The course of birch pollen seasons in Sosnowiec (Southern Poland) in 1997–2020 in relation to meteorological conditions

The study's main objective was to specify the extent to which weather conditions were related to the course of birch pollen seasons in the years 1997–2020. The impact of atmospheric conditions on the daily concentrations of birch pollen grains, the Annual pollen integral (APIn), and the length of pollen seasons were studied. The dependency between each meteorological condition and various features of the birch pollen season was determined using Spearman’s rho correlation, the Kruskal–Wallis test, and cluster analysis with the k-means method. It has been shown that the duration of sunshine and average air temperature occurring within 14 days preceding the season has the most significant influence on the beginning of a birch pollen season. The value of daily birch pollen concentrations in Sosnowiec showed a statistically significant positive correlation with the duration of sunlight and the average and maximum wind speed. The daily concentration also depended on the synoptic situation: the mass airflow direction, the type of air mass inflow, and the type of weather front. The near-ground temperature influenced the APIn of birch pollen grains during the period of 14 days before the beginning of the season and the meteorological conditions occurring in the summer of the preceding year such as the maximum temperature, duration of sunlight, the maximum and average wind speed, and the relative air humidity. It was concluded that the length of birch pollen seasons decreased year by year.

Thunderstorm allergy and asthma: state of the art

Thunderstorm-triggered asthma (TA) can be defined as the occurrence of acute asthma attacks immediately following a thunderstorm during pollen seasons. Outbreaks have occurred across the world during pollen season with the capacity to rapidly inundate a health care service, resulting in potentially catastrophic outcomes for allergicpatients. TA occurs when specific meteorological and aerobiological factors combine to affect predisposed atopic patients with IgE-mediated sentitization to pollen allergens. Thunderstorm outflows can concentrate aeroallergens, most commonly grass pollen but also other pollens such as Parietaria and moulds in TA, at ground level to release respirable allergenic particles after rupture by osmotic shock related to humidity and rainfall. Inhalation of high concentrations of these aeroallergens by sensitized individuals can induce early asthmatic responses which can be followed by a late inflammatory phase. There is evidence that, during pollen season, thunderstorms can induce allergic asthma outbreaks, sometimes also severe asthma crisis and sometimes deaths in patients suffering from pollen allergy. It has been observed that changes in the weather such as rain or humidity may induce hydratation of pollen grains during pollen seasons and sometimes also their fragmentation which generates atmospheric biological aerosols carrying allergens. Asthma attacks are induced for the high concentration at ground level of pollen grains which may release allergenic particles of respirable size after rupture by osmotic shock. In other words, it is a global health problem observed in several cities and areas of the world that can strike without sufficient warning, inducing sometimes severe clinical consequences also with deaths of asthma patients. Due to constant climate change, future TA events are likely to become more common, more disastrous and more unpredictable, as a consequence it is important to have deep knowledge on this topic to prevent asthma attacks. Other environmental factors, such as rapid changes in temperature and agricultural practices, also contribute to causing TA.

Earlier Flowering of Betula pendula Roth in Augsburg, Germany, Due to Higher Temperature, NO2 and Urbanity and Relationship with Betula spp. Pollen Season

Flowering and pollen seasons are sensitive to environmental variability and are considered climate change indicators. However, it has not been concluded to what extent flowering phenology is indeed reflected in airborne pollen season locally. The aim of this study was to investigate, for the commonly represented in temperate climates and with highly allergenic pollen Betula pendula Roth, the responsiveness of flowering to different environmental regimes and also to check for commensurate changes in the respective pollen seasons. The region of Augsburg, Bavaria, Germany, was initially screened for birch trees, which were geolocated at a radius of 25 km. Random trees across the city were then investigated during three full flowering years, 2015–2017. Flowering observations were made 3–7 times a week, from flower differentiation to flower desiccation, in a total of 43 plant individuals. Data were regressed against meteorological parameters and air pollutant levels in an attempt to identify the driving factors of flowering onset and offset. Flowering dates were compared with dates of the related airborne pollen seasons per taxon; airborne pollen monitoring took place daily using a Hirst-type volumetric sampler. The salient finding was that flowering occurred earlier during warmer years; it also started earlier at locations with higher urbanity, and peaked and ended earlier at sites with higher NO2 concentrations. Airborne pollen season of Betula spp. frequently did not coincide locally with the flowering period of Betula pendula: while flowering and pollen season were synchronized particularly in their onset, local flowering phenology alone could explain only 57.3% of the pollen season variability. This raises questions about the relationship between flowering times and airborne pollen seasons and on the rather underestimated role of the long-distance transport of pollen.

