Regional Importance of Alnus Pollen as an Aeroallergen: A Comparative Study of Alnus Pollen Counts from Worcester (UK) and Poznań (Poland)

Daily average Alnus pollen counts (1996-2005) from Worcester (UK) and Poznań (Poland) were examined with the aim of assessing the regional importance of Alnus pollen as an aeroallergen. The average number of Alnus pollen grains recorded annually at Poznań was more than 2.5 times that of Worcester. Furthermore, daily average Alnus pollen counts exceeded the thresholds of 100, 500 and 1,000 grains/m3 more times at Poznań than Worcester. Skin prick test results (1996-2005) and allergen-specific IgE(asIgE) measurements using the CAP (Pharmacia) system (2002-2005), were supplied by the Allergic Diseases Diagnostic Centre in Poznań. The annual number of positive skin prick tests to Alnus pollen allergens was significantly related (p<0.05) to seasonal variations in the magnitude of the Alnus pollen catch recorded at Poznań (r=0.70). The symptoms of patients with positive skin prick tests to Alnus pollen allergens were: 51% pollinosis, 43% atopic dermatitis, 4% asthma, 1% chronic urticaria and 1% eczema. On a scale of 0-6, 20.5% of patients examined for serum asIgE in relation to Alnus pollen allergens had asIgE measurements in classes 5 and 6. Alnus pollen is generally considered to be mildly allergenic. However, the amount of Alnus pollen released into the atmosphere in places such as Poznań may increase its impact on the population and make it one of the more important aeroallergens present.

Factors Involved in the Phenological Mechanism of Alnus Flowering in Central Europe

The objectives of this paper are to ascertain the main factors involved in the phenological mechanism of alder flowering in Central Europe by understanding the in - fluence of the main meteorological parameters, the North Atlantic Oscillation (NAO) effect and the study of the Chill and Heat requirements to overcome dormancy. Airborne pollen (1995–2007) was collected in Poznań (Poland) by means a volumetric spore trap. Temperatures for February, and January and February averages of the NAO are generally key factors affecting the timing of the alder pollen seasons. Chilling accumulation (which started in Poznań at the beginning of November, while the end took place during the month of January) of 985 CH with a threshold temperature of -0.25ºC, followed by 118 GDDºC with a threshold temperature of 0.5ºC, were necessary to overcome dormancy and produce the onset of flowering. The calculated dormancy requirements, mean tem - peratures of the four decades of the year, and January and February average NAO index recorded during the period before flowering, were used to construct linear and multiple regression models in order to forecast the start date of the alder pollen seasons Its ac - curacy was tested using data from 2007, and the difference between the predicted and observed dates ranged from 3–7 days

Relative Efficiencies of the Burkard 7-Day, Rotorod and Burkard Personal Samplers for Poaceae and Urticaceae Pollen under Field Conditions

Introduction: In aerobiological studies it is often necessary to compare concentration data recorded with different models of sampling instrument. Sampler efficiency typically varies from device to device, and depends on the target aerosol and local atmospheric conditions. To account for these differences inter-sampler correction factors may be applied, however for many pollen samplers and pollen taxa such correction factors do not exist and cannot be derived from existing published work. Materials and methods: In this study the relative efficiencies of the Burkard 7-Day Recording Volumetric Spore Trap, the Sampling Technologies Rotorod Model 20 and the Burkard Personal Volumetric Air Sampler were evaluated for Urticaceae and Poaceae pollen under field conditions, and the influence of wind speed and relative humidity on these efficiency relationships was assessed. Data for the two pollen taxa were collected during 2010 and 2011-12 respectively. Results: The three devices were found to record significantly different concentrations for both pollen taxa, with the exception of the 7-Day and Rotorod samplers for Poaceae pollen. Under the range of conditions present during the study wind speed was found to only have a significant impact on inter-sampler relationships involving the vertically orientated Burkard Personal sampler, whilst no interaction between relative efficiency and relative humidity was observed. Conclusions: Data collected with the three models of sampler should only be compared once the appropriate correction has been made, with wind speed taken into account where appropriate.

Risk of Exposure to Airborne Ambrosia Pollen from Local and Distant Sources in Europe – an Example from Denmark

Background. Ambrosia artemisiifolia L. is a noxious invasive alien species in Europe. It is an important aeroallergen and millions of people are exposed to its pollen. Objective. The main aim of this study is to show that atmospheric concentrations of Ambrosia pollen recorded in Denmark can be derived from local or more distant sources. Methods. This was achieved by using a combination of pollen measurements, air mass trajectory calculations using the HYPLIT model and mapping all known Ambrosia locations in Denmark and relating them to land cover types. Results. The annual pollen index recorded in Copenhagen during a 15-year period varied from a few pollen grains to more than 100. Since 2005, small quantities of Ambrosia pollen has been observed in the air every year. We have demonstrated, through a combination of Lagrangian back-trajectory calculations and atmospheric pollen measurements, that pollen arrived in Denmark via long-distance transport from centres of Ambrosia infection, such as the Pannonian Plain and Ukraine. Combining observations with results from a local scale dispersion model show that it is possible that Ambrosia pollen could be derived from local sources identified within Denmark. Conclusions. The high allergenic capacity of Ambrosia pollen means that only small amounts of pollen are relevant for allergy sufferers, and just a few plants will be sufficient to produce enough pollen to affect pollen allergy sufferers within a short distance from the source. It is necessary to adopt control measures to restrict Ambrosia numbers. Recommendations for the removal of all Ambrosia plants can effectively reduce the amount of local pollen, as long as the population of Ambrosia plants is small.