Mold Spores Everywhere
All mold spores found in indoor air are also normally found in outdoor air because most originate or live in the soil and on dead or decaying plants. Therefore, it is not unusual to find mold spores in indoor air.
Elevated Levels of Mold Spores
Low levels of Mold will be found during Indoor Air Quality Tests. A Mold problem exists on your property when there is visble mold or a elevated level of mold spores.
Some Mold Produce Mycotoxins
Some molds can produce mycotoxins, which are toxic substances that may be found either within or on the surface of airborne mold spores. Mycotoxins can enter a person's system through ingestion, inhalation or skin contact.
As the CDC states on their website:
source: CDC - Mold - General Information
"The term “toxic mold” is not accurate. While certain molds are toxigenic, meaning they can produce toxins (specifically mycotoxins), the molds themselves are not toxic, or poisonous. Hazards presented by molds that may produce mycotoxins should be considered the same as other common molds which can grow in your house. There is always a little mold everywhere – in the air and on many surfaces. There are very few reports that toxigenic molds found inside homes can cause unique or rare health conditions such as pulmonary hemorrhage or memory loss. These case reports are rare, and a causal link between the presence of the toxigenic mold and these conditions has not been proven."
A good Article to Read on WebMD is "Moisture and Mold Problems"
source: Moisture and Mold Problems
"Whether it's the slimy black spots on your shower curtain, the fuzzy white patches on your basement floor, or the slick orange film that forms on your kitchen drain, household mold is more than unsightly. In some cases, mold in your home can make you sick, especially if you have allergies or asthma."