engleski

Indoor airborne moulds

Moulds are ubiquitous group of saprophyte or parasite fungi ecologically very distributed in nature. Their spores have been found in soil, water, plant and other decaying organic material and from there they come to in outdoor and indoor air. The best known and most prevalent health effect of indoor fungi (especially Aspergillus spp., Cladosporium spp. and Alternaria spp.) is their ability to induce allergic respiratory disease in susceptible individuals, which typically manifests as chronic bronchitis, rhinitis, asthma or hypersensitivity pneumonitis. Other deleterious health effects of exposure to indoor fungi result from nonallergenic fungal metabolites-mycotoxins. The study on the mycoflora of the indoor air was conduced in winter 1999. Sixty-five residence (32 urban and 33 rural) were selected as indoor air-sample sites. Sampling of airborne mould spores was carried out using the "open Petri dish" method based primarily on gravity-settling principles. Sabouraud dextrose agar plates (SDA) with penicillin and streptomycin (20:40) were exposed to air a height of 100 cm for 15 min. Following the exposure, the plates was incubated at 250C + 2 and after 7 days the colonies were counted. Determination of mould species was done on the basis of their macro and microscopically characteristic sporulation after subculture on Czapek, Sabouraud or Potato dextrose agar, according to the keys. Frequency of occurrence of each genus was expressed as percentage of samples containing a given organism. Some scratch samples were taken from moldy walls and examined directly under the microscope. During the winter period of 1999, 65 indoor air samples were collected from which approximately 954 fungal colonies and 890 yeast's colonies were counted. Of the taxa isolated by qualitative methods, a total of 20 were identified to the genus level. The genus Penicillium with 61.5 % of the samples and more than 30 species occupied the first place in frequency. Cladosporium spp. was found in 53.8% of samples. The incidence of Aspergillus spores in atmosphere from 24.6% occupied the third rank among the most frequently found fungi isolates in the air. More than 50% belong to Aspergillus versicolor group, and Aspergillus glaucus group (33%) was the second in frequency. One of the most important indoor fungi from the standpoint of human health Aspergillus fumigatus was not detected. The frequency of Alternaria was recovered in moderate occurrence (23%). Other moulds showed much lower frequencies. There were the colonies, which occurred as the white or grey sterille micelia and did not produced any identifiable characteristic were placed in Sterille micelia.

Airborne moulds; Indoor air; Contamination

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