Some molds can produce highly toxic chemicals called mycotoxins under some growth conditions. Some bacteria can also produce toxic chemicals. The potential health effects of mycotoxins have been reviewed by a committee of the National Academy of Sciences, Institute of Medicine . These mycotoxins may be constituents of the particles released into indoor air. Studies with exposures to living cells and animals indicate that some mycotoxins are very potent. Documented or suspected health effects from mycotoxins in these studies include tremors, loss of coordination, lesions, increased levels of chemicals linked to inflammation, immune system suppression, cell death, and animal death. However, it is not known whether the indoor air concentrations of mycotoxins caused by microbial growth in damp buildings become high enough to cause any of these health effects.
In 1997, the toxins that can be produced by a type of mold called Stachybotrys chartarum became the suspected source of a cluster of pulmonary hemorrhages (bleeding in the lungs) and deaths among infants in Cleveland [73, 74]. These findings were broadly publicized and became controversial . A task force was convened by the Centers for Disease Control and Prevention to review the evidence, noted shortcomings in the data collection and analyses, and concluded that Stachybotrys chartarum was not a definitive cause of pulmonary hemorrhage . The Institute of Medicine committee referenced above also reviewed the related literature and concluded that there was inadequate or insufficient evidence to determine whether Stachybotrys chartarum or dampness in buildings causes pulmonary hemorrhage.
The health effects of indoor mycotoxins remains a controversial topic.