Fungal spores are present all over in the air around us. I understand that they generally range in size from about one to one-hundred microns.
What is the number density of fungal spores in air on a volume basis? I imagine this will vary based on location, season, and indoor vs. outdoor. An ideal answer would account for all of this in the ranges but I'm broadly interested in indoor air conditions around the world.
If measurements of a single spore density are too difficult, I would find the density of CFUs to be acceptable (assuming that those are multiple spores) but would appreciate being directed to information on how many spores typically make up one CFU. Similarly, a mass density of spores would be acceptable as well if experimental methods make that easier. At the simplest level, I'm just curious how much fungal spore material is in the indoor air around us.