Search Results (18)

The incidence of allergic diseases has increased notably in recent years. The reasons for this increase include air pollution, diet, and infectious factors. This study aims to analyze the interactions between aeroallergens, environmental pollutants, and meteorological factors and their impact on allergenic sensitization in Toledo, Spain. An aerobiological study was conducted over the past 30 years (1994–2023) using a Burkard collector and the SEAIC (Spanish Society of Allergology and Clinical Immunology) methodology. Meteorological data were obtained from the State Meteorological Agency (AEMET) and pollutant data were acquired from the Castilla-La Mancha Air Quality Monitoring Network. Patients presenting with seasonal allergic symptoms at the University Hospital of Toledo were selected for skin testing with various types of airborne pollen. A total of twenty pollen taxa were identified in the Toledo atmosphere, as follows: Cupressaceae (26.53%); Olea europaea (21.62%); Quercus (21.12%); Poaceae (10.30%); Urticaceae (2.58%); Plantago (2.48%); Platanus (2.00%); Amaranthaceae (1.72%); Rumex (1.68%); and Morus, Pistacia, Populus, Artemisia, Fraxinus, Alnus, Carex, and Ericaceae (less than 1% each). The average temperature increased by 1.2 °C, while the level of precipitation remained stable. Among all pollutants, only a moderate increase in ozone levels was observed; however, the concentrations of particulate matter and nitrogen oxides decreased. The prevalence of pollen sensitization in allergic patients ranged from 8% for Pinus nigra to 84% for Phleum pratense. In conclusion, the rise in temperature due to climate change, coupled with high concentrations of pollutants such as ozone, can result in increased concentrations of the main types of wind-borne pollen. Thus, this can lead to a greater sensitivity to pollen and, consequently, more people becoming allergic to pollen. Full article

Although the benefits of trees in cities are of great variety and value, attention must also be paid to the consequences for public health of the presence of pollen aeroallergens in the atmosphere, which are likely to interact with air pollutants, influencing the alteration of the immune system, facilitating allergic reactions, and enhancing the symptoms of asthmatic patients. This study analyses (using multiple linear regression calculations performed with the data analysis tool Statgraphics Centurion 19) the interaction of the concentration of six types of tree pollen (Cupressaceae, Olea, Platanus, Pinus, Ulmus, and Populus) and six atmospheric pollutants (O₃, PM₁₀ and PM_2.5, NO₂, CO, and SO₂), on asthma care episodes in the Community of Madrid (CAM). In most of the calculated equations, the adjusted R² value is higher than 30%, and in all cases, the P-value of the models obtained is lower than 0.0001. Therefore, almost all models obtained in the study period for asthma are statistically significant. Olea is the pollen type most frequently associated with asthma (followed by Pinus and Populus), in all the years studied. In the same period, O₃ is the most common air pollutant in the equations obtained for asthma. Stronger interrelations with asthma are generally found in more urban municipalities. Full article

Spain exhibits significant climatic variability across its regions, ranging from the humid oceanic climate in the north to the Mediterranean and stepped climates in the southern and central areas. These climatic differences influence environmental allergen exposure, which may, in turn, affect allergic sensitization patterns in the pediatric population. Variations in temperature, humidity, and airborne allergen distribution, such as pollen, dust mites, animal epithelia, and mold, contribute to regional disparities in allergic responses among children. Understanding how climatic conditions shape allergen recognition patterns across different geographical areas is essential for improving allergy prevention and management strategies. This study aims to shed light on this issue by identifying sensitization patterns in a pediatric population of 236 patients (with 2 age groups analyzed: 6–10 and 11–15 years old) from different climatic regions of Spain. Skin tests with standard aeroallergens were performed, and specific IgE (sIgE) analysis by Allergy Explorer of Macroarray Diagnostic test (ALEX²) and Western blot. The results revealed different sensitization trends across patients from the eight cities analyzed (Barcelona, Granada, Lugo, Sagunto, Santiago de Compostela, Valencia, and Zaragoza). Full article

This study analyzes the behavior of airborne pollen in relation to meteorological parameters. It may be helpful to understand the consequences of this interaction on the health of the population of Madrid in the form of respiratory allergic pathologies. To this end, a multivariate analysis was carried out using Spearman’s linear correlation coefficient between the concentrations in the Madrid atmosphere of six types of tree pollen (Cupressaceae, Olea, Platanus, Pinus, Ulmus and Populus) and each of the six meteorological variables: relative humidity, precipitation, temperature, wind, radiation and insolation. The meteorological parameters most correlated with pollen types, with monthly values, are temperature and insolation, followed by radiation and relative humidity. In addition, there are more significant correlations of meteorological variables with Cupressaceae, Olea, Pinus and Platanus pollen types. Radiation is the meteorological parameter with the highest ρ values, especially with Olea, with ρ > 0.8. Wind is the only variable with significant correlations, all of them positive, with pollen types. The number of statistically significant results obtained from daily values is lower compared to monthly values, and only with Populus, Cupressaceae and Olea. The inter-relationship of meteorological variables with pollen grains can lead to an increase in the number of cases of pollinosis, when there are significant positive correlations. Full article

