Exposure to powdery mildew
Is there a recommended way to protect ourselves from breathing in powdery mildew and air from other garden problems?
Hennepin County Minnesota fungus
The fungi that cause powdery mildew are not harmful to people. It does not pose the same concern like the fungi that cause black mold. There aren't any diseases that I can think of that you would find in a typical garden that you would need a respirator when you remove them.
I would advise you to clean any tools that you use to remove plants infected with powdery mildew in a mild bleach solution (1:10 bleach to water is ideal) so as not to spread the fungi to other plants.
Thanks for the quick reply. It's quite possible there is fungus as well. Does that change the answer?
No, it does not change my answer. Are you seeing anything besides the powdery mildew that you are concerned about? There are most certainly other fungi in your soil, you cannot avoid it. Most fungi are harmless to people.