Oak Pollen Season Research Articles

Modeling past and future spatiotemporal distributions of airborne allergenic pollen across the contiguous United States.

Exposures to airborne allergenic pollen have been increasing under the influence of changing climate. A modeling system incorporating pollen emissions and atmospheric transport and fate processes has been developed and applied to simulate spatiotemporal distributions of two major aeroallergens, oak and ragweed pollens, across the contiguous United States (CONUS) for both historical (year 2004) and future (year 2047) conditions. The transport and fate of pollen presented here is simulated using our adapted version of the Community Multiscale Air Quality (CMAQ) model. Model performance was evaluated using observed pollen counts at monitor stations across the CONUS for 2004. Our analysis shows that there is encouraging consistency between observed seasonal mean concentrations and corresponding simulated seasonal mean concentrations (oak: Pearson = 0.35, ragweed: Pearson = 0.40), and that the model was able to capture the statistical patterns of observed pollen concentration distributions in 2004 for most of the pollen monitoring stations. Simulation of pollen levels for a future year (2047) considered conditions corresponding to the RCP8.5 scenario. Modeling results show substantial regional variability both in the magnitude and directionality of changes in pollen metrics. Ragweed pollen season is estimated to start earlier and last longer for all nine climate regions of the CONUS, with increasing average pollen concentrations in most regions. The timing and magnitude of oak pollen season vary across the nine climate regions, with the largest increases in pollen concentrations expected in the Northeast region.

Oak pollen season in selected cities in Poland in 2022

Oak (Quercus sp.) is a common species in Poland. Que a 1, which triggers allergic reactions in spring, is the main oak allergen. The aim of the study was to compare the oak pollen season in 13 Polish cities in 2022. Pollen was monitored with the volumetric method. The analyses determined the annual sum of pollen grains, the length of the pollen season (using the 98% method), the highest peak pollen concentrations, the dates of maximum pollen concentrations, and the number of days with pollen concentrations above threshold values causing clinical allergy symptoms. The earliest onset of the oak pollen season was noted in Szczecin (April 11th), and the latest beginning was recorded in Lublin and Kielce (May 5th). The shortest and the longest pollen seasons were recorded in Cracow (22 days) and in Szczecin (48 days), respectively. The highest total daily concentration of pollen grains was recorded in Opole (5083) and the lowest value was noted in Bialystok (112) and Szczecin (328). The highest maximum concentration of oak pollen was recorded in Sosnowiec and Kielce (625 and 543 grains/m3, respectively), whereas the lowest values were noted in Bialystok and Szczecin (27 and 47 grains/m3, respectively). In most of the analyzed cities in Poland, the peak oak pollen release was recorded between May 7th and 12th. The highest risk of allergic reactions caused by oak pollen allergens was reported from Opole, Piotrkow Trybunalski, and Zielona Gora.

Oak and hornbeam pollen season in Kielce in 2021

The paper presents the characteristics of oak and hornbeam pollen seasons in Kielce in 2021. Aeropalinological measurements were carried out with the use of the volumetric method. The main oak pollen season lasted 35 days. The maximum concentration of oak pollen, i.e. 227 grains in 1 m3 of air, was recorded on May 20, and the seasonal pollen index was estimated at 1533. The hornbeam pollen season was longer, i.e. 56 days. The peak hornbeam pollen release was recorded on April 28, when 22 pollen grains in 1 m3 of air were noted, with the annual concentration sum of 207. The study also determined the effect of some meteorological factors on the concentration of pollen grains of the analyzed plant taxa. The meteorological parameters were found to exert the strongest effect on the dynamics of the hornbeam pollen season.

Treatment Effect of the Tree Pollen SLIT-Tablet on Allergic Rhinoconjunctivitis During Oak Pollen Season

