Incidence of Alternaria Nees ex Fries in dwellings of Córdoba City (Spain).

We have studied the occurrence of Alternaria, a genus of allergenic interest in the indoor atmosphere of 14 homes in Córdoba throughout 1984. The sampling was carried out by sedimentation on a broad-spectrum mycological culture medium (2% Agar-Malt extract) in Petri dishes. Samples were collected every fortnight in 14 homes (three dishes per home were exposed in the following rooms, namely the kitchen, the toilet and the bedroom, for 20 minutes) located in different areas of the city and as much as possible representing the various physical conditions found. An overall of 727 Alternaria colonies belonging to six species (A. consortiale, A. crassa, A. dendritica, A. japonica, A. tenuis and A. tenuissima) were detected. Some of them were proven allergenics. They accounted for 5.2% of all fungal colonies found indoors. A. tenuis was by far the most frequently found species, followed by A. tenuissima (second in number) and A. consortiale (the most cosmopolitan) as they were the only species found in all 14 homes. On the other hand, A. crassa was the least frequent of all species collected. We have also determined the general variation of Alternaria and that of the different species found indoors throughout the year, finding a trend with the appearance of peaks towards spring and early summer, especially in June.