Pollen spectrum and risk of pollen allergy in Central Spain.

The present work analyses the airborne pollen dynamic of the atmosphere of Toledo (central Spain), a World Heritage Site and an important tourist city receiving over 2 millions of visitors every year. The airborne pollen spectrum, the annual dynam- ics of the most important taxa, the infl uence of meteorological variables and the risk of suffering pollen allergy are analysed. Results of the present work are compared to those obtained by similar studies in nearby regions. The average annual Pollen Index is 44,632 grains, where 70-90% is recorded during February-May. The pollen calendar includes 29 pollen types, in order of importance; Cupressaceae (23.3% of the total amount of pollen grains), Quercus (21.2%), and Poaceae and Olea (11.5 and 11.2%, respectively), are the main pollen producer taxa. From an allergological viewpoint, Toledo is a high-risk local- ity for the residents and tourist who visit the area, with a great number of days exceed- ing the allergy thresholds proposed by the Spanish Aerobiological Network (REA). The types triggering most allergic processes in Toledo citizens and tourists are Cupressaceae, Platanus, Olea, Poaceae, Urticaceae and Chenopodiaceae-Amaranthaceae. Allergic risk increases in 3 main periods: winter (January-March), with the main presence of the Cu- pressaceae type; spring, characterized by Poaceae, Olea, Platanus and Urticaceae pollen types; and, fi nally, late summer (August-September), characterized by Chenopodiaceae- Amaranthaceae pollen type, which are the main cause of allergies during these months.