Birch, alder, hazel, and oak are members of the birch homologous group based on cross-reactivity toward the birch pollen allergen Betula verrucosa 1. Theoretically, allergy to these tree pollens may be treated by immunotherapy with one representative allergen extract. To evaluate post hoc whether treatment of birch pollen-induced allergic rhinoconjunctivitis with a standardized tree sublingual immunotherapy (SLIT)-tablet containing birch pollen extract reduces symptoms and symptom-relieving medication use during the oak pollen season (OPS). In a randomized, multinational, double-blind trial (EudraCT-2015-004821-15), 634 participants (ages 12-65 years) received daily tree SLIT-tablet (12 SQ-Bet) or placebo before and during tree pollen season (alder/hazel plus birch pollen season [BPS]). Symptom-relieving medication was allowed. The primary end point was the average total combined score (sum of rhinoconjunctivitis daily symptom score and daily medication score) during BPS. Outcomes during the OPS (excluding overlapping BPS days) were analyzed post hoc. Relative improvements in average total combined score, daily symptom score, and daily medication score with the tree SLIT-tablet versus placebo during the OPS were 25%, 22%, and 32%, respectively (all P < .001). Significant correlations were observed between birch and oak serum immunoglobulin E (sIgE) at baseline (r= 0.86) and between birch and oak IgG4 after treatment (r= 0.72). Oak sIgE and IgG4 kinetics in response to tree SLIT-tablet treatment were similar to birch. The tree SLIT-tablet leads to significant improvement of rhinoconjunctivitis outcomes during the OPS, supporting the clinical relevance of immunological cross-reactivity toward birch and oak allergens.

Allergy to oak pollen in North America

Background: Oak pollen is an important allergen in North America. The genus Quercus (oak) belongs to the family Fagaceae under the order Fagales. Objective: The objective of this article was to narratively review the oak pollen season, clinical and epidemiologic aspects of allergy to oak pollen, oak taxonomy, and oak allergen cross-reactivity, with a focus on the North American perspective. Methods: A PubMed literature review (no limits) was conducted. Publications related to oak pollen, oak-related allergic rhinitis with or without conjunctivitis, and oak-related allergic asthma were selected for review. Results: Oak species are common throughout the United States and contribute up to 50% to overall atmospheric pollen loads. Mean peak oak pollen counts can reach >2000 grains/m³. The start of the oak pollen season generally corresponds to the seasonal shift from winter to spring based on latitude and elevation, and may begin as early as mid February. The duration of the season can last > 100 days and, in general, is longer at lower latitudes. In the United States, ∼30% of individuals with allergy are sensitized to oak. The oak pollen season correlates with increased allergic rhinitis symptom-relieving medication use and asthma-related emergency department visits or hospitalizations. Oak falls within the birch homologous group. Extensive immunologic cross-reactivity has been demonstrated between oak pollen and birch pollen allergens, and, more specifically, their major allergens Que a 1 and Bet v 1. The cross-reactivity between oak and birch has implications for allergy immunotherapy (AIT) because guidelines suggest selecting one representative allergen within a homologous group for AIT, a principle that would apply to oak. Conclusion: Allergy to oak pollen is common in North America and has a substantial clinical impact. Oak pollen allergens are cross-reactive with birch pollen allergens, which may have implications for AIT.

Oak pollen concentration in the air of selected Polish cities in 2020

The study aims to compare the oak pollen season in selected Polish cities: Bialystok, Bydgoszcz, Cracow, Katowice, Piotrkow Trybunalski, Lublin, Olsztyn, Opole, Szczecin, Warsaw, and Wroclaw in 2020. Measurements were made using the volumetric method, with a Hirst-type sampler. Oak pollen season, defined as the period with 98% of the annual total catch, started between April 14th (in Opole) and April 25th (in Lublin). The season ended on June 1st at the latest; in Sosnowiec, Bydgoszcz, Olsztyn, and Bialystok. It lasted from 30 to 47 days (37 days on average). The maximum daily oak pollen concentrations were observed between April 24th and May 11th. The highest annual sum of oak pollen grains (SPI) was recorded in Lublin, while the lowest in Bialystok. The highest concentrations of 596 oak pollen grains/m3 were noted in Lublin on April 28th. The longest exposure to high concentrations of oak pollen (&gt; 91 grains/m3), lasting 12–13 days, was recorded in Lublin, Opole, and Wroclaw.

