Do some molds produce highly toxic byproducts?
Yes. Some fungi produce very potent toxins. Aspergillus flavus, for example, produces aflatoxin, which is the most potent, naturally occurring toxin known to man. A. flavus grows on peanuts, and the level of aflatoxin that is permitted is federally regulated. Many mycologists actually won’t eat peanuts because of this. We had a client who’s peanuts had been rejected by the government because of the levels of aflatoxin exceeded the federal limit. He sent in soil samples from his farm and it turned out that the soil was just loaded with A. flavus. It was very unfortunate. Ironically, this means that the peanut butter you get in a health food store, may actually be worse for you than some plain old peanut butter from the regular store. Note that the exposure route described here is ingestion, not inhalation.
