Seasonal and daily variation of Aspergillus Mich. Ex Fr. spores in the atmosphere of Córdoba (Spain).

The atmosphere contains a complex of spores whose concentration and variation have been the subject of much study, mainly because of the relevance of fungi to allergic and aerobiological pollution problems. This paper reports on the cataloguing of the Aspergillus species present in the atmosphere of Córdoba, their seasonal and daily variation and their potential relationship with meterological parameters. The sampling was carried out in the city of Córdoba by using a volumetric trap on a culture medium; three samplings were done daily at various times throughout the year (May 1986-April 1987). An unreplicated variance analysis was applied to two variation sources in order to check for statistically significant differences between the number of colony forming units (CFU) detected at each sampling time. Meterological data and concentrations were also contrasted through statistical correlation tests. A total of 94,200 colonies were counted; 32.3% of all were from 24 species of the Aspergillus genus, of which A. fumigatus Fresen, was found to be the most abundant. Aspergillus niger Van Tiegh, A. oryzae (Ahlburg) Cohn, A. terreus Thom and A. ochraceus Wilhelm also occurred at a high frequency. All these species were detected throughout the year and in virtually all of the samplings, but particularly in autumn, which was the most favourable period for the occurrence of their spores, which in turn seemed to be conditioned by the time at which samplings were carried out, at least for the six most frequent species--A. candidus expected as it only occurred occasionally. Finally, the occurrence of spores of this genus seems to be positively and negatively correlated with meterological factors such as the wind speed and the temperature, respectively.