Mold Irritations

Fungal exposure can also come from any volatile compounds (VOCs) that a fungi/mold creates through primary or secondary metabolism that then becomes airborne. (Primary metabolic processes are those necessary to sustain the life of an organism.) These volatile compounds may be constantly created as the fungus
consumes its food source during the primary metabolic process. VOCs can irritate the mucous membranes of the eyes and respiratory system.

Fungi that consume certain organic sources can release highly toxic gases. For instance, a fungus that grows on wallpaper often releases toxic gas arsine directly from the wallpaper that contains arsenic pigments. Thus, fungi and molds can release dangerous materials when they break down the host material. This can cause mucous
membrane irritation in sensitized individuals.

Fungal volatile compounds may impact the "common chemical sense" which senses pungency and responds to it. This sense is primarily associated with the trigeminal nerve. The sensory and motor nerves respond to pungency by trying to hold the breath, discomfort, or through sensations such as itching, burning, and skin crawling.
Changes in sensation, swelling of mucous membranes, constriction of respiratory smooth muscle, or dilation of surface blood vessels may be part of fight or flight reactions in response to trigeminal nerve stimulation. Reactions often include a reduced attention level, general disorientation, lowered reflex time, dizziness, etc.

Volatile Compounds found in or around homes can be responsible for mucous membrane irritants. It is thought that fungi can add to the already existing compounds when breaking down certain organic substances. A mold-contaminated building may have a significant contribution from its fungal contaminants that is added to common VOCs---building materials, paints, plastics and cleaners. VOCs in general can result in symptoms that include lowered attention span, headaches, lack of concentration, and dizziness.

Reaction to Mold Odors

Some individuals have very strong reactions to the smells given off by molds. Among humans, there is a high degree of variation in ability to detect these odors. Certain individuals can detect low levels of VOCs, while others can only detect relatively high levels. Those individuals who are particularly susceptible to mold odors may react with headache, nasal stuffiness, nausea or even vomiting. Asthmatics often exhibit symptoms when exposed to certain odors.