed a weak downtrend with the increase in AQI. Among 14 hub bacteria and 19 hub fungi, four bacteria Marmoricola, Asticcacaulis, Sphingomonas, and Clostridium sensu stricto were related to AQI, but none of hub fungi. In aerosols, there were many pathogenic species (33 bacteria, 17 fungi), and the abundances of pathogens were relatively high (bacteria: > 13.50%, fungi: > 12.08%). The findings presented here indicated that in Hefei in mid-spring, with a good air quality (AQI ≤ 101), the residents living around the sampling point also may be subjected to health threats by microorganisms.
PubDate: 2021-09-01

• Spatial distribution of fungi from the analysis of aerobiological data
with a gamma function

Abstract: Abstract Fungi are an important component of ecosystems. Some fungi are widely distributed, while others are limited to certain habitats. Studies based on airborne fungal spores can help to know the geographical distribution of fungi in the territory. Our aim was to show that a gamma probability density function (gpdf) based on a database of 20 airborne fungal spore taxa concentrations in eight localities of Catalonia (NE Spain) for a period of 20 years was a useful tool to map the distribution of these taxa in this region, as well as to establish a general classification on their sporulation through the alpha parameter of the validated model. This allows a more efficient study of the atmospheric dynamics of the different taxa, since the number of taxa is reduced to a representative taxon for each of the categories of the generic classification. In general, the results obtained confirmed that the scale parameter of the gamma distribution changes from year to year, depending on the meteorological conditions, while the shape parameter remains fairly stable. At the temporal scale, airborne fungal spores of Agrocybe sp. showed the highest stability; at the spatial scale, Cladosporium sp. showed the highest stability. Regarding localities, Girona was the station with greater interannual variation, while Barcelona and Vielha showed the lowest. In addition, the results obtained allowed a non-subjective classification of these taxa in five groups, based on the gamma (shape) parameter. The taxa Alternaria sp., Cladosporium sp., Ganoderma sp., Pleospora sp., Leptosphaeria sp., Aspergillus sp.-Penicillium sp. were cosmopolitan and showed a similar behavior across the whole study area, with any of them possible candidates for used in predictive models; airborne fungal spores of Agrocybe sp., Arthrinium sp., Epicoccum sp., Drechslera sp.–Helminthosporium sp., Pithomyces sp., Thelephoraceae, Stemphylium sp., Xylariaceae can be used as meteorological indicators and Agaricus sp., Coprinaceae sp., Torula sp. can be used as indicators of anthropogenic activities. The results obtained could be used to reduce the number of spore taxa analyzed and subsequently develop generic predictive models.
PubDate: 2021-09-01

• Unusually high birch (Betula spp.) pollen concentrations in Poland in 2016
related to long-range transport (LRT) and the regional pollen occurrence

Abstract: In 2016, the highest birch (Betula spp.) pollen concentrations were recorded in Kraków (Poland) since the beginning of pollen observations in 1991. The aim of this study was to ascertain the reason for this phenomenon, taking the local sources of pollen in Poland and long-range transport (LRT) episodes associated with the pollen influx from other European countries into account. Three periods of higher pollen concentrations in Kraków in 2016 were investigated with the use of pollen data, phenological data, meteorological data and the HYSPLIT numerical model to calculate trajectories up to 4 days back (96 h) at the selected Polish sites. From 5 to 8 April, the birch pollen concentrations increased in Kraków up to 4000 Pollen/m3, although no full flowering of birch trees in the city was observed. The synoptic situation with air masses advection from the South as well as backward trajectories and the general birch pollen occurrence in Europe confirm that pollen was transported mainly from Serbia, Hungary, Austria, the Czech Republic, Slovakia, into Poland. The second analyzed period (13–14 April) was related largely to the local flowering of birches, while the third one in May (6–7 May) mostly resulted from the birch pollen transport from Fennoscandia and the Baltic countries. Unusual high pollen concentrations at the beginning of the pollen season can augment the symptomatic burden of birch pollen allergy sufferers and should be considered during therapy. Such incidents also affect the estimation of pollen seasons timing and severity. Graphical
PubDate: 2021-09-01

• Community structure of environmental microorganisms associated with
COVID-19 affected patients

