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Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in Córdoba, Spain, and Évora, Portugal, using Hirst-type traps for pollen and high-volume cascade impactors for allergen. Pollen from different days released 12-fold different amounts of Ole e 1 per pollen (both locations P40% of Ole e 1 exposure in Évora was explained by high-potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.

A birch pollen emission model is described and its main features are discussed. The development of the model is based on a double-threshold temperature sum model that describes the propagation of the flowering season and naturally links to the thermal time models to predict the onset and duration of flowering. For the flowering season, the emission model considers ambient humidity and precipitation rate, both of which suppress the pollen release, as well as wind speed and turbulence intensity, which promote it. These dependencies are qualitatively evaluated using the aerobiological observations. Reflecting the probabilistic character of the flowering of an individual tree in a population, the model introduces relaxation functions at the start and end of the season. The physical basis of the suggested birch pollen emission model is compared with another comprehensive emission module reported in literature. The emission model has been implemented in the SILAM dispersion modelling system, the results of which are evaluated in a companion paper.

An evaluation of performance of the System for Integrated modeLling of Atmospheric coMposition (SILAM) in application to birch pollen dispersion is presented. The system is described in a companion paper whereas the current study evaluates the model sensitivity to details of the pollen emission module parameterisation and to the meteorological input data. The most important parameters are highlighted. The reference year considered for the analysis is 2006. It is shown that the model is capable of predicting about two-thirds of allergenic alerts, with the odds ratio exceeding 12 for the best setup. Several other statistics corroborate with these estimations. Low-pollen concentration days are also predicted correctly in more than two-thirds of cases. The model experiences certain difficulties only with intermediate pollen concentrations. It is demonstrated that the most important input parameter is the near-surface temperature, the bias of which can easily jeopardise the results. The model sensitivity to random fluctuations of temperature is much lower. Other parameters important at various stages of pollen development, release, and dispersion are precipitation and ambient humidity, as well as wind direction.

In order to study allergic people responding to daily changes in pollen concentrations, we compared personal diary data on allergic symptoms and the use of allergy medicines to daily pollen counts during the two unequal alder and birch pollen seasons of 2009 and 2010. Almost 90% of the 61 subjects with physician-diagnosed birch pollinosis developed conjunctival, nasal or other symptoms during the peak birch pollination. Most subjects (95%) also reported symptoms during the alder pollination. Despite a delay between the most severe symptoms and the pollen peaks and the increased risk of allergy symptoms between the alder and birch pollen peaks at much lower pollen concentrations, the number of subjects with allergy symptoms correlated with the daily pollen concentrations in both years (r 09 = 0.35, r 10 = 0.36, p

Relationships between temporal variations in the North Atlantic Oscillation (NAO) and grass pollen counts at 13 sites in Europe, ranging from Cordoba in the south-west and Turku in the north-east, were studied in order to determine spatial differences in the amount of influence exerted by the NAO on the timing and magnitude of grass pollen seasons. There were a number of significant (P < 0.05) relationships between the NAO and start dates of the grass pollen season at the 13 pollen-monitoring sites. The strongest associations were generally recorded near to the Atlantic coast. Several significant correlations also existed between winter averages of the NAO and grass pollen season severity. Traditional methods for predicting the start or magnitude of grass pollen seasons have centred on the use of local meteorological observations, but this study has shown the importance of considering large-scale patterns of climate variability like the NAO.

A growing number of studies are researching indoor air concentrations of pollen in buildings, but to our knowledge no studies have dealt with the precise concentration of pollen inside private cars. The aim of this study was to assess the risk of exposure to pollen in private cars throughout the Poaceae and Artemisia spp. pollen season. The study was conducted in the town of Lappeenranta and along Highway 6 in south‐east Finland between July 14 and August 17, 2003. The pollen concentrations were measured inside two moving and parked cars using rotorod‐type samplers. Surface and ambient Burkard samples were also collected. Both Poaceae and Artemisia spp. pollen were recorded only on one day and in low concentrations (

Although the number of studies of pollen concentrations inside and outside buildings is increasing, little is known about the efficiency of penetration of pollen from outdoor to indoor air, and further. We studied indoor and outdoor pollen concentrations in the town of Lappeenranta and in the municipality of Rautjarvi in SE Finland from May 3–23, 2004, i.e. throughout the Betula pollen season, and assessed the risk of exposure to pollen grains. Pollen concentrations were measured inside and outside a block of flats, a detached house, and the regional central hospital, using rotorod-type samplers; in the town of Joutseno data were compared with Burkard counts. Outdoor concentrations of Betula pollen grains ranged between low and abundant (0–855 grains m−3). The corresponding indoor concentrations near the main front doors varied from low to moderate (0–17 grains m−3) in the central hospital and were low (

