Case 1
Building | Lecture Hall at Tertiary Institution |
Location | Ceiling board |
Ventilation mode | Cooling by air-conditioning |
Sampling Method | Tape sampling, Culturing |
No. of Tape Samples | 1 |
No. of Cultured Samples (from tape) | 4 |
Medium Used | Potato Dextrose Agar (PDA) |
Temperature (°C): 22.5
Relative Humidity (RH): 56.7
Wind Speed (m/s): 0.21
Building
Renovation encompassed the changing and installation of the false ceiling system outside the air-conditioned lecture hall at the academic institution. Airborne materials were able to spread to the adjacent lecture hall through the Air Handling Unit (AHU). Measures to prevent such exposure were lacking.
Observation
Films of dark-pigmented material can be seen on ceiling boards close to the diffuser outlet, soon after commencement of renovation works. Moisture held by the dust particles prior to infiltration may serve as moisture for the spores amongst the particles to grow. Closer observation reveals sparse dark-pigmented mouldy spots.