Ecological study of the urban allergenic flora of central Italy.

Comparative analysis of allergenic potential, conducted in different urban ecosystems of central Italy, utilizing the species allergen index (SAI), revealed the differences among various urban ecosystems. Allergophyte presence and abundance are influenced by the type and duration of anthropogenic intervention, correlated to the ecological conditions of the individual urban areas and to the level of stability attained. The geographic position of the city and the layout of the urban surfaces present here are also important for the presence of the allergenic flora. The characteristic urbanistic layout of central Italian cities, which is the result of the historical and cultural vicissitudes of the human population, facilitates the establishment of allergophytes. A rich allergenic flora was found on the ancient city enclosure walls with a great risk for the inhabitants suffering from allergies. The influence of the geographic-climatic gradient on the quality of the urban allergenic contingent was observed. The group of strongly allergenic species was found in both the coastal and the hilly-vegetation belt cities. The dynamic contacts with the surrounding ecosystems and ecotonal areas are more accentuated in the cities situated in the internal, hilly zone of the territory studied. Here different potentially allergenic species coming from the surrounding ecosystems become part of the urban flora. The abundance of this flora is noted in the unstable areas of the periphery, where numerous moderately allergenic species were established too. The renewal of the allergenic flora of a city happens thus from within, through the introduction of exotic species in the cultivated areas, and from without, through the spontaneous establishment of plants from surrounding ecosystems. The results obtained can be utilized to indicate the parts of the urban territory which are not suitable for the permanence of persons who suffer from allergic diseases, in order to improve their life quality.