Comment by johnboiles

Radon and its progenitors won't produce nearly enough radiation to damage plastics like that at naturally occurring levels.

Radon is a noble gas and chemically inert. It's radioactive, which is why it's a toxicity worry. But there was enough radiation in that basement to mechanically damage plastic in three years, OP would be long since dead.

Should be solvent based.

Radon is a noble gas. It's not going to affect fiber or wiring... but yes, if you're going to spend much time down there, definitely a good idea to check for it.