Mold is probably one of the most basic and oldest forms of fungi alive today. There are literally thousands of known species of mold throughout the world. It comes in many forms including, surprisingly, the common mushroom. Like the common mushroom, mold has many different forms, coming in many different sub-species, colours and toxic / non-toxic levels.

One charactristic is in the way that it release seeds, (or more correctly), its spores. It is these spores that, when released into the air, can cause allergic reactions in people, (it is estimated that about 64% of people are adversely affected by mold in the U.S according to the CDC in Atlanta).

What does it need to grow?

Mold needs a number of things before it can grow and release spores; moisture and organic material. Moisture can be from sources such as a leaky faucet, flood or water that enters your basement through foundation wall cracks or foundation failure. You can usually tell you have an issue either by first smell a "musty" smell, (caused by microbial growth), or by seeing black / green / white patches in a location.

Mold growth requires moisture. The sources of moisture could be Washing, cooking, air humidifiers, condensation or leaks from plumbing or from the outside. Poor ventilation contributes to higher humidity levels and leads to condensation, which also allows mold growth.

Molds release small "spores" into the air. So, when mold grows indoors, the number of mold spores and fragments is usually higher indoors than it is outdoors. These spores are small enough that people can actually inhale them deep into the lungs. Inhalation of spores poses risk of developing respiratory problems. With the exception of winter months mold spores are always present outdoors.

Levels of Risk

A number of articles have been published that provide a very good background about the associated risks of exposure to mold. Individual risk and adverse health effects usually depend on the level of exposure, age and health of the individual. Seniors, the young and those with compromised immune systems / asthma / lung / respiratory issues are particularly at risk.

https://www.globalhealingcenter.com/natural-health/dangers-of-mold/

https://www.mayoclinic.org/diseases-conditions/mold-allergy/diagnosis-treatment/drc-20351525