This study investigates the seasonal dynamics, size-fractionated profiles, and respiratory health risks of airborne bioaerosols in indoor and outdoor residential environments in Pune, India. Using a viable cascade impactor during winter and summer, we characterised the personal exposure of children and adults based on regional deposition within the respiratory tract. Results indicated that indoor and outdoor bacterial concentrations peaked in summer (3097 ± 354 and 2438 ± 566 CFU m−3) compared to winter (2131 ± 85 and 1534 ± 439 CFU m−3). Similarly, indoor and outdoor fungal aerosols showed higher summer concentrations (167 ± 60 and 205 ± 43 CFU m−3) than winter (54 ± 14 and 90 ± 39 CFU m−3). Size distribution analysis revealed that bacterial aerosols were predominantly associated with stage 3 (3.3–4.7 µm) in winter and summer. In contrast, fungal aerosols shifted from stage 5 (2.1–1.1 µm) in winter and stage 3 (3.3–4.7 µm) in summer. The highest respirable microbial load was calculated for adults during summer (13.0 ± 2.6 × 103 CFU day−1). Simulated respiratory dosimetry configurations demonstrated that child exposure models under nasal inhalation parameters yielded a 34–36
Climate change is modifying meteorological conditions in ways that influence airborne pollen dynamics, with implications for human health. This study examines the relationship between extreme weather events and extreme pollen concentrations across the Iberian Peninsula from 2009 to 2021 using a quantile-based analytical approach. Data from six Spanish cities, grouped into central and southeastern regions, were analysed for eight pollen taxa, total pollen, and multiple meteorological variables using standardised monitoring methods and percentile-based classification. The results revealed clear regional contrasts: central Spain experienced higher pollen concentrations, especially from arboreal taxa such as Cupressaceae and Platanus, whereas southeastern Spain was dominated by herbaceous pollen, particularly Amaranthaceae. Extreme pollen events were more frequent and intense in central Spain. Abrupt increases in temperature were generally associated with higher pollen concentrations, particularly for Olea, Poaceae, Urticaceae and Platanus. In contrast, intense precipitation events were generally associated with reductions in arboreal pollen concentrations due to the washout effect of rainfall. Wind speed and relative humidity exerted pollen- and site-specific effects, notably sharp wind-driven increases in Olea pollen in Toledo. The findings highlight region- and taxa-specific sensitivities of pollen to weather variability, underscoring the need for localised public health and environmental management strategies. These results are relevant for the entire Mediterranean region where the impacts of extreme climate events are already evident.
Aerobiological studies in Akureyri, northern Iceland, have been conducted since 1998, but previous research focused exclusively on pollen, and no studies have yet examined airborne fungal spores in this region. This study provides the first comprehensive assessment of fungal spore diversity in Iceland. Fungi are significant contributors to respiratory allergies, accounting for up to 6
This study investigates the dispersion of infectious particles generated during a human coughing event in a consultation clinic. The objective is to identify ventilation strategies that minimize particle exposure to healthcare personnel. A simplified computational fluid dynamics model was developed to represent the consultation clinic environment and its occupants. A customizable coding approach was implemented using user-defined functions to replicate realistic, time-dependent coughing behavior. This approach overcomes the limitations of simplified steady injection methods commonly used in previous studies. The RNG k–ε turbulence model was applied to simulate airflow. The discrete phase model was used to track particle transport. The selection of these models was supported by comprehensive validation against published data. Several ventilation configurations were evaluated to examine their impact on particle concentration near the doctor’s workspace. Results show that a conventional mixing ventilation system effectively reduces particle concentration across the doctor’s working zone. It achieves a minimum value of approximately 1.0 × 10⁻5 kg/m3 within a horizontal distance of 0.728 m from the cough source. Compared to other ventilation schemes reporting a higher concentration of 1.0 × 10⁻4 kg/m3, the mixing ventilation scheme achieves a tenfold reduction. In contrast, displacement ventilation shows localized particle accumulation near the monitor, despite improved removal along the cough jet path. Overall, the findings indicate that mixing ventilation provides a more uniform and comprehensive reduction in airborne particle concentration. The outcomes offer practical guidance for optimizing ventilation design in hospital consultation environments.
