Indoor microbes can release harmful volatile organic compounds (VOCs), but how environmental factors and microbial community composition impact microbial VOC emissions is unclear. To learn more, researchers recently subjected drywall and carpet to different equilibrium relative humidity levels and quantified microbial communities and microbial VOC emissions. Fungus grew in dusty carpet when the humidity was >75% and in inoculated painted drywall when the humidity was >85%. The dust sample collection site and the material type significantly affected the fungal and bacterial species compositions. In dusty carpet, increased humidity was associated with decreased microbial species diversity. Abundant VOCs were likely released from the materials and dust themselves, but some microbial VOCs, such as C₁₀10H₁₆H⁺ (monoterpenes) and C₂H₆SH⁺ (dimethyl sulfide and ethanethiol), were released from microbes that grew in dusty carpet. At 95% humidity, dusty carpet produced 5.92 mg CO₂/h/kg, while carpet without dust produced 2.55 mg CO₂/h/kg. Although further testing is needed, the results reveal differences in microbial growth and microbial VOC emission between different building materials and may support the development of improved management and mitigation strategies to maintain healthy indoor environments