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Pollen-induced allergies are among the most prevalent non-contagious diseases, with about a quarter of the European population being sensitive to various atmospheric bioaerosols. In most European countries, pollen information is based on a weekly-cycle Hirst-type pollen trap method. This method is labour-intensive and requires narrow specialized abilities and substantial time, so that the pollen data are always delayed and subject to sampling- and counting-related uncertainties. Emerging new approaches to automatic pollen monitoring can, in principle, allow for real-time availability of the data with no human involvement. The goal of the current paper is to evaluate the capabilities of the new Plair Rapid-E pollen monitor and to construct a first-level pollen recognition algorithm. The evaluation was performed for three devices located in Lithuania, Serbia and Switzerland, with independent calibration data and classification algorithms. The Rapid-E output data include multi-angle scattering images and the fluorescence spectra recorded at several times for each particle reaching the device. Both modalities of the Rapid-E output were treated with artificial neural networks (ANNs) and the results were combined to obtain the pollen type. For the first classification experiment, the monitor was challenged with a large variety of pollen types and the quality of many-to-many classification was evaluated. It was shown that in this case, both scattering- and fluorescence-based recognition algorithms fall short of acceptable quality. The combinations of these algorithms performed better, exceeding 80 % accuracy for 5 out of 11 species. Fluorescence spectra showed similarities among different species, ending up with three well-resolved groups: (Alnus , Corylus , Betula and Quercus), (Salix and Populus) and (Festuca , Artemisia and Juniperus). Within these groups, pollen is practically indistinguishable for the first-level recognition procedure. Construction of multistep algorithms with sequential discrimination of pollen inside each group seems to be one of the possible ways forward. In order to connect the classification experiment to existing technology, a short comparison with the Hirst measurements is presented and the issue of false positive pollen detections by Rapid-E is discussed. [ABSTRACT FROM AUTHOR]

The aim of the study was to compare the airborne concentrations of pollen produced by vernal flowering trees taxa (Alnus, Betula, Carpinus, Corylus, Fraxinus, Platanus, Populus, Quercus, Taxaceae/Cupressaceae) in the cities of Timisoara (Romania), Szeged (Hungary), Novi Sad (Serbia) and Ljubljana (Slovenia) during the years 2006-2008. Annual variations in the concentration of pollen in the atmosphere were analysed by the volumetric method. In these cities, the period with the greatest diversity of pollen types is spring. These trees are found in mixed forests and are used in urban landscaping and home gardens. Inter-annual differences can be seen in the seasonal behaviour of the pollen in Novi Sad, 2008 being the year in which the highest levels of airborne pollen were reached. During the 3-year period, pollen of the representatives of the family Betulaceae accounted for a significant proportion of total pollen, predominated by Betula pollen and a considerably lower proportion of Alnus, Carpinus and Corylus airpollen. Taxaceae/Cupressaceae pollen appears in the atmospheric pollen spectra of all localities in high concentrations. These pollen grains are the main source of allergens in springtime. Results of the study reveal important differences between the cities. [ABSTRACT FROM AUTHOR]

Pollen data have been recorded at Novi Sad in Serbia since 2000. The adopted method of producing pollen counts has been the use of five longitudinal transects that examine 19.64% of total sample surface. However, counting five transects is time consuming and so the main objective of this study is to investigate whether reducing the number to three or even two transects would have a significant effect on daily average and bi-hourly pollen concentrations, as well as the main characteristics of the pollen season and long-term trends. This study has shown that there is a loss of accuracy in daily average and bi-hourly pollen concentrations (an increase in % ERROR) as the sub-sampling area is reduced from five to three or two longitudinal transects. However, this loss of accuracy does not impact on the main characteristics of the season or long-term trends. As a result, this study can be used to justify changing the sub-sampling method used at Novi Sad from five to three longitudinal transects. The use of two longitudinal transects has been ruled out because, although quicker, the counts produced: (a) had the greatest amount of % ERROR, (b) altered the amount of influence of the independent variable on the dependent variable (the slope in regression analysis) and (c) the total sampled surface (7.86%) was less than the minimum requirement recommended by the European Aerobiology Society working group on Quality Control (at least 10% of total slide area).