Aerobiology is pivotal for understanding human health risks, ecosystem dynamics, as well as plant reproduction, including phylogeny. Africa’s vast climatic and ecological diversity—from deserts to tropical rainforests—produces complex, region-specific aerobiological patterns that are often underinvestigated. Seasonal and meteorological factors, including rainfall, temperature, humidity, wind, and phenomena such as the Harmattan, significantly influence the distribution of airborne pollen and fungal spores, with direct implications for allergen exposure and the development of respiratory diseases. These complex systems are altered by anthropogenic climate change and disturbances. Despite these impacts, continent-wide aerobiological research remains limited, with most studies concentrated in research-strong nations such as South Africa and Nigeria. This review synthesizes current knowledge on African aerospora, highlighting spatial and temporal trends, dominant taxa, environmental drivers, sampling methodologies, and links to allergic disease, including projections under climate change. Data were collated from PubMed, Web of Science, Scopus, African Journals Online, and long-term monitoring initiatives. Key research gaps include sparse long-term monitoring data, inconsistent methodologies, and limited integration with public health outcomes and modelling approaches. Expanding monitoring networks and fostering interdisciplinary approaches are essential for improving our understanding of African aeroallergens and informing strategies to mitigate allergy and respiratory health risks, such as inhibiting the spread of invader plants such as Ambrosia and planting of exotic trees that produce an abundance of highly allergenic pollen, such as Morus and Platanus.
Urban environments exhibit pronounced spatial heterogeneity in atmospheric and ecological conditions driven by variations in traffic intensity, land use, vegetation structure, and pollution levels. These gradients influence human exposure to biological aerosols such as allergenic pollen; however, environmental variability is rarely incorporated into pollen allergen characterization. This exploratory study investigated whether contrasting urban microenvironments within a single city modulate the protein composition and IgE-reactive profiles of Ailanthus altissima (Mill.) Swingle pollen. Pollen was collected from male trees located at a high-traffic roadside and a low-traffic urban park in Berlin. Total protein content, protein profiles, and IgE-binding patterns were analyzed using SDS-PAGE and immunoblotting with sera from pollen-allergic individuals. Pollen from the low-traffic park exhibited higher total protein content and a more complex protein and IgE-binding profile compared to roadside pollen. Distinct site-specific differences in IgE-reactive proteins were observed, indicating environmentally driven variability in allergen expression at a fine spatial scale. These findings suggest that urban environmental heterogeneity can modulate pollen allergen composition and thereby influence spatial variability in allergen exposure. Given the exploratory design and limited sampling, the findings should be interpreted as preliminary evidence requiring validation across multiple trees and urban environments. Incorporating site-specific environmental context into pollen allergen studies may improve biometeorological exposure assessment, allergy diagnostics, and climate-sensitive urban health research.
In developing countries, indoor air quality in neonatal intensive care units (NICUs) remains an overlooked aspect of hospital safety, despite heightened awareness during the COVID-19 pandemic. This study applied a Quantitative Microbial Risk Assessment (QMRA) to evaluate occupational risks posed by airborne, antibiotic-resistant Staphylococcus aureus in a public NICU in Colombia. Mean airborne concentrations of S. aureus were 24.73 CFU/m3, and particles predominantly ranged from 0.6–7.0 µm, suggesting deposition throughout the respiratory tract, including the alveoli.Query Isolated strains exhibited resistance to beta-lactam antibiotics (ampicillin, penicillin G). To characterize uncertainty in risk estimates, a Monte Carlo simulation with 10,000 iterations was performed, with probability distributions assigned to all key input parameters. Annual infection probabilities exceeded the U.S. EPA tolerable risk threshold of 10−4 across all occupational groups. Median annual risk was highest among male nurses (0.949 pppy; 90