Changes in Timing of Spring Onset and Increased Risk of Asthma Hospitalization in Maryland: Harbinger of Climate Change

Introduction: The proposed association between climate change and increased burden of allergic diseases are based on three different thematic observational studies that have linked i) increased CO2 concentration with higher pollen production, ii) warmer air/surface temperatures with early spring onset and longer pollen season, and iii) higher pollen exposure with increased risk of asthma hospitalizations. Yet empirical evidence collectively linking climate change with pollen season and asthma exacerbation is still lacking.Methods: We used general additive (GAM, quasi Poisson), and mixed effect (negative binomial) models to investigate the association between changes in timing of spring onset (SOS)- detected using satellite observation - and risk of asthma hospitalization in Maryland during 2001-2012. To characterize the underlying mechanism, we further investigated the relationship between changes in SOS and springtime tree pollen dynamic (timing of pollen season onset, timing and intensity of peak pollen concentration, and pollen season length).Results: In the unadjusted model, very early (Incident Rate Ratio (IRR): 1.17, 95% Confidence Interval (CI): 1.07-1.28) and late (IRR: 1.07, 95% CI: 1.00-1.15) onset of spring were associated with increased risk of asthma hospitalization. When the analysis was adjusted for extreme heat event and PM2.5 concentration, the risk remained significant for very early SOS (IRR: 1.10, 95% CI: 1.02-1.20), but not for late SOS (RR: 1.03, 95% CI: 0.97-1.11). We further observed that very early SOS is significantly associated with the length for Birch and Oak pollen season (p&lt;0.05).Conclusion: Our results show that ongoing changes in timing of spring onset that are tied to climate variability and change increases risk of asthma hospitalization. Our result serve as a wake-up call to public health and medical communities regarding the need to anticipate and adapt to the ongoing changes in the timing and severity of the spring allergy season.

Oak pollen season in selected cities of Poland in 2019

The study compares the oak pollen seasons in Bialystok, Bydgoszcz, Sosnowiec, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Szczecin, Warsaw, Wroclaw and Zielona Gora in 2019. The investigations were conducted using the volumetric method. The oak season started in all measurement sites between April 6th (Szczecin) and April 24th (Lublin and Piotrkow Trybunalski). The peak values of seasonal pollen count occurred between April 25th and May 2nd. The highest daily pollen count was recorded in Lublin (273 P/m3) and the lowest pollen count in Bialystok (23 P/m3). The highest annual totals were recorded in Lublin, Piotrkow Trybunalski and Warsaw. The most days with concentration equal to or above 16 P/m3, causing symptoms in many allergic patients, were recorded in Lublin and Warsaw. Days with concentration equal to or above 91 P/m3, which causes allergy of all sensitized patients, were the most frequent in Lublin, Piotrkow Trybunalski and Warsaw.

Impacts of oak pollen on allergic asthma in the United States and potential influence of future climate change.

Future climate change is expected to lengthen and intensify pollen seasons in the U.S., potentially increasing incidence of allergic asthma. We developed a proof‐of‐concept approach for estimating asthma emergency department (ED) visits in the U.S. associated with present‐day and climate‐induced changes in oak pollen. We estimated oak pollen season length for moderate (Representative Concentration Pathway (RCP) 4.5) and severe climate change scenarios (RCP8.5) through 2090 using five climate models and published relationships between temperature, precipitation, and oak pollen season length. We calculated asthma ED visit counts associated with 1994–2010 average oak pollen concentrations and simulated future oak pollen season length changes using the Environmental Benefits Mapping and Analysis Program, driven by epidemiologically derived concentration‐response relationships. Oak pollen was associated with 21,200 (95% confidence interval, 10,000–35,200) asthma ED visits in the Northeast, Southeast, and Midwest U.S. in 2010, with damages valued at $10.4 million. Nearly 70% of these occurred among children age <18 years. Severe climate change could increase oak pollen season length and associated asthma ED visits by 5% and 10% on average in 2050 and 2090, with a marginal net present value through 2090 of $10.4 million (additional to the baseline value of $346.2 million). Moderate versus severe climate change could avoid >50% of the additional oak pollen‐related asthma ED visits in 2090. Despite several key uncertainties and limitations, these results suggest that aeroallergens pose a substantial U.S. public health burden, that climate change could increase U.S. allergic disease incidence, and that mitigating climate change may have benefits from avoided pollen‐related health impacts.

