Fraxinus pollen and allergen concentrations in Ourense (South-western Europe)

Environmental Research, 147, 2016, 241–248

http://dx.doi.org/10.1016/j.envres.2016.02.014

In temperate zones of North-Central Europe the sensitization to ash pollen is a recognized problem, also extended to the Northern areas of the Mediterranean basin. Some observations in Switzerland suggest that ash pollen season could be as important as birch pollen period. The allergenic significance of this pollen has been poorly studied in Southern Europe as the amounts of ash pollen are low. Due to the high degree of family relationship with the olive pollen major allergen (backed by a sequence identity of 88%), the Fraxinus pollen could be a significant cause of early respiratory allergy in sensitized people to olive pollen as consequence of cross-reactivity processes. Ash tree flowers in the Northwestern Spain during the winter months. The atmospheric presence of Ole e 1–like proteins (which could be related with the Fra a 1 presence) can be accurately detected using Ole e 1 antibodies. The correlation analysis showed high Spearman correlation coefficients between pollen content and rainfall (R2=−0.333, p<0.01) or allergen concentration and maximum temperature (R2=−0.271, p<0.01). In addiction CCA analysis showed not significant differences (p<0.05) between the component 1 and 2 variables. PCFA analysis plots showed that the allergen concentrations are related to the presence of the Fraxinus pollen in the air, facilitating the wind speed its submicronic allergen proteins dispersion. In order to forecast the Fraxinus allergy risk periods, two regression equations were developed with Adjusted R2 values around 0.48–0.49. The t-test for dependent samples shows no significant differences between the observed data and the estimated by the equations. The combination of the airborne pollen content and the allergen quantification must be assessed in the epidemiologic study of allergic respiratory diseases.

Assessment of the Olea pollen and its major allergen Ole e 1 concentrations in the bioearosol of two biogeographical areas

Atmospheric Environment, 145, 2016, 264–271

http://dx.doi.org/10.1016/j.atmosenv.2016.09.040

The Olea pollen is currently an important allergy source. In some regions of Southern Spain, olive pollen is the main cause of allergic sensitization exceeding 40% of the sensitized individuals. Due to the scarce presence of olive trees in Northern Spain, limited to some cultivated fields in the South of the Galicia region where they also grow wild, only 8% of the sensitized individuals showed positive results for Olea pollen. The aim of the paper was to assess the behaviour pattern of the Olea pollen and its aeroallergens in the atmosphere, as this information could help us to improve the understanding and prevention of clinical symptoms.

Airborne Olea pollen and Ole e 1 allergens were quantified in Cartagena (South-eastern Spain) and Ourense (North-western Spain). A volumetric pollen trap and a Burkard Cyclone sampler were used for pollen and allergen quantification.

The Olea flowering took place in April or May in both biometeorological sampling areas. The higher concentrations were registered in the Southern area of Spain, for both pollen and Ole e 1, with values 8 times higher for pollen concentrations and 40 times higher for allergens. An alternate bearing pattern could be observed, characterized by years with high pollen values and low allergen concentrations and vice versa. Moreover, during some flowering seasons the allergen concentrations did not correspond to the atmospheric pollen values. Variations in weather conditions or Long Distance Transport (LDT) processes could explain the discordance. The back trajectory analysis shows that the most important contributions of pollen and allergens in the atmosphere are coincident with air masses passing through potential source areas. The exposure to olive pollen may not be synonym of antigen exposure.