Aerobiologia最新文献

Pollen concentration in the atmosphere is strongly affected by changes in meteorological factors, as well as urban and suburban vegetation in the study area. The identification of atmospheric pollen sources and estimates on their concentrations are critical for the quality of life for individuals affected by pollen allergy. In this study, we evaluated the effect of wind on the concentration levels of dominant pollen types (Cupressaceae/Taxaceae, Olea europaea, Pinaceae, Poaceae, Quercus spp., and Urticaceae) recorded in the atmosphere of İzmir, Turkey’s 3rd largest city, in accordance with land cover over a 3-year period. Our results showed higher pollen concentrations for all taxa on days when wind direction was from the southeast toward the city. Elevations around the city, where arboreal taxa are widely distributed, particularly contributed to pollen concentrations through winds blowing from their directions. Besides these environmental elements, plants used in urban landscaping, such as Pinaceae, Olea europaea, and Cupressaceae/Taxaceae also contributed to pollen concentrations in the city’s atmosphere. Although we observed no significant transport from the northern part of the city, we have determined that the agricultural lands in the western and southern parts contribute to the pollen concentrations of Poaceae and Olea europaea. Additionally, we recorded the highest pollen transport for all taxa when wind speed was within the range of 1.6–3.3 m/s, while pollen concentrations declined in higher wind speeds.

COVID-19 is transmitted through droplets or aerosols containing the virus, the very small particles exhaled by infected people or exposure to items infected with the virus. These droplets, aerosols and particles may be inhaled by others, or fall into their eyes, mouth and nose. In some cases, they may contaminate the contact surface. It is most likely to be infected if they are less than 1 m away from the infected person. To evaluate the effects of different air conditioning systems on the spread of human exhaled pollutants, computational fluid dynamics (CFD) was used to study the movement and diffusion of exhaled air from two rows of 12 sitting adults in a hospital's closed transfusion room. In this paper, a closed transfusion room with 12 human models was established firstly, and the mathematical model verified by experimental test results was used to study the propagation of viral aerosol particles in the enclosed space under different air conditioning systems. The result showed that when the transverse strong air flow is generated in the room, the concentration distribution of virus particles will show a roll like distribution and the personnel inside the roll will cause new infection. The air flow generated by the air conditioning system will affect the dispersion of droplets in the air. Evaluating and guiding the air flow to avoid blowing air from one person to another may reduce the risk.

Airborne fungal spores and pollen (aerospora), synergistic with air pollution, are key triggers of allergic respiratory diseases. Effective diagnosis and treatment requires up-to-date location-specific knowledge on the temporal variability of aerospora types and levels. Johannesburg is the largest city in South Africa and has grown substantially in three decades, with changes in ground cover, population density and air pollution, yet until now, no continuous aerospora sampling has occurred. We present a daily two-year (August 2019–July 2021) aerospora assemblage for Johannesburg and explore temporal characteristics of 13 dominant aerospora in relation to daily meteorological variables (pressure, rainfall, relative humidity, temperature and wind characteristics). February–July, July–September and January-July represent high-risk periods for fungal spores [(Alternaria alternata (Fries. ex Keissler), Ascospores, Aspergillus niger (Van Tieghem), Penicillium chrysogenum (Thom), Cladosporium graminum (Corda), Epicoccum nigrum (Link), Helminthosporium solani (Durieu and Montagne) Nigrospora sphaerica (Saccardo ex. Mason), Smuts Ustilago nuda (Jensen ex. Rostrup) and Torula herbarum (Link)], trees (Cupressus, Morus and Platanus) and grass (Poaceae), respectively. Using a generalised additive model, results show that daily meteorological characteristics explained 7–32% of daily aerospora variability, with the largest effect on tree pollen. Rainfall, relative humidity and temperature influenced daily fungal spore and Poaceae counts, with moderate/low rainfall (< 20 mm), higher/mid-ranging relative humidity (~ 40–60%) and temperatures of ~ 15–20 °C associated with higher counts during high-risk periods. Rainfall predominantly influenced tree counts during high-risk periods, with higher counts occurring on low rainfall (<10 mm) days. These results update the aerospora profile of Johannesburg, South Africa, providing important information to inform allergy care.

The aim of this study was to characterize the occupational exposure to inhalable dust and airborne fungi among archive and library workers based on qualitative and quantitative analyses of stationary and personal filter samples as well as nasal swabs. The study was carried out in 3 archives and 2 libraries and involved 9 workers of these institutions. Airborne fungi and inhalable dust samples were collected by stationary and personal measurements using filter samplers. Additionally, the nasal swabs from workers were taken after work-shift and microbiologically analysed. The average concentrations of inhalable dust and airborne fungi were 49 µg/m³ (SD = 91) and 299 CFU/m³ (SD = 579), respectively. Both dust and bioaerosol concentrations obtained using personal measurements were significantly higher than that measured by stationary sampling. The correlation analysis showed strong relationships between the concentrations of inhalable dust and airborne fungi (R = 0.57; p < 0.001). The fungal concentrations in swab samples from archive workers (median: 104 CFU/ml) were significantly higher than that in swabs from librarians (median: 1.4 CFU/ml). Among the airborne fungi, the widest spectrum of species was found among Penicillium and Aspergillus (including pathogenic A. fumigatus) genera. However, in samples from archives, yeast-like fungi from Sporidiobolus and Candida (including pathogenic C. albicans) genera predominated among isolated mycobiota. The results of this study revealed that airborne fungi were able to efficiently contaminate the nasal cavity of archive and library employees. The analysis of nasal swabs can be considered as an important analytical tool supporting the assessment of workers’ exposure to bioaerosols.