Olea europaea L. pollen is one of the main causes of pollinosis and respiratory diseases in the Iberian Peninsula (IP). The aim of this study was to provide a pollen calendar in different regions of the IP, which could help allergists and allergic patients in the management of Olea europaea allergic diseases, and to update/complement what has already been reported on olive trees’ aeropalynology in this region. Airborne Olea pollen dynamics were analyzed over a period of 8 years in a total of 21 localities, 7 in Portugal and 14 in Spain. Airborne pollen monitoring was carried out using the Hirst-type spore trap method and following the recommendations of the Quality Control Working Group of the European Aerobiology Society. The daily pollen count, the annual pollen profile, the Annual Pollen Integral (APIn), the Seasonal Pollen Integral (SPIn) and the Pollen Peak, all expressed in number of pollen grains per cubic metre of air, together with the main pollen season and its characteristics, the Start Day, the End Day and the length of the pollen season, were calculated for each sampling station. Differences in mean Olea pollen concentration between odd and even years were also analyzed. On average, the main pollen season (MPS) started in April/May and ended in June, with Pollen Peaks recorded in May, except in Burgos, where it was recorded in June. The longest MPS occurred in Lisbon, Oviedo and Valencia (53 days) and the shortest in Vitoria (25 days). A high daily pollen concentration (i.e., >200 grains/m³) was recorded between 1 and 38 days along the year in all sampling stations of the southwest quadrant of the IP and in Jaén. A biannual pattern, characterized by alternating years of high and low pollen production, was found in the southwest of the IP. In conclusion, the study provided a deeper understanding of the pollination behaviour of olive trees in the IP and allowed the establishment of a representative Olea pollen calendar for this region. In addition, our results suggest the usefulness of investigating more detailed relationships between annual Olea pollen, allergen sensitization and symptoms, both for allergists involved in the study and management of allergic respiratory diseases caused by this species and for the self-management of disease in allergic subjects. Full article

Bioaerosols are small airborne particles composed of microbiological fragments, including bacteria, viruses, fungi, pollens, and/or by-products of cells, which may be viable or non-viable wherever applicable. Exposure to these agents can cause a variety of health issues, such as allergic and infectious diseases, neurological disorders, and cancer. Therefore, detecting and identifying bioaerosols is crucial, and bioaerosol sampling is a key step in any bioaerosol investigation. This review provides an overview of the current bioaerosol sampling methods, both passive and active, as well as their applications and limitations for rapid on-site monitoring. The challenges and trends for detecting airborne microorganisms using molecular and immunological methods are also discussed, along with a summary and outlook for the development of prompt monitoring technologies. Full article

Allergic diseases are a global health problem; their prevalence has increased in recent decades. The presence of allergenic airborne pollen is one of the main triggers of this disorder. For this reason, the first pollen calendar of Toluca City was developed. Daily and bihourly airborne pollen samplings with a Hirst-type Burkard Trap were performed from August 2009 to December 2013. Annual Pollen Integral (APIn), Main Pollen Season (MPS) and Diurnal Pattern (DP) were determined. Relationships with meteorological parameters were investigated. Tree pollen grain presented higher concentrations, with Cupressaceae as the most abundant taxon (52.6%), followed by Alnus sp. (13.3%), Pinaceae (7.3%), Fraxinus sp. (6.0%) and Quercus sp. (2.0%), which presented a definite seasonality. Urticaceae (3.7%) was the most abundant herbaceous pollen taxon registered. The DP obtained showed that pollen grains of most taxa are frequently found after midday and afternoon. Regression models showed the influence of environmental variables on all taxa. This study will allow us the enhancement of preventive actions and improvement of the regional design of patient tests. Full article

