Aerobiologia最新文献

In recent years, significant efforts have been made to study changes in the levels of air pollutants at regional and urban scales, and changes in bioaerosols during air pollution events have attracted increasing attention. In this study, the bacterial structure of PM_2.5 was analysed under different environmental conditions during hazy and non-hazy periods in Guilin. A total of 32 PM_2.5 samples were collected in December 2020 and July 2021, and the microbial community structures were analysed using high-throughput sequencing methods. The results show that air pollution and climate change alter the species distribution and community diversity of bacteria in PM_2.5, particularly Sphingomonas and Pseudomonas. The structure of the bacterial community composition is related to diurnal variation, vertical height, and urban area and their interactions with various environmental factors. This is a comprehensive study that characterises the variability of bacteria associated with PM_2.5 in a variety of environments, highlighting the impacts of environmental effects on the atmospheric microbial community. The results will contribute to our understanding of haze trends in China, particularly the relationship between bioaerosol communities and the urban environment.

Up-to-date reporting of atmospheric pollen contents is essential to assist doctors and allergy sufferers alike to undertake treatment or preventative measures. We have evaluated the extent of the digitally accessible knowledge (DAK) created by the Spanish network of pollen monitoring stations and analyzed the gaps in three main DAK factors: data completeness, data obsolescence, and data publication. Data from 118 distinct stations were discovered, of which one in four seemed to have discontinued publication of updated data either continuously or seasonally. While two-thirds of the sites published data through their own local portals, only about one-half also contributed daily data to the two main aggregators in the country (SEAIC and REA), which in turn were the only outlets available for one-tenth of the sites. The analysis revealed the probable existence of completely obscure sites recording, but not reporting, data. Recovering or surfacing dormant or silent sites may significantly improve the DAK about pollen in Spain.

Fungal aerosols deteriorate library collections and can impact human health, mainly via respiratory diseases. Their spread is influenced by factors such as temperature and relative humidity. This study aims to assess the concentration of fungal aerosols in the interior environment of the Popular Library of Gaira in the District of Santa Marta, Colombia, using a two-stage cascade impactor utilizing Sabouraud dextrose agar on Petri dishes for the collection of samples. The sampler was positioned at 1.5 m above ground level, operated with a flow rate of 28.3 l/min for 4 min and thermo-hygrometric conditions were also recorded. Concentrations in the air of up to 1197.0 CFU/m³ were reported, with a mean value close to 150 CFU/m³. Higher values during the morning samples were noted. Seven genera of fungi were found, Aspergillus and Curvularia were the most abundant. The temperature was between 30.80 and 33.51 °C, and the relative humidity was between 62.61 and 64.80%. Statistical analysis showed a significant correlation between the fungal aerosol concentration and relative humidity, where an increase of 10% in moisture could double the fungal aerosol concentration. We concluded that potentially favorable conditions exist indoors for the growth and survival of the following fungi: Aspergillus, Penicillium, Cladosporium, and Curvularia, and to a lesser extent for Chrysonilia, Cunninghamella, and Paecylomices. Relative humidity was seen to be the factor that affects the concentration of aerosols fungal in the library most significantly.

Pollen grains are released from plants and rupture, releasing pollen grain fragments referred to as subpollen particles (SPPs). This study is a laboratory evaluation of live oak, Quercus virginiana, to determine the environmental conditions needed to emit SPPs and measure the concentration of SPPs produced. To represent conventional SPP release, live oak branches were exposed to high relative humidity (> 95%), followed by reduced relative humidity (73.5%-76.3%) and wind (up to 1.8 m s⁻¹). In contrast, wind-driven SPP release experiments were conducted by exposing branches to constant relative humidity while cycling fans used to simulate winds. Wind-driven experiments produced maximum SPP concentrations as high as 3.3 × 10² ± 2.7 × 10² SPPs per cm³. The maximum SPP emissions during conventional SPP release experiments were as high as 7.3 × 10¹ ± 3.4 × 10¹ SPPs per cm³. The total number of SPPs emitted during conventional SPP release experiments was not significantly different from the SPP emissions during wind-driven SPP release experiments at a 5% significance level. The concentration of SPPs generated from pollen grains was used to calculate SPP emission factors. SPP emission factors were determined to be between 1.6 × 10⁴ and 9.0 × 10⁴ SPPs per pollen grain and between 4.7 × 10¹² and 2.2 × 10¹⁵ SPPs per m². These results indicate that SPPs represent a significant source of cloud-forming aerosol and have the ability to impact respiratory health.