Impacts of oak pollen on allergic asthma in the USA and potential effect of future climate change: a modelling analysis

BackgroundFuture climate change is expected to lengthen and intensify pollen seasons in the USA, potentially increasing incidence of allergic asthma. We examined the health consequences of present day oak pollen levels and climate-induced changes in oak pollen on asthma emergency department visits in the USA. MethodsWe estimated oak pollen season length for moderate (RCP4.5) and severe climate change scenarios (RCP8.5) from 2010 through to 2090 using five climate models and published relationships between temperature, precipitation, and pollen season length. We calculated asthma emergency department visit counts associated with 1994–2010 average oak pollen concentrations and with simulated future oak pollen season length changes using the Environmental Benefits Mapping and Analysis Program (BenMAP-CE), driven by epidemiologically derived concentration-response relationships. FindingsOak pollen was associated with an estimated 7400, 8800, and 5000 asthma emergency department visits in the northeast, southeast, and midwest USA, respectively, in 2010, with substantial economic damages. Most of these visits (14 600) occurred among children age younger than 18 years. Severe climate change could increase oak pollen season length and associated asthma emergency departments visits in all regions examined in 2030, 2050, 2070, and 2090, resulting in millions of dollars in health-care costs in these US regions through to 2090. Moderate versus severe climate change could mitigate much of the additional burden of oak pollen-related asthma emergency department visits. InterpretationAlthough these results were restricted to one pollen type and one health outcome, these results suggest that aeroallergens pose a substantial US public health burden, that climate change could increase US allergic disease incidence, and that mitigating climate change might have benefits from avoided pollen-related health effects. However, wide confidence intervals and several key methodological limitations constrain the strength of these conclusions. As more studies quantify the effects of climate on pollen and pollen on health, this methodology can be applied to additional pollen types and health outcomes. FundingUS Environmental Protection Agency.

Effect of nitrogen dioxide and sulfur dioxide on viability and morphology of oak pollen.

Nitrogen dioxide (NO2) and sulfur dioxide (SO2) generated by excessive coal combustion and motor vehicle emissions are major air pollutants in the large cities of China. The objective of our study was to determine the effects of the exposure of oak pollens (Quercusmongolica) to several concentrations of NO2 or SO2. Pollen grains were exposed to 0.5 ppm to 5.0 ppm NO2 or SO2 for 4 hours and assessed for morphological damage by field emission scanning electron microscopy and for viability using the trypan blue stain. Morphological changes in pollen grains were also examined after contact with acid solutions at pH 4.0 to pH 7.0. Exposure to NO2 or SO2 significantly damaged pollen grains at all concentrations investigated, compared to exposure to air; with exposure to concentrations of 0.5 ppm to 2 ppm resulting in fissures or complete breaks in the exine and a concentration of 5 ppm resulting in complete breakdown and release of pollen cytoplasmic granules. Significantly greater amounts of pollen grain were damaged after exposure to SO2 (15.5-20.4%) than after exposure to NO2 (7.1-14.7%). Similarly, exposure to NO2 or SO2 significantly decreased the viability of pollen grains, compared with exposure to air; with SO2 being slightly more detrimental than NO2. Exposure to acid solutions also induced pollen damage, which appeared to be pH-dependent (from 24.6% at pH 6.0 to 55.8% at pH 4.0; compared to 3.8% at pH 7.0). Short-term exposure of oak pollen to high concentrations of SO2 or NO2 significantly increases their fragility and disruption, leading to subsequent release of pollen cytoplasmic granules into the atmosphere. These results suggest that heightened air pollution during the oak pollen season may possibly increase the incidence of allergic airway disease in sensitized individuals by facilitating the bioavailability of airborne pollen allergens.

Variations in Quercus sp. pollen seasons (1996-2011) in Poznań, Poland, in relation to meteorological parameters.

The aim of this study is to supply detailed information about oak (Quercus sp.) pollen seasons in Poznań, Poland, based on a 16-year aerobiological data series (1996–2011). The pollen data were collected using a volumetric spore trap of the Hirst design located in Poznań city center. The limits of the pollen seasons were calculated using the 95 % method. The influence of meteorological parameters on temporal variations in airborne pollen was examined using correlation analysis. Start and end dates of oak pollen seasons in Poznań varied markedly from year-to-year (14 and 17 days, respectively). Most of the pollen grains (around 75 % of the seasonal pollen index) were recorded within the first 2 weeks of the pollen season. The tenfold variation was observed between the least and the most intensive pollen seasons. These fluctuations were significantly related to the variation in the sum of rain during the period second fortnight of March to first fortnight of April the year before pollination (r = 0.799; p < 0.001). During the analyzing period, a significant advance in oak pollen season start dates was observed (−0.55 day/year; p = 0.021), which was linked with an increase in the mean temperature during the second half of March and first half of April (+0.2 °C; p = 0.014). Daily average oak pollen counts correlated positively with mean and maximum daily temperatures, and negatively with daily rainfall and daily mean relative humidity.

