The Campus of the Sapienza University of Rome, frequented daily by several thousands of students and workers, collects allergenic airborne pollen from many sources. Here, we report the results of detailed pollen monitoring of 49 pollen types within the University Campus, allowing us to trace the main local and regional sources of airborne pollen throughout the year. The amount of allergenic pollen has been calculated for each daily record to evaluate the risk of exposure for students and workers on Campus in relation to academic activities and to suggest possible mitigation measures. Our results show that the maximum pollen concentrations are recorded from March to May, and the highest floristic richness occurs in April–June. We distinguish massive local pollen producers from pollen of regional origin and local ornamental and invasive taxa. Pollen with extreme allergenicity is dominant from mid-January to mid-March and in May with Cupressaceae/Taxaceae, Corylus and Olea; high allergenicity from late March to late April with Platanus, Ostrya, Ginkgo and Moraceae; and medium allergenicity from late April to the beginning of May with Quercus and Pinus. In August–December, pollen concentration is relatively low. Diversified mitigation actions are suggested in relation to the provenance, allergenicity and emission period of pollen.

Aim: Epidemiological surveys show substantial modification over time of pollens sensitization profiles, with relevant difference across geo-climatic zone. Climate changes can affect the onset, duration and production of the pollen season. Aim of the present study has been to assess the evolution over 33 years of the patients’ sensitization profile, together with pollen count and climate in a resident population of the Po Valley. Methods: Retrospective study of primary sensitizations to 6 major pollens (grass, pellitory, birch, olive, ragweed mugwort) from 1986 to 2019 on patients aged 12 years or older with respiratory allergic diseases living in Mantua suburbs. Pollen counts and season durations were recorded by the monitoring station of Parma. Meteorologic data have been downloaded from the historical archive of Mantua monitoring station. Results: A population of 3,489 patients who tested positive to pollens have been considered (34% to one pollen only; 66% poly-sensitized, 68% out of them to two or more pollens). Average annual temperature has risen of 1.4°C. An overall trend for extension of seasons duration and increase of pollen load has been observed. Sensitization rate to grass remained stable over time when pellitory showed a sudden decline. Sensitization rates to birch, olive and ragweed displayed a sharp increase. Conclusions: The present study proves that significant change on phenological phases of main allergenic plants, pollen load and sensitization profile of patients have occurred over the last decades. Global warming seems to be one of the main causes for these changes. More epidemiological studies differentiated by regional geo-climatic zone and a multidisciplinary approach to research on topic are needed.