Biological contaminants mainly consisting of living or dead microorganisms and compounds or fragments of plants and animal origin are gaining widespread research interest in recent years due to their ubiquitous presence along with their health effects on humans. Students spend a significant time of the day in educational institutions, which increases the cumulative health risk over the years. This review discusses the major biological contaminants, sampling strategies, health effects, and the factors affecting their prevalence in educational institutions. Fungi and bacteria were the most reported bio-contaminants followed by allergens and endotoxins. Exposure to bio-contaminants may result in acute and chronic respiratory diseases, infectious diseases, allergies, building-related illnesses, and even cancer. More research is needed to know the susceptibility of different age groups of students, formulation of guideline values, standard protocols for sampling, and proper diagnostic tests for diseases caused by bio-contaminants. Students should be made aware of the various aspects of indoor air quality such that they become inquisitive towards the same and become responsible for safety and hygiene.

Timely information on the beginning of the flowering of important plant species of pollen allergens is consequential for the entire population due to pollen allergy and its extensive clinical impact worldwide. This paper examines the prediction of the beginning of the flowering of the common hazel (Corylus avellana) based on the PhenoClim phenological model using long-term phenological observations (1991–2020) in the Czech Republic. Furthermore, temporal and spatial evaluations of the beginning of the flowering of C. avellana were examined in different climate zones in the Czech Republic within the same period. In total, 40 phenological stations at altitudes from 155 to 743 m asl located in warm, medium warm, and cold climate zones were evaluated using the Mann–Kendall test. The beginning of the flowering of C. avellana changed progressively in timing, and the difference in the rate of shifts was between −33 and + 15 days per the entire period. An extreme shift to an earlier date was detected at stations located in a warm region (W2). In contrast, the highest shift to a later date was found at stations located in the cold climate regions (C4, C6, C7). Using the PhenoClim, the base temperature and temperature sums were calculated for the beginning of the flowering of the common hazel. As the most accurate predictor for this phenological phase and species, the maximum air temperature was determined as the best predictor based on the combination of RMSE and R² values. The optimal start day for calculation was January 1st; the threshold (base temperature) was 2.7 °C with a temperature sum of 155.7 °C. The RMSE value was 5.46, and the MBE value was −0.93. The simulated data showed an excellent correlation with the observed data—the correlation coefficient was 0.932. The PhenoClim model results can be used in the forecast modelling of the beginning of the flowering of the common hazel in the Czech Republic.

Many methods have been devised to count pollen grains automatically; however, few combine speed, reliability, inexpensiveness and user friendliness. This study describes a combination of simple, glycerine-based extraction, digital imaging and free particle counting software configured to achieve semi-automated processing of a large volume of images. Pollen grains were extracted from anthers of 10 common perennial grass (Poaceae) species, all implicated in pollinosis in Europe, and samples, illuminated on slides and digitally imaged. ImageJ algorithms were designed to remove significant extraneous content and count just the pollen grains, then applied in batch mode on multiple images. Accuracy was assessed by comparing a sample of automated software counts to manual, visual counts of the same images and found to be high. Total pollen production per anther and per inflorescence was estimated by counting the number of pollen grains per anther and the number of florets per inflorescence. Methodological and natural variation in pollen counts is discussed. Results were compared to published pollen counts of the same species; new pollen production figures are published for Cynosurus cristatus. This method is portable to other plant species, and requires only readily available reagents, equipment and software, it is quick, reliable, inexpensive and user friendly.

