It would be fair to say that molds have been around since the beginning of time, and have always posed a serious threat to human living. The Bible even references mold and its remediation –

“The LORD said to Moses and Aaron … I put a spreading mildew in a house in that land (Canaan). … The priest is to order the house to be emptied before he goes in to examine the mildew, so that nothing in the house will be pronounced unclean. After this the priest is to go in and inspect the house. He is to examine the mildew on the walls, and if it has greenish or reddish depressions that appear to be deeper than the surface of the wall, the priest shall go out the doorway of the house and close it up for seven days.” (Lev.14)

Thus, even in the Biblical days, mold meant sickness and required immediate attention.