ABSTRACT
Aspergillus fumigatus is a saprophytic fungus playing an essential role in recycling the earth carbon and nitrogen (Pitt, 1994). Its natural ecological niche is the soil where it grows on organic debris. Although this species is not the world's most prevalent fungus, it is one of the most ubiquitous fungi present worldwide on most surfaces and aerial environments (Mullins et al., 1976; Nolard, 1994). It is a very thermophilic fungus. It sporulates very abundantly and the conidia released in the atmosphere have a small diameter (2-3 gm) (Samson et al., 1995). Virtually, every cubic meter of air we breathe indoor and outdoor contains spores. It can be estimated that in a normal indoor or outdoor environment every individual inhales 5-500 conidia of A. fumigatus per day.
