Fungus assessment in indoor environment of old buildings in Peninsular Malaysia

Older buildings often face challenges related to physical deterioration and material decay, which can lead to fungal contamination and the development of sick building syndrome (SBS). In Malaysia, there have been limited studies on the occurrence of fungal identification in indoor air, particularly in old buildings. This study focused on determining the fungal diversity and total fungal load (expressed in colony-forming units, CFU/m3) in selected old buildings in Peninsular Malaysia. Samples were collected from indoor air, building materials (painted walls and ceilings) and swabs at 18 sites within two selected old buildings (A and B) known to have fungal issues. A total of 182 indoor air, 76 scraped and 75 swabbed samples were collected from June to November 2021. Molecular identification was performed by extracting DNA from fungal isolates and amplifying the internal transcribed spacer (ITS) region using polymerase chain reaction (PCR). The fungal load, measured as ranging from 215 to 5235 CFU/m3, with five sites exceeding the Industry Code of Practice on Indoor Air Quality (ICOP IAQ) guidelines: two in building A and three in building B. Higher loads of fungi were identified in the indoor air samples. The most frequently identified genera in both buildings were Aspergillus spp., Penicillium spp. and Cladosporium spp. Dominant species were A. niger, P. citrinum, A. tamarii, C. haloterans and C. cladosporoides. These findings demonstrate the considerable diversity and extent of fungal contamination present in older buildings, underscoring the potential health risks associated with exposure to indoor fungi.