Matthias Werchan

Computational validation of the recently proposed pollen season definition criteria

In a recently published paper, a Task Force of the Immunotherapy and Aerobiology and Pollution Interest Groups of the EAACI suggested specific criteria for the definition of pollen exposure times for three types of pollen events: (i) pollen season (PS) start and end, (ii) high-pollen season(s) (or peak pollen period(s) (PPP)) start and end, and (iii) high-pollen days. Species addressed included birch, grasses, cypress, olive and ragweed. Two important questions arise from the aforementioned definitions: (i) Do they lead to a narrow (thus well defined) time interval identifying start and end event dates (robustness of the criteria) and (ii) if slightly altered, will they result to a narrow (thus again well defined) fluctuation of start and end event dates (sensitivity of the criteria)? In an effort to provide with responses to aforementioned questions, we analyzed Poaceae pollen count data coming from Germany (up to 40 pollen monitoring stations, years 2012-2016). The analysis addressed all pollen events for the first question and focused on the PS and PPP start and end events as well as on high-pollen days for the second question.

Intradiurnal patterns of allergenic airborne pollen near a city motorway in Berlin, Germany

In this study, the seasonally averaged intradiurnal patterns of four different pollen types (Fraxinus, Betula, Poaceae and Artemisia) and the role of traffic volume, air pollution and selected weather parameters were investigated. Measurements were carried out with a 7-day recording volumetric spore trap (Hirst type) near a congested city motorway (the A 100) in Berlin, Germany, in 2012, 2013 and partly 2011. Both Poaceae and Artemisia pollen showed distinct patterns which were similar across the years. The main period of grass pollen concentrations in the air was from 8 a.m. to 10 p.m. with peaks about midday or in the afternoon. Mugwort pollen mainly occurred between 6 a.m. and 2 p.m. with a clear maximum from 8 to 10 a.m. With regard to Fraxinus and Betula pollen, the patterns were not as clear and showed differences throughout the years. The intradiurnal patterns of traffic volume and pollen load, mainly of Poaceae in the afternoon and Artemisia in the morning, were partly coincident. The combination of both a high pollen count and air pollution, due to exhaust emissions, represents a special health threat which could result in a double burden for allergy sufferers. In the case of the daily means of Betula and Poaceae, relative humidity had a significantly negative effect on pollen concentrations on the same and/or next day/s, sunshine duration (Poaceae) and air temperature (Artemisia) a positive one.

Spatial distribution of allergenic pollen through a large metropolitan area

For nearly a decade, the majority of the world’s population has been living in cities, including a considerable percentage of people suffering from pollen allergy. The increasing concentration of people in cities results in larger populations being exposed to allergenic pollen at the same time. There is almost no information about spatial distribution of pollen within cities as well as a lack of information about the possible impact to human health. To obtain this increasing need for pollen exposure studies on an intra-urban scale, a novelty screening network of 14 weekly changed pollen traps was established within a large metropolitan area—Berlin, Germany. Gravimetric pollen traps were placed at a uniform street-level height from March until October 2014. Three important allergenic pollen types for Central Europe—birch (Betula), grasses (Poaceae), and mugwort (Artemisia)—were monitored. Remarkable spatial and temporal variations of pollen sedimentation within the city and the influences by urban local sources are shown. The observed differences between the trap with the overall highest and the trap with the overall lowest amount of pollen sedimentation were in the case of birch pollen 245%, grass pollen 306%, and mugwort pollen 1962%. Differences of this magnitude can probably lead to different health impacts on allergy sufferers in one city. Therefore, pollen should be monitored preferably in two or more appropriate locations within large cities and as a part of natural air quality regulations.

Verteilung von Pollen und Feinstaub in einem städtischen Ballungsraum am Beispiel der Großstadt Berlin

