Right now there are over 250,000 types of mold and counting. Out of those 250,000 only about 250 types of mold has been identified as “may be harmful to human health”. The reason being that they have yet to identify a single type of mold that is harmful to all people. Out of the 250 “that maybe harmful to human health”, the only people that are most susceptible to adverse effects are the very young and the very old, they either don't have a full developed immune system or they have a weaken immune system. Also those who suffer from a disease that weakens the immune system such as AIDS or HIV or already have some sort of respiratory ailment like asthma, bronchitis, leukemia and so on. Remember we've been living with mold since the dawn of time. The best defense against mold is education and if in doubt, contact a mold re-mediator.