Aerobiologia最新文献

During the month of February in 2019, the Western USA experienced elevated precipitation levels, corresponding to atmospheric river events, ending a drought period. Rainwater samples were collected at four time points across two weeks and analyzed by microscopy, analytical chemistry, and long-read sequencing methods. Quantification of whole cells showed concentrations of > 10⁶ cells/L. Imaged cells from fluorescent and scanning electron microscopy included microeukaryotes. Analytic chemistry detected Na⁺ and Cl⁻ ions, which were in agreement with back trajectories of an oceanic origin and atmospheric river occurrence. Taxonomic investigation of long-read sequences generated from the Nanopore MinION resulted in a high proportion of read assignments to fungal groups. For bacterial taxonomies, common rainwater-associated bacterial genera were present at higher proportions than other bacterial groups: Erwinia, Hymenobacter, Pseudomonas, and Pantoea. The microscopy data support the potential of intact and viable cell wet deposition into local environments and the taxonomic identification of common atmospheric-associated bacterial genera from long-read sequencing highlights the potential usefulness of this platform for atmospheric samples and field campaigns.

Aerobiology could be used as complementary data or proxy for studying phenology, especially in species which usually are not long-distance transported, such as grasses. This 21-year aerobiological study took place in Évora (South Portugal), using a seven-day recording volumetric pollen trap with the aim of analysing the temporal trends of grass pollen seasons. To this end, data were statistically tested for correlation and regression to determine the features and temporal trends of pollen seasons. Main results show that Poaceae pollen has a high representation in pollen spectrum, 20% (min: 7%; max: 44%), with a long season starting in March and lasting till August/September or October. There was an overall, but not statistically significant trend, towards an increase in the annual pollen integral and peak values, and also an overall non-statistically significant trend towards an earlier start and later end of the pollen season. Main and high pollen seasons have been lasting longer, and the days with allergenic potential have been rising in line with the local temperature rising trend. It seems that grass pollen production is being aided by warmer temperatures and increased grassland areas in Alentejo region. This could promote the increase in annual pollen levels and in the number of high pollen days over the years. In clinical terms, it means that grass allergic patients are exposed to longer periods of airborne pollen and to higher counts over a longer time. The climate conditions projected for Alentejo region, including rising temperature, and the changes in local grassland areas may help to clarify the trends of grass pollen seasons in the next decades.

There are limited studies that established significant relationships between meteorological variables and COVID-19 spread in Malaysia. Although knowledge from studies conducted in other countries can be utilised as a basis for the policy formulation in general, country-specific studies are necessary as meteorological parameters and COVID-19 spread vary from country to country. This study investigated the potential roles of five meteorological parameters (average relative humidity, maximum temperature, average temperature, minimum temperature, and average wind speed) on COVID-19 spread in each of the 13 states and the entire Malaysia. The state-wise daily COVID-19-confirmed cases and daily meteorological parameters from 1 August 2020 to 31 March 2021 were acquired from Ministry of Health Malaysia and Malaysia Meteorological Department, respectively. The correlations between state-wise daily COVID-19-confirmed cases and daily meteorological parameters were ascertained via Pearson’s and Spearman’s correlation tests at 5% significance level. Overall, significant correlations exist between all meteorological parameters considered in this study and daily COVID-19-confirmed cases throughout Malaysia. Average wind speed was positively correlated with COVID-19-confirmed cases, whereas average relative humidity, maximum temperature, average temperature, and minimum temperature were negatively associated with COVID-19-confirmed cases. These study findings build up knowledge pertaining the association between important meteorological factors and COVID-19 spread in various regions with different climates. The research outcomes could be helpful in understanding, bringing awareness, and educating Malaysian citizens through communication between citizens and governmental as well as non-governmental agencies via official portals to develop a better response mechanism for the Malaysian perspective.