Technologies for monitoring pollen concentrations in real-time made substantial advances in the past years and become increasingly available. This opens the possibility to calibrate numerical pollen forecast models in real-time and make a significant step forward regarding the quality of pollen forecasts. We present a method to use real-time pollen measurements in numerical pollen forecast models. The main idea is to calibrate model parameterizations and not to assimilate measurements in a nudging sense. This ensures that the positive effect persists throughout the forecast period and does not vanish after a few forecast hours. We propose to adapt in real-time both the model phenology scheme and the overall tuning factor that are present in any numerical pollen forecast model. To test this approach, we used the numerical pollen forecast model COSMO-ART (COnsortium for Small-scale MOdelling-Aerosols and Reactive Trace gases) on a mesh size of 1.1 km covering the greater Alpine domain. Test runs covered two pollen seasons and included Corylus, Alnus, Betula and Poaceae pollen. Comparison with daily measurements from 13 Swiss pollen stations revealed that the model improvements are large, but fine-tuning of the method remains a challenge. We conclude that the presented approach is a first valuable step towards comprehensive real-time calibration of numerical pollen forecast models.

Honeydew extracted by aphids serves as nutrient for the development of sooty moulds. Hypothetically, population dynamics of aphids should therefore have an effect on the airborne levels of the spores of fungi colonizing honeydew. In this study, the effects of seven aphid taxa on Alternaria and Cladosporium spore seasons (both pathogenic and allergenic fungi) were analysed on a total of 20-year-long dataset in Kecskemét (Hungary), Leicester (UK) and Poznań (Poland). Meteorological factors strongly effected both aphid and fungal populations. In most cases, a direct effect of weather on fungal levels were found. Direct effect of two aphid species, Acyrthosiphon pisum and Euceraphis punctipennis, on the atmospheric concentration of Alternaria spores was identified in Leicester and Poznań in June and July respectively. Other aphid species had secondary, but significant effects during other time periods. This suggests aphid population data can be informative in predicting airborne concentrations of Alternaria and Cladosporium spores.

Graphical abstract

Given the endemic nature of pollen throughout the environment, the impact upon human health, and the need for more extensive and better measurements of pollen in the USA, a preliminary project within the National Atmospheric Deposition Program’s (NADP) National Trends Network (NTN) was developed. Pollen was measured in ambient air by several methods and in precipitation wet deposition samples at three monitoring sites in the NTN. A method for counting pollen on filters was developed and provided pollen counts for NADP atmospheric wet-deposition samples and high-volume ambient air samplers (HVAS) for comparison with co-located traditional National Allergy Bureau microscopy samples and a commercially available pollen sensor (PS) counting method during the 2021 pollen season. The goals of this project were to test the potential of available air-monitoring infrastructures to obtain improved spatial measurements of aeroallergens, compare pollen counting results from the various methods, and to determine the suitability of using wet deposition samples for pollen collection. The onset and senescence of pollen seasons for general categories of genera compared favorably for each method at each site, indicating that pollen monitoring using wet-deposition and ambient air sampling filters could provide useful information to inform scientific studies, but not likely for public health objectives. Pollen counts were log transformed for Pearson product moment correlation. Tree pollen counts were correlated at all sites for daily PS data and traditional counting data (R = 0.69–0.84), but statistical correlations between methods for grass and weed pollen were weak (0.40 < R < 0.60) or considered not correlated (R < 0.40). Total pollen counts in NADP precipitation samples were correlated with traditional and PS counts at only one of three sites. Pollen counts for the weekly HVAS filter samples were correlated with PS counts for trees (R = 0.62) and with NAB counts for trees (R = 0.68) and weeds (R = 0.72). Correlations in the data between methods suggest that, given further methods development, a variety of techniques could be integrated to expand and enhance existing pollen monitoring networks. Improved ambient air and atmospheric deposition sampling methods specifically targeted for pollen capture and analysis could support the collection of accurate and efficient meaningful aeroallergen data from existing atmospheric monitoring networks.

Bioaerosol components can endanger the indoor air quality (IAQ) in hospital buildings. The bacteria present in bioaerosols may cause hospital-associated infections and increase the number of occupational diseases, harming healthcare workers and patients with vulnerable immune systems. This study aimed to assess the bacteriological contamination of bioaerosols and the IQA parameters in a tertiary hospital. The study was performed in four specialized critical hospitalization units (Infectious Disease, Clinical Oncology, Burn and Plastic Surgery, and Kidney Transplant) located at a tertiary university hospital before and during the SARS-CoV-2 pandemic. Air samples were collected by impaction; a single-stage sampler was used to quantify, to isolate, and to identify airborne bacteria. The environmental variables particulate matter concentration, carbon dioxide concentration, temperature, and relative humidity were analyzed in each sample, on appropriate equipment. The concentration of airborne bacteria varied from 51.22 ± 8.89 to 264.11 ± 161.36 CFU/m³. Of the thirteen bacterial genera identified in the samples, eleven were potentially pathogenic or opportunistic. The environmental variables temperature and relative humidity were higher than indicated. We concluded that IAQ in this hospital must be improved, and that the new sanitary parameters established during the SARS-CoV-2 pandemic influenced positively the concentration of colony-forming units and the total number of bacterial species/strains identified in the two phases of this research. We recommend analyzing other factors that affect bioaerosol composition, so that a complete view of the bioaerosol components can be achieved. A more comprehensive analysis would also allow IAQ control to be adopted in each specialized critical hospitalization unit studied here as well as in other sectors of this hospital and even in other hospitals worldwide.