Comparison of Ambrosia L. Pollen Seasons in Lublin (Poland) and Ivano-Frankivsk (Ukraine) and Presentation of the Morphotypes of Trichomes on A. artemisiifolia L. Shoots in Terms of the Allergenic Properties of the Plant

Ambrosia pollen contains strong allergens. Allergic reactions can also be caused by direct contact with the plant. The investigations of the dynamics of Ambrosia pollen seasons were conducted in Lublin (Poland) and Ivano-Frankivsk (Ukraine) in 2013–2015. The onset and end of the seasons, maximum concentrations, annual sums, and the number of days with an allergy risk were determined. Additionally, the types of trichomes present on different parts of Ambrosia artemisiifolia L. shoots were determined using light microscopy. Morphometric studies were carried out on trichomes sampled from staminate inflorescences. The maximum concentrations and annual sums of Ambrosia pollen were shown to be substantially higher in Ivano-Frankivsk than in Lublin. Similarly, the risk of allergies is higher in the study site in Ukraine. The study results indicate that the presence of Ambrosia pollen grains in Lublin may be associated with long-distance transport. The presence of non-glandular and glandular trichomes was found on the examined organs. The staminate inflorescences were covered by two types of non-glandular trichomes (short and long) and two types of glandular trichomes (linear and biseriate), whose secretory product can cause dermatitis in sensitive subjects upon contact with the plant.

Long-Term Pollen Monitoring in the Benelux: Evaluation of Allergenic Pollen Levels and Temporal Variations of Pollen Seasons

Airborne pollen is a major cause of allergic rhinitis, affecting between 10 and 30% of the population in Belgium, the Netherlands, and Luxembourg (Benelux). Allergenic pollen is produced by wind pollinating plants and released in relatively low to massive amounts. Current climate changes, in combination with increasing urbanization, are likely to affect the presence of airborne allergenic pollen with respect to exposure intensity, timing as well as duration. Detailed analysis of long-term temporal trends at supranational scale may provide more comprehensive insight into these phenomena. To this end, the Spearman correlation was used to statistically compare the temporal trends in airborne pollen concentration monitored at the aerobiological stations which gathered the longest time-series (30–44 years) in the Benelux with a focus on the allergenic pollen taxa: Alnus, Corylus, Betula, Fraxinus, Quercus, Platanus, Poaceae, and Artemisia. Most arboreal species showed an overall trend toward an increase in the annual pollen integral and peak values and an overall trend toward an earlier start and end of the pollen season, which for Betula resulted in a significant decrease in season length. For the herbaceous species (Poaceae and Artemisia), the annual pollen integral and peak values showed a decreasing trend. The season timing of Poaceae showed a trend toward earlier starts and longer seasons in all locations. In all, these results show that temporal variations in pollen levels almost always follow a common trend in the Benelux, suggesting a similar force of climate change-driven factors, especially for Betula where a clear positive correlation was found between changes in temperature and pollen release over time. However, some trends were more local-specific indicating the influence of other environmental factors, e.g., the increasing urbanization in the surroundings of these monitoring locations. The dynamics in the observed trends can impact allergic patients by increasing the severity of symptoms, upsetting the habit of timing of the season, complicating diagnosis due to overlapping pollen seasons and the emergence of new symptoms due allergens that were weak at first.

