Direct determination of allergens in ambient aerosols: methodological aspects

In Switzerland the birch tree (Betula verrucosa) major allergen Bet v 1 and the grass (Phleum pratense) pollen major allergen Phl p 5 are of particular relevance for inducing pollinosis. In this study, the protein and major allergen contents of aerosols of different aerodynamic diameters were determined. The aerosols were sampled by Andersen-Impactors and submitted to protein assays and allergen assays (ELISA) specific for Bet v 1 and Phl p 5. The total protein, Bet v 1 and Phl p 5 concentrations were correlated with the corresponding pollen counts. The presence of Bet v 1 in smaller aerosol fractions was demonstrated before and after birch pollen was counted, especially in the lower particle size ranges.