Asthma is a heterogeneous and very complex group of diseases, and includes different clinical phenotypes depending on symptoms, progression, exacerbation patterns, or responses to treatment, among other characteristics. The allergic phenotype is the most frequent, especially in pediatric asthma. It is characterized by sensitization (the production of specific IgEs) to allergens and frequent comorbidity with rhinitis as well as atopic dermatitis. Given the complexity of allergic asthma, knowledge of it must be approached from different points of view: clinical, histological, physiological, epidemiological, biochemical, and immunological, among others. Since partial approaches do not allow for the understanding of this complexity, it is necessary to have multidimensional knowledge that helps in performing the optimal management of each case, avoiding a “blind men and elephant parable” approach. Allergens are antigens that trigger the production of specific IgE antibodies in susceptible individuals, who present symptoms that will depend on the type and intensity of the allergenic load as well as the tissue where the interaction occurs. Airborne allergens cause their effects in the respiratory tract and eyes, and can be indoor or outdoor, perennial, or seasonal. Although allergens such as mites, pollens, or animal dander are generally considered single particles, it is important to note that they contain different molecules which could trigger distinct specific IgE molecules in different patients. General practitioners, pediatricians, and other physicians typically diagnose and treat asthma based on clinical and pulmonary function data in their daily practice. This nonsystematic and nonexhaustive revision aims to update other topics, especially those focused on airborne allergens, helping the diagnostic and therapeutic processes of allergic asthma and rhinitis. Full article

Airborne pollen triggers allergic reactions in up to 40% of the global population. The incidence of pollen allergies is increasing in Thessaloniki, Greece and it is predicted that more than 50% of the European Union’s inhabitants will suffer from allergic rhinitis by 2025. Thus, it is essential to investigate and predict high pollen concentrations to address this growing concern. This study utilized the Gradient Boosting Regression (GBR) technique, a machine learning approach, to estimate pollen concentrations of Oleaceae and Quercus taxa, using daily meteorological and land surface data obtained from the European Center for Medium-Range Weather Forecasts (ECMWF). The method accurately predicted pollen concentrations for both species, with an Index of Agreement (IoA) of 0.86 for Oleaceae and 0.78 for Quercus, despite the limited size of the dataset. Full article

Today a large part of the European population is exposed to levels of air pollution exceeding the standards recommended by the World Health Organization. Moreover, air pollution and the seasonal emission of allergenic pollen are progressively affecting human health and can cause severe allergic reactions, particularly when air pollution combines with pollen allergen peaks. Unlike atmospheric pollutants of anthropogenic origin, pollen sources have a pulsating trend that leads to high values in the flowering period and values close to, or equal to, zero in the rest of the year. This aspect makes essential the definition of data coverage standards for the main allergenic taxa. For air quality assessment detailed classification criteria for monitoring stations are defined by international standards, not the same from the European Standards for the Sampling and analysis of airborne pollen grains and fungal spores. This paper describes the status and the air concentration trends of the main allergenic pollen and the Alternaria spore measured in Rome from 2003 to 2019 by the Aerobiological Monitoring Center of Tor Vergata (Rome) and calculated by the Seasonal Kendall test with the open-source OpenAir R package. The analysis was carried out on the daily concentrations of the most widespread allergenic taxa in Italy: Asteraceae, Betulaceae, Corylaceae, Cupressaceae/Taxaceae, Poaceae, Oleaceae, Urticaceae and the Alternaria spores. Full article

The monitoring of airborne pollen has received much attention over the last decade, as the prevalence of pollen-induced allergies is constantly increasing. Today, the most common technique to identify airborne pollen species and to monitor their concentrations is based on manual analysis. Here, we present a new, low-cost, real-time optical pollen sensor, called Beenose, that automatically counts and identifies pollen grains by performing measurements at multiple scattering angles. We describe the data pre-processing steps and discuss the various statistical and machine learning methods that have been implemented to distinguish different pollen species. The analysis is based on a set of 12 pollen species, several of which were selected for their allergic potency. Our results show that Beenose can provide a consistent clustering of the pollen species based on their size properties, and that pollen particles can be separated from non-pollen ones. More importantly, 9 out of 12 pollen species were correctly identified with a prediction score exceeding 78%. Classification errors occur for species with similar optical behaviour, suggesting that other parameters should be considered to provide even more robust pollen identification. Full article

Existing pollen identification methods heavily rely on the scale and quality of pollen images. However, there are many impurities in real-world SEM images that should be considered. This paper proposes a collaborative learning method to jointly improve the performance of pollen segmentation and classification in a weakly supervised manner. It first locates pollen regions from the raw images based on the detection model. To improve the classification performance, we segmented the pollen grains through a pre-trained U-Net using unsupervised pollen contour features. The segmented pollen regions were fed into a deep convolutional neural network to obtain the activation maps, which were used to further refine the segmentation masks. In this way, both segmentation and classification models can be collaboratively trained, supervised by just pollen contour features and class-specific information. Extensive experiments on real-world datasets were conducted, and the results prove that our method effectively avoids impurity interference and improves pollen identification accuracy (86.6%) under the limited supervision (around 1000 images with image-level labels). Full article