Analysis of Corylus pollen season in Poland in 2021

Corylus produces allergenic pollen grains that appear in the air in early spring and cause pollen allergy in sensitive people. The aim of this study was to compare the Corylus pollen seasons in 2021 in the following 11 cities in Poland: Bialystok, Bydgoszcz, Cracow, Sosnowiec, Lublin, Olsztyn, Piotrkow Trybunalski, Szczecin, Warsaw, Wroclaw, and Zielona Gora. This research was conducted using the volumetric method and Burkard or Lanzoni pollen samplers. Pollen season duration was determined by the 95% method. The hazel pollen season in 2021 began relatively late, between February 20 and March 1. The season start was recorded earliest in Zielona Gora, while latest in Olsztyn. The highest values of maximum Corylus pollen concentration were recorded in Sosnowiec (230 P/m3) and Zielona Gora (213 P/m3), whereas the lowest ones in Bialystok (27 P/m3) and Bydgoszcz (54 P/m3). In most of these cities, the maximum daily concentration of Corylus pollen grains was recorded in the third 10 days of February or at the beginning of March and only in Lublin and Bialystok the peak value occurred later, on March 16 and March 26, respectively. The highest risk of allergy in people sensitive to the pollen of this taxon was found in Lublin, Olsztyn, and Zielona Gora. The highest values of the annual pollen integral were determined in Lublin, similarly to the previous years.

Anthropogenic climate change is worsening North American pollen seasons

Airborne pollen has major respiratory health impacts and anthropogenic climate change may increase pollen concentrations and extend pollen seasons. While greenhouse and field studies indicate that pollen concentrations are correlated with temperature, a formal detection and attribution of the role of anthropogenic climate change in continental pollen seasons is urgently needed. Here, we use long-term pollen data from 60 North American stations from 1990 to 2018, spanning 821 site-years of data, and Earth system model simulations to quantify the role of human-caused climate change in continental patterns in pollen concentrations. We find widespread advances and lengthening of pollen seasons (+20 d) and increases in pollen concentrations (+21%) across North America, which are strongly coupled to observed warming. Human forcing of the climate system contributed ∼50% (interquartile range: 19–84%) of the trend in pollen seasons and ∼8% (4–14%) of the trend in pollen concentrations. Our results reveal that anthropogenic climate change has already exacerbated pollen seasons in the past three decades with attendant deleterious effects on respiratory health.

Comparison of Artemisia L. pollen concentrations and risk of development of allergy symptoms in different regions of Poland in 2020

In central Europe, mugwort pollen is a frequent cause of pollen allergy. Poland is one of the countries with the highest airborne concentrations of pollen of this taxon. Due to its high allergenic potential, Artemisia pollen may pose a significant threat to sensitive subjects during summer months. Plants from this genus often grow in urban and suburban areas. The aim of the study was to compare mugwort pollen seasons and concentrations of airborne pollen of these plants in 12 cities located in different regions of Poland: Bialystok, Bydgoszcz, Cracow, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw, and Zielona Gora. The investigations were carried out with the volumetric method using a Hirst-type pollen sampler (Lanzoni or Burkard) operating on a 24-hour basis. The duration of the pollen season was determined with the 98% method. The earliest onset of the mugwort pollen season was noted in Opole (12.07), and the latest beginning was recorded in Cracow and Sosnowiec (23.07). The maximum pollen concentrations were reported on August 7 and 8 in Lublin (177 P/m3) and Wroclaw (100 P/m3). In all the cities, peak days were recorded on the first ten days of August. The maximum pollen concentrations in the other cities were in the range of 18-89 P/m3. The highest annual pollen sum was recorded in Lublin (1423) and Wroclaw (1050). These values coincided with the highest pollen concentrations determined in these cities. The annual Artemisia pollen sums in 2020 did not have the highest values in comparison with other years in these cities. The average annual pollen sum in the five-year period of 2001-2005 was estimated at 2065 in Lublin and 1662 in Wrocław. Therefore, it can be concluded that the risk of mugwort pollen allergy in the pollen season 2020 was lower than in some previous years.

Yew and juniper pollen season in selected cities of Poland in 2020

The study compares the yew and juniper pollen seasons in Bialystok, Bydgoszcz, Cracow, Lublin, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, and Wroclaw in 2020. The investigations were conducted using the volumetric method. The yew and juniper season started in all measurement sites between 2nd February (Szczecin) and 2nd March (Lublin). The peak values of seasonal pollen count occurred between 23rd February (in Szczecin) and 28th March. The highest daily pollen count was recorded in Lublin (867 P/m3) and the lowest pollen count in Bialystok (45 P/m3). The highest annual totals were recorded in Lublin and Wroclaw. Most days, with a concentration equal to or above 50 P/m3, causing symptoms in allergic patients were recorded in Lublin and Warsaw.