Many moulds produce secondary metabolites (mycotoxins) that are highly toxic to humans and animals. The most infamous of them, the aflotoxins, affect some species at an intake of a few parts per billion. Each toxin has its own identity and pathology. Kidney and liver damage, haemorrhages, disturbances of the central nervous system, stunting of growth, abortion, or other effects may occur, depending on the toxin.
Mycotoxins are most commonly encountered in nut products, such as peanuts, and grains. There are over 40 naturally occurring trichothecenes; those most commonly found in contaminated grains are: T-2 toxin, diacetoxyscirpenol (DAS), nivalenol and deoxynivalenol (vomitoxin). They produce a toxicosis called alimentary toxic aleukia which has been reported in several countries as a result of food poisoning by spoiled grain and suspected chemical warfare in Southeast Asia. Another mycotoxicosis, stachybotryotoxicosis, is caused by macrocyclic trichothecenes, principally verrucarin, roridin and satratoxins. It is associated with inhalation and percutaneous absorption of the toxins.
Ergotism is caused by eating bread prepared from rye infected with the fungus Claviceps purpurea. Historically, several large scale outbreaks of madness in local populations have been attributed to ergotism.