Resume Cette etude se propose, dans la perspective du rechauffement climatique, d’etudier la relation entre la temperature et la date de debut de pollinisation (DDP) du bouleau, un arbre a pollen allergisant particulierement important pour les allergiques dans le nord-ouest de l’Europe. Elle a permis de faire des projections pour les prochaines annees afin d’estimer, en fonction de l’evolution prevue des temperatures du printemps, l’evolution de la DDP du bouleau. L’etude a porte sur dix sites europeens, Kevo et Turku (Finlande), Londres (Royaume-Uni), Paris et Lyon (France), Bruxelles (Belgique), Zurich (Suisse), Vienne (Autriche), Poznan et Cracovie (Pologne). La periode d’etude couvrait une duree de six a 28 ans selon le site. Les pollens ont ete recueillis quotidiennement a l’aide de capteurs volumetriques de type Hirst, et les donnees comparees aux temperatures mensuelles de janvier a mai au moyen de correlations et de regressions multiples. Les resultats ont montre qu’en dehors de Kevo ou la tendance va vers des printemps plus froids et des DDP plus tardives, dans les autres sites on constate un rechauffement printanier associe a des DDP plus precoce : cette tendance est tres nette a Turku, Zurich, Londres, Vienne et Bruxelles, moins marquee en France et absente en Pologne. Les resultats de ce travail devront conduire a une mise a jour des calendriers polliniques et des modeles de prediction de la DDP, dans les sites ou se dessine une tendance nette.

BACKGROUND: Allergies to grass pollen are the number one cause of outdoor hay fever. The human immune system reacts with symptoms to allergen from pollen. OBJECTIVE: We investigated the natural variability in release of the major group 5 allergen from grass pollen across Europe. METHODS: Airborne pollen and allergens were simultaneously collected daily with a volumetric spore trap and a high-volume cascade impactor at 10 sites across Europe for 3 consecutive years. Group 5 allergen levels were determined with a Phl p 5-specific ELISA in 2 fractions of ambient air: particulate matter of greater than 10μm in diameter and particulate matter greater than 2.5μm and less than 10μm in diameter. Mediator release by ambient air was determined in FcεRI-humanized basophils. The origin of pollen was modeled and condensed to pollen potency maps. RESULTS: On average, grass pollen released 2.3 pg of Phl p 5 per pollen. Allergen release per pollen (potency) varied substantially, ranging from less than 1 to 9 pg of Phl p 5 per pollen (5% to 95% percentile). The main variation was locally day to day. Average potency maps across Europe varied between years. Mediator release from basophilic granulocytes correlated better with allergen levels per cubic meter (r(2)=0.80, P&nbsp

This paper considers the feasibility of numerical simulation of large-scale atmospheric transport of allergenic pollen. It is shown that at least small grains, such as birch pollen, can stay in the air for a few days, which leads to a characteristic scale for their transport of approximately 10(3) km. The analytical consideration confirmed the applicability of existing dispersion models to the pollen transport task and provided some reference parameterizations of the key processes, including dry and wet deposition. The results were applied to the Finnish Emergency Dispersion Modelling System (SILAM), which was then used to analyze pollen transport to Finland during spring time in 2002-2004. Solutions of the inverse problems (source apportionment) showed that the main source areas, from which the birch flowering can affect Finnish territory, are the Baltic States, Russia, Germany, Poland, and Sweden-depending on the particular meteorological situation. Actual forecasting of pollen dispersion required a birch forest map of Europe and a unified European model for birch flowering, both of which were nonexistent before this study. A map was compiled from the national forest inventories of Western Europe and satellite images of broadleaf forests. The flowering model was based on the mean climatological dates for the onset of birch forests rather than conditions of any specific year. Utilization of probability forecasting somewhat alleviated the problem, but the development of a European-wide flowering model remains the main obstacle for real-time forecasting of large-scale pollen distribution.

