Airborne birch pollen antigens in different particle sizes

Abstract

Two particle samplers for ambient air, situated together: a static size-selective bio-aerosol sampler (SSBAS) and a Burkard pollen and spore trap were compared in sampling intact birch pollen grains through one flowering period of Betula (a total of 44 days). The SSBAS trapped pollen grains three times more efficiently than the Burkard trap, but the variations in pollen counts were significantly correlated. In contrast, birch pollen antigenic activity and the pollen count in the Burkard samples were not closely correlated. The antigenic concentration was occasionally high both before and after the pollination period. There was a high birch pollen antigenic activity in particle size classes where intact pollen grains were absent, even on days when the pollen count was very low. Correspondingly, on days with high birch pollen counts in the air, pollen antigenic activity was on several occasions low, indicating that pollen grains were empty of antigenic material. The small particle size classes are especially important to allergic patients because they are able to penetrate immediately into the alveoli and provoke asthmatic reactions. Therefore, aerobiological information systems based on pollen and spore counts should be supplemented with information concerning antigenic activities in the air.

Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

“…This shows that the only source of allergen is birch pollen, in agreement with previous results where allergens were monitored for several years on a row at one location (Buters et al, 2010). Birch allergen containing particles were reported in the fractions PM < 10 mm (birch pollen have a geometric diameter of 21e24 mm (Brown and Irving, 1973;Rantio-Lehtimäki et al, 1994;Schäppi et al, 1999)) indicating in combination with our results that if such particles exist, their appearance is rare and might need specific atmospheric conditions like thunderstorms (D'Amato et al, 2008), which did not occur during our experiments.…”

Fungal Fragments as Indoor Air Biocontaminants

“…The presence of fragments was confirmed by SEM observations. The presence of airborne fragments is clearly documented with pollen exposures, as the onset of seasonal allergies is shown to start several weeks before the respective pollen grains are detected in the air (43,52). In contrast, the role of fragments in fungal exposures has not been sufficiently recognized.…”

“…The principal new finding reported here is that fungal fragments are released together with spores from contaminated surfaces. While the presence of fragments is docu-mented with pollen exposures (43,52), fungal fragments have gained much less attention. The role of fungal fragments is particularly interesting in the light of recent epidemiological studies on the relationship between outdoor air particulate pollution and health effects.…”

Classification, analysis and interaction of solid airborne particles in urban environments

“…It is also a period of atmospheric instability in the Mediterranean area, characterized by storms and heavy rainfall, sometimes over 50mm/day. As suggested earlier, this may lead to the disruption and alteration of some pollen grains, giving rise to paucimicronic particles with allergenic activity (Spieksma et al [12], Rantio-Lehtimaki et al [13]). Although the methods used here could not confirm the presence of such paucimicronic particles in the < 10 micron fraction, other authors measuring the potential allergenic activity of non-pollen airborne particles report intense activity following the Olea pollination period in particles of ≤ 3.3 microns (De Linares et al [14]).…”

“…Paucimicronic allergen particles measuring less than 2.5 microns have been detected in air quality tests (Spieksma et al [12], Rantio-Lehtimaki et al [13], De Linares et al [14]), and research has shown that pollen grains are the major cause of deterioration of biological air quality (Cariñanos et al [15]). …”