ZusammenfassungHintergrund:Die Studie beinhaltet Erkenntnisse zur Verteilung von Pollen und Feinstaub (Partikel < 10 μm; PM10) und deren möglicher Zusammenhang in einem großstädtischen Ballungsraum am Beispiel von Berlin.Methoden:Im Mai und Juni 2011 wurden im Stadtgebiet für sechs Wochen parallele Messungen des Pollen- und PM10-Gehalts der Luft an drei verschiedenen Standorten mit unterschiedlichen Umgebungssituationen (innerstädtisch, vorstädtisch, verkehrsreich) durchgeführt.Ergebnisse:Sowohl für die Gräserpollen als auch für den Feinstaub wurden die höchsten Konzentrationen an dem verkehrsreichen Standort registriert. An allen Messstationen erreichten die Gräserpollenkonzentrationen an einigen Tagen die zur Auslösung allergischer Symptome erforderlichen Grenzwerte. Zwischen den Stationen ergaben sich für die Pollen- wie auch für die PM10-Konzentrationen gute Korrelationen. Ebenso konnte ein positiver Zusammenhang der jeweiligen Aufkommen mit den Tagesmaximaltemperaturen festgestellt werden. Schlussfolgerung: Die Konzentrationen von Gräserpollen an verschiedenen Plätzen innerhalb einer Stadt zeigen eine positive Korrelation, sie ist am höchsten an einem verkehrsreichen Standort. Höhere Temperaturen sind mit höheren Gräserpollenkonzentrationen verbunden.AbstractBackground:The study shows the findings concerning the distribution of pollen and particulate matter (particles < 10 μm; PM10) within an urban agglomeration using the example of Berlin.Methods:Parallel measurements of pollen and PM10 in the air were carried out during six weeks at three monitoring sites in the city with different environment (inner-city park, suburban, traffic) in May/June 2011.Results:Both grass pollen and PM10 reached their highest concentrations at the traffic hot spot. For some days at all monitoring sites grass pollen concentrations reached the threshold values that are required to initiate allergenic symptoms. For both pollen and PM10 concentrations good correlations were found between the sites. Moreover, it could be determined a positive correlation between these concentrations and daily maximum temperatures. Conclusion: Grass pollen counts show positive correlations between different places in a city with highest concentrations near to a a traffic hot spot. Higher temperatures correlate with higher grass pollen counts.

The distribution of pollen and particulate matter in an urban agglomeration using the city of Berlin as an example

ZusammenfassungHintergrund:Die Studie beinhaltet Erkenntnisse zur Verteilung von Pollen und Feinstaub (Partikel < 10 μm; PM10) und deren möglicher Zusammenhang in einem großstädtischen Ballungsraum am Beispiel von Berlin.Methoden:Im Mai und Juni 2011 wurden im Stadtgebiet für sechs Wochen parallele Messungen des Pollen- und PM10-Gehalts der Luft an drei verschiedenen Standorten mit unterschiedlichen Umgebungssituationen (innerstädtisch, vorstädtisch, verkehrsreich) durchgeführt.Ergebnisse:Sowohl für die Gräserpollen als auch für den Feinstaub wurden die höchsten Konzentrationen an dem verkehrsreichen Standort registriert. An allen Messstationen erreichten die Gräserpollenkonzentrationen an einigen Tagen die zur Auslösung allergischer Symptome erforderlichen Grenzwerte. Zwischen den Stationen ergaben sich für die Pollen- wie auch für die PM10-Konzentrationen gute Korrelationen. Ebenso konnte ein positiver Zusammenhang der jeweiligen Aufkommen mit den Tagesmaximaltemperaturen festgestellt werden.Schlussfolgerung:Die Konzentrationen von Gräserpollen an verschiedenen Plätzen innerhalb einer Stadt zeigen eine positive Korrelation, sie ist am höchsten an einem verkehrsreichen Standort. Höhere Temperaturen sind mit höheren Gräserpollenkonzentrationen verbunden.SummaryBackground:The study shows the findings concerning the distribution of pollen and particulate matter (particles < 10 μm; PM10) within an urban agglomeration, using the example of the city of Berlin as an example.Methods:Parallel measurements of pollen and PM10 in the air were carried out overduring six 6 weeks at three mon-itoring sites in the city with different environments (inner-city park, suburban, heavily trafficked) in May/June 2011.Results:Both grass pollen and PM10 reached their highest concentrations at the traffic hot spot. For some days, at all monitoring sites grass pollen concentrations at all monitoring sites reached the threshold values that are required to initiate allergenic symptoms. For both pollen and PM10 concentrations good correlations were found between the sites. Moreover, it could be determined a positive correlation between these concentrations and daily maximum temperatures.Conclusion:Grass pollen counts show positive correlations between different places in a city with the highest con-centrations near to a a traffic hot spot. Higher temperatures correlate with higher grass pollen counts.

The grass pollen season 2015: a proof of concept multi-approach study in three different European cities

BackgroundGrasses release the most widespread aeroallergens with considerable sensitization rates, while different species produce several pollen concentration peaks throughout the season. This study analyzed the prevalence of grass species in three different European city areas and compared the flowering period of these species with daily pollen concentrations and the symptom loads of grass pollen allergy sufferers.MethodsThe most prevalent grass species in Vienna (Austria), Berlin (Germany) and Turku (Finland) were studied and examined by use of three different approaches: phenology, pollen monitoring and symptom load evaluation. A mobile pollen exposure chamber was employed to observe reaction patterns of grass pollen allergy sufferers to three common grass species evaluated in this study versus placebo.ResultsCommon meadow grass (Poa pratensis) and the fescue grass species (Festuca spp.) are important contributors within the grass pollen season. The pollination period of orchard grass (Dactylis glomerata) and false-oat grass (Arrhenatherum elatius) indicated a greater importance in Berlin and Vienna, whereas a broader spectrum of grass species contributed in Turku to the main pollen season. The standardized provocation induced a nasal symptom load, reduction in nasal flow and increased secretion, in contrary to the placebo control group in grass pollen allergic subjects.ConclusionThe phenological observations, pollen measurements and symptom data evaluation provided unique insights into the contribution of multiple grass species in different European regions. All investigated grass species in the provocation induced rhinitis symptoms of comparable significance, with some degree of variation in symptom patterns.

