As climate change induces heavier rainfall, higher temperatures, and elevated humidity, the likelihood of flooding or excessive indoor humidity increases. Both of these—by saturating interior building materials—lead to conditions ideal for mold growth; and, thus, are predicted to worsen the already commonplace problem of mold growth in homes. Despite the urgency and ubiquity of this problem, the ways in which mold growth after water damage changes residents’ exposure to airborne fungi remains unknown. In this talk, I will discuss two ways in which my PhD research sought to better explain the connection between mold growth on damp building materials and negative human health impacts. In the first part of the talk, I will share a de novo metatranscriptomic study of fungi in house dust that suggests that the toxicity of fungal cells may increase on a per spore basis at high water activities that favor the gene expression of allergens and other toxins. I will then present a highly-spatially resolved study of a single-family home which demonstrates that distance from a mold source (a factor previously ignored in epidemiological studies) is an important parameter influencing occupant mold exposure. Together, these results suggest that for future studies to quantitatively link mold with negative health effects, it is essential to account for the ways exposure changes with both distance from a mold source and variable environmental conditions within a home.
