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Multivariate analysis on simulated moisture damage emission to indoor air
V Lappalainen1, J Sorvari2, E Sohlberg3
1University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. BOX 1627, FI-70211, Kuopio, Finland; VTT Technical Research Centre of Finland, P.O. BOX 1000, FI-02044, VTT, Finland; University of Oulu, Civil Engineering, P.O. BOX 8000, FI-90014, Finland.
The Science of the Total Environment
|February 13, 2026
Summary
High material humidity significantly increases volatile organic compound (VOC) emissions from moldy building materials. Specific ketones were identified as key microbial VOC indicators, crucial for assessing indoor air quality.
Area of Science:
- Building Science
- Environmental Health
- Analytical Chemistry
Background:
- Moisture damage in buildings is a major source of indoor air pollution, releasing volatile organic compounds (VOCs) and microbially produced VOCs (MVOCs).
- Interpreting MVOCs as direct indicators of mold is difficult due to diverse sources and analytical limitations.
- Understanding factors influencing VOC emissions from damaged structures is critical for indoor air quality (IAQ) management.
Purpose of the Study:
- To identify critical factors affecting VOC emissions from moisture-damaged wall structures into indoor environments.
- To investigate the transport of airborne impurities from mold-contaminated building components.
- To determine the most influential parameters impacting IAQ degradation in damp building structures.
Main Methods:
- Utilized the VTT Indoor Air Quality (IAQ) Simulator for realistic building condition simulations.
- Employed Principal Component Analysis (PCA) for multivariate analysis of the generated dataset.
- Systematically manipulated key environmental parameters to assess their impact on VOC emissions.
Main Results:
- Material relative humidity was the most significant factor, with higher humidity consistently increasing VOC emissions.
- Four specific ketones (2-pentanone, 2-hexanone, 2-heptanone, 2-octanone) were identified as originating from microbial growth.
- Pressure differentials and insulation layers showed minimal impact on VOC emissions from gypsum boards.
Conclusions:
- Relative humidity is a critical determinant of indoor VOC profiles in moisture-damaged buildings.
- Specific ketones serve as reliable indicators of active mold growth and associated IAQ issues.
- Multivariate analysis is valuable for assessing complex indoor air quality problems related to mold and moisture damage.
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