Pollen season of European beech (Fagus sylvatica L.) and temperature trends at two German monitoring sites over a more than 30-year period

Although beech (Fagus) pollen are often disregarded, they play an allergological role. This study focused on pollen season (PS) of European beech (Fagus sylvatica L.) and mean yearly temperatures (T) at two climatically different sites (lowlands vs. Alps) in Germany. Pollen sampling was conducted with 7-day recording volumetric spore traps between 1982 and 2014. Both PS parameters (start, peak, length, annual pollen index [PI]) and T were compared in two periods (1982–1991 and 1992–2014), and correlations between PS and T were analysed. At both sites, average PS occurred earlier in the second period. Statistically significant differences were proved at the alpine site in terms of start and peak of the season, and PI. On average, PS in the lowlands was shorter and occurred earlier than in the Alps. As is the case with a lot of temperate tree species, beeches show the masting phenomenon and PI differed greatly among the years. Mast years were much less frequent than non-mast years, and the differences between the pollen sums were significant. Average pollen counts at the alpine site were about three times higher than in the lowlands. At both sites, higher T was significantly correlated with an earlier start and peak of the season, and an increased PI. Trends of T over the years were significantly positive. Temperature increase as a part of climate change may contribute to an earlier occurrence of the flowering season of European beech and to higher airborne pollen concentrations.

The Pollator: a personal pollen sampling device

No reliable data exist on the amount of airborne pollen and fungal spores individuals are actually exposed to in their day to day life. In past and current trials the exposure is usually extrapolated using pollen measurements from stationary pollen traps on the roof of nearby buildings. These measurements, and to a much lesser degree, such extrapolations, do not reflect actual individual pollen exposure levels [1]. To track individual pollen exposure, the actual air breathed has to be analyzed continuously over several days for the pollen content (type and quantity). Since, for various reasons, a non-invasive measurement of allergenic particles in the air immediately in front of the upper airways (probably 2 dm3 around the mouth) is problematic, the best feasible solution is to measure the particle concentration in close proximity to the upper airways, whilst not hindering or disturbing the individual wearing the device. Even though re-

New European Academy of Allergy and Clinical Immunology definition on pollen season mirrors symptom load for grass and birch pollen-induced allergic rhinitis

The use of allergen immunotherapy (AIT) for allergic rhinitis and its clinical efficacy in clinical trials depends on the effective determination of pollen allergen exposure time periods. We evaluate pollen data from Germany to examine the new definitions on pollen season and peak pollen period start and end as proposed by the European Academy of Allergy and Clinical Immunology (EAACI) in a recently published Position Paper. The aim was to demonstrate the ability of these definitions to mirror symptom loads for grass and birch pollen‐induced allergic rhinitis based on real‐life data.

Environmental grass pollen levels in utero and at birth and cord blood IgE: Analysis of three birth cohorts

BACKGROUND Early life factors are associated with allergic respiratory diseases, but the role of high grass pollen concentrations during pregnancy and shortly after birth is not known. OBJECTIVE To assess outdoor levels of grass pollen during the intrauterine period and at birth during peak pollen season on cord blood IgE in birth cohorts. METHODS Three birth cohorts were included: MACS (n = 429), Australia; COPSAC2000 (n = 200), Denmark; and LISA (n = 1968), Germany. Cord blood IgE was categorized (<0.5 kU/L, 0.5-1 kU/L, >1 kU/L) and dichotomized (high IgE ≥ 0.5 kU/L). Birth during the grass pollen season months and cumulative exposure to outdoor grass pollen counts during pregnancy with cord blood IgE were analysed using multinomial regression and analysed in meta-analysis using binomial regression adjusted for potential confounders. RESULTS Birth during the grass pollen season had higher pooled odds of cord blood IgE >0.5 kU/L 1.37 (95% CI 1.06, 1.77) in a meta-analysis with little heterogeneity between the three cohorts. Cumulative exposure to outdoor grass pollen counts during the entire pregnancy was associated with slightly lower pooled odds but significant (OR = 0.98, 95% CI: 0.96 to 0.99). CONCLUSIONS Birth during grass pollen seasons were associated with increased risk of high cord blood IgE in cities from both hemispheres, but high pollen loads in the environment during the entire pregnancy appeared protective. As IgE responses develop during the first months of life, our study findings provide new insights into the mechanisms of grass pollen exposure at birth and shortly after on possible allergic respiratory diseases.