Pollen Calendar Research Articles (Page 1)

A 15-year survey of pollen aeroallergens in North Texas.

Abstract Climate change is affecting the timing and intensity of pollen seasons for allergenic plant species. This creates a growing need to monitor pollen season trends and update tools for allergy management. In this study, we analysed pollen season characteristics – onset, end, duration, and intensity (seasonal pollen integral and peak pollen concentration) – over a 20-year period (2002–2023) in five cities across Slovakia and the Czech Republic. By comparing two timeframes (2002–2012 and 2013–2023), we constructed progressive pollen calendars to visualise the shifts over time. We identified regional differences, including an earlier start to woody plant pollen seasons in Slovak cities, contrasted with a delayed onset in Czech cities. We also observed an intensification of the Ambrosia pollen season in Slovakia, while its intensity remained stable or declined in the Czech Republic. The most consistent trends included earlier and extended pollen seasons for Alnus and Cupressaceae and a reduced intensity of the Artemisia pollen season. These findings highlight the importance of localised pollen monitoring and the need to regularly update pollen calendars, providing valuable tools for urban healthcare planning and public awareness of climate-driven allergenic risks.

Flowering seasonality and airborne pollen recent trends in Sierra de las Nieves, the southernmost National Park in continental Spain

Abstract The allergenic nature of ash (Fraxinus sp.), an important element of the dehesas, has been poorly studied in meridional Europe owing to the low concentrations of this pollen type in the atmosphere. However, it has cross-reactivity with Olea L. and other homologous allergens of trees and herbaceous species, leading to earlier and more prolonged respiratory allergenic symptoms. The main aims of this work were to characterize the main pollen season (MPS) of ash from 2011 to 2022, to evaluate the influence of meteorological variables on airborne concentrations of this pollen type and to elaborate a pollen calendar for Fraxinus in Salamanca. The aeropalynological analysis for the eleven years of the study shows that the MPS for Fraxinus begins on 27 th December until 4 th April with an average duration of 100 days, a mean peak value of 57 grains/m3 reached on 22 nd February and a mean annual pollen integral of 567 grains/m3, observing an earlier onset of MPS, an increase in its duration and a decrease in its concentrations, presumably linked to climate change. Regarding the influence of meteorological parameters on pollen concentrations, positive correlations were found for maximum and mean temperatures and insolation, as well as southeast winds and frequency of calms, while negative correlations were reported for precipitation, relative humidity, and wind speed. The analyze of Fraxinus pollen could be used to predict seasonal behavior and warn people who may suffer pollinosis either from ash pollen or from cross-reactivity events.

Abstract Pollen morphology, involving the physical characteristics of pollen grains from seed plants during reproduction, plays an important role in plant biology, ecology, and evolution. High pollen concentrations in the air can degrade air quality and exacerbate respiratory conditions such as asthma. Understanding pollen morphology and its implications for air quality is significant for mitigating respiratory health risks. Conventionally, fluorescence microscopy is used for pollen imaging, but photobleaching, quenching, and phototoxicity affect the surface morphology and do not provide quantitative data on the pollen grains. For this study, we used bright field (BF) imaging and quantitative phase imaging (QPI), a label-free interferometric microscopy method, to look at differences in the shape of pollen. BF imaging provides information about the shape and size of the different pollens but has a limitation of low contrast. To obtain high-contrast images and quantitative data on the pollen grains without any exogenous agents, we employed QPI and BF imaging in the present study. QPI enables the extraction of detailed information regarding the cell wall, aperture, and thickness of pollen while also maintaining their natural state without the need for chemical treatments. In the present work, we sampled the ambient air from May 2023 to January 2024 on the IIT Delhi campus. Subsequently, QPI and BF imaging have been done for pollen identification and phase analysis of arboreal and non-arboreal pollen. Further, by utilizing the information obtained from BF microscopy and QPI, different species of pollen have been identified, and a pollen calendar has been prepared for exhibiting pollen season throughout the year. To the best of the authors’ knowledge, they have conducted the QPI of airborne pollen grains for the first time; this technique holds great potential for characterizing airborne pollens without the need for staining or sample preparation.

