Abstract
A survey was conducted with two free standing houses to study the diurnal variation of airborne fungi in rooms of common houses. One of the two houses was located in Kodaira City in Tokyo and the other in Ageo City in Saitama Prefecture. Examination was carried out twice, each lasting two days, in July 2012. An air sampler, Dichloran 18% glycerol agar, was used to collect airborne fungi in rooms every two hours to a total of 13 times and collected fungi were cultured. Concentrations (cfu/m3) of airborne fungi were calculated from numbers of colonies, from which fungi were isolated and identified.
Results of this study showed that concentrations of airborne fungi tended to increase in both houses in the morning from 4 a.m. to 8 a.m. This tendency was remarkable in fungi of genus Aspergillus, which is believed to pose problems as an allergen. Among isolated fungi of genus Aspergillus, many species belonged to Aspergillus section Restricti. Results of this survey indicate that allergenic fungi inhaled by residents in their sleep are a possible cause of asthmatic seizures occurring from midnight to early morning.