Abstract: Abstract To clarify the characteristics and distribution of hospital environmental microbiome associated with confirmed COVID-19 patients. Environmental samples with varying degrees of contamination which were associated with confirmed COVID-19 patients were collected, including 13 aerosol samples collected near eight patients in different wards, five swabs from one patient’s skin and his personal belongings, and two swabs from the surface of positive pressure respiratory protective hood and the face shield from a physician who had close contact with one patient. Metagenomic next-generation sequencing (mNGS) was used to analyze the composition of the microbiome. One of the aerosol samples (near patient 4) was detected positive for COVID-19, and others were all negative. The environmental samples collected in different wards possessed protean compositions and community structures, the dominant genera including Pseudomonas, Corynebacterium, Neisseria, Staphylococcus, Acinetobacter, and Cutibacterium. Top 10 of genera accounted for more than 76.72%. Genera abundance and proportion of human microbes and pathogens radiated outward from the patient, while the percentage of environmental microbes increased. The abundance of the pathogenic microorganism of medical supplies is significantly higher than other surface samples. The microbial compositions of the aerosol collected samples nearby the patients were mostly similar to those from the surfaces of the patient's skin and personal belongings, but the abundance varied greatly. The positive rate of COVID-19 RNA detected from aerosol around patients in general wards was quite low. The ward environment was predominantly inhabited by species closely related to admitted patients. The spread of hospital microorganisms via aerosol was influenced by the patients’ activity.
PubDate: 2021-09-01

• Relevance of aerobiological studies in Nigeria: a two-year aerospora
record of Lagos

Abstract: Abstract Pollen and fungal spores (aerospora) are major atmospheric bioaerosols for pollen allergy sufferers. Aerospora types and concentration vary seasonally, depending upon the flowering period and meteorological factors which are variable in different geographical regions. The aim of this study was to analyze a two-year record of aerospora from two locations (Epe and Ojo) in Lagos (Nigeria), from May 2014 to April 2016. Aerospora were monitored with a modified Tauber sampler. The residual solution was harvested monthly throughout the duration of the study and acetolyzed, and microscopic slides were prepared. Aerospora were analyzed with light and scanning electron microscopy (SEM). SEM studies were applied to reach a higher level of pollen identification. A plant enumeration was carried out in the surroundings of the sampling sites. The aerobiological study revealed seasonal distribution patterns of various aerospora. The highest total pollen counts for 2014–2015 and 2015–2016 were recorded in April–July for both sites while minima occurred in January–December. Pollen of Poaceae, Euphorbiaceae, Convolvulaceae, Cyperaceae was dominant. Other taxa include Borreria sp., Elaeis guineensis, Amaranthus sp., Tridax procumbens. Fungal spores showed a high recovery for the months April–August for Epe in 2014–2015 and 2015–2016. In Ojo, fungal spores were high in July–August for 2014–2015 and in April–August for 2015–2016. Common fungal spores include those of Alternaria, Nigrospora, and Curvularia. The relationship between the aerospora spectra and the vegetation at the study locations was qualitatively investigated. There is a need to further test the allergenicity of pollen of common plants in Nigeria to inform pollen-hypersensitive individuals.
PubDate: 2021-09-01

• Forecasting Betula and Poaceae airborne pollen concentrations on a
3-hourly resolution in Augsburg, Germany: toward automatically generated,
real-time predictions

Abstract: Abstract Airborne allergenic pollen impact the health of a great part of the global population. Under climate change conditions, the abundance of airborne pollen has been rising dramatically and so is the effect on sensitized individuals. The first line of allergy management is allergen avoidance, which, to date, is by rule achieved via forecasting of daily pollen concentrations. The aim of this study was to elaborate on 3-hourly predictive models, one of the very few to the best of our knowledge, attempting to forecast pollen concentration based on near-real-time automatic pollen measurements. The study was conducted in Augsburg, Germany, during four years (2016–2019) focusing on Betula and Poaceae pollen, the most abundant and allergenic in temperate climates. ARIMA and dynamic regression models were employed, as well as machine learning techniques, viz. artificial neural networks and neural network autoregression models. Air temperature, relative humidity, precipitation, air pressure, sunshine duration, diffuse radiation, and wind speed were additionally considered for the development of the models. It was found that air temperature and precipitation were the most significant variables for the prediction of airborne pollen concentrations. At such fine temporal resolution, our forecasting models performed well showing their ability to explain most of the variability of pollen concentrations for both taxa. However, predictive power of Betula forecasting model was higher achieving R2 up to 0.62, whereas Poaceae up to 0.55. Neural autoregression was superior in forecasting Betula pollen concentrations, whereas, for Poaceae, seasonal ARIMA performed best. The good performance of seasonal ARIMA in describing variability of pollen concentrations of both examined taxa suggests an important role of plants’ phenology in observed pollen abundance. The present study provides novel insight on per-hour forecasts to be used in real-time mobile apps by pollen allergic patients. Despite the huge need for real-time, short-term predictions for everyday clinical practice, extreme weather events, like in the year 2019 in our case, still comprise an obstacle toward highly performing forecasts at such fine timescales, highlighting that there is still a way to go to this direction.
PubDate: 2021-09-01

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