Aspergillus sp. in dwellings and health implications of indoor fungi.


Elena Piecková,
Not Known


According to his/her life style, a person can commonly spend 75 - 90 % of their time in an indoor environment. That is one reason why the effects of different indoor factors on human health are studied very carefully. Indoor bacteria or fungi can cause allergic, infectious, toxic or inflammatory diseases i. e. building-related illnesses. A complex of health troubles, bad feelings and general discomfort due to a stay in certain buildings is known as sick building syndrome (Kroeling, 1998).Problems connected with the presence of microscopic fungi in the working environment and their effects on the health status of employees have been studied in many papers. It has been found that the health of people working with moldy materials can be seriously affected. The air of working environments may contain as much as 109 viable germs or particles (not only spores, also hyphal fragments etc.) of microscopic filamentous fungi and yeasts per m3 and a large amount of various mycotoxins. Regarding the character of manufactured substrates, irritation of eye, nose and mouth mucous membranes were found, as well as serious acute and chronic damage of respiratory organs, i.e. bronchitis, allergic alveolitis farmer´s lung, lung mycotoxicoses and similar disorders. Some mycotoxins can also possess carcinogenic properties affecting lung tissue (Dutkiewicz, 1997, Dutkiewicz et al., 1994, Jesenskà¡, 1993, Sorenson et al., 1991).While the work with moldy materials is mostly sporadic and the possible adverse effects of the microscopic fungi and their toxins can be foreseen and thus the exposed persons can be protected using respiratory filters, families including infants living in homes with moldy walls are exposed to these noxae for a long periods of time. The amount of fungal colony forming units (cfu)/m3 can vary from a standard of 500 - 1000 to 6000 - 450000 cfu/m3 in moldy houses (Nevalainen et al., 1991). Spores are liberated into the air in places with higher turbulence e.g. during home maintenance, cleaning, dusting, vacuum cleaning, vegetable peeling, when door is opened, when pets enter or leave etc. These activities can cause an increase in air spore amount up to 3000-fold (Lehtonen and Reponen, 1993). Many species of micromycetes (according to Hunter et al. (1988) up to 56) have been isolated from miscellaneous objects and walls in residences.Allergies of inhabitants have been studied very extensively in connection with moldy dwellings. Cytoplasmic glycoproteins of fungal spores are important aeroallergens in genetically pre-determined humans (Linas et al., 1998). In dwellings occupied by children suffering from asthma, significantly greater spore counts of Cladosporium sp. and Penicillium sp. were found (Li et al., 1995).In some case studies, explicit relations between the presence of the fungus in dwellings and allergic reactions of their occupants were found. After cleaning the contaminated sites, or when the occupants moved into a new home, the symptoms disappeared (Senkpiel et al., 1996).