Since ghouls are healed by radiation. Just a thought.

Atomic! doesn't heal you.
However, RADChild does.

Technically, RAD Child's first appearance was in Fallout Tactics, and it was a ghoul exclusive perk, so if any of them make you "ghoulish," it's RAD Child, though obviously Atomic! could be ghoul-related as well.

Well you dont really turn ghoul but like longknife said its ghoulish.