Grass pollen is one of the major causes of allergy. Aerobiological monitoring is a necessary element of the complex of anti-allergic measures, but the similar pollen morphology of Poaceae species makes it challenging to discriminate species in airborne pollen mixes, which impairs the quality of aerobiological monitoring. One of the solutions to this problem is the metabarcoding approach employing DNA barcodes for taxonomical identification of species in a mix by high-throughput sequencing of the pollen DNA. A diverse set of 14 grass species of different genera were selected to create a local reference database of nuclear ITS1, ITS2, 5′-ETS, and plastome trnL-F DNA barcodes. Sequences for the database were Sanger sequenced from live field and herbarium specimens and collected from GenBank. New Poaceae-specific primers for 5′-ETS were designed and tested to obtain a 5′-ETS region less than 600 bp long, suitable for high-throughput sequencing. The DNA extraction method for single-species pollen samples and mixes was optimized to increase the yield for amplification and sequencing of pollen DNA. Barcode sequences were analyzed and compared by the barcoding gap and intra- and interspecific distances. Their capability to correctly identify grass pollen was tested on artificial pollen mixes of various complexity. Metabarcoding analysis of the artificial pollen mixes showed that nuclear DNA barcodes ITS1, ITS2, and 5′-ETS proved to be more efficient than the plastome barcode in both amplification from pollen DNA and identification of grass species. Although the metabarcoding results were qualitatively congruent with the actual composition of the pollen mixes in most cases, the quantitative results based on read-counts did not match the actual ratio of pollen grains in the mixes. Full article

Cupressaceae pollen is responsible for winter respiratory allergies in the Mediterranean area. Pollen grains of this diverse family share the same characteristics under light microscopy. Consequently, the partial contribution of each Cupressaceae species to the airborne pollen spectrum cannot be determined with conventional aerobiological methods. Studies on major aeroallergens offer better information on the allergic sensitization and appearance of symptoms in patients sensitized to airborne pollen and spores. Our aim was to determine if airborne Cupressaceae pollen concentrations correspond to aerodynamics of the major allergen of Cupressus (Cup a 1), as well as the aeroallergen correlation with different-sized particles. The air was sampled in two cities of Southern Spain (Granada and Córdoba) using the Hirst-type volumetric sampler for airborne pollen detection during 2006 to 2008 and the Andersen Cascade Impactor for aeroallergen detection during the main pollination period of Cupressaceae in the same period. The samples were analyzed by the methodology proposed by the Spanish Aerobiology Network (REA), the minimum requirements of the European Aeroallergen Society (EAS) for pollen, and by ELISA immunoassay to detect airborne Cup a 1. The distribution patterns of airborne Cupressaceae pollen and Cup a 1 were observed throughout the sampling period, although with some irregular oscillations. Cupressaceae pollen and Cup a 1 showed positive and significant correlation during the period of maximum concentrations (January to March). However, the results of this study showed that the period of exposure of aeroallergens depends on the Cupressus species and their abundance in cities. According to the allergy potential obtained, species like C. arizonica could release more allergens than other species like C. sempervirens. Full article

Research Highlights: Daily airborne Cupressaceae pollen disruption ranged from 20 to 90%; relative humidity (RH), rainfall and atmospheric pressure (AtP) were the major meteorological determinants of this phenomenon. Background and Objectives: Cupressaceae family includes several species that are widely used as ornamental plants pollinating in late winter-early spring and might be responsible for allergic outbreaks. Cupressaceae pollen disruption may favour allergen dissemination, potentiating its allergenicity. The aim of this work was to characterize the Cupressaceae pollen aerobiology in Évora, South of Portugal, in 2017 and 2018, particularly the pollen disruption, and to identify the meteorological parameters contributing to this phenomenon. Materials and Methods: Pollen was collected using a Hirst type 7-day pollen trap and was identified following the standard methodology. Temperature, RH, rainfall, global solar radiation (Global Srad), AtP, wind speed and direction were obtained from a weather station installed side-by-side to the Hirst platform. Back trajectories (12-h) of air masses arriving at Évora were calculated using the HYSPLIT model. Results: Cupressaceae pollen index was higher in 2017 compared to 2018 (>5994 and 3175 pollen/m³, respectively) and 36 ± 19% (2017) and 64 ± 17% (2018) of the pollen was disrupted. Higher levels of disrupted pollen coincided with RH > 60% and rainfall. Temperature, Global Srad and AtP correlated negatively with pollen disruption. Wind speed and wind direction did not significantly correlate with pollen disruption. Intra-diurnal pollen pattern peaked between 9:00 am–2:00 pm, suggesting local origin, confirmed by the back trajectory analysis. Intra-diurnal pollen disruption profile followed hourly pollen pattern and it negatively correlated with AtP, temperature and Global Srad but was uncorrelated with RH. Conclusions: The results suggest that RH, rainfall and AtP are the main factors affecting airborne Cupressaceae pollen integrity and in conjunction with daily pollen concentration may be used to predict the risk of allergy outbreaks to this pollen type. Full article