Although airborne fungal spores are known allergens and plant pathogens, a whole season aerobiological assessment of fungal spores has not previously been conducted in Serbia. The aims of this study are to describe seasonality and diurnal patterns of concentrations of fungal spores measured over one full year, relate them to meteorological factors and set the foundation for representative sampling for molecular-based exploration of taxonomic and functional diversity of airborne fungi. This study revealed that Cladosporium, Alternaria and Agaricaceae-morphotype accounted for on average over 80
Ragweed (Ambrosia artemisiifolia L.) pollen represents a major aeroallergen in urban environments across Central and Southeastern Europe, yet quantitative assessments of its seasonal dynamics and meteorological drivers remain limited for many regions. This study examines the characteristics of the ragweed pollen season and daily meteorological drivers in Zagreb, Croatia, utilizing five consecutive years of monitoring data (2020–2024). Daily airborne pollen concentrations were analysed alongside local meteorological variables using a main pollen season (MPS) definition using the 5–95
Airborne fungal contamination in equine facilities remains insufficiently understood despite their high organic matter load and seasonally restricted ventilation. This study examined the seasonal variability, species composition, and environmental relevance of culturable airborne fungi in a traditional English-style horse stable, with particular emphasis on the genus Aspergillus. A total of 180 indoor and 60 outdoor air samples were collected in autumn, winter, and spring via an MAS-100 impactor and three culture media (SAB, MEA, DG18). Fungal concentrations showed pronounced seasonality, with winter displaying the highest levels (up to 5,110 CFU/m3 indoors and 32,170 CFU/m3 outdoors on DG18), whereas spring presented the lowest values (921–1631 CFU/m3). The autumn concentrations were intermediate. Significant medium-dependent differences occurred only in spring (Friedman, p = 0.0038), where SAB produced the lowest counts. No significant correlations were found between total fungal concentrations and temperature or humidity across media and sample types, except for a strong positive correlation with temperature and a moderate negative correlation with humidity in winter (examined samples on MEA), and a very strong negative correlation with humidity in spring (control samples on SAB). Aspergillus spp. dominated across all the seasons, with A. versicolor (25
Airborne bacterial contamination in hospitals poses significant risk, particularly for immunocompromised patients. This study investigated seasonal variation in airborne bacterial loads and disinfectant resistance across six sites of a public hospital in Islamabad, Pakistan. Airborne samples were collected using passive sampling across four seasons while environmental parameters (carbon dioxide, temperature, and relative humidity) were recorded to assess associations with bacterial loads. Carbon dioxide exceeded Indoor Climate and Occupational Parameters Indoor Air Quality guidelines 2010 limits across seasons, while temperatures exceeded thresholds in summer and autumn seasons. Bacterial identification using 16S rRNA gene sequencing revealed predominant Gram-positive genera, particularly Staphylococcus, Bacillus, and Corynebacterium. Disinfectant resistance testing showed high resistance (65–80
Pollen allergy is a prevalent clinical concern. In Rawalpindi/Islamabad, the information about the association between pollen exposure and clinical manifestations is limited. Therefore, this research investigates the factors influencing clinical pollen allergy sensitizations among 400 consented patients at the Allergy Center. Questionnaire-based data were assessed for sociodemographic and clinical factors by descriptive statistics and the Chi-square test at a 0.05 significance level. The participants were 41.8
In this study, the viability and morphological changes of Fraxinus uhdei pollen grains exposed to particulate matter (PM₁₀) in the Metropolitan Area of the Valley of Mexico (ZMVM) were experimentally assessed. Samples of both anthers and air were collected and examined using viability tests (TTC), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The results demonstrated a notable reduction in pollen viability in areas with elevated PM₁₀ levels, particularly in the north (Ecatepec) and east (Iztapalapa), compared to the west (Cuajimalpa) and south (Coyoacán). Significant structural disruptions in the exine and dense accumulation of particles on the surface of airborne pollen were also observed. Elemental analysis indicated the presence of silicon, calcium, aluminum, and iron, linked to both geogenic and anthropogenic sources. These findings confirm the potential of F. uhdei as a sensitive bioindicator of air quality and emphasize the ecological and health implications of urban air pollution.