Determining the start of the birch pollen season requires the reliable separation of non‐local from locally produced birch pollen. The research was undertaken close to the latitudinal birch tree line at the Kevo Subarctic Research Institute (69°45′N 27°01′E) in northern Finland. By comparing phenological and aerobiological observations, the proportion of birch pollen present in the air before local anthesis commences can be delimited. We coupled this with data of pollen deposition monitored by means of a modified Tauber trap. The dominant birch species at Kevo is the mountain birch Betula pubescens ssp. czerepanovii, whereas B. pubescens ssp. pubescens is very rare, hence we consider the proportion of the southerly B. pubescens‐type pollen deposited in the pollen trap to be non‐local in origin. We did not observe any trend towards an earlier start of the phenologically observed mountain birch anthesis at Kevo as predicted from work elsewhere. Moreover, the fixed 2.5% threshold method for determining the b...

Summary Background During specific pollen immunotherapy (SIT) there is a local mucosal shift from Th2- to Th1- type cytokine predominance, with IL-12 having a major role in this shift. IL-10-induced tolerance is supposed to be a key phenomenon in venom immunotherapy (VIT). However, the role of Th1-promoting cytokines, on the one hand, and the role of regulatory cytokines, on the other hand, have not been studied in parallel during SIT. Objective This study was undertaken to analyse the allergen-induced in vitro mRNA expression of Th1-type effector cytokine IL-18 and regulatory cytokines IL-10 and TGF-β during SIT in peripheral blood mononuclear cells (PBMC) of allergic rhinitis (AR) patients. Methods Thirty patients with AR undergoing pollen SIT and 10 patients with AR who were not treated with SIT were included in the study. The symptoms and medications were registered post-seasonally before the beginning of SIT and after 1 year of therapy. PBMC samples were collected and stimulated with pollen allergen extract prior to the treatment, at the maintenance phase in 12 patients and after 1 year of the treatment. The cytokine mRNA expression was assessed using kinetic real-time RT-PCR (TaqMan®). Results There was a clear increase in the treated AR patients, in comparison with untreated AR patients, in the expression of both IL-10 (mean change from baseline (SEM): 3.1 (0.8) vs. −0.3 (0.3), P

A shift in the timing of birch pollen seasons is important because it is well known to be a significant aeroallergen, especially in NW Europe where it is a notable cause of hay fever and pollen-related asthma. The research reported in this paper aims to investigate temporal patterns in the start dates of Betula (birch) pollen seasons at selected sites across Europe. In particular it investigates relationships between the changes in start dates and changes in spring temperatures over approximately the last 20 years. Daily birch pollen counts were used from Kevo, Turku, London, Brussels, Zurich and Vienna, for the core period from 1982 to 1999 and, in some cases, from 1970 to 2000. The sites represent a range of biogeographical situations from just within the Arctic Circle through to North West Maritime and Continental Europe. Pollen samples were taken with Hirst-type volumetric spore traps. Weather data were obtained from the sites nearest to the pollen traps. The timing of birch pollen seasons is known to depend mostly on a non-linear balance between the winter chilling required to break dormancy, and spring temperatures. Pollen start dates and monthly mean temperatures for January through to May were compiled to 5-year running means to examine trends. The start dates for the next 10 years were calculated from regression equations for each site, on the speculative basis that the current trends would continue. The analyses show regional contrasts. Kevo shows a marked trend towards cooler springs and later starts. If this continues the mean start date will become about 6 days later over the next 10 years. Turku exhibits cyclic patterns in start dates. A current trend towards earlier starts is expected to continue until 2007, followed by another fluctuation. London, Brussels, Zurich and Vienna show very similar patterns in the trends towards earlier start dates. If the trend continues the mean start dates at these sites will advance by about 6 days over the next 10 years. Following this work, amendments will be needed to pollen calendars and local predictive models. It will also be important to assess the implications of earlier seasons for allergy sufferers.

The association between moisture-related microbial growth (mesophilic fungi and bacteria) within insulated exterior walls and microbial concentrations in the indoor air was studied. The studied apartment buildings with precast concrete external walls were situated in a subarctic zone. Actinomycetes in the insulation layer were found to have increased concentrations in the indoor air. The moisture content of the indoor air significantly affected all measurable airborne concentrations.