Oak Pollen Season in the Midwestern US

RATIONALE: Oak trees are native to the Midwestern US and produce abundant pollen in the spring. Oak pollen production and dispersal is sensitive to dramatic changes in weather common to this region. To determine the impact weather has on initiation and intensity of oak pollen season we conducted the following studies.

Forecasting the start of Quercus pollen season using several methods – the evaluation of their efficiency

Forecasting the time when the atmospheric pollen season of allergenic plants begins is particularly important for doctors and their patients. The aim of this paper is to determine whether it is possible to forecast the start of the oak (Quercus) pollen season in Rzeszów, Poland. In the elaboration of the most effective model, various forecasting techniques were tested: growth degree days (GDD degrees C); meteorological factors; bioclimatic factors; and indicator taxon. The aerobiological monitoring was carried out in 1997-2005 and 2007 in Rzeszów (SE Poland). In the presented investigation, three methods defining the start of the Quercus pollen season were selected on the basis of accumulated sums of pollen or the constant occurrence of pollen grains in air. Despite the application of different combinations of GDD degrees C methods and threshold temperatures, the correlation coefficients between the expected and obtained values were low. In some cases, however, they proved highly effective for the test years (2005, 2007) with the accuracy of a few days. For GDD degrees C methods, the best threshold temperatures range between 5 and 6 degrees C. Models based on bioclimatic indices and meteorological variables were not satisfactory. On the basic of the 10 years of results, the method of indicator species were good for forecast the start of oak pollen season. Birch was the best indicator taxa.

Modelling start of oak pollen season in different climatic zones in Spain

Quercus pollen and meteorological data for several years from eight sites in Spain have been statistically analysed to select the threshold temperature and calculate the mean heat accumulation for predicting the Quercus pollination start in different climatic areas. The growing degree days method, which assumes the daily temperature varies as a sine wave, was used for heat accumulation calculations. Threshold temperatures between 4 and 12 °C were chosen using linear regression equations forced through the origin and their root mean square error (RMSE) of predicted against the observed dates for each observation site. Above the threshold, the average growing degree days (up to 1999) for the studied years was taken as the predictor value. Results showed a relationship between the selected threshold and elevation and a stronger and statistically significant correlation between threshold and yearly mean temperature, for each site. Regression analysis indicated that the selected threshold and the calculated heat accumulation were optimum for most of the localities. The validity of the results was tested using the meteorological data for the year 2000 as independent variable and this confirmed that there were only a few days difference between the predicted and observed day of the first pollen release for most of the studied localities.

A study of oak-pollen production and phenology in northern California: Prediction of annual variation in pollen counts based on geographic and meterologic factors

To assess the characteristics of oak-pollen production and dispersal, 9 years of weekly volumetric air sampling, with modified swing-shield rotoslide pollen samplers, were obtained in San Francisco and San Jose, Calif. The Mediterranean climate of coastal California supports 9 million acres of oaks of nine different species. The major pollen contributors in the two sampling areas are coast live oak (Quercus agrifolia Neé) and valley oak (Quercus lobata neé). Sampling data indicate that grains may be wind transported at least 16 km (10 miles). A strong correlation exists between pollen capture and total rainfall a full year before pollen release. The correlation is statistically significant, based on a Spearman rank test. A positive regression line slope demonstrates that the greater the precipitation, the stronger the stimulus for pollen production. The median count can be predicted within a factor of two with high probability a full year before release. During most seasons, the peak pollen collection from coast live oak and valley oak occurs in early April. A second peak production period, in mid-May, represents the conglomerate of other oak-pollen types. However, there are major yearly differences in the relative amounts of pollen released during these two periods. Consequently, individual oak pollinosis may depend as much on variable production by the major species as on the total quantity of airborne oak pollen. These data will help clinicians predict and prepare for the intensity of the oak-pollen season and explain seasonal variations in clinical symptoms from year to year. The question of cross-reacting and specific allergens among oak species can be answered by RAST-inhibition studies.(ABSTRACT TRUNCATED AT 250 WORDS)