Potential contribution of distant sources to airborne Betula pollen levels in Northeastern Iberian Peninsula
MetadataShow full item record
Pollen concentration peak and seasonSource regionsMesoscale and Lagrangian modelsOrographyRole of long-range transport
Marta Alarcón... [et al.]. Potential contribution of distant sources to airborne Betula pollen levels in Northeastern Iberian Peninsula, Science of The Total Environment, Volume 818, 2022, 151827, ISSN 0048-9697, [https://doi.org/10.1016/j.scitotenv.2021.151827]
SponsorshipEuropean Commission European Commission Joint Research Centre ENV4-CT98-0755; Spanish Government; European Commission CGL2004-21166-E CGL2005-07543/CLI CGL2009-11205 CGL2012-39523-C02-01/CLI CGL2012-39523-C02-02 CGL2016-75996-R CTM2017-89565-C2-1 CTM2017-89565-C2-2 CSD 2007-00067; Diputacio de Tarragona; Sociedad Espanola de Alergologia e Inmunologia Clinica (SEAIC); Laboratorios LETI PHARMA; Societat Catalana d'Allergia i Immunologia Clinica (SCAIC); J Uriach y Compania; Maria de Maeztu Programme for Units of Excellence of the Spanish Ministry of Science and Innovation CEX2019-000940-M; Catalan Government 2005SGR00519 2009SGR1102 2017SGR1692
Betula (birch) pollen is one of the most important causes of respiratory allergy in Northern and Central Europe. While birch trees are abundant in Central, Northern, and Eastern Europe, they are scarce in the Mediterranean territories, especially in the Iberian Peninsula (IP), where they grow only in the northern regions and as ornamental trees in urban areas. However, the airborne birch pollen patterns in Catalonia (Northeastern IP) show abrupt high concentrations in areas with usually low local influence. The intensity of the derived health problems can be increased by outbreaks due to long-range pollen transport. The present work evaluates the different potential contributions to Catalonia from the main source regions: Pyrenees, Cantabria, and the forests of France and Central Europe. To this end, we computed the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back trajectories of air masses associated with the main Betula pollen peaks occurring simultaneously over different Catalan monitoring stations, and we studied their provenance over a 15-year period. The Vielha aerobiological station on the northern slopes of the Central Pyrenees was used to identify the dates of the pollen season in the Pyrenean region. In order to better understand the role of the Pyrenees, which is the nearest of the four birch forested regions, we classified the pollen peaks in the other Catalan stations into three groups based on the relationship between the peak and the pollen season in the Pyrenees. Our analysis of back-trajectory residence time, combined with the associated pollen concentration, reveals that two principal routes other than the Pyrenean forest sustain the northerly fluxes that enter Catalonia and carry significant concentrations of Betula pollen. This study has also allowed quantifying the differentiated contributions of the potential source regions. In addition, theWeather Research Forecast (WRF) mesoscale model has been used to study three specific episodes. Both models, HYSPLIT and WRF, complement each other and have allowed for better understanding of the main mechanisms governing the entry of birch pollen to the region.