An updated proposal of the Potential Allergenicity of 150 ornamental Trees and shrubs in Mediterranean Cities

The allergenic potency of the pollen emitted by urban vegetation is one of the effects that need the most attention in the near future due to its high impact on the quality of air and the health of citizens. Many of the problems derived from the allergenic behavior of urban flora have their origin in the lack of knowledge about the intrinsic allergenic capacity to the most common species of urban forests, as well as the lack of consensus among the few existing lists. This work aims to check and update the value of potential allergenic (VPA) of 150 frequent trees and shrubs in Mediterranean cities. Two of the most complete current lists and with the most realistic allergenicity assignments have been used to build up the list. For each of the taxa included, a detailed evaluation of the attributes that participate in the allergenic potential of the species has been carried out, and according to them, each species has been assigned an allergenicity class. In the event of discord in the information from different sources, the most conservative criterion has been applied. For the taxa in which the current class is significantly higher than the previously assigned: Ailanthus altissima, Celtis australis, Eucalyptus camaldulensis, Fraxinus excelsior, Gingo biloba, Juglans regia or Liquidambar styraciflua among them, a more detailed specific section has been included. This update of the VPA of 150 Mediterranean urban forests species become a useful tool for management and planning of green areas, and also a risk mitigation measure for people affected by pollen allergen.