Aerobiologia最新文献

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.

This paper focuses on studying the microbiological properties of the Tibetan Palace Museum, which is located on the Qinghai-Tibet Plateau and contains a vast collection of cultural heritage artifacts. The air quality of the museum is critical to the preservation of these artifacts, and factors such as microbial species, concentration, and particle size distribution are important indicators of air quality. The paper examines the concentration levels, particle size distribution, species diversity, and correlation between environmental factors and microorganisms in the museum. The study found that the concentration of bacteria was 2–3 times higher than normal, while the concentration of fungi was lower than average. The predominant microorganisms in the museum were Bacillus cereus, Bacillus psychrodurans, and Neurospora terricola. The research also discovered that the concentration of microorganisms was positively correlated with PM2.5 concentration and negatively correlated with temperature, relative humidity, and PM10 concentration. The study concludes that the museum's micro-environment is not ideal for the preservation of ancient books and cultural relics, and more research is necessary to identify the general microbiological traits and eradicate hazardous species in plateau museums.

During an international campaign organized in Munich (Germany) in 2021 to test the performance of automatic pollen traps, we ran four manual Hirst-type pollen traps in parallel. All 4 Hirst-type pollen traps were set and monitored on a weekly basis for the entire campaign to 10 L/min using the same standard hand-held rotameter. Afterwards, a hand-held heat-wire anemometer (easyFlux®) was used additionally to obtain the correct flow without internal resistance. Uncorrected pollen concentrations were 26.5% (hourly data) and 21.0% (daily data) higher than those obtained after correction with the easyFlux®. After mathematical flow correction, the average coefficient of variation between the four Hirst traps was 42.6% and 16.5% (hourly and daily averages, respectively) for birch and 36.8% and 16.8% (hourly and daily averages, respectively) for grasses. When using the correct flow of each pollen trap (i.e. the resistance free anemometer measured flow), for hourly values, the median standard deviation across the traps for the eight pollen types was reduced by 28.2% (p < 0.001) compared to the uncorrected data. For daily values, a significant decrease in the median standard deviation (21.6%) between traps was observed for 7 out of 8 of the pollen types, (p < 0.05 or lower). We therefore recommend continuing to calibrate Hirst-type pollen traps with standard hand-held rotameters to avoid changing the impacting characteristics of the instruments, but simultaneously also measure with resistance-free flow meters to be able to apply flow corrections to the final pollen concentrations reported. This method improved the accuracy of the final results.

Ramularia leaf spot is a major economic disease of barley caused by the dothidiomycete fungus Ramularia collo-cygni. The fungus has a complex life cycle which includes extensive late season spore release events and a seed-borne phase. Predicting disease epidemics during the growing season remains a difficult challenge. To better understand the interaction between spore movement and disease epidemics, spore samplers were set up in Germany (2 sites over 4 years), Poland (7 sites over 2 years) and the UK (2 sites over 9 years), where the disease has been observed. Spore concentrations were determined using a real-time PCR assay, and meteorological data were obtained from co-located automatic stations. Spore release events were seen to peak in June on mainland Europe and July in the UK. The pattern of spore release was broadly similar across countries with earlier peaks in mainland Europe. A relationship was observed in the UK between July spore levels and disease in following winter barley crops. Rainfall and temperature were proposed as significant drivers of spore release in these months. The major environmental parameter associated with spore release across the two UK sites was crop surface wetness, although some site-specific interactions were noted for rainfall and wind movement. Regression analysis of spore patterns and disease epidemics indicates a relationship between spore levels 75 and 105 days pre-harvest and final disease levels in UK winter barley crops. This relationship was not observed in spring barley. The implications on risk forecasts are discussed.

Due to the increase in allergies, aerobiological studies carried out in cities are essential to keep the population informed about the pollen atmospheric concentrations detected. However, the high cost and complexity of aerobiological studies often mean that the information is generated from a single sampling point that may not be representative of the entire city. In this study, the data obtained by two volumetric pollen traps, located in the coastal city of Malaga (Spain) were analyzed. One of the pollen traps was situated in the city center while the other was located on the city outskirts, 5 km away from the first. This was complemented with a meteorological and land use analysis to determine their influence on the pollen concentrations. Despite being located within the same city, the data obtained from both collectors showed significant differences in the relative abundance and annual integrals of the main pollen types, as well as in the periods in which elapse their main pollen seasons. These differences were more notable in the case of Amaranthaceae, Casuarina, Parietaria and Plantago pollen types due to the asymmetric distribution of green areas, agro-forestry areas and urban surfaces within the city, as well as the influence of local wind dynamics on the airborne pollen detected. Despite that, some differences were also observed in the other pollen types. For all the above, we consider that it is important to keep operational several sampling points in cities of a certain magnitude to provide more detailed information about atmospheric pollen concentrations.

Impact of climate change affects chilling and heat accumulation that phenological development of plant needs, air temperature being determinant for flowering, pollination and fruit production, but few knowledges are available in the winter and spring climate of Tétouan. The physiological mechanisms of the reproductive cycle that controls pollen emission are related with temperature, and different environmental factors regulate strongly the reproductive phases of the plant’s life cycle. However, from an empirical point of view, the alternance between endodormancy and ecodormancy is not well detectable. Our work focuses on determining the heat accumulation periods associated with the thermal balance needed to fulfill the chilling and heat required for budbreak and bloom timing. To evaluate Morus, Pistacia, Quercus and Olea response to changes in chill and heat accumulation rates, the Dynamic Model and the Growing Degree-Days Method were used. Regression analyses identified the chilling and forcing periods for these taxa. Over the past 12 years, chill accumulation during tree dormancy increased significantly for most of woody taxa studied, while heat accumulation decreased not significantly for all taxa. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation.