Urban allergophytes of central Italy

This research was designed to compare allergenic flora of various cities of central Italy. Because the data on this problem are rather scant, we wanted to highlight the relationships among the ecological conditions of the urban habitats, and the plants whose pollens cause allergic manifestations in the human population. Our results pointed out that the structural design of the urban land use types play an important role in the distribution of allergophytes. The compact structure of the historic city center does not impede the establishment of allergophytes. Actually, it promotes some species that come from the dry pastures and rocky walls of the surrounding ecosystems. Allergenicity was revealed throughout the urban area, with a prevalence of species with monoporate pollens characteristic of the Poaceae. Highly allergenic plants are present in the central zone (within the city walls) and in some peripheral land use models (urban road verges). The particular abundance of Urticaceae with small triporate pollen grains and of various cultivated species, introduced by man for aesthetic reasons, contributes to the increase of allergophytism. The study points out the role of the interactions between the allergenic flora, human impact through the land use patterns, urban fauna, and the meso- and microclimatic conditions of the cities studied.