Southern Africa’s floral, topographic and climatic diversity manifests in distinctive bioregions where aerobiology studies are needed to manage allergenic health problems, especially in urban areas. Previous studies underline different seasonal pollen fluctuations for the biomes, encouraging regional studies. These studies have been previously restricted to large cities such as Cape Town, Johannesburg and Pretoria whereas small cities such as Potchefstroom in the North-West province are understudied. The South African Pollen Monitoring Network (SAPNET) seeks to fill this lacuna, enhancing ecological and health-related knowledge, with regard to the allergenicity of the recorded pollen. Here, we investigate plant phenology and resulting pollen production within the Grassland and Savanna biomes around Potchefstroom, a fast-growing city in the North West province, comparing it with other SAPNET sites. As a SAPNET initiative, pollen monitoring in Potchefstroom involved monthly collections using a Lanzoni 7-day spore trap over 13 months from December 2022 to 2023. This facilitated the development of a preliminary pollen calendar and a pollen atlas, detailing pollen types’ morphology, ecology, pollination modes, and allergenicity. Initial findings revealed Potchefstroom’s pollen calendar, with tree pollen (60% of the Annual Pollen Index (API)) mainly from northern hemisphere species such as Cupressus (c. 11% of API) and Platanus (c. 18%), which released pollen in spring. Grass pollen was predominant from November to April (c. 18% of API). Potchefstroom recorded South Africa’s highest levels of Ambrosia pollen (c. 7% of API), a major allergen, in March and April. Noteworthy is the unusual abundance of pollen of the neophyte Ulmus (c. 14%) in December. This study highlights the pollen patterns of the Grassland and Savanna biomes around Potchefstroom. The region, with its mosaic of urban spaces, natural grass-/woodland, and agricultural land, exhibits distinct characteristics when contrasted with major, more densely populated cities such as Bloemfontein, Pretoria, and Johannesburg.

Background: Pollen calendars and allergic pollen studies are crucial in understanding the timing and distribution of allergic pollen in a specific region. By studying pollen calendars and allergenic pollen, researchers can identify peak pollen periods and regions, develop targeted treatment strategies and enhanced public awareness and education. Methods: Pollen sampling is done using traps or collectors, and the data is analyzed to create a calendar showing the peak pollen periods. Results: To identity the timing and duration of the pollen release, helping allergy sufferers, researchers and healthcare professionals. Discussion: Pollen calendars and aero allergence data can inform personalized treatment plans for allergy sufferers. To identify areas for further research, like developing novel treatments or exploring new diagnostic methods. Interpretation: by interpreting pollen calendars and aero allergence, we can better understand and address pollen allergies, ultimately improving the lights of those affected.

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.

Floral source and pollen calendar of pollinating insects amidst agro-ecosystems of Kodagu district, Karnataka, India

Simple SummaryAmong the aeroallergens present in the air that cause allergies, pollen holds a significant place. The majority of these pollen are dispersed by the wind. Numerous studies have been conducted in various regions of Türkiye and the world to determine the concentration of allergenic pollen in the atmosphere. The density of pollen in the atmosphere depends on meteorological factors, the flora of the region, altitude, and other similar factors. Therefore, the pollen concentration and the relationship of dominant pollen types with meteorological factors in the Sarıkamış region, one of the highest altitude areas in Türkiye and the world, have been studied. Based on the obtained data, a pollen calendar for the region has been prepared. Additionally, the main pollen seasons for pollen with high concentrations and the number of risky days for sensitive individuals have been identified.Atmospheric pollen was investigated using the Lanzoni VPSS 2000 (Lanzoni, Bologna- Italy) device for 2 years between 2012 and 2013 in the Sarıkamış district of Kars province, one of the highest regions of Türkiye. A total of 37,909 pollen grains were collected: 15,298 pollen grains in 2012 and 22,611 pollen grains in 2013. Out of 43 identified taxa, 21 were arboreal, and 22 were non-arboreal. Pollen from arboreal plants accounted for 36.34% (13,778 pollen grains) of the total, while pollen from non-arboreal plants accounted for 63.56% (24,095 pollen grains). Additionally, 0.10% (36 pollen grains) belonged to unidentified pollen. The most frequent arboreal plant pollen in the Sarıkamış atmosphere were Pinaceae (29.79%), Cupressaceae/Taxaceae (2.54%), and Morus (1.30%). The main non-arboreal plant pollen in the atmosphere of Sarıkamış were Poaceae (44.60%), Artemisia (2.98%), Amaranthaceae (2.79%), Rumex (2.41%), Urticaceae (2.33%), Plantago (2.19%), and Boraginaceae (1.40%). The maximum pollen concentration was observed in June and was associated with the pollination of Pinaceae and Poaceae.

