See "Hypersensitivity pneumonitis antigens" (Agent), "Mold and algae derived allergens" (Agent), and "Sapronoses" in IDdx (category of diseases).
"Molds are fungi that can be found anywhere - inside or outside - throughout the year. About 1,000 species of mold can be found in the United States, with more than 100,000 known species worldwide. . . . While it is impossible to eliminate all molds and mold spores, controlling moisture can control indoor mold growth. All molds share the characteristic of being able to grow without sunlight; . . . Currently, there are no federal standards or recommendations, (e.g., OSHA, NIOSH, EPA) for airborne concentrations of mold or mold spores. . . . Molds can cause adverse effects by producing allergens (substances that can cause allergic reactions). . . . Molds may cause localized skin or mucosal infections but, in general, do not cause systemic infections in humans, except for persons with impaired immunity, AIDS, uncontrolled diabetes, or those taking immune suppressive drugs. . . . Molds can also cause asthma attacks in some individuals who are allergic to mold. Some specific species of mold produce mycotoxins under certain environmental conditions. Potential health effects from mycotoxins are the subject of ongoing scientific research and are beyond the scope of this document." [See Reference #1] Fungi could cause lung fibrosis in the context of hypersensitivity pneumonitis.