Mold produces a byproduct as it grows and matures. That byproduct is called a mycotoxin. The US National Library of Medicine, National Institute of Health states, “Mycotoxins are secondary metabolites produced by mold." As the name implies, it is a toxin.

In the United States, one in 10 children suffers from asthma but the potential environmental factors contributing to the disease are not well known. Cincinnati-based researchers now report new evidence that exposure to three types of mold during infancy may have a direct link to asthma development during childhood, according to ScienceDaily.