The landscape of allergy practice in India is undergoing transformative changes, shifting from traditional symptom management to embracing advanced diagnostic and therapeutic modalities for disease modification. This evolution is propelled by the integration of subcutaneous immunotherapy, biologic treatments, and the exploration of probiotics, alongside advancements in diagnostic approaches such as component-resolved diagnostics (CRD) and basophil activation tests. Despite the promising potential of these innovations to enhance patient care, their implementation faces challenges, including limited awareness, safety concerns, accessibility, and affordability. Moreover, the development and standardization of allergy diagnostics, such as CRD, along with the establishment of regional pollen calendars, are crucial for improving the precision of allergy care. This abstract underscores the need for overcoming existing barriers and leveraging emerging technologies and treatments to significantly improve the management of allergic diseases in India, aiming for a future where allergies are not just managed but effectively controlled and prevented.

Progressive pollen calendar to detect long-term changes in the biological air quality of cities in the Madrid Region, Spain

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.

Pollen monitoring has been discontinuously undertaken in South Africa, a country with high biodiversity, a seasonal rainfall gradient, and nine biomes from arid to subtropical. The South African Pollen Monitoring Network was set up in 2019 to conduct the first long-term national aerospora monitoring across multiple biomes, providing weekly reports to allergy sufferers and healthcare providers. Daily airborne pollen concentrations were measured from August 2019 to August 2021 in seven cities across South Africa. Updated pollen calendars were created for the major pollen types (>3%), the average Annual Pollen Index over 12 months was calculated, and the results were compared to available historical data. The main pollen types were from exotic vegetation. The most abundant taxa were Poaceae, Cupressaceae, Moraceae and Buddleja. The pollen season start, peak and end varied widely according to the biome and suite of pollen taxa. The main tree season started in the last week of August, peaked in September and ended in early December. Grass seasons followed rainfall patterns: September-January and January-April for summer and winter rainfall areas, respectively. Major urban centres, for example, Johannesburg and Pretoria in the same biome with similar rainfall, showed substantive differences in pollen taxa and abundance. Some major differences in pollen spectra were detected compared with historical data. However, we are cognisant that we are describing only 2years of data that may be skewed by short-term weather patterns. Differences in pollen spectra and concentrations were noted across biomes and between geographically close urban centres. Comparison with historical data suggests pollen spectra and seasons may be changing due to anthropogenic climate change and landscaping. These data stress the importance of regional and continuous pollen monitoring for informed care of pollinosis.

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.

Aerobiological studies are still scarce in northwestern Mexico where allergenic pollen have great impacts on health. Current global pollution and climate change problems are closely related to many allergic diseases, enhancing the need to continue researching these issues and improve life quality. This study provides the first Pollen Calendar for Hermosillo, Sonora, México. Airborne pollen were continuously collected for 5years (2015-2019). The standardized methodology with a Hirst-type spore trap proposed for global aerobiological studies was used. Weather data were also taken from a station located in the city and used to explore correlations between climate and airborne pollen concentrations in different seasons. The most important pollen taxa recorded in air belongs to herbaceous pollen, such as Poaceae, Ambrosia, Asteraceae, Chenopodiaceae-Amaranthaceae, and some shrub trees typical of this arid region, such as Nyctaginaceae, Prosopis, Parkinsonia, and Fabaceae. The most critical herbaceous pollen related to allergies have a long mean pollen season throughout the years, and the most critical periods with high pollen concentration in air occur in two seasons, spring (March-April) and summer-fall (August-October). In these 5years, the correlation analyses for these two peaks indicate that a link exists between pollen in the air and decreases in precipitation and temperatures, and an increase in relative humidity. An inter-annual variability in pollen concentrations was recorded related to different weather conditions. Although pollen calendars are location-specific, they are useful for future research on biological air quality scenarios in different cities. Using this standardized method for other regions can provide pollen calendars that have been proven clinically important in allergic disease management worldwide.

The article presents data on the composition and seasonal dynamics of airborne pollen in Cherepovets and Vologda. The study was carried out from April 10 to September 30, 2014 and from April 16 to August 31, 2015 in Cherepovets, and from June 3 to September 30, 2019 in Vologda. Pollen data were obtained from the Durham gravimetric samplers. Samples were collected daily. Twenty-one types of pollen have been identified, ten of which are the most common allergenic types (Alnus, Artemisia, Betula, Fraxinus, Salix, Plantago, Poaceae, Quercus, Rumex, Urtica), which account for more than 50% of all pollen that has been registered. The article contains pollen calendars showing two peaks of pollen grain quantity: spring (from last decade of April to May), summer (from the end of June to the middle of July). Betula (30%) and Asteraceae (28%) pollen dominate in the pollen spectrum. Pinus (20%), Plantago (6%) and Poaceae (5%) also play an important role in the regional spectrum. The results show the presence of allergenic pollen from different taxa throughout the study. The proportion of damaged pollen grains is approximately 2%, which corresponds to the norm in natural population in normal condition. This data can become the basis for developing recommendations for reducing the level of pollinosis in the Vologda Region.