Seasonal pollen allergy is a major public health concern, with many different pollen aeroallergens being present in the atmosphere at varying levels during the season. In Norway, information about spatiotemporal variation of pollen aeroallergens is currently lacking, leading to reduced ability to manage and treat seasonal allergies. Seven pollen aeroallergens (alder, hazel, willow, birch, pine, grass and mugwort) were monitored daily for 16 years from 12 regions and coalesced to create regional pollen calendars. Seasonal statistics, such as seasonal pollen integral (SPIn), onset, duration and periods of high and very high concentrations, were calculated for all pollen types and regions. High days were further modelled with SPIn in a linear regression framework to investigate the connection between the strength of the season and number of days above high pollen thresholds. The tree pollen season occurred between January and mid-July, with the pollen aeroallergens birch and pine being the most prominent in all regions. The herb pollen season was observed to occur between June and mid-August, although mugwort was almost completely absent. The grass pollen season was mostly mild on average but more severe in some regions, primarily Kristiansand. South-east regions of Oslo, Kristiansand and Lillehammer had the overall highest pollen load, while northern regions of Bodø, Tromsø and Kirkenes had the overall lowest pollen loads. SPIn and days above high pollen thresholds had positive highly significant relationships (R² > 0.85) for all pollen types, bar mugwort. Regional pollen calendars and seasonal statistics contribute to reliable information that can be used by medical professionals to effectively and timely manage and treat seasonal pollen allergies in Norway. Further research is needed to determine sensitization profiles of pine and willow.

Air harbors a substantial number of microorganisms the assessment of which is critical for healthy human living. The assessment of airborne bacteria and fungi in and around three hospitals in southwest Nigeria; the University Teaching hospital Ibadan, Oyo state, the State hospital Ota, Ogun state and a private hospital in Lagos state were carried out using the open petri dish sedimentation technique for three months between March and May 2014 at two weeks intervals. The survey yielded numerous and diverse assemblages of bacteria and fungi. Nineteen bacterial species belonging to twelve genera were isolated namely Alpha-haemolytic Streptococcus, Staphylococcus aureus, S. epidermidis, Escherichia coli, Enterobacter sp., Micrococcus luteus, M. varians, Corynebacterium xerosis, C. kutsceri, Lactobacillus fermentum, L. casei, L. delbruekii, Pseudomonas aureginosa, Clostridium sp., Enterobacter sp., Proteus sp., Streptococcus sp., Klebsiella sp., and Mycobacterium sp. The fungal assemblages were composed of Aspergillus fumigatus, A. flavus, A. niger, Arthrobotrys sp., Alternaria sp., Bipolaris spicifera, Curvularia clavata, C. affinis, Chrysosporium corda, Candida albicans, Cladosporium sp., Cryptococcus sp., Diplodia sp., Esepedonium sp., Fusarium sp., Geotrichum sp., Humicola sp., Monilia sp., Mucor sp., Penicillium sp., Rhizopus nigricans, R. stolonifer, Talaromyces sp., Torula nigra, and Trichoderma sp. Among these are pathogenic species to which both patients and visitors get exposed to while visiting the hospitals, thereby coming down with nosocomial infections. Some end up worse than they were, while healthy ones get infected coming down with different diseases. The overall assessment highlighted the sanitary conditions of the different units in the hospitals and the need for more aggressive sanitation measures.

Temuco city is categorized as one of the most air-polluted cities in Latin America; consequently, an air quality monitoring (AQM) program based on low-volume air samplers has been established by the Chilean government. However, AQM program does not consider any microbiological parameters to be analyzed. In this context, we firstly investigated the bacterial communities contained in particulate matter fractions (PM₁₀ and PM_2.5) collected by AQM program in Temuco city. Secondly, we compared the bacterial communities collected by AQM program with those collected by an environmental monitoring (EM) sampling using a high-volume air sampler. The potential relation between bacterial abundances and some environmental parameters was also addressed. In AQM samples, significant differences of bacterial abundances between PM fractions were not revealed by qPCR, although DNA metabarcoding analysis showed significant differences in bacterial diversities between PM fractions. When both EM and AQM sampling methods were compared, significant differences in abundance and diversity were observed, but differences between PM factions in each method were not found. Independent of sampling method, a negative relation between bacterial abundances and relative humidity was observed. Similarly, Proteobacteria (Pseudomonadota), Bacteroidetes (Bacteroidota) and Actinobacteria (Actinomycetota) were the dominant phyla observed in both methods by DNA metabarcoding analysis. Here, we demonstrated that the AQM program may be used as a source of samples for airborne bacteria studies; however, in case microbiological parameters will be incorporated or adopted in the AQM program, those data should be complemented with other sampling methods.

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.