Inhalation of olive pollen (Olea europaea L.) is one of the main causes of allergy in Mediterranean countries and some areas of North America. The response to allergens consists in the production of inflammatory cytokines which is mediated by the deregulation of Ca²⁺ signals. In this study, the biological activity of the material released in olive pollen hydration (PMR) was tested on Ca²⁺ cytosolic of PE/CA-PJ15 cells (PJ-15). Ca²⁺ cytosolic was determined by fluorometric assay with the cell line PE/CA-PJ15 (PJ-15) labeled with the fluorescent probe FURA 2 AM. The material released in olive pollen hydration (PMR) was analyzed by HPLC for the determination of phenolic acids. PMR was subjected to fractionation by gel filtration, and the fractions with Ca²⁺-chelating activity were tested with SDS-PAGE and the single bands characterized by proteomic analysis. PMR showed high Ca²⁺-chelating activity and is able of blocking the increase Ca²⁺-cytosolic produced by thapsigargin (TG). PMR then restored Ca²⁺ homeostasis in PJ-15 cells deregulated by the endoplasmic reticulum Ca²⁺-ATPases inhibitor. It is therefore possible that PMR can antagonize the effects of allergens on Ca²⁺ cytosolic. The analytical characterization of the material released by the pollen highlighted in the pollen allergen Ole e 3 and in the p-coumaric acid the possible culprits of the Ca²⁺-antagonist activity of PMR. Furthermore, the sequence of Ole e 3 could provide information for the possible construction of a synthetic peptide to be used in an allergy-targeted Ca²⁺-antagonist therapy.

The aim of this study was to identify and quantify the airborne fungal spore content in the Cathedral of Jaén (South Spain). The evaluation of the microclimatic conditions and their relationship with the presence of airborne fungal spores in different indoor areas was also tested. Airborne fungal spores were recorded during 2019 by using a volumetric sampler. The Choir was the study area with the maximum airborne fungal spore concentrations, representing 55% of the total compared to the minimum representation of 12% sampled in the Museum. Regarding the seasonality, winter records represented only 20% of the total the airborne spore monitoring. Peaks in the daily spore concentrations were mainly recorded in the first half of spring and during the middle of the summer. A total of 29 taxa were identified. Cladosporium and Aspergillus/Penicillium were the potentially biodeteriogen fungal spores that were more frequently recorded in all of the study areas. Of the total airborne fungal spores recorded in the indoor environment, 82.5% belong to biodeteriogen fungi that, under suitable conditions for their germination, could have a negative effect on the preservation of artistic-historical heritage. The installation and correct maintenance of air-conditioning systems and the aeromycological analysis in suspected places would be recommended.

Inhalation of grass pollen can result in acute exacerbation of asthma, prompting questions about how grass pollen reaches metropolitan areas. We establish typical atmospheric Poaceae (grass) pollen concentrations recorded at two pollen samplers within the Sydney basin in eastern Australia and analyse their correlation with each other and meteorological variables. We determine the effect of synoptic and regional airflow on Poaceae pollen transport during a period of extreme (≥ 100 grains m⁻³ air) concentration and characterise the meteorology. Finally, we tested the hypothesis that most Poaceae pollen captured by the pollen samplers originated from local sources. Fifteen months of daily pollen data, three days of hourly atmospheric Poaceae pollen concentrations and fifteen months of hourly meteorology from two locations within the Sydney basin were used. Weather Research Forecasting (WRF), Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) modelling and conditional bivariate probability functions (CBPF) were used to assess Poaceae pollen transport. Most Poaceae pollen collected was estimated to be from local sources under low wind speeds. Extreme daily Poaceae pollen concentrations were rare, and there was no strong evidence to support long-distance Poaceae pollen transport into the Sydney basin or across the greater Sydney metropolitan area. Daily average pollen concentrations mask sudden increases in atmospheric Poaceae pollen, which may put a significant and sudden strain on the healthcare system. Mapping of Poaceae pollen sources within Sydney and accurate prediction of pollen concentrations are the first steps to an advanced warning system necessary to pre-empt the healthcare resources needed during pollen season.