Moho Mate is an at-home mold monitoring kit designed to help observe mold presence in indoor environments. It exists to make certain features of a space more visible over time, without diagnosing, predicting, or interpreting outcomes. This distinction matters when looking at how researchers study indoor environments.
Much of what is known about indoor spaces does not come from dramatic events or visible changes, but from quiet measurement. One area where this is especially clear is the study of airborne fungal communities inside buildings.
A widely cited study by Adams et al. (2015) examined how indoor fungal presence is shaped by outdoor air, building characteristics, and human occupancy. Rather than focusing on effects, the researchers focused on distribution — what is present indoors, where it comes from, and what influences it.
Indoor Environments Are Systems
Buildings are not sealed containers. Air moves through them continuously, carrying particles from outdoors while interacting with interior materials and surfaces. As a result, indoor environments reflect a combination of external inputs and internal conditions.
In this study, researchers collected air samples from multiple indoor environments and compared them with outdoor samples taken nearby. By analyzing fungal DNA, they were able to identify which fungi were present and how indoor communities differed from those found outside.
The goal was not to evaluate impact, but to understand structure.
The Role of Outdoor Air
One of the central observations was that many fungi detected indoors closely mirrored those found outdoors. This suggested that outdoor air plays a significant role in shaping what is present inside a building.
However, the relationship was not one-to-one. While outdoor air influenced indoor composition, it did not fully determine it. Indoor fungal communities showed patterns that reflected how air entered the building, how it circulated, and how long particles remained suspended or settled.
In other words, what enters a space is only part of the story.
How Buildings Influence Presence
The study also examined how building-related factors influenced indoor fungal communities. Ventilation strategies, air exchange rates, and occupancy levels were all associated with differences in what was detected indoors.
Spaces with higher air exchange rates tended to show stronger similarities to outdoor air, while more enclosed environments showed greater divergence over time. Human activity also played a role, not as a source of fungi, but as a factor influencing air movement and particle resuspension.
These findings reinforced the idea that buildings actively shape their own internal environments.
Presence Without Visibility
Importantly, the fungi identified in this study were not necessarily visible. Detection relied on sampling and molecular analysis rather than surface inspection or observation.
This highlights a recurring theme in environmental research: many aspects of indoor environments exist beyond immediate perception. They accumulate, circulate, and persist quietly, influenced by design choices and daily use.
Understanding a space often begins not with what is seen, but with what is measured.
Observation as a Starting Point
The authors of the study were careful not to extend their findings beyond what the data supported. Their work documented presence and patterns, not implications or outcomes.
That restraint is characteristic of well-designed environmental research. Before conclusions can be considered, researchers first establish what exists, where it exists, and how it changes.
In that sense, observation is not an answer. It is an opening.
Indoor environments are shaped continuously by air, materials, and movement. Much of what defines them operates quietly, without drawing attention — until someone decides to look more closely.
Reference
Adams, R. I., Bhangar, S., Pasut, W., Arens, E. A., Taylor, J. W., Lindow, S. E., Nazaroff, W. W., & Bruns, T. D. (2015). Indoor fungal communities are influenced by outdoor air, building characteristics, and human occupancy. Indoor Air, 25(6), 554–563. https://doi.org/10.1111/ina.12183
Written by
Elliot R. Hale
Environmental Research Editor