Early symptoms of pollen allergies arefrequently reported before pollination periodof allergenic plant starts. At northernlatitudes the main concern is Betulaceae-trees(alders, hazel, birches). Pollen allergeninformation, based on the analysis of actualairborne allergen concentrations, beside thetraditional pollen reports, based on pollencounts, has been given in SW Finland since1998. 1–2 weeks before the onset of floweringpollen allergens are detected airborne inquantities high enough to provoke symptoms.Information is given on radio and in localnewspapers. During the first season of the newservice (1998) we carried out a questionnairestudy. The results showed that new informationservice, though not as frequently used as wehad hoped for, was useful to allergic personsfor starting their medication in time. Theyalso received explanation for their earlierinexplicable symptoms. We recommend bothinformation services to be run concurrently togive the best information to the public.

OBJECTIVE: To evaluate the origin and identification of mysterious particles in Papanicolaou smears from healthy, asymptomatic women participating in a local mass screening program. STUDY DESIGN: The material consisted of 16,000 cervicovaginal smears studied at the cytology laboratory of Pathology Laboratory of South-Western Finland Ltd. Unidentified particles were found in four apparently independent smears. All the slides were rescreened, but no further positive cases were found. RESULTS: Several swab samples were collected from the investigation room, but all were negative. Attempts at identification included numerous consultations, A telepathology consultation with the Cellular Division, Armed Forces Institute of Pathology, Washington, D.C., U.S.A., was conducted. Another teleconsultation with the reference laboratory for intestinal parasites in Iceland was conducted. Finally, the Aerobiology Unit, University of Turku, was consulted. The aerobiologist suggested that the particles were most probably summer spores of birch rust fungus (Melampsoridium betulinum). To confirm this we obtained a reference specimen of the fungus from the herbarium at the University of Turku. The morphology of the spore particles was identical to that in the cervicovaginal smears, proving that the smears were contaminated with birch rust fungus spores. CONCLUSION: Birch rust is ubiquitous in Finland. Outside the hospital window there is a wide lawn behind which, at a distance of 70 m, there is a forest of birch trees. It is most likely that the rust spores flew in through the open window, to settle down on the surface of material that was used in sample taking. Airborne dust may cause misleading and surprising artefacts. Protection of specimens and instruments against dust should minimize the problem.

Geographical and temporal variations in the start dates of grass pollen seasons are described for selected sites of the European Pollen Information Service. Daily average grass pollen counts are derived from Network sites in Finland, the Netherlands, Denmark, United Kingdom, Austria, Italy and Spain, giving a broad longitudinal transect over Western Europe. The study is part of a larger project that also examines annual and regional variations in the severity, timing of the peak and duration of the grass pollen seasons. For several sites, data are available for over twenty years enabling long term trends to be discerned. The analyses show notable contrasts in the progression of the seasons annually with differing lag times occurring between southern and northern sites in various years depending on the weather conditions. The patterns identified provide some insight into geographical differences and temporal trends in the incidence of pollinosis. The paper discusses the main difficulties involved in this type of analysis and notes possibilities for using data from the European Pollen Information service to construct pan European predictive models for pollen seasons.

Bet v 1, the major allergen of birch pollen, has been reported to be synthetized in pollen grains shortly before anthesis. In order to obtain a better understanding of the causative agents of allergic symptoms which appear before the actual pollen season, the activity birch pollen antigen in outdoor air have been studied, using polyclonal antibodies against birch pollen, and monoclonal antibodies against Bet v 1. Using a size‐selective bioaerosol sampler (SSBAS), birch pollen antigen concentrations were analysed separately in different particle size classes, down to the molecular size range. About a week before the anthesis of alder, antigens were already detected in outdoor air samples. They were found mainly in the smallest particle size classes and might have had their origin in the developing leaves and flower structures of Betulaceae trees. At the beginning of birch anthesis Bet v 1 activity in the air increased markedly. The smallest particles may have been orbicules (2–4 μm) and starch granules (0....

Sensitive pollen-allergic patients have been reported to show allergic symptoms not only during the pollen release of allergenic plants but also both before and after the pollen season. Symptoms before the season are evidently provoked by small-sized particles originating partly from developing pollen grains, partly from other plant parts. After the pollen season, antigenic material settles on various surfaces, which thus form a new source of allergenic material. Measuring the allergen concentrations in indoor and outdoor environments demands an effective sampling method and a rapid and sensitive immunochemical analysis, especially for particles of small-sized fractions which are not detected in microscopic analyses. The efficiency of an ELISA and an immunochemical staining method was tested with monoclonal IgG against Phl p 5, the main grass allergen. The Burkard trap and MPC impactor (Marple personal cascade impactor with six-stage particle size fractionation) were compared. The sampling was carried out in southwestern Finland in the summer of 1994. The number of grass-pollen antigen spots greatly exceeded the simultaneous pollen count, indicating considerable antigen activity outside the pollen grains. The counts were especially high in small-sized fractions after the pollen season, when hardly any airborne pollen was found. Spots and pollen divided according to size were highly intercorrelated, indicating that the threshold values used were appropriate.

Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in C ordoba, Spain, and Evora, Portugal, using Hirst-type traps for pollen and high-volume cascade impactors for allergen. Pollen from different days released 12-fold different amounts of Ole e 1 per pollen (both locations P < 0.001). Average allergen release from pollen (pollen potency) was much higher in C ordoba (3.9 pg Ole e 1/pollen) than in Evora (0.8 pg Ole e 1/pollen, P = 0.004). Indeed, yearly olive pollen counts in C ordoba were 2.4 times higher than in Evora, but Ole e 1 concentrations were 7.6 times higher. When modeling the origin of the pollen, >40% of Ole e 1 exposure in Evora was explained by high-potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.

Introduction. Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content in ambient air is unknown. HIALINE therefore monitored atmospheric concentrations of Betula, Poaceae and Olea pollen grains and matched their major allergens Bet v1, Phl p5 and Ole e1 across Europe. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessment. New knowledge through the use of new experimental approaches in the field of aerobiological monitoring will enable better in the prevention and clinical management of pollinosis. In order to disseminate the knowledge of the project we present the results of first year of birch pollen grains and the matched major pollen allergen Bet v1 monitored in Parma (UNIPR), Italy with a short reference to the results obtained by the other participants and about developing models of dissemination and forecasts of pollen and allergens. Materials and methods. The pollen was sampled by a Hirst pollen trap. Allergens was collected with a CHEMVOL® high-volume cascade impactor, extracted from pollen and quantified by ELISA. Antibodies for analysis of Bet v1 are delivered by the industrial partner in this project. Quality control has been carried out for the monitoring pollen activities and allergen concentrations. Results. The project has highlighted that it is possible also to measure pollen allergen in ambient air in different European areas. The results obtained from the center of Parma and other European partners have highlighted the different allergenic powers of pollen of Betula, in different geographical areas. Moreover, daily in each area the allergenic power of pollen grains was very variable. Discussion. HIALINE has been a very important project to understand the mechanisms of sensitization, clinical management of pollinosis and to improve immunotherapy towards a tailored immunotherapy. The results of the project will help medical doctors, authorities and patients, to better manage the different aspects related to pollinosis.

The paper considers the possibilities of modelling the release and dispersion of the pollen of common ragweed (Ambrosia artemisiifolia L.), a highly allergenic invasive weed, which is spreading through southern and central Europe. In order to provide timely warnings for the allergy sufferers, a model was developed for forecasting ragweed pollen concentrations in the air. The development was based on the system for integrated modelling of atmospheric composition (SILAM) and concentrated on spatio-temporal modelling of ragweed flowering season and pollen release, which constitutes the emission term. Evaluation of the new model against multi-annual ragweed pollen observations demonstrated that the model reproduces well the main ragweed pollen season in the areas with major plant presence, such as the Pannonian Plain, the Lyon area in France, the Milan region in Italy, Ukraine and southern Russia. The predicted start of the season is mostly within 3 days of the observed for the majority of stations in these areas. The temporal correlation between modelled and observed concentrations exceeds 0.6 for the bulk of the stations. Model application to the seasons of 2005–2011 indicated the regions with high ragweed pollen concentrations, in particular the areas where allergenic thresholds are exceeded. It is demonstrated that, due to long-range transport of pollen, high-concentration areas are substantially more extensive than the heavily infested territories.

The reasons for the occurrence of high birch pollen antigen concentrations in the air, especially in small particle sizes and before the birch flowering period, have been closely studied. Some particles with pollen antigenic activity are known to be emitted from other parts of the tree in addition to the catkins. Pollen from related species which flower before the birch, or simultaneously with it, may provide another explanation for these antigen peaks. In the study reported here, birch pollen antigenic activity before flowering was analysed in 1993 and 1994 using IgG-ELISA with polyclonal antibodies. A clear indication of the emission of small micronic particles with pollen antigenic activity before birch flowering was a peak before and during the pollen period of alder. Alder is the first tree to flower in the spring in Finland. Because of the high homology in the major allergens of the family Betulaceae, either polyclonal antibodies against birch pollen or monoclonal Bet v I can be recommended...