The magnitude of people acquiring respiratory allergies by pollen allergens is on the rise worldwide. The pollen from Parthenium hysterophorus is a proven allergen, and its allergens trigger allergic rhinitis and bronchial asthma in atopic individuals. Despite several clinical reports available worldwide, substantive characterization of allergens of P. hysterophorus has been lacking. This study aimed to analyse the molecular, structural, and immunological characterization of P. hysterophorus pollen allergens. A total of 484 patients with allergic rhinitis and bronchial asthma were screened for sensitization to P. hysterophorus by skin prick test. Proteins from pollen of P. hysterophorus were extracted. Immunoblotting and immunoinhibition assays were carried out using sera from sensitized patients to identify the specific allergen. Molecular characterization of the specific pollen allergen was carried out by sequencing, and its structural details were analysed using bioinformatic tools. Out of the eighteen patients who tested positive by skin prick test (SPT), only five had a history of direct exposure to P. hysterophorus with significantly elevated levels of total IgE. Immunoblotting and immunoinhibition analysis of P. hysterophorus antigenic extract revealed that a 40 kDa protein was allergenic. The molecular characterization and in silico analysis revealed that the allergen was pectin methylesterase. Sensitization to P. hysterophorus pollens was evident by SPT in patients with allergic rhinitis and bronchial asthma from Puducherry. Immunoblotting and immunoinhibition studies in the sensitized patients revealed that a 40 kDa protein was allergenic. Using molecular and bioinformatics tools the allergenic protein was identified as pectin methylesterase.
Spores of Cladosporium and Alternaria are significant airborne allergens and major agricultural pathogens. This study evaluates the seasonal, intra-diurnal, and transport-related dynamics of these taxa over a two-year period (2018–2019) in Bingöl, eastern Anatolia. Atmospheric sampling was conducted using a Hirst-type volumetric trap, and the influence of meteorological factors and air mass transport was assessed using statistical analyses and HYSPLIT back-trajectory modeling. Cladosporium was approximately four times more abundant than Alternaria, and both taxa exhibited peak concentrations in May. Alternaria exceeded the clinical allergy threshold (100 spores/m3) on six days, whereas Cladosporium remained below its critical threshold (3000 spores/m3) throughout the study period. Mean temperature was identified as the primary meteorological driver of spore concentrations, and a significant delayed response to precipitation was observed, with concentrations increasing following a 1–3-day lag. A clear intra-diurnal pattern was observed, with Alternaria peaking in the morning predominantly under northerly winds, whereas Cladosporium reached maximum levels in the afternoon mainly under southerly air masses. HYSPLIT analysis indicated that peak episodes were associated with air masses originating from the southern sector, particularly over the Mesopotamian plains. An anomalous early-season peak of Alternaria in February, occurring during periods of local dormancy and snow cover, was associated with air masses originating from the southern sector. Vertical trajectory profiles showed that air masses approached the study area at low altitudes with a consistent descending pattern. These findings highlight the combined influence of local meteorology, basin morphology, and regional air mass transport on airborne spore dynamics.
Climate change is reshaping pollen season dynamics across Europe, with significant implications for allergic populations. This study presents the first comprehensive long-term analysis of pollen season trends in Slovenia, a region characterized by high phytogeographic diversity at the intersection of Mediterranean, Alpine, Dinaric, and Pannonian climatic influences. Daily airborne pollen concentration data from three monitoring stations were analyzed for 14 allergenic taxa over 23 years (2002–2024). Pollen season timing was determined using a normalized cumulative-sum approach, and linear regression quantified temporal trends in season onset, termination, duration, and total annual pollen load. Results reveal general advancement in season onset across most taxa, particularly pronounced for arboreal species in the Mediterranean region. Season termination exhibited asymmetric patterns: earlier endings for spring-flowering trees and delayed termination for herbaceous taxa, especially Poaceae. Notably, trees showed compressed seasons due to faster advancement of season end relative to onset, potentially leading to more intense allergen exposure despite shorter duration. Significant increases in annual pollen load were detected for Poaceae, Urticaceae, and Plantago, while Artemisia showed widespread decline. The coastal Mediterranean site exhibited significantly earlier onset, later termination, and longer seasons compared to continental stations, which showed strong inter-site synchrony. These findings demonstrate asymmetric seasonal responses to climate forcing across small spatial scales, with important implications for region-specific public health strategies.
