• Simoleit, A., Werchan, M., Werchan, B. et al. Birch, grass, and mugwort pollen concentrations and intradiurnal patterns at two different urban sites in Berlin, Germany. Allergo J Int 26, 155–164 (2017). doi.org/10.1007/s40629-017-0012-4
    (First published: 15 March 2017)
    Abstract: Purpose The study investigated the seasonal courses and intradiurnal patterns of birch (Betula), grass (Poaceae), and mugwort (Artemisia) pollen at two sites in the city of Berlin in 2014 and 2015. Methods The “Motorway Site” was situated at a busy city motorway and the “City Center Site” on the roof of a large hospital. Sampling was undertaken with 7?day recording volumetric spore traps. Light microscopic analysis led to daily means (pollen/m3 air) and 2?h means (daily %). Correlation coefficients were calculated to compare pollen season between the sites. Rainless days were examined for their intradiurnal maximum of pollen concentration and corresponding wind direction in order to identify the impact of local pollen sources. Birch trees, grassed areas, and mugwort/field sagewort stems were mapped at both sites. Results The seasonal courses of Betula, Poaceae, and Artemisia pollen each showed significantly positive correlations between the sites, but absolute counts were higher at the motorway. Artemisia pollen showed a distinct morning profile at both sites. Poaceae pollen concentrated on the second half of the day peaking in the evening or at night. Betula pollen offered no clear trend, but the main period mostly started at 8 am and lasted until the end of day. Conclusions Higher pollen counts at the motorway seem to be associated with the local vegetation that was much more abundant than at the city center. Local sources of weeds (Artemisia) and grasses (Poaceae) releasing pollen at low heights appear to be more contributing for local pollen load than trees (Betula) at these sites.
  • Werchan, B., Werchan, M., Mücke, HG. et al. Spatial distribution of allergenic pollen through a large metropolitan area. Environ Monit Assess 189, 169 (2017). doi.org/10.1007/s10661-017-5876-8
    (First published: 18 March 2017)
    Abstract: 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.