That fungus is called Cladosporium sphaerospermum, and some scientists think its dark pigment – melanin – may allow it to harness ionizing radiation through a process similar to the way plants harness light for photosynthesis. This proposed mechanism is even referred to as radiosynthesis.
Although scientists have shown that the fungus flourishes in the presence of ionizing radiation, no one has been able to pin down how or why. Radiosynthesis is a theory, one that’s difficult to prove.
we still don’t know what the fungus is actually doing.
…Because we know how radio waves work?
I think the point is that even if this fungus developed a “shield” to protect itself from the radiation, it’s not doing to really do anything about the radiation.
Radioactivity is not related to waves of any kind.
Radioactivity is related to particles from the atomic nucleus ( electrons, protons or neutrons ) getting free from an atom and shooting really fast in any direction. usually because an unstable atom like uranium or plutonium, or radium, split itself and there was a left over particle that’s not part of the new atoms.