Fungal colonization on building materials under reduced barometric pressure: A laboratory study

Fungal growth on building materials is influenced by complex interactions between environmental conditions, material characteristics, and architectural features. While extensive research has explored the relationships between environmental factors such as temperature and relative humidity (RH, %) on fungal growth, the role of barometric pressure, a vital environmental parameter, has not been sufficiently studied. In this study, six representative fungal spore suspensions were inoculated onto five typical building materials (pine, spruce, gypsum, latex paint, and wallpaper) and tested under three RH levels (75%, 85%, and 97%) at 21°C, at three different barometric pressures (0.60, 0.80, and 1.00 atm). The results indicated the heterogeneous effects of barometric pressure on various materials under different RH conditions. Fungal growth on all tested materials was minimal and similar at 75% and 85% RH. At 97% RH, only the wallpaper showed significant differences among the different barometric pressure groups, with the low-pressure groups (0.60 and 0.80 atm) exhibiting stable and significant differences in fungal growth compared to the atmospheric pressure group (1.00 atm) from weeks 8 to 14 after incubation. However, from week 15, this significant difference disappeared. Latex paint showed no signs of fungal growth under different barometric pressures and was therefore excluded from the analysis. Pine, spruce, and gypsum occasionally exhibited significant differences between the barometric pressure groups, with the only commonality being the significant differences between 0.60 and 0.80 atm. The results enhance our understanding of fungal growth behavior on building materials across different altitudinal regions, providing insights that can help refine strategies for predicting fungal contamination in various environmental conditions. • Minimal fungal growth at 75% and 85% RH despite barometric pressure differences • No consistent fungal growth pattern across materials under different pressures • Wallpaper exhibited enhanced fungal growth under low barometric pressure