Molds are ubiquitous, they grow optimally under high humidity, inadequate ventilation, and poor lighting, especially indoors. Components of molds (i.e., β-glucans from the cell wall of spores and hyphal fragments) and toxic metabolites they produce (e.g., mycotoxins and microbial volatile organic compounds, mVOCs) are known to cause adverse health effects in humans. Indoors, components of molds easily reach unsafe levels. Most of the adverse health effects from mold exposure are routinely attributed to spores, hyphal fragments, and toxic mycotoxins while possible role of mVOCs is mostly overlooked. Here we report a case of 43-year old healthy African American male who was exposed mostly to mVOCs, emitted by molds inside the non-concrete walls and ceiling while living for ~3.5 months in a mold-infested apartment with overwhelming moldy smell. He worked from home; therefore, spent most of his time inside the apartment. The apartment was professionally cleaned and shampooed before he move-in and twice during the subject’s brief stay in the apartment. Additionally, subject kept the apartment very clean by rigorous cleaning (vacuuming, dusting, brooming, wiping, and moping – sometimes multiple times a day, especially vacuuming 2–3 times every day) after finding some molds and to get rid of the musty moldy smell. Consequently, very few mold spores were found in the air and dust of the apartment and negligible levels of mycotoxins in his urine. The subject started to suffer from rashes, ichthyosis, desquamation, dyspnea, fatigue, nocturnal awakening, headaches, dizziness, and syncope mostly from the exposure to mVOCs.

Mold indoors, Mold toxicity, Microbial volatile organic compounds, mVOCs, mVOC risk assessment, Importance of mVOCs in mold toxicity