International Journal of Scientific Research and Engineering Development

Indoor fungal contamination poses a recognized public health risk in tropical climates; however, surface-level fungal data from residential settings in Southeast Asia remain limited. This study aimed to quantify surface fungal loads, characterize yeast-to-mold distributions, and identify principal contamination hotspots across eight indoor room types in Bangkok households. A cross-sectional study was conducted in multiple residential units in Bangkok and its surrounding areas, Thailand, from October to December 2025. A total of 139 surface samples were collected from bedrooms, living rooms, bathrooms, kitchens, dining rooms, laundry areas, storage rooms, and pet rooms using sterile swabs and adhesive tape-lift methods. Samples were cultured on Potato Dextrose Agar supplemented with chloramphenicol and incubated at 28°C for 14 days. Fungal colonies were counted as colony-forming units per milliliter (CFU/ml) and provisionally classified as yeast, mold, or mixed types based on macroscopic morphology confirmed by Lactophenol Cotton Blue microscopy for representative isolates. All 139 samples tested positive (prevalence = 100%), with an overall mean load of 8.92 × 10² CFU/ml. The highest mean loads were recorded in bathrooms (1.49 × 10³ CFU/ml), kitchens (1.34 × 10³ CFU/ml), and laundry areas (1.04 × 10³ CFU/ml), reflecting the influence of moisture, organic matter accumulation, and limited ventilation. The most contaminated surfaces were shower areas, curtains, and washing machines. Yeasts predominated on fabric and human-contact surfaces, while molds were more frequent in high-moisture zones. These findings support targeted control measures to reduce fungal exposure in tropical households, including maintaining indoor relative humidity below 60%, routine textile laundering at ≥60°C, and regular cleaning of air-conditioning filters.

Phuwit Kanjanarujee, Nunnaphat Wongsuwan, Arunrat Suwanvoradit, Napinprapa Angkanavisan, Chawanakorn Klumwilai, Sarunrak Wiwatwongsakul, Ratnapee Mornchan, Thanunchanok Tosomsakul, Khwanchai Pramoonsap,"Prevalence and Distribution of Fungal Contamination Across Indoor Microenvironments in Tropical Residential Settings: A Cross-Sectional Study in Bangkok, Thailand" International Journal of Scientific Research and Engineering Development, V9(3): Page(2734-2743) May-June 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.