Dusty's message is an unused holotape in the Fallout 4 add-on Nuka World. It is recorded by Dusty Polanski.
Transcript
Hey, Sabir, it's Dusty. Some guy named Ernie Messinger came up in here today. Said we can't store anymore waste under the bottling plant while we're waiting for the new disposal system to come online. Seems like some of the barrels started leaking, so they got a bit of a mess on their hands. Luckily, the run off's just going into their little river of Quantum. Long as kids keep their hands inside the ride, we're good. Anyway, see if you can give Troy a call and get him to let us use Fizztop. There's so much room in there, no reason we shouldn't be able to use that for storage.
Notes
Its filename in the Creation Kit is DLC04PowerPlant_DustyHolotape.