Microbes in indoor environments can cause all of the following problems:
Microbes are too small to be seen by the naked eye so, when you can see them, you are not looking at one microorganism, but at hundreds, or even millions. At that point it is no longer a question of whether you have a microbial contamination or not. The answer is simple: you do!
The question that you need to be asking is: how bad is it and how dangerous are these organisms?”