The impact of pollen on human health is primarily evident in allergic diseases. Sensitized patients can respond to pollen by symptoms of nose, eyes and bronchi. Pollen threshold levels for sensitization are unknown; instead most studies focus on the prevalence of sensitization for different pollen species. The pollen thresholds for symptom development vary among the different studies. Factors that influence the threshold level of a pollen species for symptom development are discussed. (i) Differences in response are observed among individual patients, but also among (ii) ethnic populations, (iii) changes in response to pollen concentrations during the pollen season occur, (iv) the amount of allergens carried by the pollen grains can differ in per region, from day to day and from year to year, and finally (v) threshold levels are affected by environmental factors, like weather conditions (temperature, pressure and storms), and air pollutants.The diversity of factors that influence the health impact of pollen has hampered the definition of a straight forward relationship between pollen and the severity of symptoms. However, within the public, the policymakers and the pharmaceutical industry there is a need for a definition of threshold pollen levels. A first approach to meet this need could be to define preliminary threshold values for different regions, followed by a validation of these preliminary threshold levels with patient symptom scores that can be collected by using new information and communication technology (ICT).

Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network). Pollen count was assessed with Hirst type pollen traps at 10 I min(-1) at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 I min(-1) with a Chemvol (R) high-volume cascade impactor equipped with stages PM > 10 mu m, 10 mu m > PM > 2.5 mu m, and in Germany also 2.5 mu m > PM > 0.12 mu m. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FC epsilon R1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient. Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 mu m fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration. Although Bet v 1 is a mixture of different isoforms, its fingerprint is constant across Europe. Bet v 1 was also exclusively linked to pollen. Pollen from different days varied >10-fold in allergen release. Thus exposure to allergen is inaccurately monitored by only monitoring birch pollen grains. Indeed, a humanized basophil activation test correlated much better with allergen concentrations in ambient air than with pollen count. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessment. European Commission Christine Kühne - Center for Allergy Research and Education

ln general it has been observed similar profiles lor airborne pollen and aeroallergens content in the air, being aeroal/ergens more associated to XL Iraction stage. On the olher hand, ii has been delected al/ergenic activity out Irom pol/en season, especiaily in the case 01 M stage. Smaller particles are more exposed to medium-Iong distant transporto Moreover, results have provides strong evidence that similar value 01 airbome pol/en evokes different ambient air allergen loads in different geographicai areas. Even more, when lhe same area is considered the allergen load of the pol/en can vary within lhe season. Pollen differs in allergen release between European countries. Our sludy suoports lhe importance 01 lhe aeroal/ergen quantificatlon logether wilh airborne pol/en counls, in order to define the ouldoor air allergenic load. Conclusions: Under these results, the expected outcomes are lhe implementation 01 a network of European outdoor allergen measurements to belter predict allergic symploms. Also lhe climafic lactors that govem allergen exposure in ouldoor air will be eslablished. These can be used lo calculate the effect 01 climate change on lhe health effecls 01 airborne al/ergens. Pol/eninlo.org offers a new 1001 on Patient's Hayfever Diary (PHD).

The results in Italy should be compared with those from partners in other counlries. II will be important to confirm some observations during the first and second year of the projecl activity which showed the presence of a different allergenic power in difleren! geographical areas as observed for other types of pollen (Poaceae and Olea). The aim of lhe project was to measure the pollen's capacity to release allergens and this will result inlo an allergen exposure forecast, taking into consideration pollen counts and allergen release trom diflerent locations. The results of the project will help medical doctors, authorities and patients to better manage lhe diflerent aspects related to pollinosis.

The antigenity of outdoor dust which has settled on surfaces has been a neglected subject in aerobiological and allergological studies, although this dust is undoubtedly one of the main sources of airborne antigenic particles which cause allergic symptoms. Dust samples for birch pollen antigen analyses were taken with a vacuum sampler from horizontal surfaces, and from birch and maple leaves once a week after the peak birch pollination period. The samples were analysed by a modification of the IgG-ELISA-procedure. The antigenicity of dust on all surfaces remained high for months after birch pollination, even on days when no pollen grains were microscopically detected in the dust samples. Outdoor dust being one of the sources of indoor dust is thus a component of the mixture which brings about an allergy to house dust. Dust with a high antigenicity, carried inside from outdoors may be one cause of the occurrence of allergic symptoms outside of the pollen season.