I understand so far that most of the air surrounding us contains mold spores so that given the right environment and a food source they start to grow. I assume this is true for air close to the earth. But how high mold spores are still common?
To clarify: I don't want to grow mold, I want to know how high into the air on earth mold spores are usually common.
Air currents can carry bacteria and mold spores into stratospheric altitudes. Early balloon collections found bacteria and mold in air samples at a little above 71 thousand feet altitude. There were only a few colonies, but we also know that our bacterial media often do not allow many microorganisms to grow.