Pollen calendars created for residential areas play a vital role in protecting and treating the sufferers of allergic diseases. In this regard, gravimetric and volumetric pollen traps are placed in the city and town centers. In the process of creating the Emirgan Grove’s pollen calendar, the gravimetric method was utilized together with the Durham sampler between March and September 2020. During this seasonal year, a total of 13464 pollen grains were recorded. According to the obtained pollen analysis results, the pollen grains of 44 taxa including 32 arboreal and 12 non-arboreal taxa were determined. Total pollen grains consisted of 90.95 % grains from arboreal plants, 9.05 % grains from non-arboreal plants. The period with the highest amount of pollen was detected as April. The taxon with the highest pollen concentration was Pinus. In terms of pollen concentrations, Pinus was followed by Cupressaceae, Tilia, Abies, Poaceae, Prunus, Morus and Quercus respectively. This study has been the first pollen calendar study conducted for groves and parks in Turkey.

Respiratory allergies triggered by pollen allergens represent a significant health concern to the Irish public. Up to now, Ireland has largely refrained from participating in long-term aerobiological studies. Recently, pollen monitoring has commenced in several sampling locations around Ireland. The first results of the pollen monitoring campaigns for Dublin (urban) and Carlow (rural) concerning the period 2017–2019 and 2018–2019, respectively, are presented herein. Additional unpublished pollen data from 1978–1980 and, 2010–2011 were also incorporated in creating the first pollen calendar for Dublin. During the monitoring period over 60 pollen types were identified with an average Annual Pollen Integral (APIn) of 32,217 Pollen × day/m3 for Dublin and 78,411 Pollen × day/m3 for Carlow. The most prevalent pollen types in Dublin were: Poaceae (32%), Urticaceae (29%), Cupressaceae/Taxaceae (11%), Betula (10%), Quercus (4%), Pinus (3%), Fraxinus (2%), Alnus (2%) and Platanus (1%). The predominant pollen types in Carlow were identified as Poaceae (70%), Urticaceae (12%), Betula (10%), Quercus (2%), Fraxinus (1%) and Pinus (1%). These prevalent pollen types increased in annual pollen concentration in both locations from 2018 to 2019 except for Fraxinus. Although higher pollen concentrations were observed for the Carlow (rural) site a greater variety of pollen types were identified for the Dublin (urban) site. The general annual trend in the pollen season began with the release of tree pollen in early spring, followed by the release of grass and herbaceous pollen which dominated the summer months with the annual pollen season coming to an end in October. This behaviour was illustrated for 21 different pollen types in the Dublin pollen calendar. The correlation between ambient pollen concentration and meteorological parameters was also examined and differed greatly depending on the location and study year. A striking feature was a substantial fraction of the recorded pollen sampled in Dublin did not correlate with the prevailing wind directions. However, using non-parametric wind regression, specific source regions could be determined such as Alnus originating from the Southeast, Betula originating from the East and Poaceae originating from the Southwest.

The stingless bee Melipona quadrifasciata anthidioides is a major pollinator of the Brazilian semi-arid region (Caatinga), it is widely used in meliponiculture due to the economic value of the honey. The goals of this study were to identify the floral resources exploited by these bees in a human-modified area from Caatinga in Bahia, and to provide a pollen calendar that might be helpful to beekeepers. Pollen loads were collected monthly from each colony over a 7-month period. Twenty pollen morphotypes were identified with high frequencies of pollen types belonging to Myrtaceae, Fabaceae-Caesalpinioideae and Solanaceae. The dominant pollens were represented by Mimosa 1 and Mimosa arenosa (Fabaceae-Caesalpinioideae). The accessory types were Mimosa tenuiflora, and Psidium guajava (Myrtaceae), while Solanum 1 and Solanum 2 represented major isolated pollen types. Some morphotypes, such as those from Mimosa are common in anthropized areas, thus playing a major role in the survival of bee colonies from areas where floral resources are limited. The present result revealed that Melipona quadrifasciata anthidioides interacts with several plant species, thus highlighting the importance of conserving the regional flora. Moreover, the pollen calendar obtained is particularly useful to the management of this stingless bee in meliponary since it provides information about the plants that can be used as pollen source throughout the year. This information is also helpful for both the conservation of regional biodiversity and beekeeping in local agriculture.