Parameters such as height, temperature, relative humidity and the presence of air criteria pollutants (particulate matter (PM10 and PM2.5), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and lead (Pb)) significantly influence the Colony Forming Units (CFU) for various airborne fungal strains. Categorized as biological contaminants, these fungi are known to induce various health issues. As urban centers continue to expand vertically, it becomes crucial to determine whether fungal loads decrease at higher altitudes, potentially offering safer environments at greater heights. To observe these fluctuations through a whole year, sampling was conducted at two different locations with different heights (146 m and 60 m) comparing them to ground-level fungal loads; abiotic data was measured in real time, while data on criteria pollutants was taken from the Sistema Integral de Monitoreo Ambiental (SIMA) stations. Distinct seasonal shifts in fungal genera were observed throughout the year, fungal loads at the 60 m and 146 m sites were 24.3
Rice (Oryza sativa) is susceptible to diseases that can cause significant yield losses. Therefore, rice disease management is of great importance to increase rice production. Although several predictive models have been developed for disease prediction, they may not be applicable universally due to different bioclimatic regions. This study aims to evaluate the relationships between meteorological parameters and airborne rice pathogens and to develop predictive aerobiological models for potential use in early disease prediction. Sampling was conducted using a Burkard 7-day volumetric spore trap at Wasan rice field, Brunei Darussalam (4.78840 N, 114.82210 E) on a raised ground area from 7th July 2022 until 31st August 2022 and from 2nd May 2023 until 31st August 2023. We applied Spearman’s correlation test and principal component analysis (PCA) to determine the influence of meteorological parameters on the airborne rice pathogens. The highest correlation variables from the Spearman results were integrated for predictive aerobiological model development using multiple linear regression (MLR) and principal component regression (PCR). Further, disease inspection was conducted to determine the disease severity. Generally, PCA results showed the negative influence of RH, rain, and WS on airborne spore concentration, while temperature and dew mostly showed positive correlations. Our developed models showed satisfactory performance using PCR (R2 0.542–0.999) compared to MLR (R2 0.313–0.779). The root mean square error (RMSE), variance of factor (VIF), Durbin-Watson (DB), Shapiro–Wilk normality test (SW), and Breusch-Pagan (BP) are within an acceptable range. Further, average weekly spore thresholds were determined: Alternaria sp. with 43 spores/m3, Bipolaris sp. with 100 spores/m3, Curvularia sp. with 104 spores/m3, Fusarium sp. with 262 spores/m3, Nigrospora sp. with 207 spores/m3, and Pyricularia sp. with 25 spores/m3, which can be used as an indirect signal to anticipate disease infections.
A diverse microbiome from surface ecosystems is transported in the atmosphere, where fluctuating environmental conditions and limited nutrients challenge its survival and functioning. Among the viable bacteria frequently recovered from air are potential photoheterotrophs usually associated with vegetation. Such a specific biological trait is known to be beneficial to survival in oligotrophic environments, and we postulate here that this may contribute to the maintenance and survival during aerial transport. In this study, aerobic photoheterotrophic bacteria isolated from clouds (Methylobacterium sp. R17b-9) and expressing or lacking bacteriochlorophyll pigment, i.e., phototrophic capabilities ([Bchl +] or [Bchl-] phenotype, respectively), were injected into an atmospheric simulation chamber and monitored for their abundance, viability, cultivability and ATP content while exposed to different light intensities as aerosols. We demonstrate that phototrophy strongly enhances bacterial viability during aerial transport: whereas the fraction of cultivable cells devoid of phototrophic pigment sharply decreased under exposure to light, halving every 2 h or less, no significant loss could be observed in phototrophic cells, which also exhibited higher ATP content. The phototrophic phenotype also directly influenced the aerial dispersal range of bacteria by shortening Bchl + cells’ atmospheric residence time by a factor of 1.7, with half-times of 152 min versus 89 min, due to 8
Pollen allergies are an increasing global health concern. Linden pollen has traditionally been considered low-allergenic, leading to the widespread planting of linden trees in urban green spaces. However, this allergenic potential may be underestimated, resulting in linden pollen allergy being unrecognized. This review aims to identify and analyze the available literature on linden pollen allergy and provide, for the first time, a comprehensive synthesis of current knowledge. The reviewed studies offer evidence on the allergenic potential of linden pollen, its prevalence, associated clinical manifestations, and diagnostic approaches. However, significant knowledge gaps remain, including scarce epidemiological data, the absence of well-characterized linden pollen allergens, limited understanding of potential cross-reactivity, and undefined threshold exposure levels that may impact human health. The existing body of literature indicates that linden pollen has the potential to cause sensitization and allergic symptoms, thereby challenging its long-standing classification as low-allergenic pollen. The identified research gaps highlight the need for further interdisciplinary studies, spanning immunology, epidemiology, botany, and environmental science, to deepen our understanding of linden pollen allergenicity and its impact on human health.
